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Helper to abstract vma handling in media layer

PATCH In review Jan Kara 5 participants 19 messages Jul 13, 2015 – Jul 20, 2015

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Jan Kara

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#0 lore raw

v7 cover Helper to abstract vma handling in media layer

From: Jan Kara <[email protected]>

Hello,

I'm sending the seventh version of my patch series to abstract vma handling from the various media drivers. Since the previous version there are just minor cleanups and fixes (see detailed changelog at the end of the email).

After this patch set drivers have to know much less details about vmas, their types, and locking. Also quite some code is removed from them. As a bonus drivers get automatically VM_FAULT_RETRY handling. The primary motivation for this series is to remove knowledge about mmap_sem locking from as many places a possible so that we can change it with reasonable effort.

The core of the series is the new helper get_vaddr_frames() which is given a virtual address and it fills in PFNs / struct page pointers (depending on VMA type) into the provided array. If PFNs correspond to normal pages it also grabs references to these pages. The difference from get_user_pages() is that this function can also deal with pfnmap, and io mappings which is what the media drivers need.

I have tested the patches with vivid driver so at least vb2 code got some exposure. Conversion of other drivers was just compile-tested (for x86 so e.g. exynos driver which is only for Samsung platform is completely untested).

Hans, can you please pull the changes? Thanks!

Honza

Changes since v6:
* Fixed compilation error introduced into exynos driver
* Folded patch allowing get_vaddr_pfn() code to be selected by a config option into previous patches
* Rebased on top of linux-media tree

Changes since v5:
* Moved mm helper into a separate file and behind a config option
* Changed the first patch pushing mmap_sem down in videobuf2 core to avoid possible deadlock

Changes since v4:
* Minor cleanups and fixes pointed out by Mel and Vlasta
* Added Acked-by tags

Changes since v3:
* Added include <linux/vmalloc.h> into mm/gup.c as it's needed for some archs
* Fixed error path for exynos driver

Changes since v2:
* Renamed functions and structures as Mel suggested
* Other minor changes suggested by Mel
* Rebased on top of 4.1-rc2
* Changed functions to get pointer to array of pages / pfns to perform conversion if necessary. This fixes possible issue in the omap I may have introduced in v2 and generally makes the API less errorprone.

author
#1 lore raw

PATCH v7 1/9 vb2: Push mmap_sem down to memops

From: Jan Kara <[email protected]>

Currently vb2 core acquires mmap_sem just around call to __qbuf_userptr(). However since commit f035eb4e976ef5 (videobuf2: fix lockdep warning) it isn't necessary to acquire it so early as we no longer have to drop queue mutex before acquiring mmap_sem. So push acquisition of mmap_sem down into .get_userptr memop so that the semaphore is acquired for a shorter time and it is clearer what it is needed for.

Note that we also need mmap_sem in .put_userptr memop since that ends up calling vb2_put_vma() which calls vma->vm_ops->close() which should be called with mmap_sem held. However we didn't hold mmap_sem in some code paths anyway (e.g. when called via vb2_ioctl_reqbufs() -> __vb2_queue_free() -> vb2_dma_sg_put_userptr()) and getting mmap_sem in put_userptr() introduces a lock inversion with queue->mmap_lock in the above mentioned call path.

Luckily this whole locking mess will get resolved once we convert videobuf2 core to the new mm helper which avoids the need for mmap_sem in .put_userptr memop altogether.

---
 drivers/media/v4l2-core/videobuf2-core.c       | 2 --
 drivers/media/v4l2-core/videobuf2-dma-contig.c | 5 +++++
 drivers/media/v4l2-core/videobuf2-dma-sg.c     | 4 ++++
 drivers/media/v4l2-core/videobuf2-vmalloc.c    | 4 +++-
 4 files changed, 12 insertions(+), 3 deletions(-)
drivers/media/v4l2-core/videobuf2-core.c +0 -2
index 93b315459098..4df6dfc47fc8 100644
@@ -1675,9 +1675,7 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		ret = __qbuf_mmap(vb, b);
 		break;
 	case V4L2_MEMORY_USERPTR:
-		down_read(&current->mm->mmap_sem);
 		ret = __qbuf_userptr(vb, b);
-		up_read(&current->mm->mmap_sem);
 		break;
 	case V4L2_MEMORY_DMABUF:
 		ret = __qbuf_dmabuf(vb, b);
drivers/media/v4l2-core/videobuf2-dma-contig.c +5 -0
index 94c1e6455d36..c548ce425701 100644
@@ -616,6 +616,7 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 		goto fail_buf;
 	}
 
+	down_read(&current->mm->mmap_sem);
 	/* current->mm->mmap_sem is taken by videobuf2 core */
 	vma = find_vma(current->mm, vaddr);
 	if (!vma) {
@@ -642,6 +643,7 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	if (ret) {
 		unsigned long pfn;
 		if (vb2_dc_get_user_pfn(start, n_pages, vma, &pfn) == 0) {
+			up_read(&current->mm->mmap_sem);
 			buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, pfn);
 			buf->size = size;
 			kfree(pages);
@@ -651,6 +653,7 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 		pr_err("failed to get user pages\n");
 		goto fail_vma;
 	}
+	up_read(&current->mm->mmap_sem);
 
 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt) {
@@ -713,10 +716,12 @@ fail_get_user_pages:
 		while (n_pages)
 			put_page(pages[--n_pages]);
 
+	down_read(&current->mm->mmap_sem);
 fail_vma:
 	vb2_put_vma(buf->vma);
 
 fail_pages:
+	up_read(&current->mm->mmap_sem);
 	kfree(pages); /* kfree is NULL-proof */
 
 fail_buf:
drivers/media/v4l2-core/videobuf2-dma-sg.c +4 -0
index 7289b81bd7b7..d2cf113d1933 100644
@@ -264,6 +264,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	if (!buf->pages)
 		goto userptr_fail_alloc_pages;
 
+	down_read(&current->mm->mmap_sem);
 	vma = find_vma(current->mm, vaddr);
 	if (!vma) {
 		dprintk(1, "no vma for address %lu\n", vaddr);
@@ -302,6 +303,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 					     1, /* force */
 					     buf->pages,
 					     NULL);
+	up_read(&current->mm->mmap_sem);
 
 	if (num_pages_from_user != buf->num_pages)
 		goto userptr_fail_get_user_pages;
@@ -331,8 +333,10 @@ userptr_fail_get_user_pages:
 	if (!vma_is_io(buf->vma))
 		while (--num_pages_from_user >= 0)
 			put_page(buf->pages[num_pages_from_user]);
+	down_read(&current->mm->mmap_sem);
 	vb2_put_vma(buf->vma);
 userptr_fail_find_vma:
+	up_read(&current->mm->mmap_sem);
 	kfree(buf->pages);
 userptr_fail_alloc_pages:
 	kfree(buf);
drivers/media/v4l2-core/videobuf2-vmalloc.c +3 -1
index 2fe4c27f524a..63bef959623e 100644
@@ -89,7 +89,7 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
 
-
+	down_read(&current->mm->mmap_sem);
 	vma = find_vma(current->mm, vaddr);
 	if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
 		if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
@@ -121,6 +121,7 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 		if (!buf->vaddr)
 			goto fail_get_user_pages;
 	}
+	up_read(&current->mm->mmap_sem);
 
 	buf->vaddr += offset;
 	return buf;
@@ -133,6 +134,7 @@ fail_get_user_pages:
 	kfree(buf->pages);
 
 fail_pages_array_alloc:
+	up_read(&current->mm->mmap_sem);
 	kfree(buf);
 
 	return NULL;
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author
#2 lore raw

PATCH v7 2/9 mm: Provide new get_vaddr_frames() helper

In reply to Jan Kara

From: Jan Kara <[email protected]>

Provide new function get_vaddr_frames(). This function maps virtual addresses from given start and fills given array with page frame numbers of the corresponding pages. If given start belongs to a normal vma, the function grabs reference to each of the pages to pin them in memory. If start belongs to VM_IO | VM_PFNMAP vma, we don't touch page structures. Caller must make sure pfns aren't reused for anything else while he is using them.

This function is created for various drivers to simplify handling of their buffers.

---
 include/linux/mm.h |  44 ++++++++++
 mm/Kconfig         |   3 +
 mm/Makefile        |   1 +
 mm/frame_vector.c  | 231 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 279 insertions(+)
 create mode 100644 mm/frame_vector.c
include/linux/mm.h +44 -0
index 2e872f92dbac..79ad29a8a60a 100644
@@ -20,6 +20,7 @@
 #include <linux/shrinker.h>
 #include <linux/resource.h>
 #include <linux/page_ext.h>
+#include <linux/err.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -1198,6 +1199,49 @@ long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
 		    int write, int force, struct page **pages);
 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 			struct page **pages);
+
+/* Container for pinned pfns / pages */
+struct frame_vector {
+	unsigned int nr_allocated;	/* Number of frames we have space for */
+	unsigned int nr_frames;	/* Number of frames stored in ptrs array */
+	bool got_ref;		/* Did we pin pages by getting page ref? */
+	bool is_pfns;		/* Does array contain pages or pfns? */
+	void *ptrs[0];		/* Array of pinned pfns / pages. Use
+				 * pfns_vector_pages() or pfns_vector_pfns()
+				 * for access */
+};
+
+struct frame_vector *frame_vector_create(unsigned int nr_frames);
+void frame_vector_destroy(struct frame_vector *vec);
+int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,
+		     bool write, bool force, struct frame_vector *vec);
+void put_vaddr_frames(struct frame_vector *vec);
+int frame_vector_to_pages(struct frame_vector *vec);
+void frame_vector_to_pfns(struct frame_vector *vec);
+
+static inline unsigned int frame_vector_count(struct frame_vector *vec)
+{
+	return vec->nr_frames;
+}
+
+static inline struct page **frame_vector_pages(struct frame_vector *vec)
+{
+	if (vec->is_pfns) {
+		int err = frame_vector_to_pages(vec);
+
+		if (err)
+			return ERR_PTR(err);
+	}
+	return (struct page **)(vec->ptrs);
+}
+
+static inline unsigned long *frame_vector_pfns(struct frame_vector *vec)
+{
+	if (!vec->is_pfns)
+		frame_vector_to_pfns(vec);
+	return (unsigned long *)(vec->ptrs);
+}
+
 struct kvec;
 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
 			struct page **pages);
mm/Kconfig +3 -0
index e79de2bd12cd..7f146dd32fc5 100644
@@ -654,3 +654,6 @@ config DEFERRED_STRUCT_PAGE_INIT
 	  when kswapd starts. This has a potential performance impact on
 	  processes running early in the lifetime of the systemm until kswapd
 	  finishes the initialisation.
+
+config FRAME_VECTOR
+	bool
mm/Makefile +1 -0
index 98c4eaeabdcb..be5d5c866305 100644
@@ -78,3 +78,4 @@ obj-$(CONFIG_CMA)	+= cma.o
 obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o
 obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
 obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o
+obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o
mm/frame_vector.c new file +231 -0

231 lines not on this page · raw message

Signature · 1 line
2.1.4
#3 lore raw

Re: [PATCH 2/9] mm: Provide new get_vaddr_frames() helper

Quoted 10 lines · Jan Kara

From: Jan Kara <[email protected]>

Provide new function get_vaddr_frames(). This function maps virtual addresses from given start and fills given array with page frame numbers of the corresponding pages. If given start belongs to a normal vma, the function grabs reference to each of the pages to pin them in memory. If start belongs to VM_IO | VM_PFNMAP vma, we don't touch page structures. Caller must make sure pfns aren't reused for anything else while he is using them.

Quoted 6 lines

This function is created for various drivers to simplify handling of their buffers.

I'd like to see an Acked-by from Andrew or mm-maintainers before I merge this.

Anyone?

Regards,

Hans

Quoted 328 lines
---
 include/linux/mm.h |  44 ++++++++++
 mm/Kconfig         |   3 +
 mm/Makefile        |   1 +
 mm/frame_vector.c  | 231 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 279 insertions(+)
 create mode 100644 mm/frame_vector.c
include/linux/mm.h +44 -0
index 2e872f92dbac..79ad29a8a60a 100644
@@ -20,6 +20,7 @@
 #include <linux/shrinker.h>
 #include <linux/resource.h>
 #include <linux/page_ext.h>
+#include <linux/err.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -1198,6 +1199,49 @@ long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
 		    int write, int force, struct page **pages);
 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 			struct page **pages);
+
+/* Container for pinned pfns / pages */
+struct frame_vector {
+	unsigned int nr_allocated;	/* Number of frames we have space for */
+	unsigned int nr_frames;	/* Number of frames stored in ptrs array */
+	bool got_ref;		/* Did we pin pages by getting page ref? */
+	bool is_pfns;		/* Does array contain pages or pfns? */
+	void *ptrs[0];		/* Array of pinned pfns / pages. Use
+				 * pfns_vector_pages() or pfns_vector_pfns()
+				 * for access */
+};
+
+struct frame_vector *frame_vector_create(unsigned int nr_frames);
+void frame_vector_destroy(struct frame_vector *vec);
+int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,
+		     bool write, bool force, struct frame_vector *vec);
+void put_vaddr_frames(struct frame_vector *vec);
+int frame_vector_to_pages(struct frame_vector *vec);
+void frame_vector_to_pfns(struct frame_vector *vec);
+
+static inline unsigned int frame_vector_count(struct frame_vector *vec)
+{
+	return vec->nr_frames;
+}
+
+static inline struct page **frame_vector_pages(struct frame_vector *vec)
+{
+	if (vec->is_pfns) {
+		int err = frame_vector_to_pages(vec);
+
+		if (err)
+			return ERR_PTR(err);
+	}
+	return (struct page **)(vec->ptrs);
+}
+
+static inline unsigned long *frame_vector_pfns(struct frame_vector *vec)
+{
+	if (!vec->is_pfns)
+		frame_vector_to_pfns(vec);
+	return (unsigned long *)(vec->ptrs);
+}
+
 struct kvec;
 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
 			struct page **pages);
mm/Kconfig +3 -0
index e79de2bd12cd..7f146dd32fc5 100644
@@ -654,3 +654,6 @@ config DEFERRED_STRUCT_PAGE_INIT
 	  when kswapd starts. This has a potential performance impact on
 	  processes running early in the lifetime of the systemm until kswapd
 	  finishes the initialisation.
+
+config FRAME_VECTOR
+	bool
mm/Makefile +1 -0
index 98c4eaeabdcb..be5d5c866305 100644
@@ -78,3 +78,4 @@ obj-$(CONFIG_CMA)	+= cma.o
 obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o
 obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
 obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o
+obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o
mm/frame_vector.c new file +231 -0
new file mode 100644
index 000000000000..f76b579e46f1
@@ -0,0 +1,231 @@
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+
+/*
+ * get_vaddr_frames() - map virtual addresses to pfns
+ * @start:	starting user address
+ * @nr_frames:	number of pages / pfns from start to map
+ * @write:	whether pages will be written to by the caller
+ * @force:	whether to force write access even if user mapping is
+ *		readonly. See description of the same argument of
+		get_user_pages().
+ * @vec:	structure which receives pages / pfns of the addresses mapped.
+ *		It should have space for at least nr_frames entries.
+ *
+ * This function maps virtual addresses from @start and fills @vec structure
+ * with page frame numbers or page pointers to corresponding pages (choice
+ * depends on the type of the vma underlying the virtual address). If @start
+ * belongs to a normal vma, the function grabs reference to each of the pages
+ * to pin them in memory. If @start belongs to VM_IO | VM_PFNMAP vma, we don't
+ * touch page structures and the caller must make sure pfns aren't reused for
+ * anything else while he is using them.
+ *
+ * The function returns number of pages mapped which may be less than
+ * @nr_frames. In particular we stop mapping if there are more vmas of
+ * different type underlying the specified range of virtual addresses.
+ * When the function isn't able to map a single page, it returns error.
+ *
+ * This function takes care of grabbing mmap_sem as necessary.
+ */
+int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
+		     bool write, bool force, struct frame_vector *vec)
+{
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma;
+	int ret = 0;
+	int err;
+	int locked;
+
+	if (nr_frames == 0)
+		return 0;
+
+	if (WARN_ON_ONCE(nr_frames > vec->nr_allocated))
+		nr_frames = vec->nr_allocated;
+
+	down_read(&mm->mmap_sem);
+	locked = 1;
+	vma = find_vma_intersection(mm, start, start + 1);
+	if (!vma) {
+		ret = -EFAULT;
+		goto out;
+	}
+	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
+		vec->got_ref = true;
+		vec->is_pfns = false;
+		ret = get_user_pages_locked(current, mm, start, nr_frames,
+			write, force, (struct page **)(vec->ptrs), &locked);
+		goto out;
+	}
+
+	vec->got_ref = false;
+	vec->is_pfns = true;
+	do {
+		unsigned long *nums = frame_vector_pfns(vec);
+
+		while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) {
+			err = follow_pfn(vma, start, &nums[ret]);
+			if (err) {
+				if (ret == 0)
+					ret = err;
+				goto out;
+			}
+			start += PAGE_SIZE;
+			ret++;
+		}
+		/*
+		 * We stop if we have enough pages or if VMA doesn't completely
+		 * cover the tail page.
+		 */
+		if (ret >= nr_frames || start < vma->vm_end)
+			break;
+		vma = find_vma_intersection(mm, start, start + 1);
+	} while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP));
+out:
+	if (locked)
+		up_read(&mm->mmap_sem);
+	if (!ret)
+		ret = -EFAULT;
+	if (ret > 0)
+		vec->nr_frames = ret;
+	return ret;
+}
+EXPORT_SYMBOL(get_vaddr_frames);
+
+/**
+ * put_vaddr_frames() - drop references to pages if get_vaddr_frames() acquired
+ *			them
+ * @vec:	frame vector to put
+ *
+ * Drop references to pages if get_vaddr_frames() acquired them. We also
+ * invalidate the frame vector so that it is prepared for the next call into
+ * get_vaddr_frames().
+ */
+void put_vaddr_frames(struct frame_vector *vec)
+{
+	int i;
+	struct page **pages;
+
+	if (!vec->got_ref)
+		goto out;
+	pages = frame_vector_pages(vec);
+	/*
+	 * frame_vector_pages() might needed to do a conversion when
+	 * get_vaddr_frames() got pages but vec was later converted to pfns.
+	 * But it shouldn't really fail to convert pfns back...
+	 */
+	if (WARN_ON(IS_ERR(pages)))
+		goto out;
+	for (i = 0; i < vec->nr_frames; i++)
+		put_page(pages[i]);
+	vec->got_ref = false;
+out:
+	vec->nr_frames = 0;
+}
+EXPORT_SYMBOL(put_vaddr_frames);
+
+/**
+ * frame_vector_to_pages - convert frame vector to contain page pointers
+ * @vec:	frame vector to convert
+ *
+ * Convert @vec to contain array of page pointers.  If the conversion is
+ * successful, return 0. Otherwise return an error. Note that we do not grab
+ * page references for the page structures.
+ */
+int frame_vector_to_pages(struct frame_vector *vec)
+{
+	int i;
+	unsigned long *nums;
+	struct page **pages;
+
+	if (!vec->is_pfns)
+		return 0;
+	nums = frame_vector_pfns(vec);
+	for (i = 0; i < vec->nr_frames; i++)
+		if (!pfn_valid(nums[i]))
+			return -EINVAL;
+	pages = (struct page **)nums;
+	for (i = 0; i < vec->nr_frames; i++)
+		pages[i] = pfn_to_page(nums[i]);
+	vec->is_pfns = false;
+	return 0;
+}
+EXPORT_SYMBOL(frame_vector_to_pages);
+
+/**
+ * frame_vector_to_pfns - convert frame vector to contain pfns
+ * @vec:	frame vector to convert
+ *
+ * Convert @vec to contain array of pfns.
+ */
+void frame_vector_to_pfns(struct frame_vector *vec)
+{
+	int i;
+	unsigned long *nums;
+	struct page **pages;
+
+	if (vec->is_pfns)
+		return;
+	pages = (struct page **)(vec->ptrs);
+	nums = (unsigned long *)pages;
+	for (i = 0; i < vec->nr_frames; i++)
+		nums[i] = page_to_pfn(pages[i]);
+	vec->is_pfns = true;
+}
+EXPORT_SYMBOL(frame_vector_to_pfns);
+
+/**
+ * frame_vector_create() - allocate & initialize structure for pinned pfns
+ * @nr_frames:	number of pfns slots we should reserve
+ *
+ * Allocate and initialize struct pinned_pfns to be able to hold @nr_pfns
+ * pfns.
+ */
+struct frame_vector *frame_vector_create(unsigned int nr_frames)
+{
+	struct frame_vector *vec;
+	int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames;
+
+	if (WARN_ON_ONCE(nr_frames == 0))
+		return NULL;
+	/*
+	 * This is absurdly high. It's here just to avoid strange effects when
+	 * arithmetics overflows.
+	 */
+	if (WARN_ON_ONCE(nr_frames > INT_MAX / sizeof(void *) / 2))
+		return NULL;
+	/*
+	 * Avoid higher order allocations, use vmalloc instead. It should
+	 * be rare anyway.
+	 */
+	if (size <= PAGE_SIZE)
+		vec = kmalloc(size, GFP_KERNEL);
+	else
+		vec = vmalloc(size);
+	if (!vec)
+		return NULL;
+	vec->nr_allocated = nr_frames;
+	vec->nr_frames = 0;
+	return vec;
+}
+EXPORT_SYMBOL(frame_vector_create);
+
+/**
+ * frame_vector_destroy() - free memory allocated to carry frame vector
+ * @vec:	Frame vector to free
+ *
+ * Free structure allocated by frame_vector_create() to carry frames.
+ */
+void frame_vector_destroy(struct frame_vector *vec)
+{
+	/* Make sure put_vaddr_frames() got called properly... */
+	VM_BUG_ON(vec->nr_frames > 0);
+	kvfree(vec);
+}
+EXPORT_SYMBOL(frame_vector_destroy);
+
maintainer Acked-by
#4 lore raw

Re: [PATCH 2/9] mm: Provide new get_vaddr_frames() helper

Quoted 11 lines · On Fri, 17 Jul 2015 12:23:40 +0200 Hans Verkuil <[email protected]> wrote:
Quoted 10 lines · Jan Kara

From: Jan Kara <[email protected]>

Provide new function get_vaddr_frames(). This function maps virtual addresses from given start and fills given array with page frame numbers of the corresponding pages. If given start belongs to a normal vma, the function grabs reference to each of the pages to pin them in memory. If start belongs to VM_IO | VM_PFNMAP vma, we don't touch page structures. Caller must make sure pfns aren't reused for anything else while he is using them.

Quoted 8 lines
Quoted 6 lines

This function is created for various drivers to simplify handling of their buffers.

I'd like to see an Acked-by from Andrew or mm-maintainers before I merge this.

I think I already acked this but it got lost.

author
#5 lore raw

PATCH v7 3/9 media: omap_vout: Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns()

In reply to Jan Kara

From: Jan Kara <[email protected]>

Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns() instead of hand made mapping of virtual address to physical address. Also the function leaked page reference from get_user_pages() so fix that by properly release the reference when omap_vout_buffer_release() is called.

---
 drivers/media/platform/omap/Kconfig     |  1 +
 drivers/media/platform/omap/omap_vout.c | 67 +++++++++++++++------------------
 2 files changed, 32 insertions(+), 36 deletions(-)
drivers/media/platform/omap/Kconfig +1 -0
index dc2aaab54aef..217d613b0fe7 100644
@@ -10,6 +10,7 @@ config VIDEO_OMAP2_VOUT
 	select OMAP2_DSS if HAS_IOMEM && ARCH_OMAP2PLUS
 	select OMAP2_VRFB if ARCH_OMAP2 || ARCH_OMAP3
 	select VIDEO_OMAP2_VOUT_VRFB if VIDEO_OMAP2_VOUT && OMAP2_VRFB
+	select FRAME_VECTOR
 	default n
 	---help---
 	  V4L2 Display driver support for OMAP2/3 based boards.
drivers/media/platform/omap/omap_vout.c +31 -36

97 lines not on this page · raw message

Signature · 1 line
2.1.4
author
#6 lore raw

PATCH v7 4/9 vb2: Provide helpers for mapping virtual addresses

In reply to Jan Kara

From: Jan Kara <[email protected]>

Provide simple helper functions to map virtual address range into an array of pfns / pages.

---
 drivers/media/v4l2-core/Kconfig            |  1 +
 drivers/media/v4l2-core/videobuf2-memops.c | 58 ++++++++++++++++++++++++++++++
 include/media/videobuf2-memops.h           |  5 +++
 3 files changed, 64 insertions(+)
drivers/media/v4l2-core/Kconfig +1 -0
index b4b022933e29..82876a67f144 100644
@@ -84,6 +84,7 @@ config VIDEOBUF2_CORE
 
 config VIDEOBUF2_MEMOPS
 	tristate
+	select FRAME_VECTOR
 
 config VIDEOBUF2_DMA_CONTIG
 	tristate
drivers/media/v4l2-core/videobuf2-memops.c +58 -0

64 lines not on this page · raw message

include/media/videobuf2-memops.h +5 -0
index f05444ca8c0c..2f0564ff5f31 100644
@@ -15,6 +15,7 @@
 #define _MEDIA_VIDEOBUF2_MEMOPS_H
 
 #include <media/videobuf2-core.h>
+#include <linux/mm.h>
 
 /**
  * vb2_vmarea_handler - common vma refcount tracking handler
@@ -36,5 +37,9 @@ int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
 struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma);
 void vb2_put_vma(struct vm_area_struct *vma);
 
+struct frame_vector *vb2_create_framevec(unsigned long start,
+					 unsigned long length,
+					 bool write);
+void vb2_destroy_framevec(struct frame_vector *vec);
 
 #endif
Signature · 1 line
2.1.4
author
#7 lore raw

PATCH v7 5/9 media: vb2: Convert vb2_dma_sg_get_userptr() to use frame vector

In reply to Jan Kara

From: Jan Kara <[email protected]>

---
 drivers/media/v4l2-core/videobuf2-dma-sg.c | 95 +++++-------------------------
 1 file changed, 15 insertions(+), 80 deletions(-)
drivers/media/v4l2-core/videobuf2-dma-sg.c +15 -80
index d2cf113d1933..be7bd6535c9d 100644
@@ -38,6 +38,7 @@ struct vb2_dma_sg_buf {
 	struct device			*dev;
 	void				*vaddr;
 	struct page			**pages;
+	struct frame_vector		*vec;
 	int				offset;
 	enum dma_data_direction		dma_dir;
 	struct sg_table			sg_table;
@@ -51,7 +52,6 @@ struct vb2_dma_sg_buf {
 	unsigned int			num_pages;
 	atomic_t			refcount;
 	struct vb2_vmarea_handler	handler;
-	struct vm_area_struct		*vma;
 
 	struct dma_buf_attachment	*db_attach;
 };
@@ -225,25 +225,17 @@ static void vb2_dma_sg_finish(void *buf_priv)
 	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
 }
 
-static inline int vma_is_io(struct vm_area_struct *vma)
-{
-	return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
-}
-
 static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 				    unsigned long size,
 				    enum dma_data_direction dma_dir)
 {
 	struct vb2_dma_sg_conf *conf = alloc_ctx;
 	struct vb2_dma_sg_buf *buf;
-	unsigned long first, last;
-	int num_pages_from_user;
-	struct vm_area_struct *vma;
 	struct sg_table *sgt;
 	DEFINE_DMA_ATTRS(attrs);
+	struct frame_vector *vec;
 
 	dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
-
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
 		return NULL;
@@ -254,63 +246,19 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	buf->offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
 	buf->dma_sgt = &buf->sg_table;
+	vec = vb2_create_framevec(vaddr, size, buf->dma_dir == DMA_FROM_DEVICE);
+	if (IS_ERR(vec))
+		goto userptr_fail_pfnvec;
+	buf->vec = vec;
 
-	first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;
-	last  = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
-	buf->num_pages = last - first + 1;
-
-	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
-			     GFP_KERNEL);
-	if (!buf->pages)
-		goto userptr_fail_alloc_pages;
-
-	down_read(&current->mm->mmap_sem);
-	vma = find_vma(current->mm, vaddr);
-	if (!vma) {
-		dprintk(1, "no vma for address %lu\n", vaddr);
-		goto userptr_fail_find_vma;
-	}
-
-	if (vma->vm_end < vaddr + size) {
-		dprintk(1, "vma at %lu is too small for %lu bytes\n",
-			vaddr, size);
-		goto userptr_fail_find_vma;
-	}
-
-	buf->vma = vb2_get_vma(vma);
-	if (!buf->vma) {
-		dprintk(1, "failed to copy vma\n");
-		goto userptr_fail_find_vma;
-	}
-
-	if (vma_is_io(buf->vma)) {
-		for (num_pages_from_user = 0;
-		     num_pages_from_user < buf->num_pages;
-		     ++num_pages_from_user, vaddr += PAGE_SIZE) {
-			unsigned long pfn;
-
-			if (follow_pfn(vma, vaddr, &pfn)) {
-				dprintk(1, "no page for address %lu\n", vaddr);
-				break;
-			}
-			buf->pages[num_pages_from_user] = pfn_to_page(pfn);
-		}
-	} else
-		num_pages_from_user = get_user_pages(current, current->mm,
-					     vaddr & PAGE_MASK,
-					     buf->num_pages,
-					     buf->dma_dir == DMA_FROM_DEVICE,
-					     1, /* force */
-					     buf->pages,
-					     NULL);
-	up_read(&current->mm->mmap_sem);
-
-	if (num_pages_from_user != buf->num_pages)
-		goto userptr_fail_get_user_pages;
+	buf->pages = frame_vector_pages(vec);
+	if (IS_ERR(buf->pages))
+		goto userptr_fail_sgtable;
+	buf->num_pages = frame_vector_count(vec);
 
 	if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
 			buf->num_pages, buf->offset, size, 0))
-		goto userptr_fail_alloc_table_from_pages;
+		goto userptr_fail_sgtable;
 
 	sgt = &buf->sg_table;
 	/*
@@ -326,19 +274,9 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 
 userptr_fail_map:
 	sg_free_table(&buf->sg_table);
-userptr_fail_alloc_table_from_pages:
-userptr_fail_get_user_pages:
-	dprintk(1, "get_user_pages requested/got: %d/%d]\n",
-		buf->num_pages, num_pages_from_user);
-	if (!vma_is_io(buf->vma))
-		while (--num_pages_from_user >= 0)
-			put_page(buf->pages[num_pages_from_user]);
-	down_read(&current->mm->mmap_sem);
-	vb2_put_vma(buf->vma);
-userptr_fail_find_vma:
-	up_read(&current->mm->mmap_sem);
-	kfree(buf->pages);
-userptr_fail_alloc_pages:
+userptr_fail_sgtable:
+	vb2_destroy_framevec(vec);
+userptr_fail_pfnvec:
 	kfree(buf);
 	return NULL;
 }
@@ -366,11 +304,8 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
 	while (--i >= 0) {
 		if (buf->dma_dir == DMA_FROM_DEVICE)
 			set_page_dirty_lock(buf->pages[i]);
-		if (!vma_is_io(buf->vma))
-			put_page(buf->pages[i]);
 	}
-	kfree(buf->pages);
-	vb2_put_vma(buf->vma);
+	vb2_destroy_framevec(buf->vec);
 	kfree(buf);
 }
 
Signature · 1 line
2.1.4
author
#8 lore raw

PATCH v7 6/9 media: vb2: Convert vb2_vmalloc_get_userptr() to use frame vector

In reply to Jan Kara

From: Jan Kara <[email protected]>

Convert vb2_vmalloc_get_userptr() to use frame vector infrastructure. When we are doing that there's no need to allocate page array and some code can be simplified.

---
 drivers/media/v4l2-core/videobuf2-vmalloc.c | 92 +++++++++++------------------
 1 file changed, 36 insertions(+), 56 deletions(-)
drivers/media/v4l2-core/videobuf2-vmalloc.c +36 -56
index 63bef959623e..ecb8f0c7f025 100644
@@ -23,11 +23,9 @@
 
 struct vb2_vmalloc_buf {
 	void				*vaddr;
-	struct page			**pages;
-	struct vm_area_struct		*vma;
+	struct frame_vector		*vec;
 	enum dma_data_direction		dma_dir;
 	unsigned long			size;
-	unsigned int			n_pages;
 	atomic_t			refcount;
 	struct vb2_vmarea_handler	handler;
 	struct dma_buf			*dbuf;
@@ -76,10 +74,8 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 				     enum dma_data_direction dma_dir)
 {
 	struct vb2_vmalloc_buf *buf;
-	unsigned long first, last;
-	int n_pages, offset;
-	struct vm_area_struct *vma;
-	dma_addr_t physp;
+	struct frame_vector *vec;
+	int n_pages, offset, i;
 
 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 	if (!buf)
@@ -88,53 +84,36 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	buf->dma_dir = dma_dir;
 	offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
-
-	down_read(&current->mm->mmap_sem);
-	vma = find_vma(current->mm, vaddr);
-	if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
-		if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
-			goto fail_pages_array_alloc;
-		buf->vma = vma;
-		buf->vaddr = (__force void *)ioremap_nocache(physp, size);
-		if (!buf->vaddr)
-			goto fail_pages_array_alloc;
+	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
+	if (IS_ERR(vec))
+		goto fail_pfnvec_create;
+	buf->vec = vec;
+	n_pages = frame_vector_count(vec);
+	if (frame_vector_to_pages(vec) < 0) {
+		unsigned long *nums = frame_vector_pfns(vec);
+
+		/*
+		 * We cannot get page pointers for these pfns. Check memory is
+		 * physically contiguous and use direct mapping.
+		 */
+		for (i = 1; i < n_pages; i++)
+			if (nums[i-1] + 1 != nums[i])
+				goto fail_map;
+		buf->vaddr = (__force void *)
+				ioremap_nocache(nums[0] << PAGE_SHIFT, size);
 	} else {
-		first = vaddr >> PAGE_SHIFT;
-		last  = (vaddr + size - 1) >> PAGE_SHIFT;
-		buf->n_pages = last - first + 1;
-		buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
-				     GFP_KERNEL);
-		if (!buf->pages)
-			goto fail_pages_array_alloc;
-
-		/* current->mm->mmap_sem is taken by videobuf2 core */
-		n_pages = get_user_pages(current, current->mm,
-					 vaddr & PAGE_MASK, buf->n_pages,
-					 dma_dir == DMA_FROM_DEVICE,
-					 1, /* force */
-					 buf->pages, NULL);
-		if (n_pages != buf->n_pages)
-			goto fail_get_user_pages;
-
-		buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
+		buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
 					PAGE_KERNEL);
-		if (!buf->vaddr)
-			goto fail_get_user_pages;
 	}
-	up_read(&current->mm->mmap_sem);
 
+	if (!buf->vaddr)
+		goto fail_map;
 	buf->vaddr += offset;
 	return buf;
 
-fail_get_user_pages:
-	pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
-		 buf->n_pages);
-	while (--n_pages >= 0)
-		put_page(buf->pages[n_pages]);
-	kfree(buf->pages);
-
-fail_pages_array_alloc:
-	up_read(&current->mm->mmap_sem);
+fail_map:
+	vb2_destroy_framevec(vec);
+fail_pfnvec_create:
 	kfree(buf);
 
 	return NULL;
@@ -145,20 +124,21 @@ static void vb2_vmalloc_put_userptr(void *buf_priv)
 	struct vb2_vmalloc_buf *buf = buf_priv;
 	unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
 	unsigned int i;
+	struct page **pages;
+	unsigned int n_pages;
 
-	if (buf->pages) {
+	if (!buf->vec->is_pfns) {
+		n_pages = frame_vector_count(buf->vec);
+		pages = frame_vector_pages(buf->vec);
 		if (vaddr)
-			vm_unmap_ram((void *)vaddr, buf->n_pages);
-		for (i = 0; i < buf->n_pages; ++i) {
-			if (buf->dma_dir == DMA_FROM_DEVICE)
-				set_page_dirty_lock(buf->pages[i]);
-			put_page(buf->pages[i]);
-		}
-		kfree(buf->pages);
+			vm_unmap_ram((void *)vaddr, n_pages);
+		if (buf->dma_dir == DMA_FROM_DEVICE)
+			for (i = 0; i < n_pages; i++)
+				set_page_dirty_lock(pages[i]);
 	} else {
-		vb2_put_vma(buf->vma);
 		iounmap((__force void __iomem *)buf->vaddr);
 	}
+	vb2_destroy_framevec(buf->vec);
 	kfree(buf);
 }
 
Signature · 7 lines
2.1.4

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to [email protected].  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>
author
#9 lore raw

PATCH v7 7/9 media: vb2: Convert vb2_dc_get_userptr() to use frame vector

In reply to Jan Kara

From: Jan Kara <[email protected]>

Convert vb2_dc_get_userptr() to use frame vector infrastructure. When we are doing that there's no need to allocate page array and some code can be simplified.

---
 drivers/media/v4l2-core/videobuf2-dma-contig.c | 212 ++++---------------------
 1 file changed, 34 insertions(+), 178 deletions(-)
drivers/media/v4l2-core/videobuf2-dma-contig.c +34 -178
index c548ce425701..2397ceb1dc6b 100644
@@ -32,15 +32,13 @@ struct vb2_dc_buf {
 	dma_addr_t			dma_addr;
 	enum dma_data_direction		dma_dir;
 	struct sg_table			*dma_sgt;
+	struct frame_vector		*vec;
 
 	/* MMAP related */
 	struct vb2_vmarea_handler	handler;
 	atomic_t			refcount;
 	struct sg_table			*sgt_base;
 
-	/* USERPTR related */
-	struct vm_area_struct		*vma;
-
 	/* DMABUF related */
 	struct dma_buf_attachment	*db_attach;
 };
@@ -49,24 +47,6 @@ struct vb2_dc_buf {
 /*        scatterlist table functions        */
 /*********************************************/
 
-
-static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
-	void (*cb)(struct page *pg))
-{
-	struct scatterlist *s;
-	unsigned int i;
-
-	for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
-		struct page *page = sg_page(s);
-		unsigned int n_pages = PAGE_ALIGN(s->offset + s->length)
-			>> PAGE_SHIFT;
-		unsigned int j;
-
-		for (j = 0; j < n_pages; ++j, ++page)
-			cb(page);
-	}
-}
-
 static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
 {
 	struct scatterlist *s;
@@ -429,92 +409,12 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags)
 /*       callbacks for USERPTR buffers       */
 /*********************************************/
 
-static inline int vma_is_io(struct vm_area_struct *vma)
-{
-	return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
-}
-
-static int vb2_dc_get_user_pfn(unsigned long start, int n_pages,
-	struct vm_area_struct *vma, unsigned long *res)
-{
-	unsigned long pfn, start_pfn, prev_pfn;
-	unsigned int i;
-	int ret;
-
-	if (!vma_is_io(vma))
-		return -EFAULT;
-
-	ret = follow_pfn(vma, start, &pfn);
-	if (ret)
-		return ret;
-
-	start_pfn = pfn;
-	start += PAGE_SIZE;
-
-	for (i = 1; i < n_pages; ++i, start += PAGE_SIZE) {
-		prev_pfn = pfn;
-		ret = follow_pfn(vma, start, &pfn);
-
-		if (ret) {
-			pr_err("no page for address %lu\n", start);
-			return ret;
-		}
-		if (pfn != prev_pfn + 1)
-			return -EINVAL;
-	}
-
-	*res = start_pfn;
-	return 0;
-}
-
-static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
-	int n_pages, struct vm_area_struct *vma,
-	enum dma_data_direction dma_dir)
-{
-	if (vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) {
-			unsigned long pfn;
-			int ret = follow_pfn(vma, start, &pfn);
-
-			if (!pfn_valid(pfn))
-				return -EINVAL;
-
-			if (ret) {
-				pr_err("no page for address %lu\n", start);
-				return ret;
-			}
-			pages[i] = pfn_to_page(pfn);
-		}
-	} else {
-		int n;
-
-		n = get_user_pages(current, current->mm, start & PAGE_MASK,
-			n_pages, dma_dir == DMA_FROM_DEVICE, 1, pages, NULL);
-		/* negative error means that no page was pinned */
-		n = max(n, 0);
-		if (n != n_pages) {
-			pr_err("got only %d of %d user pages\n", n, n_pages);
-			while (n)
-				put_page(pages[--n]);
-			return -EFAULT;
-		}
-	}
-
-	return 0;
-}
-
-static void vb2_dc_put_dirty_page(struct page *page)
-{
-	set_page_dirty_lock(page);
-	put_page(page);
-}
-
 static void vb2_dc_put_userptr(void *buf_priv)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 	struct sg_table *sgt = buf->dma_sgt;
+	int i;
+	struct page **pages;
 
 	if (sgt) {
 		DEFINE_DMA_ATTRS(attrs);
@@ -526,13 +426,15 @@ static void vb2_dc_put_userptr(void *buf_priv)
 		 */
 		dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
 				   buf->dma_dir, &attrs);
-		if (!vma_is_io(buf->vma))
-			vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);
-
+		pages = frame_vector_pages(buf->vec);
+		/* sgt should exist only if vector contains pages... */
+		BUG_ON(IS_ERR(pages));
+		for (i = 0; i < frame_vector_count(buf->vec); i++)
+			set_page_dirty_lock(pages[i]);
 		sg_free_table(sgt);
 		kfree(sgt);
 	}
-	vb2_put_vma(buf->vma);
+	vb2_destroy_framevec(buf->vec);
 	kfree(buf);
 }
 
@@ -572,13 +474,10 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 {
 	struct vb2_dc_conf *conf = alloc_ctx;
 	struct vb2_dc_buf *buf;
-	unsigned long start;
-	unsigned long end;
+	struct frame_vector *vec;
 	unsigned long offset;
-	struct page **pages;
-	int n_pages;
+	int n_pages, i;
 	int ret = 0;
-	struct vm_area_struct *vma;
 	struct sg_table *sgt;
 	unsigned long contig_size;
 	unsigned long dma_align = dma_get_cache_alignment();
@@ -604,75 +503,43 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	buf->dev = conf->dev;
 	buf->dma_dir = dma_dir;
 
-	start = vaddr & PAGE_MASK;
 	offset = vaddr & ~PAGE_MASK;
-	end = PAGE_ALIGN(vaddr + size);
-	n_pages = (end - start) >> PAGE_SHIFT;
-
-	pages = kmalloc(n_pages * sizeof(pages[0]), GFP_KERNEL);
-	if (!pages) {
-		ret = -ENOMEM;
-		pr_err("failed to allocate pages table\n");
+	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
+	if (IS_ERR(vec)) {
+		ret = PTR_ERR(vec);
 		goto fail_buf;
 	}
+	buf->vec = vec;
+	n_pages = frame_vector_count(vec);
+	ret = frame_vector_to_pages(vec);
+	if (ret < 0) {
+		unsigned long *nums = frame_vector_pfns(vec);
 
-	down_read(&current->mm->mmap_sem);
-	/* current->mm->mmap_sem is taken by videobuf2 core */
-	vma = find_vma(current->mm, vaddr);
-	if (!vma) {
-		pr_err("no vma for address %lu\n", vaddr);
-		ret = -EFAULT;
-		goto fail_pages;
-	}
-
-	if (vma->vm_end < vaddr + size) {
-		pr_err("vma at %lu is too small for %lu bytes\n", vaddr, size);
-		ret = -EFAULT;
-		goto fail_pages;
-	}
-
-	buf->vma = vb2_get_vma(vma);
-	if (!buf->vma) {
-		pr_err("failed to copy vma\n");
-		ret = -ENOMEM;
-		goto fail_pages;
-	}
-
-	/* extract page list from userspace mapping */
-	ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, dma_dir);
-	if (ret) {
-		unsigned long pfn;
-		if (vb2_dc_get_user_pfn(start, n_pages, vma, &pfn) == 0) {
-			up_read(&current->mm->mmap_sem);
-			buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, pfn);
-			buf->size = size;
-			kfree(pages);
-			return buf;
-		}
-
-		pr_err("failed to get user pages\n");
-		goto fail_vma;
+		/*
+		 * Failed to convert to pages... Check the memory is physically
+		 * contiguous and use direct mapping
+		 */
+		for (i = 1; i < n_pages; i++)
+			if (nums[i-1] + 1 != nums[i])
+				goto fail_pfnvec;
+		buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, nums[0]);
+		goto out;
 	}
-	up_read(&current->mm->mmap_sem);
 
 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt) {
 		pr_err("failed to allocate sg table\n");
 		ret = -ENOMEM;
-		goto fail_get_user_pages;
+		goto fail_pfnvec;
 	}
 
-	ret = sg_alloc_table_from_pages(sgt, pages, n_pages,
+	ret = sg_alloc_table_from_pages(sgt, frame_vector_pages(vec), n_pages,
 		offset, size, GFP_KERNEL);
 	if (ret) {
 		pr_err("failed to initialize sg table\n");
 		goto fail_sgt;
 	}
 
-	/* pages are no longer needed */
-	kfree(pages);
-	pages = NULL;
-
 	/*
 	 * No need to sync to the device, this will happen later when the
 	 * prepare() memop is called.
@@ -694,8 +561,9 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	}
 
 	buf->dma_addr = sg_dma_address(sgt->sgl);
-	buf->size = size;
 	buf->dma_sgt = sgt;
+out:
+	buf->size = size;
 
 	return buf;
 
@@ -704,25 +572,13 @@ fail_map_sg:
 			   buf->dma_dir, &attrs);
 
 fail_sgt_init:
-	if (!vma_is_io(buf->vma))
-		vb2_dc_sgt_foreach_page(sgt, put_page);
 	sg_free_table(sgt);
 
 fail_sgt:
 	kfree(sgt);
 
-fail_get_user_pages:
-	if (pages && !vma_is_io(buf->vma))
-		while (n_pages)
-			put_page(pages[--n_pages]);
-
-	down_read(&current->mm->mmap_sem);
-fail_vma:
-	vb2_put_vma(buf->vma);
-
-fail_pages:
-	up_read(&current->mm->mmap_sem);
-	kfree(pages); /* kfree is NULL-proof */
+fail_pfnvec:
+	vb2_destroy_framevec(vec);
 
 fail_buf:
 	kfree(buf);
Signature · 1 line
2.1.4
author
#10 lore raw

PATCH v7 8/9 media: vb2: Remove unused functions

In reply to Jan Kara

From: Jan Kara <[email protected]>

Conversion to the use of pinned pfns made some functions unused. Remove them. Also there's no need to lock mmap_sem in __buf_prepare() anymore.

---
 drivers/media/v4l2-core/videobuf2-memops.c | 114 -----------------------------
 include/media/videobuf2-memops.h           |   6 --
 2 files changed, 120 deletions(-)
drivers/media/v4l2-core/videobuf2-memops.c +0 -114
index 0ec186d41b9b..48c6a49c4928 100644
@@ -23,120 +23,6 @@
 #include <media/videobuf2-memops.h>
 
 /**
- * vb2_get_vma() - acquire and lock the virtual memory area
- * @vma:	given virtual memory area
- *
- * This function attempts to acquire an area mapped in the userspace for
- * the duration of a hardware operation. The area is "locked" by performing
- * the same set of operation that are done when process calls fork() and
- * memory areas are duplicated.
- *
- * Returns a copy of a virtual memory region on success or NULL.
- */
-struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma)
-{
-	struct vm_area_struct *vma_copy;
-
-	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-	if (vma_copy == NULL)
-		return NULL;
-
-	if (vma->vm_ops && vma->vm_ops->open)
-		vma->vm_ops->open(vma);
-
-	if (vma->vm_file)
-		get_file(vma->vm_file);
-
-	memcpy(vma_copy, vma, sizeof(*vma));
-
-	vma_copy->vm_mm = NULL;
-	vma_copy->vm_next = NULL;
-	vma_copy->vm_prev = NULL;
-
-	return vma_copy;
-}
-EXPORT_SYMBOL_GPL(vb2_get_vma);
-
-/**
- * vb2_put_userptr() - release a userspace virtual memory area
- * @vma:	virtual memory region associated with the area to be released
- *
- * This function releases the previously acquired memory area after a hardware
- * operation.
- */
-void vb2_put_vma(struct vm_area_struct *vma)
-{
-	if (!vma)
-		return;
-
-	if (vma->vm_ops && vma->vm_ops->close)
-		vma->vm_ops->close(vma);
-
-	if (vma->vm_file)
-		fput(vma->vm_file);
-
-	kfree(vma);
-}
-EXPORT_SYMBOL_GPL(vb2_put_vma);
-
-/**
- * vb2_get_contig_userptr() - lock physically contiguous userspace mapped memory
- * @vaddr:	starting virtual address of the area to be verified
- * @size:	size of the area
- * @res_paddr:	will return physical address for the given vaddr
- * @res_vma:	will return locked copy of struct vm_area for the given area
- *
- * This function will go through memory area of size @size mapped at @vaddr and
- * verify that the underlying physical pages are contiguous. If they are
- * contiguous the virtual memory area is locked and a @res_vma is filled with
- * the copy and @res_pa set to the physical address of the buffer.
- *
- * Returns 0 on success.
- */
-int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
-			   struct vm_area_struct **res_vma, dma_addr_t *res_pa)
-{
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma;
-	unsigned long offset, start, end;
-	unsigned long this_pfn, prev_pfn;
-	dma_addr_t pa = 0;
-
-	start = vaddr;
-	offset = start & ~PAGE_MASK;
-	end = start + size;
-
-	vma = find_vma(mm, start);
-
-	if (vma == NULL || vma->vm_end < end)
-		return -EFAULT;
-
-	for (prev_pfn = 0; start < end; start += PAGE_SIZE) {
-		int ret = follow_pfn(vma, start, &this_pfn);
-		if (ret)
-			return ret;
-
-		if (prev_pfn == 0)
-			pa = this_pfn << PAGE_SHIFT;
-		else if (this_pfn != prev_pfn + 1)
-			return -EFAULT;
-
-		prev_pfn = this_pfn;
-	}
-
-	/*
-	 * Memory is contigous, lock vma and return to the caller
-	 */
-	*res_vma = vb2_get_vma(vma);
-	if (*res_vma == NULL)
-		return -ENOMEM;
-
-	*res_pa = pa + offset;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(vb2_get_contig_userptr);
-
-/**
  * vb2_create_framevec() - map virtual addresses to pfns
  * @start:	Virtual user address where we start mapping
  * @length:	Length of a range to map
include/media/videobuf2-memops.h +0 -6
index 2f0564ff5f31..830b5239fd8b 100644
@@ -31,12 +31,6 @@ struct vb2_vmarea_handler {
 
 extern const struct vm_operations_struct vb2_common_vm_ops;
 
-int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
-			   struct vm_area_struct **res_vma, dma_addr_t *res_pa);
-
-struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma);
-void vb2_put_vma(struct vm_area_struct *vma);
-
 struct frame_vector *vb2_create_framevec(unsigned long start,
 					 unsigned long length,
 					 bool write);
Signature · 1 line
2.1.4
author
#11 lore raw

PATCH v7 9/9 drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

In reply to Jan Kara

From: Jan Kara <[email protected]>

Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames(). This removes the knowledge about vmas and mmap_sem locking from exynos driver. Also it fixes a problem that the function has been mapping user provided address without holding mmap_sem.

---
 drivers/gpu/drm/exynos/Kconfig          |  1 +
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 91 ++++++++++---------------------
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
 3 files changed, 30 insertions(+), 159 deletions(-)
drivers/gpu/drm/exynos/Kconfig +1 -0
index 43003c4ad80b..b364562dc6c1 100644
@@ -77,6 +77,7 @@ config DRM_EXYNOS_VIDI
 config DRM_EXYNOS_G2D
 	bool "Exynos DRM G2D"
 	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
+	select FRAME_VECTOR
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.
 
drivers/gpu/drm/exynos/exynos_drm_g2d.c +29 -62

154 lines not on this page · raw message

drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -97

103 lines not on this page · raw message

Signature · 1 line
2.1.4
#12 lore raw

Re: [PATCH 9/9] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

Quoted 6 lines · Jan Kara

From: Jan Kara <[email protected]>

Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames(). This removes the knowledge about vmas and mmap_sem locking from exynos driver. Also it fixes a problem that the function has been mapping user provided address without holding mmap_sem.

I'd like to see an Ack from one of the exynos drm driver maintainers before I merge this.

Inki, Marek?

Regards,

Hans

Quoted 293 lines
---
 drivers/gpu/drm/exynos/Kconfig          |  1 +
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 91 ++++++++++---------------------
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
 3 files changed, 30 insertions(+), 159 deletions(-)
drivers/gpu/drm/exynos/Kconfig +1 -0
index 43003c4ad80b..b364562dc6c1 100644
@@ -77,6 +77,7 @@ config DRM_EXYNOS_VIDI
 config DRM_EXYNOS_G2D
 	bool "Exynos DRM G2D"
 	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
+	select FRAME_VECTOR
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.
 
drivers/gpu/drm/exynos/exynos_drm_g2d.c +29 -62
index 81a250830808..1d8d9a508373 100644
@@ -190,10 +190,8 @@ struct g2d_cmdlist_userptr {
 	dma_addr_t		dma_addr;
 	unsigned long		userptr;
 	unsigned long		size;
-	struct page		**pages;
-	unsigned int		npages;
+	struct frame_vector	*vec;
 	struct sg_table		*sgt;
-	struct vm_area_struct	*vma;
 	atomic_t		refcount;
 	bool			in_pool;
 	bool			out_of_list;
@@ -363,6 +361,7 @@ static void g2d_userptr_put_dma_addr(struct drm_device *drm_dev,
 {
 	struct g2d_cmdlist_userptr *g2d_userptr =
 					(struct g2d_cmdlist_userptr *)obj;
+	struct page **pages;
 
 	if (!obj)
 		return;
@@ -382,19 +381,21 @@ out:
 	exynos_gem_unmap_sgt_from_dma(drm_dev, g2d_userptr->sgt,
 					DMA_BIDIRECTIONAL);
 
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
+	pages = frame_vector_pages(g2d_userptr->vec);
+	if (!IS_ERR(pages)) {
+		int i;
 
-	exynos_gem_put_vma(g2d_userptr->vma);
+		for (i = 0; i < frame_vector_count(g2d_userptr->vec); i++)
+			set_page_dirty_lock(pages[i]);
+	}
+	put_vaddr_frames(g2d_userptr->vec);
+	frame_vector_destroy(g2d_userptr->vec);
 
 	if (!g2d_userptr->out_of_list)
 		list_del_init(&g2d_userptr->list);
 
 	sg_free_table(g2d_userptr->sgt);
 	kfree(g2d_userptr->sgt);
-
-	drm_free_large(g2d_userptr->pages);
 	kfree(g2d_userptr);
 }
 
@@ -408,9 +409,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 	struct exynos_drm_g2d_private *g2d_priv = file_priv->g2d_priv;
 	struct g2d_cmdlist_userptr *g2d_userptr;
 	struct g2d_data *g2d;
-	struct page **pages;
 	struct sg_table	*sgt;
-	struct vm_area_struct *vma;
 	unsigned long start, end;
 	unsigned int npages, offset;
 	int ret;
@@ -456,65 +455,38 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 		return ERR_PTR(-ENOMEM);
 
 	atomic_set(&g2d_userptr->refcount, 1);
+	g2d_userptr->size = size;
 
 	start = userptr & PAGE_MASK;
 	offset = userptr & ~PAGE_MASK;
 	end = PAGE_ALIGN(userptr + size);
 	npages = (end - start) >> PAGE_SHIFT;
-	g2d_userptr->npages = npages;
-
-	pages = drm_calloc_large(npages, sizeof(struct page *));
-	if (!pages) {
-		DRM_ERROR("failed to allocate pages.\n");
-		ret = -ENOMEM;
+	g2d_userptr->vec = frame_vector_create(npages);
+	if (!g2d_userptr->vec)
 		goto err_free;
-	}
 
-	down_read(&current->mm->mmap_sem);
-	vma = find_vma(current->mm, userptr);
-	if (!vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get vm region.\n");
+	ret = get_vaddr_frames(start, npages, true, true, g2d_userptr->vec);
+	if (ret != npages) {
+		DRM_ERROR("failed to get user pages from userptr.\n");
+		if (ret < 0)
+			goto err_destroy_framevec;
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
-
-	if (vma->vm_end < userptr + size) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("vma is too small.\n");
+	if (frame_vector_to_pages(g2d_userptr->vec) < 0) {
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
 
-	g2d_userptr->vma = exynos_gem_get_vma(vma);
-	if (!g2d_userptr->vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to copy vma.\n");
-		ret = -ENOMEM;
-		goto err_free_pages;
-	}
-
-	g2d_userptr->size = size;
-
-	ret = exynos_gem_get_pages_from_userptr(start & PAGE_MASK,
-						npages, pages, vma);
-	if (ret < 0) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get user pages from userptr.\n");
-		goto err_put_vma;
-	}
-
-	up_read(&current->mm->mmap_sem);
-	g2d_userptr->pages = pages;
-
 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt) {
 		ret = -ENOMEM;
-		goto err_free_userptr;
+		goto err_put_framevec;
 	}
 
-	ret = sg_alloc_table_from_pages(sgt, pages, npages, offset,
-					size, GFP_KERNEL);
+	ret = sg_alloc_table_from_pages(sgt,
+					frame_vector_pages(g2d_userptr->vec),
+					npages, offset, size, GFP_KERNEL);
 	if (ret < 0) {
 		DRM_ERROR("failed to get sgt from pages.\n");
 		goto err_free_sgt;
@@ -549,16 +521,11 @@ err_sg_free_table:
 err_free_sgt:
 	kfree(sgt);
 
-err_free_userptr:
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
-
-err_put_vma:
-	exynos_gem_put_vma(g2d_userptr->vma);
+err_put_framevec:
+	put_vaddr_frames(g2d_userptr->vec);
 
-err_free_pages:
-	drm_free_large(pages);
+err_destroy_framevec:
+	frame_vector_destroy(g2d_userptr->vec);
 
 err_free:
 	kfree(g2d_userptr);
drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -97
index 0d5b9698d384..47068ae44ced 100644
@@ -378,103 +378,6 @@ int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
 	return 0;
 }
 
-struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
-{
-	struct vm_area_struct *vma_copy;
-
-	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-	if (!vma_copy)
-		return NULL;
-
-	if (vma->vm_ops && vma->vm_ops->open)
-		vma->vm_ops->open(vma);
-
-	if (vma->vm_file)
-		get_file(vma->vm_file);
-
-	memcpy(vma_copy, vma, sizeof(*vma));
-
-	vma_copy->vm_mm = NULL;
-	vma_copy->vm_next = NULL;
-	vma_copy->vm_prev = NULL;
-
-	return vma_copy;
-}
-
-void exynos_gem_put_vma(struct vm_area_struct *vma)
-{
-	if (!vma)
-		return;
-
-	if (vma->vm_ops && vma->vm_ops->close)
-		vma->vm_ops->close(vma);
-
-	if (vma->vm_file)
-		fput(vma->vm_file);
-
-	kfree(vma);
-}
-
-int exynos_gem_get_pages_from_userptr(unsigned long start,
-						unsigned int npages,
-						struct page **pages,
-						struct vm_area_struct *vma)
-{
-	int get_npages;
-
-	/* the memory region mmaped with VM_PFNMAP. */
-	if (vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
-			unsigned long pfn;
-			int ret = follow_pfn(vma, start, &pfn);
-			if (ret)
-				return ret;
-
-			pages[i] = pfn_to_page(pfn);
-		}
-
-		if (i != npages) {
-			DRM_ERROR("failed to get user_pages.\n");
-			return -EINVAL;
-		}
-
-		return 0;
-	}
-
-	get_npages = get_user_pages(current, current->mm, start,
-					npages, 1, 1, pages, NULL);
-	get_npages = max(get_npages, 0);
-	if (get_npages != npages) {
-		DRM_ERROR("failed to get user_pages.\n");
-		while (get_npages)
-			put_page(pages[--get_npages]);
-		return -EFAULT;
-	}
-
-	return 0;
-}
-
-void exynos_gem_put_pages_to_userptr(struct page **pages,
-					unsigned int npages,
-					struct vm_area_struct *vma)
-{
-	if (!vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; i++) {
-			set_page_dirty_lock(pages[i]);
-
-			/*
-			 * undo the reference we took when populating
-			 * the table.
-			 */
-			put_page(pages[i]);
-		}
-	}
-}
-
 int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
 				struct sg_table *sgt,
 				enum dma_data_direction dir)
maintainer Acked-by
#13 lore raw

Re: [PATCH 9/9] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

Quoted 8 lines · Hans Verkuil
Quoted 6 lines · Jan Kara

From: Jan Kara <[email protected]>

Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames(). This removes the knowledge about vmas and mmap_sem locking from exynos driver. Also it fixes a problem that the function has been mapping user provided address without holding mmap_sem.

Quoted 4 lines

I'd like to see an Ack from one of the exynos drm driver maintainers before I merge this.

Inki, Marek?

I already gave Ack but it seems that Jan missed it while updating.

Anyway,

Thanks,
Inki Dae

Quoted 304 lines

Regards,

Hans

Quoted 283 lines
---
 drivers/gpu/drm/exynos/Kconfig          |  1 +
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 91 ++++++++++---------------------
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
 3 files changed, 30 insertions(+), 159 deletions(-)
drivers/gpu/drm/exynos/Kconfig +1 -0
index 43003c4ad80b..b364562dc6c1 100644
@@ -77,6 +77,7 @@ config DRM_EXYNOS_VIDI
 config DRM_EXYNOS_G2D
 	bool "Exynos DRM G2D"
 	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
+	select FRAME_VECTOR
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.
 
drivers/gpu/drm/exynos/exynos_drm_g2d.c +29 -62
index 81a250830808..1d8d9a508373 100644
@@ -190,10 +190,8 @@ struct g2d_cmdlist_userptr {
 	dma_addr_t		dma_addr;
 	unsigned long		userptr;
 	unsigned long		size;
-	struct page		**pages;
-	unsigned int		npages;
+	struct frame_vector	*vec;
 	struct sg_table		*sgt;
-	struct vm_area_struct	*vma;
 	atomic_t		refcount;
 	bool			in_pool;
 	bool			out_of_list;
@@ -363,6 +361,7 @@ static void g2d_userptr_put_dma_addr(struct drm_device *drm_dev,
 {
 	struct g2d_cmdlist_userptr *g2d_userptr =
 					(struct g2d_cmdlist_userptr *)obj;
+	struct page **pages;
 
 	if (!obj)
 		return;
@@ -382,19 +381,21 @@ out:
 	exynos_gem_unmap_sgt_from_dma(drm_dev, g2d_userptr->sgt,
 					DMA_BIDIRECTIONAL);
 
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
+	pages = frame_vector_pages(g2d_userptr->vec);
+	if (!IS_ERR(pages)) {
+		int i;
 
-	exynos_gem_put_vma(g2d_userptr->vma);
+		for (i = 0; i < frame_vector_count(g2d_userptr->vec); i++)
+			set_page_dirty_lock(pages[i]);
+	}
+	put_vaddr_frames(g2d_userptr->vec);
+	frame_vector_destroy(g2d_userptr->vec);
 
 	if (!g2d_userptr->out_of_list)
 		list_del_init(&g2d_userptr->list);
 
 	sg_free_table(g2d_userptr->sgt);
 	kfree(g2d_userptr->sgt);
-
-	drm_free_large(g2d_userptr->pages);
 	kfree(g2d_userptr);
 }
 
@@ -408,9 +409,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 	struct exynos_drm_g2d_private *g2d_priv = file_priv->g2d_priv;
 	struct g2d_cmdlist_userptr *g2d_userptr;
 	struct g2d_data *g2d;
-	struct page **pages;
 	struct sg_table	*sgt;
-	struct vm_area_struct *vma;
 	unsigned long start, end;
 	unsigned int npages, offset;
 	int ret;
@@ -456,65 +455,38 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 		return ERR_PTR(-ENOMEM);
 
 	atomic_set(&g2d_userptr->refcount, 1);
+	g2d_userptr->size = size;
 
 	start = userptr & PAGE_MASK;
 	offset = userptr & ~PAGE_MASK;
 	end = PAGE_ALIGN(userptr + size);
 	npages = (end - start) >> PAGE_SHIFT;
-	g2d_userptr->npages = npages;
-
-	pages = drm_calloc_large(npages, sizeof(struct page *));
-	if (!pages) {
-		DRM_ERROR("failed to allocate pages.\n");
-		ret = -ENOMEM;
+	g2d_userptr->vec = frame_vector_create(npages);
+	if (!g2d_userptr->vec)
 		goto err_free;
-	}
 
-	down_read(&current->mm->mmap_sem);
-	vma = find_vma(current->mm, userptr);
-	if (!vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get vm region.\n");
+	ret = get_vaddr_frames(start, npages, true, true, g2d_userptr->vec);
+	if (ret != npages) {
+		DRM_ERROR("failed to get user pages from userptr.\n");
+		if (ret < 0)
+			goto err_destroy_framevec;
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
-
-	if (vma->vm_end < userptr + size) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("vma is too small.\n");
+	if (frame_vector_to_pages(g2d_userptr->vec) < 0) {
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
 
-	g2d_userptr->vma = exynos_gem_get_vma(vma);
-	if (!g2d_userptr->vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to copy vma.\n");
-		ret = -ENOMEM;
-		goto err_free_pages;
-	}
-
-	g2d_userptr->size = size;
-
-	ret = exynos_gem_get_pages_from_userptr(start & PAGE_MASK,
-						npages, pages, vma);
-	if (ret < 0) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get user pages from userptr.\n");
-		goto err_put_vma;
-	}
-
-	up_read(&current->mm->mmap_sem);
-	g2d_userptr->pages = pages;
-
 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt) {
 		ret = -ENOMEM;
-		goto err_free_userptr;
+		goto err_put_framevec;
 	}
 
-	ret = sg_alloc_table_from_pages(sgt, pages, npages, offset,
-					size, GFP_KERNEL);
+	ret = sg_alloc_table_from_pages(sgt,
+					frame_vector_pages(g2d_userptr->vec),
+					npages, offset, size, GFP_KERNEL);
 	if (ret < 0) {
 		DRM_ERROR("failed to get sgt from pages.\n");
 		goto err_free_sgt;
@@ -549,16 +521,11 @@ err_sg_free_table:
 err_free_sgt:
 	kfree(sgt);
 
-err_free_userptr:
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
-
-err_put_vma:
-	exynos_gem_put_vma(g2d_userptr->vma);
+err_put_framevec:
+	put_vaddr_frames(g2d_userptr->vec);
 
-err_free_pages:
-	drm_free_large(pages);
+err_destroy_framevec:
+	frame_vector_destroy(g2d_userptr->vec);
 
 err_free:
 	kfree(g2d_userptr);
drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -90
index 0d5b9698d384..47068ae44ced 100644
@@ -378,103 +378,6 @@ int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
 	return 0;
 }
 
-struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
-{
-	struct vm_area_struct *vma_copy;
-
-	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-	if (!vma_copy)
-		return NULL;
-
-	if (vma->vm_ops && vma->vm_ops->open)
-		vma->vm_ops->open(vma);
-
-	if (vma->vm_file)
-		get_file(vma->vm_file);
-
-	memcpy(vma_copy, vma, sizeof(*vma));
-
-	vma_copy->vm_mm = NULL;
-	vma_copy->vm_next = NULL;
-	vma_copy->vm_prev = NULL;
-
-	return vma_copy;
-}
-
-void exynos_gem_put_vma(struct vm_area_struct *vma)
-{
-	if (!vma)
-		return;
-
-	if (vma->vm_ops && vma->vm_ops->close)
-		vma->vm_ops->close(vma);
-
-	if (vma->vm_file)
-		fput(vma->vm_file);
-
-	kfree(vma);
-}
-
-int exynos_gem_get_pages_from_userptr(unsigned long start,
-						unsigned int npages,
-						struct page **pages,
-						struct vm_area_struct *vma)
-{
-	int get_npages;
-
-	/* the memory region mmaped with VM_PFNMAP. */
-	if (vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
-			unsigned long pfn;
-			int ret = follow_pfn(vma, start, &pfn);
-			if (ret)
-				return ret;
-
-			pages[i] = pfn_to_page(pfn);
-		}
-
-		if (i != npages) {
-			DRM_ERROR("failed to get user_pages.\n");
-			return -EINVAL;
-		}
-
-		return 0;
-	}
-
-	get_npages = get_user_pages(current, current->mm, start,
-					npages, 1, 1, pages, NULL);
-	get_npages = max(get_npages, 0);
-	if (get_npages != npages) {
-		DRM_ERROR("failed to get user_pages.\n");
-		while (get_npages)
-			put_page(pages[--get_npages]);
-		return -EFAULT;
-	}
-
-	return 0;
-}
-
-void exynos_gem_put_pages_to_userptr(struct page **pages,
-					unsigned int npages,
-					struct vm_area_struct *vma)
-{
-	if (!vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; i++) {
-			set_page_dirty_lock(pages[i]);
-
-			/*
-			 * undo the reference we took when populating

drivers/gpu/drm/exynos/exynos_drm_gem.c int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data, · line 383

Quoted 10 lines
drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -7
-			 * the table.
-			 */
-			put_page(pages[i]);
-		}
-	}
-}
-
 int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
 				struct sg_table *sgt,
 				enum dma_data_direction dir)

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#14 lore raw

Re: [PATCH 9/9] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

Quoted 12 lines · Inki Dae
Quoted 11 lines · Hans Verkuil
Quoted 6 lines · Jan Kara

From: Jan Kara <[email protected]>

Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames(). This removes the knowledge about vmas and mmap_sem locking from exynos driver. Also it fixes a problem that the function has been mapping user provided address without holding mmap_sem.

I'd like to see an Ack from one of the exynos drm driver maintainers before I merge this.

Quoted 6 lines
Quoted 1 line

Inki, Marek?

I already gave Ack but it seems that Jan missed it while updating.

Anyway,

Thanks!

BTW, I didn't see your earlier Ack either. Was it posted to the linux-media list as well? It didn't turn up there.

Regards,

Hans

Quoted 314 lines

Thanks,
Inki Dae

Quoted 295 lines

Regards,

Hans

Quoted 290 lines
---
 drivers/gpu/drm/exynos/Kconfig          |  1 +
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 91 ++++++++++---------------------
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
 3 files changed, 30 insertions(+), 159 deletions(-)
drivers/gpu/drm/exynos/Kconfig +1 -0
index 43003c4ad80b..b364562dc6c1 100644
@@ -77,6 +77,7 @@ config DRM_EXYNOS_VIDI
 config DRM_EXYNOS_G2D
 	bool "Exynos DRM G2D"
 	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
+	select FRAME_VECTOR
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.
 
drivers/gpu/drm/exynos/exynos_drm_g2d.c +29 -62
index 81a250830808..1d8d9a508373 100644
@@ -190,10 +190,8 @@ struct g2d_cmdlist_userptr {
 	dma_addr_t		dma_addr;
 	unsigned long		userptr;
 	unsigned long		size;
-	struct page		**pages;
-	unsigned int		npages;
+	struct frame_vector	*vec;
 	struct sg_table		*sgt;
-	struct vm_area_struct	*vma;
 	atomic_t		refcount;
 	bool			in_pool;
 	bool			out_of_list;
@@ -363,6 +361,7 @@ static void g2d_userptr_put_dma_addr(struct drm_device *drm_dev,
 {
 	struct g2d_cmdlist_userptr *g2d_userptr =
 					(struct g2d_cmdlist_userptr *)obj;
+	struct page **pages;
 
 	if (!obj)
 		return;
@@ -382,19 +381,21 @@ out:
 	exynos_gem_unmap_sgt_from_dma(drm_dev, g2d_userptr->sgt,
 					DMA_BIDIRECTIONAL);
 
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
+	pages = frame_vector_pages(g2d_userptr->vec);
+	if (!IS_ERR(pages)) {
+		int i;
 
-	exynos_gem_put_vma(g2d_userptr->vma);
+		for (i = 0; i < frame_vector_count(g2d_userptr->vec); i++)
+			set_page_dirty_lock(pages[i]);
+	}
+	put_vaddr_frames(g2d_userptr->vec);
+	frame_vector_destroy(g2d_userptr->vec);
 
 	if (!g2d_userptr->out_of_list)
 		list_del_init(&g2d_userptr->list);
 
 	sg_free_table(g2d_userptr->sgt);
 	kfree(g2d_userptr->sgt);
-
-	drm_free_large(g2d_userptr->pages);
 	kfree(g2d_userptr);
 }
 
@@ -408,9 +409,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 	struct exynos_drm_g2d_private *g2d_priv = file_priv->g2d_priv;
 	struct g2d_cmdlist_userptr *g2d_userptr;
 	struct g2d_data *g2d;
-	struct page **pages;
 	struct sg_table	*sgt;
-	struct vm_area_struct *vma;
 	unsigned long start, end;
 	unsigned int npages, offset;
 	int ret;
@@ -456,65 +455,38 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 		return ERR_PTR(-ENOMEM);
 
 	atomic_set(&g2d_userptr->refcount, 1);
+	g2d_userptr->size = size;
 
 	start = userptr & PAGE_MASK;
 	offset = userptr & ~PAGE_MASK;
 	end = PAGE_ALIGN(userptr + size);
 	npages = (end - start) >> PAGE_SHIFT;
-	g2d_userptr->npages = npages;
-
-	pages = drm_calloc_large(npages, sizeof(struct page *));
-	if (!pages) {
-		DRM_ERROR("failed to allocate pages.\n");
-		ret = -ENOMEM;
+	g2d_userptr->vec = frame_vector_create(npages);
+	if (!g2d_userptr->vec)
 		goto err_free;
-	}
 
-	down_read(&current->mm->mmap_sem);
-	vma = find_vma(current->mm, userptr);
-	if (!vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get vm region.\n");
+	ret = get_vaddr_frames(start, npages, true, true, g2d_userptr->vec);
+	if (ret != npages) {
+		DRM_ERROR("failed to get user pages from userptr.\n");
+		if (ret < 0)
+			goto err_destroy_framevec;
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
-
-	if (vma->vm_end < userptr + size) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("vma is too small.\n");
+	if (frame_vector_to_pages(g2d_userptr->vec) < 0) {
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
 
-	g2d_userptr->vma = exynos_gem_get_vma(vma);
-	if (!g2d_userptr->vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to copy vma.\n");
-		ret = -ENOMEM;
-		goto err_free_pages;
-	}
-
-	g2d_userptr->size = size;
-
-	ret = exynos_gem_get_pages_from_userptr(start & PAGE_MASK,
-						npages, pages, vma);
-	if (ret < 0) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get user pages from userptr.\n");
-		goto err_put_vma;
-	}
-
-	up_read(&current->mm->mmap_sem);
-	g2d_userptr->pages = pages;
-
 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt) {
 		ret = -ENOMEM;
-		goto err_free_userptr;
+		goto err_put_framevec;
 	}
 
-	ret = sg_alloc_table_from_pages(sgt, pages, npages, offset,
-					size, GFP_KERNEL);
+	ret = sg_alloc_table_from_pages(sgt,
+					frame_vector_pages(g2d_userptr->vec),
+					npages, offset, size, GFP_KERNEL);
 	if (ret < 0) {
 		DRM_ERROR("failed to get sgt from pages.\n");
 		goto err_free_sgt;
@@ -549,16 +521,11 @@ err_sg_free_table:
 err_free_sgt:
 	kfree(sgt);
 
-err_free_userptr:
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
-
-err_put_vma:
-	exynos_gem_put_vma(g2d_userptr->vma);
+err_put_framevec:
+	put_vaddr_frames(g2d_userptr->vec);
 
-err_free_pages:
-	drm_free_large(pages);
+err_destroy_framevec:
+	frame_vector_destroy(g2d_userptr->vec);
 
 err_free:
 	kfree(g2d_userptr);
drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -97
index 0d5b9698d384..47068ae44ced 100644
@@ -378,103 +378,6 @@ int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
 	return 0;
 }
 
-struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
-{
-	struct vm_area_struct *vma_copy;
-
-	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-	if (!vma_copy)
-		return NULL;
-
-	if (vma->vm_ops && vma->vm_ops->open)
-		vma->vm_ops->open(vma);
-
-	if (vma->vm_file)
-		get_file(vma->vm_file);
-
-	memcpy(vma_copy, vma, sizeof(*vma));
-
-	vma_copy->vm_mm = NULL;
-	vma_copy->vm_next = NULL;
-	vma_copy->vm_prev = NULL;
-
-	return vma_copy;
-}
-
-void exynos_gem_put_vma(struct vm_area_struct *vma)
-{
-	if (!vma)
-		return;
-
-	if (vma->vm_ops && vma->vm_ops->close)
-		vma->vm_ops->close(vma);
-
-	if (vma->vm_file)
-		fput(vma->vm_file);
-
-	kfree(vma);
-}
-
-int exynos_gem_get_pages_from_userptr(unsigned long start,
-						unsigned int npages,
-						struct page **pages,
-						struct vm_area_struct *vma)
-{
-	int get_npages;
-
-	/* the memory region mmaped with VM_PFNMAP. */
-	if (vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
-			unsigned long pfn;
-			int ret = follow_pfn(vma, start, &pfn);
-			if (ret)
-				return ret;
-
-			pages[i] = pfn_to_page(pfn);
-		}
-
-		if (i != npages) {
-			DRM_ERROR("failed to get user_pages.\n");
-			return -EINVAL;
-		}
-
-		return 0;
-	}
-
-	get_npages = get_user_pages(current, current->mm, start,
-					npages, 1, 1, pages, NULL);
-	get_npages = max(get_npages, 0);
-	if (get_npages != npages) {
-		DRM_ERROR("failed to get user_pages.\n");
-		while (get_npages)
-			put_page(pages[--get_npages]);
-		return -EFAULT;
-	}
-
-	return 0;
-}
-
-void exynos_gem_put_pages_to_userptr(struct page **pages,
-					unsigned int npages,
-					struct vm_area_struct *vma)
-{
-	if (!vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; i++) {
-			set_page_dirty_lock(pages[i]);
-
-			/*
-			 * undo the reference we took when populating
-			 * the table.
-			 */
-			put_page(pages[i]);
-		}
-	}
-}
-
 int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
Quoted 9 lines

drivers/gpu/drm/exynos/exynos_drm_gem.c int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data, · line 383

Quoted 3 lines
drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -0
 				struct sg_table *sgt,
 				enum dma_data_direction dir)

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maintainer
#15 lore raw

Re: [PATCH 9/9] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

Quoted 13 lines · Hans Verkuil
Quoted 12 lines · Inki Dae
Quoted 11 lines · Hans Verkuil
Quoted 6 lines · Jan Kara

From: Jan Kara <[email protected]>

Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames(). This removes the knowledge about vmas and mmap_sem locking from exynos driver. Also it fixes a problem that the function has been mapping user provided address without holding mmap_sem.

I'd like to see an Ack from one of the exynos drm driver maintainers before I merge this.

Quoted 8 lines
Quoted 6 lines
Quoted 1 line

Inki, Marek?

I already gave Ack but it seems that Jan missed it while updating.

Anyway,

Thanks!

Oops, sorry. This patch would incur a build warning. Below is my comment.

Quoted 3 lines

BTW, I didn't see your earlier Ack either. Was it posted to the linux-media list as well? It didn't turn up there.

I thought posted but I couldn't find the email in my mailbox so I may mistake.

Quoted 102 lines

Regards,

Hans

Quoted 97 lines

Thanks,
Inki Dae

Quoted 93 lines

Regards,

Hans

Quoted 88 lines
---
 drivers/gpu/drm/exynos/Kconfig          |  1 +
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 91 ++++++++++---------------------
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
 3 files changed, 30 insertions(+), 159 deletions(-)
drivers/gpu/drm/exynos/Kconfig +1 -0
index 43003c4ad80b..b364562dc6c1 100644
@@ -77,6 +77,7 @@ config DRM_EXYNOS_VIDI
 config DRM_EXYNOS_G2D
 	bool "Exynos DRM G2D"
 	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
+	select FRAME_VECTOR
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.
 
drivers/gpu/drm/exynos/exynos_drm_g2d.c +11 -11
index 81a250830808..1d8d9a508373 100644
@@ -190,10 +190,8 @@ struct g2d_cmdlist_userptr {
 	dma_addr_t		dma_addr;
 	unsigned long		userptr;
 	unsigned long		size;
-	struct page		**pages;
-	unsigned int		npages;
+	struct frame_vector	*vec;
 	struct sg_table		*sgt;
-	struct vm_area_struct	*vma;
 	atomic_t		refcount;
 	bool			in_pool;
 	bool			out_of_list;
@@ -363,6 +361,7 @@ static void g2d_userptr_put_dma_addr(struct drm_device *drm_dev,
 {
 	struct g2d_cmdlist_userptr *g2d_userptr =
 					(struct g2d_cmdlist_userptr *)obj;
+	struct page **pages;
 
 	if (!obj)
 		return;
@@ -382,19 +381,21 @@ out:
 	exynos_gem_unmap_sgt_from_dma(drm_dev, g2d_userptr->sgt,
 					DMA_BIDIRECTIONAL);
 
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
+	pages = frame_vector_pages(g2d_userptr->vec);
+	if (!IS_ERR(pages)) {
+		int i;
 
-	exynos_gem_put_vma(g2d_userptr->vma);
+		for (i = 0; i < frame_vector_count(g2d_userptr->vec); i++)
+			set_page_dirty_lock(pages[i]);
+	}
+	put_vaddr_frames(g2d_userptr->vec);
+	frame_vector_destroy(g2d_userptr->vec);
 
 	if (!g2d_userptr->out_of_list)
 		list_del_init(&g2d_userptr->list);
 
 	sg_free_table(g2d_userptr->sgt);
 	kfree(g2d_userptr->sgt);
-
-	drm_free_large(g2d_userptr->pages);
 	kfree(g2d_userptr);
 }
 
@@ -408,9 +409,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 	struct exynos_drm_g2d_private *g2d_priv = file_priv->g2d_priv;
 	struct g2d_cmdlist_userptr *g2d_userptr;
 	struct g2d_data *g2d;
-	struct page **pages;
 	struct sg_table	*sgt;
-	struct vm_area_struct *vma;
 	unsigned long start, end;
 	unsigned int npages, offset;
 	int ret;
@@ -456,65 +455,38 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 		return ERR_PTR(-ENOMEM);
 
 	atomic_set(&g2d_userptr->refcount, 1);
+	g2d_userptr->size = size;
 
Quoted 12 lines
Quoted 4 lines
Quoted 4 lines
Quoted 4 lines
drivers/gpu/drm/exynos/exynos_drm_g2d.c +0 -0
 	start = userptr & PAGE_MASK;
 	offset = userptr & ~PAGE_MASK;
 	end = PAGE_ALIGN(userptr + size);
 	npages = (end - start) >> PAGE_SHIFT;
Quoted 8 lines
Quoted 8 lines

drivers/gpu/drm/exynos/exynos_drm_g2d.c static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev, · line 465

Quoted 8 lines
drivers/gpu/drm/exynos/exynos_drm_g2d.c +2 -6
-	g2d_userptr->npages = npages;
-
-	pages = drm_calloc_large(npages, sizeof(struct page *));
-	if (!pages) {
-		DRM_ERROR("failed to allocate pages.\n");
-		ret = -ENOMEM;
+	g2d_userptr->vec = frame_vector_create(npages);
+	if (!g2d_userptr->vec)

You would need ret = -EFAULT here. And below is a patch posted already,

	http://www.spinics.net/lists/dri-devel/msg85321.html

ps. please, ignore the codes related to build error in the patch.

With the change, Acked-by: Inki Dae <[email protected]>

Thanks,
Inki Dae

Quoted 207 lines
Quoted 205 lines
Quoted 190 lines
Quoted 190 lines
drivers/gpu/drm/exynos/exynos_drm_g2d.c +16 -45
 		goto err_free;
-	}
 
-	down_read(&current->mm->mmap_sem);
-	vma = find_vma(current->mm, userptr);
-	if (!vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get vm region.\n");
+	ret = get_vaddr_frames(start, npages, true, true, g2d_userptr->vec);
+	if (ret != npages) {
+		DRM_ERROR("failed to get user pages from userptr.\n");
+		if (ret < 0)
+			goto err_destroy_framevec;
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
-
-	if (vma->vm_end < userptr + size) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("vma is too small.\n");
+	if (frame_vector_to_pages(g2d_userptr->vec) < 0) {
 		ret = -EFAULT;
-		goto err_free_pages;
+		goto err_put_framevec;
 	}
 
-	g2d_userptr->vma = exynos_gem_get_vma(vma);
-	if (!g2d_userptr->vma) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to copy vma.\n");
-		ret = -ENOMEM;
-		goto err_free_pages;
-	}
-
-	g2d_userptr->size = size;
-
-	ret = exynos_gem_get_pages_from_userptr(start & PAGE_MASK,
-						npages, pages, vma);
-	if (ret < 0) {
-		up_read(&current->mm->mmap_sem);
-		DRM_ERROR("failed to get user pages from userptr.\n");
-		goto err_put_vma;
-	}
-
-	up_read(&current->mm->mmap_sem);
-	g2d_userptr->pages = pages;
-
 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt) {
 		ret = -ENOMEM;
-		goto err_free_userptr;
+		goto err_put_framevec;
 	}
 
-	ret = sg_alloc_table_from_pages(sgt, pages, npages, offset,
-					size, GFP_KERNEL);
+	ret = sg_alloc_table_from_pages(sgt,
+					frame_vector_pages(g2d_userptr->vec),
+					npages, offset, size, GFP_KERNEL);
 	if (ret < 0) {
 		DRM_ERROR("failed to get sgt from pages.\n");
 		goto err_free_sgt;
@@ -549,16 +521,11 @@ err_sg_free_table:
 err_free_sgt:
 	kfree(sgt);
 
-err_free_userptr:
-	exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-					g2d_userptr->npages,
-					g2d_userptr->vma);
-
-err_put_vma:
-	exynos_gem_put_vma(g2d_userptr->vma);
+err_put_framevec:
+	put_vaddr_frames(g2d_userptr->vec);
 
-err_free_pages:
-	drm_free_large(pages);
+err_destroy_framevec:
+	frame_vector_destroy(g2d_userptr->vec);
 
 err_free:
 	kfree(g2d_userptr);
drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -97
index 0d5b9698d384..47068ae44ced 100644
@@ -378,103 +378,6 @@ int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
 	return 0;
 }
 
-struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
-{
-	struct vm_area_struct *vma_copy;
-
-	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-	if (!vma_copy)
-		return NULL;
-
-	if (vma->vm_ops && vma->vm_ops->open)
-		vma->vm_ops->open(vma);
-
-	if (vma->vm_file)
-		get_file(vma->vm_file);
-
-	memcpy(vma_copy, vma, sizeof(*vma));
-
-	vma_copy->vm_mm = NULL;
-	vma_copy->vm_next = NULL;
-	vma_copy->vm_prev = NULL;
-
-	return vma_copy;
-}
-
-void exynos_gem_put_vma(struct vm_area_struct *vma)
-{
-	if (!vma)
-		return;
-
-	if (vma->vm_ops && vma->vm_ops->close)
-		vma->vm_ops->close(vma);
-
-	if (vma->vm_file)
-		fput(vma->vm_file);
-
-	kfree(vma);
-}
-
-int exynos_gem_get_pages_from_userptr(unsigned long start,
-						unsigned int npages,
-						struct page **pages,
-						struct vm_area_struct *vma)
-{
-	int get_npages;
-
-	/* the memory region mmaped with VM_PFNMAP. */
-	if (vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
-			unsigned long pfn;
-			int ret = follow_pfn(vma, start, &pfn);
-			if (ret)
-				return ret;
-
-			pages[i] = pfn_to_page(pfn);
-		}
-
-		if (i != npages) {
-			DRM_ERROR("failed to get user_pages.\n");
-			return -EINVAL;
-		}
-
-		return 0;
-	}
-
-	get_npages = get_user_pages(current, current->mm, start,
-					npages, 1, 1, pages, NULL);
-	get_npages = max(get_npages, 0);
-	if (get_npages != npages) {
-		DRM_ERROR("failed to get user_pages.\n");
-		while (get_npages)
-			put_page(pages[--get_npages]);
-		return -EFAULT;
-	}
-
-	return 0;
-}
-
-void exynos_gem_put_pages_to_userptr(struct page **pages,
-					unsigned int npages,
-					struct vm_area_struct *vma)
-{
-	if (!vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; i++) {
-			set_page_dirty_lock(pages[i]);
-
-			/*
-			 * undo the reference we took when populating
-			 * the table.
-			 */
-			put_page(pages[i]);
-		}
-	}
-}
-
 int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
Quoted 9 lines

drivers/gpu/drm/exynos/exynos_drm_gem.c int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data, · line 383

Quoted 3 lines
drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -0
 				struct sg_table *sgt,
 				enum dma_data_direction dir)

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#16 lore raw

Re: [PATCH 9/9] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()

Quoted 45 lines · Inki Dae
Quoted 13 lines · Hans Verkuil
Quoted 12 lines · Inki Dae
Quoted 11 lines · Hans Verkuil
Quoted 6 lines · Jan Kara

From: Jan Kara <[email protected]>

Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames(). This removes the knowledge about vmas and mmap_sem locking from exynos driver. Also it fixes a problem that the function has been mapping user provided address without holding mmap_sem.

I'd like to see an Ack from one of the exynos drm driver maintainers before I merge this.

Quoted 8 lines
Quoted 6 lines
Quoted 1 line

Inki, Marek?

I already gave Ack but it seems that Jan missed it while updating.

Anyway,

Thanks!

Oops, sorry. This patch would incur a build warning. Below is my comment.

Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
drivers/gpu/drm/exynos/exynos_drm_g2d.c +1 -0
@@ -456,65 +455,38 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
 		return ERR_PTR(-ENOMEM);
 
 	atomic_set(&g2d_userptr->refcount, 1);
+	g2d_userptr->size = size;
 
Quoted 12 lines
Quoted 4 lines
Quoted 4 lines
Quoted 4 lines
drivers/gpu/drm/exynos/exynos_drm_g2d.c +0 -0
 	start = userptr & PAGE_MASK;
 	offset = userptr & ~PAGE_MASK;
 	end = PAGE_ALIGN(userptr + size);
 	npages = (end - start) >> PAGE_SHIFT;
Quoted 8 lines
Quoted 8 lines

drivers/gpu/drm/exynos/exynos_drm_g2d.c static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev, · line 465

Quoted 8 lines
drivers/gpu/drm/exynos/exynos_drm_g2d.c +2 -6
-	g2d_userptr->npages = npages;
-
-	pages = drm_calloc_large(npages, sizeof(struct page *));
-	if (!pages) {
-		DRM_ERROR("failed to allocate pages.\n");
-		ret = -ENOMEM;
+	g2d_userptr->vec = frame_vector_create(npages);
+	if (!g2d_userptr->vec)

You would need ret = -EFAULT here. And below is a patch posted already,

Quoted 1 line
	http://www.spinics.net/lists/dri-devel/msg85321.html

The error should IMHO be -ENOMEM because frame_vector_create() fails only if we fail to allocate the structure. Attached is the updated version of the patch. Hans, can you please pick this one?

Quoted 3 lines

ps. please, ignore the codes related to build error in the patch.

With the change, Acked-by: Inki Dae <[email protected]>

Thanks and sorry for making so many stupid mistakes in the Exynos driver.

Honza

Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
Quoted 1 line

From e1ce3781eb0a3ffe045055f4145bc60ee7b2a6b5 Mon Sep 17 00:00:00 2001

From: Jan Kara <[email protected]>
Date: Wed, 4 Dec 2013 14:41:22 +0100
Subject: [PATCH 9/9] drm/exynos: Convert g2d_userptr_get_dma_addr() to use
get_vaddr_frames()

Convert g2d_userptr_get_dma_addr() to pin pages using get_vaddr_frames(). This removes the knowledge about vmas and mmap_sem locking from exynos driver. Also it fixes a problem that the function has been mapping user provided address without holding mmap_sem.

---
 drivers/gpu/drm/exynos/Kconfig          |  1 +
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 89 ++++++++++--------------------
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 97 ---------------------------------
 3 files changed, 30 insertions(+), 157 deletions(-)
drivers/gpu/drm/exynos/Kconfig +1 -0
index 43003c4ad80b..b364562dc6c1 100644
@@ -77,6 +77,7 @@ config DRM_EXYNOS_VIDI
 config DRM_EXYNOS_G2D
 	bool "Exynos DRM G2D"
 	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
+	select FRAME_VECTOR
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.
 
drivers/gpu/drm/exynos/exynos_drm_g2d.c +29 -60

154 lines not on this page · raw message

drivers/gpu/drm/exynos/exynos_drm_gem.c +0 -97

103 lines not on this page · raw message

Signature · 1 line
2.1.4
#17 lore raw
In reply to Jan Kara
Quoted 21 lines · Jan Kara

From: Jan Kara <[email protected]>

Hello,

I'm sending the seventh version of my patch series to abstract vma handling from the various media drivers. Since the previous version there are just minor cleanups and fixes (see detailed changelog at the end of the email).

After this patch set drivers have to know much less details about vmas, their types, and locking. Also quite some code is removed from them. As a bonus drivers get automatically VM_FAULT_RETRY handling. The primary motivation for this series is to remove knowledge about mmap_sem locking from as many places a possible so that we can change it with reasonable effort.

The core of the series is the new helper get_vaddr_frames() which is given a virtual address and it fills in PFNs / struct page pointers (depending on VMA type) into the provided array. If PFNs correspond to normal pages it also grabs references to these pages. The difference from get_user_pages() is that this function can also deal with pfnmap, and io mappings which is what the media drivers need.

Quoted 5 lines

I have tested the patches with vivid driver so at least vb2 code got some exposure. Conversion of other drivers was just compile-tested (for x86 so e.g. exynos driver which is only for Samsung platform is completely untested).

Hans, can you please pull the changes? Thanks!

Scheduled for Friday or the following Monday!

Thanks,

Hans

Quoted 34 lines

Honza

Changes since v6:
* Fixed compilation error introduced into exynos driver
* Folded patch allowing get_vaddr_pfn() code to be selected by a config option into previous patches
* Rebased on top of linux-media tree

Changes since v5:
* Moved mm helper into a separate file and behind a config option
* Changed the first patch pushing mmap_sem down in videobuf2 core to avoid possible deadlock

Changes since v4:
* Minor cleanups and fixes pointed out by Mel and Vlasta
* Added Acked-by tags

Changes since v3:
* Added include <linux/vmalloc.h> into mm/gup.c as it's needed for some archs
* Fixed error path for exynos driver

Changes since v2:
* Renamed functions and structures as Mel suggested
* Other minor changes suggested by Mel
* Rebased on top of 4.1-rc2
* Changed functions to get pointer to array of pages / pfns to perform conversion if necessary. This fixes possible issue in the omap I may have introduced in v2 and generally makes the API less errorprone.
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#18 lore raw
In reply to Jan Kara

Hi Jan,

Quoted 21 lines · Jan Kara

From: Jan Kara <[email protected]>

Hello,

I'm sending the seventh version of my patch series to abstract vma handling from the various media drivers. Since the previous version there are just minor cleanups and fixes (see detailed changelog at the end of the email).

After this patch set drivers have to know much less details about vmas, their types, and locking. Also quite some code is removed from them. As a bonus drivers get automatically VM_FAULT_RETRY handling. The primary motivation for this series is to remove knowledge about mmap_sem locking from as many places a possible so that we can change it with reasonable effort.

The core of the series is the new helper get_vaddr_frames() which is given a virtual address and it fills in PFNs / struct page pointers (depending on VMA type) into the provided array. If PFNs correspond to normal pages it also grabs references to these pages. The difference from get_user_pages() is that this function can also deal with pfnmap, and io mappings which is what the media drivers need.

Quoted 5 lines

I have tested the patches with vivid driver so at least vb2 code got some exposure. Conversion of other drivers was just compile-tested (for x86 so e.g. exynos driver which is only for Samsung platform is completely untested).

Hans, can you please pull the changes? Thanks!

I've done some testing myself and it all looks fine to me. All I need is an additional Ack for the mm patch from Andrew or other mm maintainers.

Regards,

Hans

Quoted 34 lines

Honza

Changes since v6:
* Fixed compilation error introduced into exynos driver
* Folded patch allowing get_vaddr_pfn() code to be selected by a config option into previous patches
* Rebased on top of linux-media tree

Changes since v5:
* Moved mm helper into a separate file and behind a config option
* Changed the first patch pushing mmap_sem down in videobuf2 core to avoid possible deadlock

Changes since v4:
* Minor cleanups and fixes pointed out by Mel and Vlasta
* Added Acked-by tags

Changes since v3:
* Added include <linux/vmalloc.h> into mm/gup.c as it's needed for some archs
* Fixed error path for exynos driver

Changes since v2:
* Renamed functions and structures as Mel suggested
* Other minor changes suggested by Mel
* Rebased on top of 4.1-rc2
* Changed functions to get pointer to array of pages / pfns to perform conversion if necessary. This fixes possible issue in the omap I may have introduced in v2 and generally makes the API less errorprone.
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