lkml.org 
[lkml]   [2013]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v6 16/19] arm,arm64: do not always merge biovec if we are running on Xen
Date
This is similar to what it is done on X86: biovecs are prevented from merging
otherwise every dma requests would be forced to bounce on the swiotlb buffer.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
arch/arm/include/asm/io.h | 8 ++++++++
arch/arm64/include/asm/io.h | 9 +++++++++
drivers/xen/biomerge.c | 4 +++-
3 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index d070741..c45effc 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -24,9 +24,11 @@
#ifdef __KERNEL__

#include <linux/types.h>
+#include <linux/blk_types.h>
#include <asm/byteorder.h>
#include <asm/memory.h>
#include <asm-generic/pci_iomap.h>
+#include <xen/xen.h>

/*
* ISA I/O bus memory addresses are 1:1 with the physical address.
@@ -372,6 +374,12 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
#define BIOVEC_MERGEABLE(vec1, vec2) \
((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))

+extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
+ const struct bio_vec *vec2);
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
+ (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) && \
+ (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
+
#ifdef CONFIG_MMU
#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 1d12f89..c163287b 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -22,11 +22,14 @@
#ifdef __KERNEL__

#include <linux/types.h>
+#include <linux/blk_types.h>

#include <asm/byteorder.h>
#include <asm/barrier.h>
#include <asm/pgtable.h>

+#include <xen/xen.h>
+
/*
* Generic IO read/write. These perform native-endian accesses.
*/
@@ -263,5 +266,11 @@ extern int devmem_is_allowed(unsigned long pfn);
*/
#define xlate_dev_kmem_ptr(p) p

+extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
+ const struct bio_vec *vec2);
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
+ (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) && \
+ (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
+
#endif /* __KERNEL__ */
#endif /* __ASM_IO_H */
diff --git a/drivers/xen/biomerge.c b/drivers/xen/biomerge.c
index 0edb91c..f323a2d 100644
--- a/drivers/xen/biomerge.c
+++ b/drivers/xen/biomerge.c
@@ -2,6 +2,7 @@
#include <linux/io.h>
#include <linux/export.h>
#include <xen/page.h>
+#include <xen/features.h>

bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
const struct bio_vec *vec2)
@@ -9,7 +10,8 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
unsigned long mfn1 = pfn_to_mfn(page_to_pfn(vec1->bv_page));
unsigned long mfn2 = pfn_to_mfn(page_to_pfn(vec2->bv_page));

- return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
+ return !xen_feature(XENFEAT_auto_translated_physmap) &&
+ __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
((mfn1 == mfn2) || ((mfn1+1) == mfn2));
}
EXPORT_SYMBOL(xen_biovec_phys_mergeable);
--
1.7.2.5


\
 
 \ /
  Last update: 2013-09-27 19:01    [W:0.242 / U:5.556 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site