Patch "xen/arm,arm64: fix xen_dma_ops after 815dd18 "Consolidate get_dma_ops..."" has been added to the 4.11-stable tree

PATCH [email protected] 1 participant 1 message May 11, 2017

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Stable branch Arm (32-bit) arm64 Xen hypervisor interface

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2017-05-11 12:19 UTC #0 lore raw

This is a note to let you know that I've just added the patch titled

    xen/arm,arm64: fix xen_dma_ops after 815dd18 "Consolidate get_dma_ops..."

to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     xen-arm-arm64-fix-xen_dma_ops-after-815dd18-consolidate-get_dma_ops.patch

and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From e058632670b709145730a134acc3f83f392f7aa7 Mon Sep 17 00:00:00 2001

From: Stefano Stabellini <[email protected]>
Date: Thu, 13 Apr 2017 14:04:21 -0700
Subject: xen/arm,arm64: fix xen_dma_ops after 815dd18 "Consolidate get_dma_ops..."

From: Stefano Stabellini <[email protected]>

commit e058632670b709145730a134acc3f83f392f7aa7 upstream.

The following commit:

commit 815dd18788fe0d41899f51b91d0560279cf16b0d
Author: Bart Van Assche <[email protected]>
Date: Fri Jan 20 13:04:04 2017 -0800

treewide: Consolidate get_dma_ops() implementations

rearranges get_dma_ops in a way that xen_dma_ops are not returned when running on Xen anymore, dev->dma_ops is returned instead (see arch/arm/include/asm/dma-mapping.h:get_arch_dma_ops and include/linux/dma-mapping.h:get_dma_ops).

Fix the problem by storing dev->dma_ops in dev_archdata, and setting dev->dma_ops to xen_dma_ops. This way, xen_dma_ops is returned naturally by get_dma_ops. The Xen code can retrieve the original dev->dma_ops from dev_archdata when needed. It also allows us to remove __generic_dma_ops from common headers.

Signed-off-by Stefano Stabellini <[email protected]>

Tested-by Julien Grall <[email protected]>

Reviewed-by Catalin Marinas <[email protected]>

CC [email protected]

CC Julien Grall <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 arch/arm/include/asm/device.h        |    3 +++
 arch/arm/include/asm/dma-mapping.h   |   12 +-----------
 arch/arm/mm/dma-mapping.c            |    7 +++++++
 arch/arm64/include/asm/device.h      |    3 +++
 arch/arm64/include/asm/dma-mapping.h |   13 +------------
 arch/arm64/mm/dma-mapping.c          |    7 +++++++
 include/xen/arm/page-coherent.h      |    8 ++++++++
 7 files changed, 30 insertions(+), 23 deletions(-)

arch/arm/include/asm/device.h +3 -0

@@ -16,6 +16,9 @@ struct dev_archdata {
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 	struct dma_iommu_mapping	*mapping;
 #endif
+#ifdef CONFIG_XEN
+	const struct dma_map_ops *dev_dma_ops;
+#endif
 	bool dma_coherent;
 };

arch/arm/include/asm/dma-mapping.h +1 ~~-11~~

@@ -16,19 +16,9 @@
 extern const struct dma_map_ops arm_dma_ops;
 extern const struct dma_map_ops arm_coherent_dma_ops;
 
-static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
-{
-	if (dev && dev->dma_ops)
-		return dev->dma_ops;
-	return &arm_dma_ops;
-}
-
 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (xen_initial_domain())
-		return xen_dma_ops;
-	else
-		return __generic_dma_ops(NULL);
+	return &arm_dma_ops;
 }
 
 #define HAVE_ARCH_DMA_SUPPORTED 1

arch/arm/mm/dma-mapping.c +7 -0

@@ -2414,6 +2414,13 @@ void arch_setup_dma_ops(struct device *d
 		dma_ops = arm_get_dma_map_ops(coherent);
 
 	set_dma_ops(dev, dma_ops);
+
+#ifdef CONFIG_XEN
+	if (xen_initial_domain()) {
+		dev->archdata.dev_dma_ops = dev->dma_ops;
+		dev->dma_ops = xen_dma_ops;
+	}
+#endif
 }
 
 void arch_teardown_dma_ops(struct device *dev)

arch/arm64/include/asm/device.h +3 -0

@@ -20,6 +20,9 @@ struct dev_archdata {
 #ifdef CONFIG_IOMMU_API
 	void *iommu;			/* private IOMMU data */
 #endif
+#ifdef CONFIG_XEN
+	const struct dma_map_ops *dev_dma_ops;
+#endif
 	bool dma_coherent;
 };

arch/arm64/include/asm/dma-mapping.h +1 ~~-12~~

@@ -27,11 +27,8 @@
 #define DMA_ERROR_CODE	(~(dma_addr_t)0)
 extern const struct dma_map_ops dummy_dma_ops;
 
-static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (dev && dev->dma_ops)
-		return dev->dma_ops;
-
 	/*
 	 * We expect no ISA devices, and all other DMA masters are expected to
 	 * have someone call arch_setup_dma_ops at device creation time.

@@ -39,14 +36,6 @@ static inline const struct dma_map_ops *
 	return &dummy_dma_ops;
 }
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	if (xen_initial_domain())
-		return xen_dma_ops;
-	else
-		return __generic_dma_ops(NULL);
-}
-
 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 			const struct iommu_ops *iommu, bool coherent);
 #define arch_setup_dma_ops	arch_setup_dma_ops

arch/arm64/mm/dma-mapping.c +7 -0

@@ -977,4 +977,11 @@ void arch_setup_dma_ops(struct device *d
 
 	dev->archdata.dma_coherent = coherent;
 	__iommu_setup_dma_ops(dev, dma_base, size, iommu);
+
+#ifdef CONFIG_XEN
+	if (xen_initial_domain()) {
+		dev->archdata.dev_dma_ops = dev->dma_ops;
+		dev->dma_ops = xen_dma_ops;
+	}
+#endif
 }

include/xen/arm/page-coherent.h +8 -0

@@ -2,8 +2,16 @@
 #define _ASM_ARM_XEN_PAGE_COHERENT_H
 
 #include <asm/page.h>
+#include <asm/dma-mapping.h>
 #include <linux/dma-mapping.h>
 
+static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
+{
+	if (dev && dev->archdata.dev_dma_ops)
+		return dev->archdata.dev_dma_ops;
+	return get_arch_dma_ops(NULL);
+}
+
 void __xen_dma_map_page(struct device *hwdev, struct page *page,
 	     dma_addr_t dev_addr, unsigned long offset, size_t size,
 	     enum dma_data_direction dir, unsigned long attrs);

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/xen-revert-commits-da72ff5bfcb0-and-72a9b186292d.patch queue-4.11/xen-arm-arm64-fix-xen_dma_ops-after-815dd18-consolidate-get_dma_ops.patch