Move dma_generic_alloc_coherent() out of x86 code and create
corresponding dma_generic_free_coherent() for symmetry. These
can then be used by IOMMU drivers attempting to implement
passthrough mode.
Signed-off-by: Alex Williamson <alex.williamson@xxxxxx>
---
arch/x86/include/asm/dma-mapping.h | 3 --
arch/x86/kernel/pci-dma.c | 31 -------------------------
arch/x86/kernel/pci-nommu.c | 10 +++++++-
include/linux/dma-mapping.h | 44 ++++++++++++++++++++++++++++++++++++
4 files changed, 52 insertions(+), 36 deletions(-)
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 0ee770d..e6d2c9f 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -52,9 +52,6 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
extern int dma_supported(struct device *hwdev, u64 mask);
extern int dma_set_mask(struct device *dev, u64 mask);
-extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_addr, gfp_t flag);
-
static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
{
if (!dev->dma_mask)
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index b2a71dc..ecd9df0 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -144,37 +144,6 @@ void __init pci_iommu_alloc(void)
pci_swiotlb_init();
}
-void *dma_generic_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_addr, gfp_t flag)
-{
- unsigned long dma_mask;
- struct page *page;
- dma_addr_t addr;
-
- dma_mask = dma_alloc_coherent_mask(dev, flag);
-
- flag |= __GFP_ZERO;
-again:
- page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
- if (!page)
- return NULL;
-
- addr = page_to_phys(page);
- if (addr + size > dma_mask) {
- __free_pages(page, get_order(size));
-
- if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) {
- flag = (flag & ~GFP_DMA32) | GFP_DMA;
- goto again;
- }
-
- return NULL;
- }
-
- *dma_addr = addr;
- return page_address(page);
-}
-
/*
* See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter
* documentation.
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index a3933d4..ed9e12e 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -73,10 +73,16 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
return nents;
}
+static void *nommu_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_addr, gfp_t flag)
+{
+ return dma_generic_alloc_coherent(dev, size, dma_addr, flag);
+}
+
static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_addr)
{
- free_pages((unsigned long)vaddr, get_order(size));
+ dma_generic_free_coherent(dev, size, vaddr, dma_addr);
}
static void nommu_sync_single_for_device(struct device *dev,
@@ -95,7 +101,7 @@ static void nommu_sync_sg_for_device(struct device *dev,
}
struct dma_map_ops nommu_dma_ops = {
- .alloc_coherent = dma_generic_alloc_coherent,
+ .alloc_coherent = nommu_alloc_coherent,
.free_coherent = nommu_free_coherent,
.map_sg = nommu_map_sg,
.map_page = nommu_map_page,
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 91b7618..285043c 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -232,4 +232,48 @@ struct dma_attrs;
#endif /* CONFIG_HAVE_DMA_ATTRS */
+static inline void *dma_generic_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_addr, gfp_t flag)
+{
+ unsigned long dma_mask;
+ struct page *page;
+ dma_addr_t addr;
+
+ dma_mask = dev->coherent_dma_mask;
+ if (!dma_mask) {
+#ifdef CONFIG_ISA
+ dma_mask = (flag & GFP_DMA) ? DMA_BIT_MASK(24)
+ : DMA_BIT_MASK(32);
+#else
+ dma_mask = DMA_BIT_MASK(32);
+#endif
+ }
+
+ flag |= __GFP_ZERO;
+again:
+ page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
+ if (!page)
+ return NULL;
+
+ addr = page_to_phys(page);
+ if (addr + size > dma_mask) {
+ __free_pages(page, get_order(size));
+
+ if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) {
+ flag = (flag & ~GFP_DMA32) | GFP_DMA;
+ goto again;
+ }
+
+ return NULL;
+ }
+
+ *dma_addr = addr;
+ return page_address(page);
+}
+
+static inline void dma_generic_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_addr)
+{
+ free_pages((unsigned long)vaddr, get_order(size));
+}
#endif
--
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