MAP_POPULATE for device memory

index e2d892b201b0..54151af88ee0 100644
@@ -1993,6 +1993,7 @@ struct file_operations {
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
+	int (*populate)(struct file *, unsigned long start, unsigned long end);
 	unsigned long mmap_supported_flags;
 	int (*open) (struct inode *, struct file *);
 	int (*flush) (struct file *, fl_owner_t id);

index a9d4d724aef7..1f3a1d0b6e0d 100644
@@ -1519,8 +1519,11 @@ long populate_vma_page_range(struct vm_area_struct *vma,
 	 * We made sure addr is within a VMA, so the following will
 	 * not result in a stack expansion that recurses back here.
 	 */
-	return __get_user_pages(mm, start, nr_pages, gup_flags,
-				NULL, NULL, locked);
+	if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) && vma->vm_file->f_op->populate)
+		return vma->vm_file->f_op->populate(vma->vm_file, start, end);
+	else
+		return __get_user_pages(mm, start, nr_pages, gup_flags,
+					NULL, NULL, locked);
 }
 
 /*

@@ -1598,6 +1601,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
 	struct vm_area_struct *vma = NULL;
 	int locked = 0;
 	long ret = 0;
+	bool is_io;
 
 	end = start + len;
 

@@ -1619,7 +1623,8 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
 		 * range with the first VMA. Also, skip undesirable VMA types.
 		 */
 		nend = min(end, vma->vm_end);
-		if (vma->vm_flags & (VM_IO | VM_PFNMAP))
+		is_io = !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
+		if (is_io && !(is_io && vma->vm_file->f_op->populate))
 			continue;
 		if (nstart < vma->vm_start)
 			nstart = vma->vm_start;

index f24a41d3ec70..0256918b2c2f 100644
@@ -913,6 +913,44 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm,
 	return ret;
 }
 
+struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
+					  unsigned long offset,
+					  u64 secinfo_flags)
+{
+	struct sgx_encl_page *encl_page;
+	unsigned long prot;
+
+	encl_page = kzalloc(sizeof(*encl_page), GFP_KERNEL);
+	if (!encl_page)
+		return ERR_PTR(-ENOMEM);
+
+	encl_page->desc = encl->base + offset;
+	encl_page->encl = encl;
+
+	prot = _calc_vm_trans(secinfo_flags, SGX_SECINFO_R, PROT_READ)  |
+	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_W, PROT_WRITE) |
+	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_X, PROT_EXEC);
+
+	/*
+	 * TCS pages must always RW set for CPU access while the SECINFO
+	 * permissions are *always* zero - the CPU ignores the user provided
+	 * values and silently overwrites them with zero permissions.
+	 */
+	if ((secinfo_flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS)
+		prot |= PROT_READ | PROT_WRITE;
+
+	/* Calculate maximum of the VM flags for the page. */
+	encl_page->vm_max_prot_bits = calc_vm_prot_bits(prot, 0);
+
+	/*
+	 * At time of allocation, the runtime protection bits are the same
+	 * as the maximum protection bits.
+	 */
+	encl_page->vm_run_prot_bits = encl_page->vm_max_prot_bits;
+
+	return encl_page;
+}
+
 /**
  * sgx_zap_enclave_ptes() - remove PTEs mapping the address from enclave
  * @encl: the enclave

index 1b6ce1da7c92..3df0d3faf3a1 100644
@@ -113,6 +113,9 @@ int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
 void sgx_encl_put_backing(struct sgx_backing *backing, bool do_write);
 int sgx_encl_test_and_clear_young(struct mm_struct *mm,
 				  struct sgx_encl_page *page);
+struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
+					  unsigned long offset,
+					  u64 secinfo_flags);
 void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr);
 struct sgx_epc_page *sgx_alloc_va_page(void);
 unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page);

index d8c3c07badb3..3e3ca27a6f72 100644
@@ -169,44 +169,6 @@ static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg)
 	return ret;
 }
 
-static struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
-						 unsigned long offset,
-						 u64 secinfo_flags)
-{
-	struct sgx_encl_page *encl_page;
-	unsigned long prot;
-
-	encl_page = kzalloc(sizeof(*encl_page), GFP_KERNEL);
-	if (!encl_page)
-		return ERR_PTR(-ENOMEM);
-
-	encl_page->desc = encl->base + offset;
-	encl_page->encl = encl;
-
-	prot = _calc_vm_trans(secinfo_flags, SGX_SECINFO_R, PROT_READ)  |
-	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_W, PROT_WRITE) |
-	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_X, PROT_EXEC);
-
-	/*
-	 * TCS pages must always RW set for CPU access while the SECINFO
-	 * permissions are *always* zero - the CPU ignores the user provided
-	 * values and silently overwrites them with zero permissions.
-	 */
-	if ((secinfo_flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS)
-		prot |= PROT_READ | PROT_WRITE;
-
-	/* Calculate maximum of the VM flags for the page. */
-	encl_page->vm_max_prot_bits = calc_vm_prot_bits(prot, 0);
-
-	/*
-	 * At time of allocation, the runtime protection bits are the same
-	 * as the maximum protection bits.
-	 */
-	encl_page->vm_run_prot_bits = encl_page->vm_max_prot_bits;
-
-	return encl_page;
-}
-
 static int sgx_validate_secinfo(struct sgx_secinfo *secinfo)
 {
 	u64 perm = secinfo->flags & SGX_SECINFO_PERMISSION_MASK;

index aa9b8b868867..848938334e8a 100644
@@ -9,6 +9,7 @@
 #include <asm/traps.h>
 #include "driver.h"
 #include "encl.h"
+#include "encls.h"
 
 u64 sgx_attributes_reserved_mask;
 u64 sgx_xfrm_reserved_mask = ~0x3;

@@ -101,6 +102,132 @@ static int sgx_mmap(struct file *file, struct vm_area_struct *vma)
 	return 0;
 }
 
+static int sgx_encl_augment_page(struct sgx_encl *encl, unsigned long offset)
+{
+	struct sgx_pageinfo pginfo = {0};
+	struct sgx_encl_page *encl_page;
+	struct sgx_epc_page *epc_page;
+	struct sgx_va_page *va_page;
+	u64 secinfo_flags;
+	int ret;
+
+	/*
+	 * Ignore internal permission checking for dynamically added pages.
+	 * They matter only for data added during the pre-initialization phase.
+	 * The enclave decides the permissions by the means of EACCEPT,
+	 * EACCEPTCOPY and EMODPE.
+	 */
+	secinfo_flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_X;
+	encl_page = sgx_encl_page_alloc(encl, offset, secinfo_flags);
+	if (IS_ERR(encl_page))
+		return PTR_ERR(encl_page);
+
+	epc_page = sgx_alloc_epc_page(encl_page, true);
+	if (IS_ERR(epc_page)) {
+		ret = PTR_ERR(epc_page);
+		goto err_alloc_epc_page;
+	}
+
+	va_page = sgx_encl_grow(encl);
+	if (IS_ERR(va_page)) {
+		ret = PTR_ERR(va_page);
+		goto err_grow;
+	}
+
+	mutex_lock(&encl->lock);
+
+	/*
+	 * Adding to encl->va_pages must be done under encl->lock.  Ditto for
+	 * deleting (via sgx_encl_shrink()) in the error path.
+	 */
+	if (va_page)
+		list_add(&va_page->list, &encl->va_pages);
+
+	/*
+	 * Insert prior to EADD in case of OOM.  EADD modifies MRENCLAVE, i.e.
+	 * can't be gracefully unwound, while failure on EADD/EXTEND is limited
+	 * to userspace errors (or kernel/hardware bugs).
+	 */
+	ret = xa_insert(&encl->page_array, PFN_DOWN(encl_page->desc),
+			encl_page, GFP_KERNEL);
+
+	/*
+	 * If ret == -EBUSY then page was created in another flow while
+	 * running without encl->lock
+	 */
+	if (ret)
+		goto err_xa_insert;
+
+	pginfo.secs = (unsigned long)sgx_get_epc_virt_addr(encl->secs.epc_page);
+	pginfo.addr = encl_page->desc & PAGE_MASK;
+	pginfo.metadata = 0;
+
+	ret = __eaug(&pginfo, sgx_get_epc_virt_addr(epc_page));
+	if (ret)
+		goto err_eaug;
+
+	encl_page->encl = encl;
+	encl_page->epc_page = epc_page;
+	encl_page->type = SGX_PAGE_TYPE_REG;
+	encl->secs_child_cnt++;
+
+	sgx_mark_page_reclaimable(encl_page->epc_page);
+
+	mutex_unlock(&encl->lock);
+
+	return 0;
+
+err_eaug:
+	xa_erase(&encl->page_array, PFN_DOWN(encl_page->desc));
+
+err_xa_insert:
+	sgx_encl_shrink(encl, va_page);
+	mutex_unlock(&encl->lock);
+
+err_grow:
+	sgx_encl_free_epc_page(epc_page);
+
+err_alloc_epc_page:
+	kfree(encl_page);
+
+	return VM_FAULT_SIGBUS;
+}
+
+/*
+ * Add new pages to the enclave sequentially with ENCLS[EAUG]. Note that
+ * sgx_mmap() validates that the given VMA is within the enclave range. Calling
+ * here sgx_encl_may_map() second time would too time consuming.
+ */
+static int sgx_populate(struct file *file, unsigned long start, unsigned long end)
+{
+	struct sgx_encl *encl = file->private_data;
+	unsigned long length = end - start;
+	unsigned long pos;
+	int ret;
+
+	/* EAUG works only for initialized enclaves. */
+	if (!test_bit(SGX_ENCL_INITIALIZED, &encl->flags))
+		return -EINVAL;
+
+	for (pos = 0 ; pos < length; pos += PAGE_SIZE) {
+		if (signal_pending(current)) {
+			if (!pos)
+				ret = -ERESTARTSYS;
+
+			break;
+		}
+
+		if (need_resched())
+			cond_resched();
+
+		ret = sgx_encl_augment_page(encl, start + pos);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
 static unsigned long sgx_get_unmapped_area(struct file *file,
 					   unsigned long addr,
 					   unsigned long len,

@@ -133,6 +260,7 @@ static const struct file_operations sgx_encl_fops = {
 	.compat_ioctl		= sgx_compat_ioctl,
 #endif
 	.mmap			= sgx_mmap,
+	.populate		= sgx_populate,
 	.get_unmapped_area	= sgx_get_unmapped_area,
 };