[PATCH 03/13] x86: use dma-direct

Christoph Hellwig
2018-03-05T17:49:39Z

The generic dma-direct implementation is now functionally equivalent to
the x86 nommu dma_map implementation, so switch over to using it.

Note that the various iommu drivers are switched from x86_dma_supported
to dma_direct_supported to provide identical functionality, although the
checks looks fairly questionable for at least some of them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/dma-mapping.h | 8 -----
arch/x86/include/asm/iommu.h | 3 --
arch/x86/kernel/Makefile | 2 +-
arch/x86/kernel/amd_gart_64.c | 7 ++--
arch/x86/kernel/pci-calgary_64.c | 3 +-
arch/x86/kernel/pci-dma.c | 66 +-------------------------------------
arch/x86/kernel/pci-swiotlb.c | 5 ++-
arch/x86/pci/sta2x11-fixup.c | 2 +-
drivers/iommu/amd_iommu.c | 7 ++--
drivers/iommu/intel-iommu.c | 3 +-
11 files changed, 17 insertions(+), 90 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c1236b187824..7272bb3768d7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -83,6 +83,7 @@ config X86
select CLOCKSOURCE_VALIDATE_LAST_CYCLE
select CLOCKSOURCE_WATCHDOG
select DCACHE_WORD_ACCESS
+ select DMA_DIRECT_OPS
select EDAC_ATOMIC_SCRUB
select EDAC_SUPPORT
select GENERIC_CLOCKEVENTS
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 545bf3721bc0..df9816b385eb 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -36,14 +36,6 @@ int arch_dma_supported(struct device *dev, u64 mask);
bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
#define arch_dma_alloc_attrs arch_dma_alloc_attrs

-extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_addr, gfp_t flag,
- unsigned long attrs);
-
-extern void dma_generic_free_coherent(struct device *dev, size_t size,
- void *vaddr, dma_addr_t dma_addr,
- unsigned long attrs);
-
static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
{
if (dev->coherent_dma_mask <= DMA_BIT_MASK(24))
diff --git a/arch/x86/include/asm/iommu.h b/arch/x86/include/asm/iommu.h
index 1e5d5d92eb40..baedab8ac538 100644
--- a/arch/x86/include/asm/iommu.h
+++ b/arch/x86/include/asm/iommu.h
@@ -2,13 +2,10 @@
#ifndef _ASM_X86_IOMMU_H
#define _ASM_X86_IOMMU_H

-extern const struct dma_map_ops nommu_dma_ops;
extern int force_iommu, no_iommu;
extern int iommu_detected;
extern int iommu_pass_through;

-int x86_dma_supported(struct device *dev, u64 mask);
-
/* 10 seconds */
#define DMAR_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000)

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 29786c87e864..2e8c8a09ecab 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -57,7 +57,7 @@ obj-$(CONFIG_X86_ESPFIX64) += espfix_64.o
obj-$(CONFIG_SYSFS) += ksysfs.o
obj-y += bootflag.o e820.o
obj-y += pci-dma.o quirks.o topology.o kdebugfs.o
-obj-y += alternative.o i8253.o pci-nommu.o hw_breakpoint.o
+obj-y += alternative.o i8253.o hw_breakpoint.o
obj-y += tsc.o tsc_msr.o io_delay.o rtc.o
obj-y += pci-iommu_table.o
obj-y += resource.o
diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index ecd486cb06ab..52e3abcf3e70 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -501,8 +501,7 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
}
__free_pages(page, get_order(size));
} else
- return dma_generic_alloc_coherent(dev, size, dma_addr, flag,
- attrs);
+ return dma_direct_alloc(dev, size, dma_addr, flag, attrs);

return NULL;
}
@@ -513,7 +512,7 @@ gart_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_addr, unsigned long attrs)
{
gart_unmap_page(dev, dma_addr, size, DMA_BIDIRECTIONAL, 0);
- dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
+ dma_direct_free(dev, size, vaddr, dma_addr, attrs);
}

static int gart_mapping_error(struct device *dev, dma_addr_t dma_addr)
@@ -705,7 +704,7 @@ static const struct dma_map_ops gart_dma_ops = {
.alloc = gart_alloc_coherent,
.free = gart_free_coherent,
.mapping_error = gart_mapping_error,
- .dma_supported = x86_dma_supported,
+ .dma_supported = dma_direct_supported,
};

static void gart_iommu_shutdown(void)
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 35c461f21815..5647853053bd 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -33,6 +33,7 @@
#include <linux/string.h>
#include <linux/crash_dump.h>
#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
#include <linux/bitmap.h>
#include <linux/pci_ids.h>
#include <linux/pci.h>
@@ -493,7 +494,7 @@ static const struct dma_map_ops calgary_dma_ops = {
.map_page = calgary_map_page,
.unmap_page = calgary_unmap_page,
.mapping_error = calgary_mapping_error,
- .dma_supported = x86_dma_supported,
+ .dma_supported = dma_direct_supported,
};

static inline void __iomem * busno_to_bbar(unsigned char num)
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index b59820872ec7..db0b88ea8d1b 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -18,7 +18,7 @@

static int forbid_dac __read_mostly;

-const struct dma_map_ops *dma_ops = &nommu_dma_ops;
+const struct dma_map_ops *dma_ops = &dma_direct_ops;
EXPORT_SYMBOL(dma_ops);

static int iommu_sac_force __read_mostly;
@@ -76,60 +76,6 @@ void __init pci_iommu_alloc(void)
}
}
}
-void *dma_generic_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_addr, gfp_t flag,
- unsigned long attrs)
-{
- struct page *page;
- unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- dma_addr_t addr;
-
-again:
- page = NULL;
- /* CMA can be used only in the context which permits sleeping */
- if (gfpflags_allow_blocking(flag)) {
- page = dma_alloc_from_contiguous(dev, count, get_order(size),
- flag);
- if (page) {
- addr = phys_to_dma(dev, page_to_phys(page));
- if (addr + size > dev->coherent_dma_mask) {
- dma_release_from_contiguous(dev, page, count);
- page = NULL;
- }
- }
- }
- /* fallback */
- if (!page)
- page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
- if (!page)
- return NULL;
-
- addr = phys_to_dma(dev, page_to_phys(page));
- if (addr + size > dev->coherent_dma_mask) {
- __free_pages(page, get_order(size));
-
- if (dev->coherent_dma_mask < DMA_BIT_MASK(32) &&
- !(flag & GFP_DMA)) {
- flag = (flag & ~GFP_DMA32) | GFP_DMA;
- goto again;
- }
-
- return NULL;
- }
- memset(page_address(page), 0, size);
- *dma_addr = addr;
- return page_address(page);
-}
-
-void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_addr, unsigned long attrs)
-{
- unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- struct page *page = virt_to_page(vaddr);
-
- if (!dma_release_from_contiguous(dev, page, count))
- free_pages((unsigned long)vaddr, get_order(size));
-}

bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
{
@@ -243,16 +189,6 @@ int arch_dma_supported(struct device *dev, u64 mask)
}
EXPORT_SYMBOL(arch_dma_supported);

-int x86_dma_supported(struct device *dev, u64 mask)
-{
- /* Copied from i386. Doesn't make much sense, because it will
- only work for pci_alloc_coherent.
- The caller just has to use GFP_DMA in this case. */
- if (mask < DMA_BIT_MASK(24))
- return 0;
- return 1;
-}
-
static int __init pci_iommu_init(void)
{
struct iommu_table_entry *p;
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 0ee0f8f34251..bcb6a9bf64ad 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -30,8 +30,7 @@ void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
*/
flags |= __GFP_NOWARN;

- vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags,
- attrs);
+ vaddr = dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
if (vaddr)
return vaddr;

@@ -45,7 +44,7 @@ void x86_swiotlb_free_coherent(struct device *dev, size_t size,
if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr)))
swiotlb_free_coherent(dev, size, vaddr, dma_addr);
else
- dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
+ dma_direct_free(dev, size, vaddr, dma_addr, attrs);
}

static const struct dma_map_ops x86_swiotlb_dma_ops = {
diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
index 75577c1490c4..6c712fe11bdc 100644
--- a/arch/x86/pci/sta2x11-fixup.c
+++ b/arch/x86/pci/sta2x11-fixup.c
@@ -193,7 +193,7 @@ static const struct dma_map_ops sta2x11_dma_ops = {
.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
.sync_sg_for_device = swiotlb_sync_sg_for_device,
.mapping_error = swiotlb_dma_mapping_error,
- .dma_supported = x86_dma_supported,
+ .dma_supported = dma_direct_supported,
};

/* At setup time, we use our own ops if the device is a ConneXt one */
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 74788fdeb773..0bf19423b588 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -28,6 +28,7 @@
#include <linux/debugfs.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
#include <linux/iommu-helper.h>
#include <linux/iommu.h>
#include <linux/delay.h>
@@ -2193,7 +2194,7 @@ static int amd_iommu_add_device(struct device *dev)
dev_name(dev));

iommu_ignore_device(dev);
- dev->dma_ops = &nommu_dma_ops;
+ dev->dma_ops = &dma_direct_ops;
goto out;
}
init_iommu_group(dev);
@@ -2680,7 +2681,7 @@ static void free_coherent(struct device *dev, size_t size,
*/
static int amd_iommu_dma_supported(struct device *dev, u64 mask)
{
- if (!x86_dma_supported(dev, mask))
+ if (!dma_direct_supported(dev, mask))
return 0;
return check_device(dev);
}
@@ -2794,7 +2795,7 @@ int __init amd_iommu_init_dma_ops(void)
* continue to be SWIOTLB.
*/
if (!swiotlb)
- dma_ops = &nommu_dma_ops;
+ dma_ops = &dma_direct_ops;

if (amd_iommu_unmap_flush)
pr_info("AMD-Vi: IO/TLB flush on unmap enabled\n");
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 582fd01cb7d1..fd899b2a12bb 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -45,6 +45,7 @@
#include <linux/pci-ats.h>
#include <linux/memblock.h>
#include <linux/dma-contiguous.h>
+#include <linux/dma-direct.h>
#include <linux/crash_dump.h>
#include <asm/irq_remapping.h>
#include <asm/cacheflush.h>
@@ -3871,7 +3872,7 @@ const struct dma_map_ops intel_dma_ops = {
.unmap_page = intel_unmap_page,
.mapping_error = intel_mapping_error,
#ifdef CONFIG_X86
- .dma_supported = x86_dma_supported,
+ .dma_supported = dma_direct_supported,
#endif
};

--
2.14.2