xen: dma-buf support for grant device

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +13 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H

include/xen/mem-reservation.h new file +41 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+	clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+					    struct page **pages,
+					    xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+					   struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned long count,
+							struct page **pages,
+							xen_pfn_t *frames)
+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+	if (!xen_feature(XENFEAT_auto_translated_physmap))
+		__xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned long count,
+						       struct page **pages)
+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+	if (!xen_feature(XENFEAT_auto_translated_physmap))
+		__xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 26 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +18 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H
+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+

include/xen/mem-reservation.h line 23

Quoted 5 lines

include/xen/mem-reservation.h new file +5 -0

+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

-boris

Quoted 44 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +8 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned long 

count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +12 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 29 lines · Boris Ostrovsky

Quoted 26 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +18 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H
+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+

Quoted 9 lines

include/xen/mem-reservation.h line 23

Quoted 5 lines

include/xen/mem-reservation.h new file +5 -0

+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

Yes, it seems that the header can only have
#include <xen/page.h>
Will move the rest into the .c file

Quoted 47 lines

-boris

Quoted 44 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +8 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned long 

count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +12 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 39 lines · Oleksandr Andrushchenko

Quoted 38 lines · Boris Ostrovsky

Quoted 21 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +13 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H

include/xen/mem-reservation.h line 23

Quoted 10 lines

include/xen/mem-reservation.h new file +10 -0

+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

Quoted 3 lines

Yes, it seems that the header can only have
#include <xen/page.h>
Will move the rest into the .c file

You may need something for clear_highpage() and maybe for Xen feature flags. But you'll find out for sure when you try to build. ;-)

-boris

Quoted 48 lines

Quoted 47 lines

-boris

Quoted 44 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +8 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned 

long count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +12 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 42 lines · Boris Ostrovsky

Quoted 39 lines · Oleksandr Andrushchenko

Quoted 38 lines · Boris Ostrovsky

Quoted 21 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +13 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H

include/xen/mem-reservation.h line 23

Quoted 10 lines

include/xen/mem-reservation.h new file +10 -0

+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

Quoted 7 lines

Quoted 3 lines

Yes, it seems that the header can only have
#include <xen/page.h>
Will move the rest into the .c file

You may need something for clear_highpage() and maybe for Xen feature flags. But you'll find out for sure when you try to build. ;-)

#include <asm/tlb.h>

;)

Quoted 53 lines

-boris

Quoted 49 lines

Quoted 48 lines

-boris

Quoted 45 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +4 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, 

frames);

include/xen/mem-reservation.h new file +4 -0

+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned 

long count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +12 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 42 lines · Boris Ostrovsky

Quoted 39 lines · Oleksandr Andrushchenko

Quoted 38 lines · Boris Ostrovsky

Quoted 21 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +13 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H

include/xen/mem-reservation.h line 23

Quoted 10 lines

include/xen/mem-reservation.h new file +10 -0

+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

Quoted 7 lines

Quoted 3 lines

Yes, it seems that the header can only have
#include <xen/page.h>
Will move the rest into the .c file

You may need something for clear_highpage() and maybe for Xen feature flags. But you'll find out for sure when you try to build. ;-)

#include <asm/tlb.h>

;)

Quoted 53 lines

-boris

Quoted 49 lines

Quoted 48 lines

-boris

Quoted 45 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +4 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, 

frames);

include/xen/mem-reservation.h new file +4 -0

+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned 

long count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +12 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 39 lines · Oleksandr Andrushchenko

Quoted 38 lines · Boris Ostrovsky

Quoted 21 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +13 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H

include/xen/mem-reservation.h line 23

Quoted 10 lines

include/xen/mem-reservation.h new file +10 -0

+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

Quoted 3 lines

Yes, it seems that the header can only have
#include <xen/page.h>
Will move the rest into the .c file

You may need something for clear_highpage() and maybe for Xen feature flags. But you'll find out for sure when you try to build. ;-)

-boris

Quoted 48 lines

Quoted 47 lines

-boris

Quoted 44 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +8 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned 

long count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +12 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 29 lines · Boris Ostrovsky

Quoted 26 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +18 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H
+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+

Quoted 9 lines

include/xen/mem-reservation.h line 23

Quoted 5 lines

include/xen/mem-reservation.h new file +5 -0

+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

Yes, it seems that the header can only have
#include <xen/page.h>
Will move the rest into the .c file

Quoted 39 lines

-boris

Quoted 36 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +8 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned long 

count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +5 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif

Quoted 8 lines

include/xen/mem-reservation.h line 64

Quoted 8 lines

include/xen/mem-reservation.h new file +7 -0

+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

Quoted 26 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +18 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H
+#define _XENMEM_RESERVATION_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+

include/xen/mem-reservation.h line 23

Quoted 5 lines

include/xen/mem-reservation.h new file +5 -0

+#include <asm/xen/hypercall.h>
+#include <asm/tlb.h>
+
+#include <xen/interface/memory.h>
+#include <xen/page.h>

I should have noticed this in the previous post but I suspect most of these includes belong in the C file. For example, there is no reason for hypercall.h here.

-boris

Quoted 36 lines

include/xen/mem-reservation.h new file +18 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+    clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+                        struct page **pages,
+                        xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+                       struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned 

long count,
+                            struct page **pages,
+                            xen_pfn_t *frames)

include/xen/mem-reservation.h new file +8 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned long 

count,
+                               struct page **pages)

include/xen/mem-reservation.h new file +5 -0

+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+    if (!xen_feature(XENFEAT_auto_translated_physmap))
+        __xenmem_reservation_va_mapping_reset(count, pages);
+#endif

include/xen/mem-reservation.h line 64

Quoted 8 lines

include/xen/mem-reservation.h new file +7 -0

+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif

From: Oleksandr Andrushchenko <[email protected]>

include/xen/mem-reservation.h new file +13 -0

new file mode 100644
index 000000000000..e0939387278d
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H

include/xen/mem-reservation.h new file +31 -0

+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+	clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+					    struct page **pages,
+					    xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+					   struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned long count,
+							struct page **pages,
+							xen_pfn_t *frames)
+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+	if (!xen_feature(XENFEAT_auto_translated_physmap))
+		__xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned long count,
+						       struct page **pages)
+{
+#ifdef CONFIG_XEN_HAVE_PVMMU

drivers/xen/mem-reservation.c new file +4 -0

+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames)
+{
+	struct xen_memory_reservation reservation = {

drivers/xen/mem-reservation.c new file +12 -0

+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames)
+{
+	struct xen_memory_reservation reservation = {
+		.address_bits = 0,
+		.extent_order = EXTENT_ORDER,
+		.domid        = DOMID_SELF
+	};
+
+	set_xen_guest_handle(reservation.extent_start, frames);
+	reservation.nr_extents = count;
+	return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);

On 06/12/2018 09:41 AM, Oleksandr Andrushchenko wrote:

One more thing: please add a comment here saying that frames array is array of PFNs (in Xen granularity), which is what XENMEM_populate_physmap requires. And remove (or update to name the actual call you are making) the corresponding comment in increase_reservation().

Quoted 10 lines

drivers/xen/mem-reservation.c new file +9 -0

+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames)
+{
+    struct xen_memory_reservation reservation = {
+        .address_bits = 0,
+        .extent_order = EXTENT_ORDER,
+        .domid        = DOMID_SELF
+    };
+

Review

Quoted 5 lines

+    set_xen_guest_handle(reservation.extent_start, frames); +    reservation.nr_extents = count;
+    return HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);

(quoted diff) +2 -0

+}
+EXPORT_SYMBOL_GPL(xenmem_reservation_increase);

And similarly, here we are requesting GFNs, and update decrease_reservation().

-boris

Quoted 13 lines

drivers/xen/mem-reservation.c new file +12 -0

+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames)
+{
+    struct xen_memory_reservation reservation = {
+        .address_bits = 0,
+        .extent_order = EXTENT_ORDER,
+        .domid        = DOMID_SELF
+    };
+
+    set_xen_guest_handle(reservation.extent_start, frames);
+    reservation.nr_extents = count;
+    return HYPERVISOR_memory_op(XENMEM_decrease_reservation, 

&reservation);

On 06/12/2018 09:41 AM, Oleksandr Andrushchenko wrote:

One more thing: please add a comment here saying that frames array is array of PFNs (in Xen granularity), which is what XENMEM_populate_physmap requires. And remove (or update to name the actual call you are making) the corresponding comment in increase_reservation().

Quoted 10 lines

drivers/xen/mem-reservation.c new file +9 -0

+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames)
+{
+    struct xen_memory_reservation reservation = {
+        .address_bits = 0,
+        .extent_order = EXTENT_ORDER,
+        .domid        = DOMID_SELF
+    };
+

Review

Quoted 5 lines

+    set_xen_guest_handle(reservation.extent_start, frames); +    reservation.nr_extents = count;
+    return HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);

(quoted diff) +2 -0

+}
+EXPORT_SYMBOL_GPL(xenmem_reservation_increase);

And similarly, here we are requesting GFNs, and update decrease_reservation().

-boris

Quoted 5 lines

drivers/xen/mem-reservation.c new file +5 -0

+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames)
+{
+    struct xen_memory_reservation reservation = {
+        .address_bits = 0,

Quoted 8 lines

+        .extent_order = EXTENT_ORDER,
+        .domid        = DOMID_SELF
+    };
+
+    set_xen_guest_handle(reservation.extent_start, frames); +    reservation.nr_extents = count;
+    return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);

drivers/xen/mem-reservation.c new file +4 -0

+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames)
+{
+	struct xen_memory_reservation reservation = {

From: Oleksandr Andrushchenko <[email protected]>

Extend grant table module API to allow allocating buffers that can be used for DMA operations and mapping foreign grant references on top of those.
The resulting buffer is similar to the one allocated by the balloon driver in terms that proper memory reservation is made ({increase|decrease}_reservation and VA mappings updated if needed). This is useful for sharing foreign buffers with HW drivers which cannot work with scattered buffers provided by the balloon driver, but require DMAable memory instead.

Signed-off-by Oleksandr Andrushchenko <[email protected]>

---
  drivers/xen/Kconfig       | 13 ++++++
  drivers/xen/grant-table.c | 97 +++++++++++++++++++++++++++++++++++++++
  include/xen/grant_table.h | 18 ++++++++
  3 files changed, 128 insertions(+)

drivers/xen/Kconfig +0 -0

index e5d0c28372ea..39536ddfbce4 100644
@@ -161,6 +161,19 @@ config XEN_GRANT_DEV_ALLOC
  	  to other domains. This can be used to implement frontend drivers
  	  or as part of an inter-domain shared memory channel.

Quoted 12 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

Extend grant table module API to allow allocating buffers that can be used for DMA operations and mapping foreign grant references on top of those.
The resulting buffer is similar to the one allocated by the balloon driver in terms that proper memory reservation is made ({increase|decrease}_reservation and VA mappings updated if needed). This is useful for sharing foreign buffers with HW drivers which cannot work with scattered buffers provided by the balloon driver, but require DMAable memory instead.

Quoted 1 line

Signed-off-by Oleksandr Andrushchenko <[email protected]>

Reviewed-by Boris Ostrovsky <[email protected]>

with a small nit below

Quoted 16 lines

---
  drivers/xen/Kconfig       | 13 ++++++ drivers/xen/grant-table.c | 97 +++++++++++++++++++++++++++++++++++++++ include/xen/grant_table.h | 18 ++++++++

  3 files changed, 128 insertions(+)

drivers/xen/Kconfig +0 -0

index e5d0c28372ea..39536ddfbce4 100644
@@ -161,6 +161,19 @@ config XEN_GRANT_DEV_ALLOC

        to other domains. This can be used to implement frontend drivers or as part of an inter-domain shared memory channel. +config XEN_GRANT_DMA_ALLOC
+    bool "Allow allocating DMA capable buffers with grant reference module"

Quoted 8 lines

+    depends on XEN && HAS_DMA
+    help
+      Extends grant table module API to allow allocating DMA capable +      buffers and mapping foreign grant references on top of it. +      The resulting buffer is similar to one allocated by the balloon +      driver in terms that proper memory reservation is made +      ({increase|decrease}_reservation and VA mappings updated if needed).

I think you should drop the word "terms" and say "is made *by*" and "VA mappings *are* updated"

And similar change in the commit message.

-boris

Quoted 12 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

Extend grant table module API to allow allocating buffers that can be used for DMA operations and mapping foreign grant references on top of those.
The resulting buffer is similar to the one allocated by the balloon driver in terms that proper memory reservation is made ({increase|decrease}_reservation and VA mappings updated if needed). This is useful for sharing foreign buffers with HW drivers which cannot work with scattered buffers provided by the balloon driver, but require DMAable memory instead.

Quoted 1 line

Signed-off-by Oleksandr Andrushchenko <[email protected]>

Reviewed-by Boris Ostrovsky <[email protected]>

with a small nit below

Quoted 16 lines

---
  drivers/xen/Kconfig       | 13 ++++++ drivers/xen/grant-table.c | 97 +++++++++++++++++++++++++++++++++++++++ include/xen/grant_table.h | 18 ++++++++

  3 files changed, 128 insertions(+)

drivers/xen/Kconfig +0 -0

index e5d0c28372ea..39536ddfbce4 100644
@@ -161,6 +161,19 @@ config XEN_GRANT_DEV_ALLOC

        to other domains. This can be used to implement frontend drivers or as part of an inter-domain shared memory channel. +config XEN_GRANT_DMA_ALLOC
+    bool "Allow allocating DMA capable buffers with grant reference module"

Quoted 8 lines

+    depends on XEN && HAS_DMA
+    help
+      Extends grant table module API to allow allocating DMA capable +      buffers and mapping foreign grant references on top of it. +      The resulting buffer is similar to one allocated by the balloon +      driver in terms that proper memory reservation is made +      ({increase|decrease}_reservation and VA mappings updated if needed).

I think you should drop the word "terms" and say "is made *by*" and "VA mappings *are* updated"

And similar change in the commit message.

-boris

From: Oleksandr Andrushchenko <[email protected]>

Extend grant table module API to allow allocating buffers that can be used for DMA operations and mapping foreign grant references on top of those.
The resulting buffer is similar to the one allocated by the balloon driver in terms that proper memory reservation is made ({increase|decrease}_reservation and VA mappings updated if needed). This is useful for sharing foreign buffers with HW drivers which cannot work with scattered buffers provided by the balloon driver, but require DMAable memory instead.

Signed-off-by Oleksandr Andrushchenko <[email protected]>

---
  drivers/xen/Kconfig       | 13 ++++++
  drivers/xen/grant-table.c | 97 +++++++++++++++++++++++++++++++++++++++
  include/xen/grant_table.h | 18 ++++++++
  3 files changed, 128 insertions(+)

drivers/xen/Kconfig +0 -0

index e5d0c28372ea..39536ddfbce4 100644
@@ -161,6 +161,19 @@ config XEN_GRANT_DEV_ALLOC
  	  to other domains. This can be used to implement frontend drivers
  	  or as part of an inter-domain shared memory channel.

drivers/xen/gntdev.c +25 -1

+		args.nr_pages = map->count;
+		args.pages = map->pages;
+		args.frames = map->frames;
+		args.vaddr = map->dma_vaddr;
+		args.dev_bus_addr = map->dma_bus_addr;
+
+		gnttab_dma_free_pages(&args);
+	} else
+#endif
  	if (map->pages)
  		gnttab_free_pages(map->count, map->pages);
+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+	kfree(map->frames);
+#endif
  	kfree(map->pages);
  	kfree(map->grants);
  	kfree(map->map_ops);

@@ -132,7 +176,8 @@ static void gntdev_free_map(struct grant_map *map)
  	kfree(map);
  }
 
-static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
+static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
+					  int dma_flags)
  {
  	struct grant_map *add;
  	int i;

@@ -155,6 +200,37 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
  	    NULL == add->pages)
  		goto err;
 
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+	add->dma_flags = dma_flags;
+
+	/*
+	 * Check if this mapping is requested to be backed
+	 * by a DMA buffer.
+	 */
+	if (dma_flags & (GNTDEV_DMA_FLAG_WC | GNTDEV_DMA_FLAG_COHERENT)) {
+		struct gnttab_dma_alloc_args args;
+

drivers/xen/gntdev.c +11 -0

+		args.nr_pages = count;
+		args.pages = add->pages;
+		args.frames = add->frames;
+
+		if (gnttab_dma_alloc_pages(&args))
+			goto err;
+
+		add->dma_vaddr = args.vaddr;
+		add->dma_bus_addr = args.dev_bus_addr;
+	} else
+#endif
  	if (gnttab_alloc_pages(count, add->pages))
  		goto err;
 

drivers/xen/gntdev.c +5 -0

+
+			mfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
+			map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(mfn);
+		}
+#endif
  	}
  	return err;
  }

On 06/12/2018 09:41 AM, Oleksandr Andrushchenko wrote:

Quoted 10 lines

    static void gntdev_print_maps(struct gntdev_priv *priv,

drivers/xen/gntdev.c +0 -0

@@ -121,8 +146,27 @@ static void gntdev_free_map(struct grant_map *map)
       if (map == NULL)
           return;

  +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    if (map->dma_vaddr) {
+        struct gnttab_dma_alloc_args args;
+
+        args.dev = map->dma_dev;
+        args.coherent = map->dma_flags & GNTDEV_DMA_FLAG_COHERENT;

args.coherent = !!(map->dma_flags & GNTDEV_DMA_FLAG_COHERENT);

Quoted 48 lines

+        args.nr_pages = map->count;
+        args.pages = map->pages;
+        args.frames = map->frames;
+        args.vaddr = map->dma_vaddr;
+        args.dev_bus_addr = map->dma_bus_addr;

drivers/xen/gntdev.c +4 -0

+
+        gnttab_dma_free_pages(&args);
+    } else
+#endif

      if (map->pages) gnttab_free_pages(map->count, map->pages);

drivers/xen/gntdev.c +4 -0

+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    kfree(map->frames);
+#endif

      kfree(map->pages);
      kfree(map->grants);
      kfree(map->map_ops);

drivers/xen/gntdev.c +2 -0

@@ -132,7 +176,8 @@ static void gntdev_free_map(struct grant_map *map)
       kfree(map);
   }
   -static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
+static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, 
 int count,
+                      int dma_flags)
   {
       struct grant_map *add;

      int i;

drivers/xen/gntdev.c +0 -0

@@ -155,6 +200,37 @@ static struct grant_map *gntdev_alloc_map(struct 
 gntdev_priv *priv, int count)
           NULL == add->pages)
           goto err;

  +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    add->dma_flags = dma_flags;

drivers/xen/gntdev.c +13 -0

+
+    /*
+     * Check if this mapping is requested to be backed
+     * by a DMA buffer.
+     */
+    if (dma_flags & (GNTDEV_DMA_FLAG_WC | GNTDEV_DMA_FLAG_COHERENT)) {
+        struct gnttab_dma_alloc_args args;
+
+        add->frames = kcalloc(count, sizeof(add->frames[0]),
+                      GFP_KERNEL);
+        if (!add->frames)
+            goto err;
+

Quoted 5 lines

+        /* Remember the device, so we can free DMA memory. */ +        add->dma_dev = priv->dma_dev;
+
+        args.dev = priv->dma_dev;
+        args.coherent = dma_flags & GNTDEV_DMA_FLAG_COHERENT;

And again here.

Quoted 16 lines

+        args.nr_pages = count;
+        args.pages = add->pages;
+        args.frames = add->frames;

drivers/xen/gntdev.c +8 -0

+
+        if (gnttab_dma_alloc_pages(&args))
+            goto err;
+
+        add->dma_vaddr = args.vaddr;
+        add->dma_bus_addr = args.dev_bus_addr;
+    } else
+#endif

      if (gnttab_alloc_pages(count, add->pages))
          goto err;
  @@ -325,6 +401,14 @@ static int map_grant_pages(struct grant_map *map) map->unmap_ops[i].handle = map->map_ops[i].handle;

Quoted 5 lines

          if (use_ptemod)
              map->kunmap_ops[i].handle = map->kmap_ops[i].handle; +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+        else if (map->dma_vaddr) {
+            unsigned long mfn;

This should be called bfn now.

Quoted 16 lines

drivers/xen/gntdev.c +5 -0

+
+            mfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
+            map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(mfn);
+        }
+#endif

      }
      return err;
  }

drivers/xen/gntdev.c +3 -0

@@ -548,6 +632,17 @@ static int gntdev_open(struct inode *inode, 
 struct file *flip)
       }
         flip->private_data = priv;
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    priv->dma_dev = gntdev_miscdev.this_device;
+

Quoted 5 lines

(quoted diff) +2 -0

+    /*
+     * The device is not spawn from a device tree, so 

arch_setup_dma_ops
+     * is not called, thus leaving the device with dummy DMA ops. +     * Fix this call of_dma_configure() with a NULL node to set

"Fix this by calling ..." I think.

Quoted 7 lines

+     * default DMA ops.
+     */
+    of_dma_configure(priv->dma_dev, NULL);
+#endif
      pr_debug("priv %p\n", priv);
        return 0;

With those fixed,

Reviewed-by Boris Ostrovsky <[email protected]>

On 06/12/2018 09:41 AM, Oleksandr Andrushchenko wrote:

Quoted 10 lines

    static void gntdev_print_maps(struct gntdev_priv *priv,

drivers/xen/gntdev.c +0 -0

@@ -121,8 +146,27 @@ static void gntdev_free_map(struct grant_map *map)
       if (map == NULL)
           return;

  +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    if (map->dma_vaddr) {
+        struct gnttab_dma_alloc_args args;
+
+        args.dev = map->dma_dev;
+        args.coherent = map->dma_flags & GNTDEV_DMA_FLAG_COHERENT;

args.coherent = !!(map->dma_flags & GNTDEV_DMA_FLAG_COHERENT);

Quoted 48 lines

+        args.nr_pages = map->count;
+        args.pages = map->pages;
+        args.frames = map->frames;
+        args.vaddr = map->dma_vaddr;
+        args.dev_bus_addr = map->dma_bus_addr;

drivers/xen/gntdev.c +4 -0

+
+        gnttab_dma_free_pages(&args);
+    } else
+#endif

      if (map->pages) gnttab_free_pages(map->count, map->pages);

drivers/xen/gntdev.c +4 -0

+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    kfree(map->frames);
+#endif

      kfree(map->pages);
      kfree(map->grants);
      kfree(map->map_ops);

drivers/xen/gntdev.c +2 -0

@@ -132,7 +176,8 @@ static void gntdev_free_map(struct grant_map *map)
       kfree(map);
   }
   -static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
+static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, 
 int count,
+                      int dma_flags)
   {
       struct grant_map *add;

      int i;

drivers/xen/gntdev.c +0 -0

@@ -155,6 +200,37 @@ static struct grant_map *gntdev_alloc_map(struct 
 gntdev_priv *priv, int count)
           NULL == add->pages)
           goto err;

  +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    add->dma_flags = dma_flags;

drivers/xen/gntdev.c +13 -0

+
+    /*
+     * Check if this mapping is requested to be backed
+     * by a DMA buffer.
+     */
+    if (dma_flags & (GNTDEV_DMA_FLAG_WC | GNTDEV_DMA_FLAG_COHERENT)) {
+        struct gnttab_dma_alloc_args args;
+
+        add->frames = kcalloc(count, sizeof(add->frames[0]),
+                      GFP_KERNEL);
+        if (!add->frames)
+            goto err;
+

Quoted 5 lines

+        /* Remember the device, so we can free DMA memory. */ +        add->dma_dev = priv->dma_dev;
+
+        args.dev = priv->dma_dev;
+        args.coherent = dma_flags & GNTDEV_DMA_FLAG_COHERENT;

And again here.

Quoted 16 lines

+        args.nr_pages = count;
+        args.pages = add->pages;
+        args.frames = add->frames;

drivers/xen/gntdev.c +8 -0

+
+        if (gnttab_dma_alloc_pages(&args))
+            goto err;
+
+        add->dma_vaddr = args.vaddr;
+        add->dma_bus_addr = args.dev_bus_addr;
+    } else
+#endif

      if (gnttab_alloc_pages(count, add->pages))
          goto err;
  @@ -325,6 +401,14 @@ static int map_grant_pages(struct grant_map *map) map->unmap_ops[i].handle = map->map_ops[i].handle;

Quoted 5 lines

          if (use_ptemod)
              map->kunmap_ops[i].handle = map->kmap_ops[i].handle; +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+        else if (map->dma_vaddr) {
+            unsigned long mfn;

This should be called bfn now.

Quoted 16 lines

drivers/xen/gntdev.c +5 -0

+
+            mfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
+            map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(mfn);
+        }
+#endif

      }
      return err;
  }

drivers/xen/gntdev.c +3 -0

@@ -548,6 +632,17 @@ static int gntdev_open(struct inode *inode, 
 struct file *flip)
       }
         flip->private_data = priv;
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    priv->dma_dev = gntdev_miscdev.this_device;
+

Quoted 5 lines

(quoted diff) +2 -0

+    /*
+     * The device is not spawn from a device tree, so 

arch_setup_dma_ops
+     * is not called, thus leaving the device with dummy DMA ops. +     * Fix this call of_dma_configure() with a NULL node to set

"Fix this by calling ..." I think.

Quoted 7 lines

+     * default DMA ops.
+     */
+    of_dma_configure(priv->dma_dev, NULL);
+#endif
      pr_debug("priv %p\n", priv);
        return 0;

With those fixed,

Reviewed-by Boris Ostrovsky <[email protected]>

drivers/xen/gntdev.c +25 -1

+		args.nr_pages = map->count;
+		args.pages = map->pages;
+		args.frames = map->frames;
+		args.vaddr = map->dma_vaddr;
+		args.dev_bus_addr = map->dma_bus_addr;
+
+		gnttab_dma_free_pages(&args);
+	} else
+#endif
  	if (map->pages)
  		gnttab_free_pages(map->count, map->pages);
+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+	kfree(map->frames);
+#endif
  	kfree(map->pages);
  	kfree(map->grants);
  	kfree(map->map_ops);

@@ -132,7 +176,8 @@ static void gntdev_free_map(struct grant_map *map)
  	kfree(map);
  }
 
-static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
+static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
+					  int dma_flags)
  {
  	struct grant_map *add;
  	int i;

@@ -155,6 +200,37 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
  	    NULL == add->pages)
  		goto err;
 
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+	add->dma_flags = dma_flags;
+
+	/*
+	 * Check if this mapping is requested to be backed
+	 * by a DMA buffer.
+	 */
+	if (dma_flags & (GNTDEV_DMA_FLAG_WC | GNTDEV_DMA_FLAG_COHERENT)) {
+		struct gnttab_dma_alloc_args args;
+

drivers/xen/gntdev.c +11 -0

+		args.nr_pages = count;
+		args.pages = add->pages;
+		args.frames = add->frames;
+
+		if (gnttab_dma_alloc_pages(&args))
+			goto err;
+
+		add->dma_vaddr = args.vaddr;
+		add->dma_bus_addr = args.dev_bus_addr;
+	} else
+#endif
  	if (gnttab_alloc_pages(count, add->pages))
  		goto err;
 

drivers/xen/gntdev.c +5 -0

+
+			mfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
+			map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(mfn);
+		}
+#endif
  	}
  	return err;
  }

+#endif
pr_debug("priv %p\n", priv);

return 0;

+#endif
pr_debug("priv %p\n", priv);

return 0;

From: Oleksandr Andrushchenko <[email protected]>

This is in preparation for adding support of DMA buffer
functionality: make map/unmap related code and structures, used privately by gntdev, ready for dma-buf extension, which will re-use these. Rename corresponding structures as those become non-private to gntdev now.

Signed-off-by Oleksandr Andrushchenko <[email protected]>

---
  drivers/xen/gntdev-common.h |  86 +++++++++++++++++++++++
  drivers/xen/gntdev.c        | 132 ++++++++++++------------------------
  2 files changed, 128 insertions(+), 90 deletions(-)

create mode 100644 drivers/xen/gntdev-common.h

drivers/xen/gntdev-common.h new file +13 -0

new file mode 100644
index 000000000000..7a9845a6bee9
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Common functionality of grant device.
+ *
+ * Copyright (c) 2006-2007, D G Murray.
+ *           (c) 2009 Gerd Hoffmann <[email protected]>
+ *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _GNTDEV_COMMON_H
+#define _GNTDEV_COMMON_H
+

Quoted 39 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

This is in preparation for adding support of DMA buffer
functionality: make map/unmap related code and structures, used privately by gntdev, ready for dma-buf extension, which will re-use these. Rename corresponding structures as those become non-private to gntdev now.

Signed-off-by Oleksandr Andrushchenko <[email protected]>

---
  drivers/xen/gntdev-common.h |  86 +++++++++++++++++++++++ drivers/xen/gntdev.c        | 132 ++++++++++++------------------------

  2 files changed, 128 insertions(+), 90 deletions(-)

  create mode 100644 drivers/xen/gntdev-common.h

drivers/xen/gntdev-common.h new file +18 -0

new file mode 100644
index 000000000000..7a9845a6bee9
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Common functionality of grant device.
+ *
+ * Copyright (c) 2006-2007, D G Murray.
+ *           (c) 2009 Gerd Hoffmann <[email protected]>
+ *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _GNTDEV_COMMON_H
+#define _GNTDEV_COMMON_H
+
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/mmu_notifier.h>
+#include <linux/types.h>
+

drivers/xen/gntdev-common.h line 23

Quoted 5 lines

drivers/xen/gntdev-common.h new file +5 -0

+struct gntdev_priv {
+    /* maps with visible offsets in the file descriptor */
+    struct list_head maps;
+    /* maps that are not visible; will be freed on munmap.
+     * Only populated if populate_freeable_maps == 1 */

Since you are touching this code please fix comment style.

drivers/xen/gntdev-common.h line 34

Quoted 12 lines

drivers/xen/gntdev-common.h new file +11 -0

+    struct list_head freeable_maps;
+    /* lock protects maps and freeable_maps */
+    struct mutex lock;
+    struct mm_struct *mm;
+    struct mmu_notifier mn;
+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    /* Device for which DMA memory is allocated. */
+    struct device *dma_dev;
+#endif
+};

With that fixed,

Reviewed-by Boris Ostrovsky <[email protected]>

Quoted 39 lines · Oleksandr Andrushchenko

From: Oleksandr Andrushchenko <[email protected]>

This is in preparation for adding support of DMA buffer
functionality: make map/unmap related code and structures, used privately by gntdev, ready for dma-buf extension, which will re-use these. Rename corresponding structures as those become non-private to gntdev now.

Signed-off-by Oleksandr Andrushchenko <[email protected]>

---
  drivers/xen/gntdev-common.h |  86 +++++++++++++++++++++++ drivers/xen/gntdev.c        | 132 ++++++++++++------------------------

  2 files changed, 128 insertions(+), 90 deletions(-)

  create mode 100644 drivers/xen/gntdev-common.h

drivers/xen/gntdev-common.h new file +18 -0

new file mode 100644
index 000000000000..7a9845a6bee9
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Common functionality of grant device.
+ *
+ * Copyright (c) 2006-2007, D G Murray.
+ *           (c) 2009 Gerd Hoffmann <[email protected]>
+ *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _GNTDEV_COMMON_H
+#define _GNTDEV_COMMON_H
+
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/mmu_notifier.h>
+#include <linux/types.h>
+

drivers/xen/gntdev-common.h line 23

Quoted 5 lines

drivers/xen/gntdev-common.h new file +5 -0

+struct gntdev_priv {
+    /* maps with visible offsets in the file descriptor */
+    struct list_head maps;
+    /* maps that are not visible; will be freed on munmap.
+     * Only populated if populate_freeable_maps == 1 */

Since you are touching this code please fix comment style.

drivers/xen/gntdev-common.h line 34

Quoted 12 lines

drivers/xen/gntdev-common.h new file +11 -0

+    struct list_head freeable_maps;
+    /* lock protects maps and freeable_maps */
+    struct mutex lock;
+    struct mm_struct *mm;
+    struct mmu_notifier mn;
+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+    /* Device for which DMA memory is allocated. */
+    struct device *dma_dev;
+#endif
+};

With that fixed,

Reviewed-by Boris Ostrovsky <[email protected]>

From: Oleksandr Andrushchenko <[email protected]>

This is in preparation for adding support of DMA buffer
functionality: make map/unmap related code and structures, used privately by gntdev, ready for dma-buf extension, which will re-use these. Rename corresponding structures as those become non-private to gntdev now.

Signed-off-by Oleksandr Andrushchenko <[email protected]>

---
  drivers/xen/gntdev-common.h |  86 +++++++++++++++++++++++
  drivers/xen/gntdev.c        | 132 ++++++++++++------------------------
  2 files changed, 128 insertions(+), 90 deletions(-)

create mode 100644 drivers/xen/gntdev-common.h

drivers/xen/gntdev-common.h new file +13 -0

new file mode 100644
index 000000000000..7a9845a6bee9
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Common functionality of grant device.
+ *
+ * Copyright (c) 2006-2007, D G Murray.
+ *           (c) 2009 Gerd Hoffmann <[email protected]>
+ *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _GNTDEV_COMMON_H
+#define _GNTDEV_COMMON_H
+