Re: [PATCH 2/3] swiotlb: prefix dma_to_phys and phys_to_dma functions
From: Robin Murphy
Date: Fri Mar 18 2016 - 08:12:33 EST
On 17/03/16 22:02, Sinan Kaya wrote:
Prefixing dma_to_phys and phys_to_dma API with swiotlb so that
they are no longer part of the DMA API. These APIs do not exist
on all architectures and breaks compatibility.
In preparation for the clean up, also make the ARCH implementation
known by defining swiotlb_phys_do_dma and swiotlb_dma_to_phys.
Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
---
arch/arm/include/asm/dma-mapping.h | 8 ++-
arch/arm64/include/asm/dma-mapping.h | 9 ++-
arch/arm64/mm/dma-mapping.c | 75 ++++++++++++++--------
[...]
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index a6e757c..ada00c3 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -107,7 +107,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
if (!page)
return NULL;
- *dma_handle = phys_to_dma(dev, page_to_phys(page));
+ *dma_handle = swiotlb_phys_to_dma(dev, page_to_phys(page));
addr = page_address(page);
memset(addr, 0, size);
return addr;
@@ -121,7 +121,7 @@ static void __dma_free_coherent(struct device *dev, size_t size,
struct dma_attrs *attrs)
{
bool freed;
- phys_addr_t paddr = dma_to_phys(dev, dma_handle);
+ phys_addr_t paddr = swiotlb_dma_to_phys(dev, dma_handle);
if (dev == NULL) {
WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
@@ -151,7 +151,8 @@ static void *__dma_alloc(struct device *dev, size_t size,
void *addr = __alloc_from_pool(size, &page, flags);
if (addr)
- *dma_handle = phys_to_dma(dev, page_to_phys(page));
+ *dma_handle = swiotlb_phys_to_dma(dev,
+ page_to_phys(page));
return addr;
}
@@ -187,7 +188,7 @@ static void __dma_free(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
- void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
+ void *swiotlb_addr = phys_to_virt(swiotlb_dma_to_phys(dev, dma_handle));
size = PAGE_ALIGN(size);
@@ -208,7 +209,8 @@ static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
if (!is_device_dma_coherent(dev))
- __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+ __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)),
+ size, dir);
return dev_addr;
}
@@ -218,8 +220,11 @@ static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- if (!is_device_dma_coherent(dev))
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+ if (!is_device_dma_coherent(dev)) {
+ phys_addr_t phys = swiotlb_dma_to_phys(dev, dev_addr);
+
+ __dma_unmap_area(phys_to_virt(phys), size, dir);
+ }
swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
}
@@ -232,9 +237,12 @@ static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, ret, i)
- __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
+ for_each_sg(sgl, sg, ret, i) {
+ dma_addr_t dma = sg->dma_address;
+ phys_addr_t phys = swiotlb_dma_to_phys(dev, dma);
+
+ __dma_map_area(phys_to_virt(phys), sg->length, dir);
+ }
return ret;
}
@@ -248,9 +256,12 @@ static void __swiotlb_unmap_sg_attrs(struct device *dev,
int i;
if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, nelems, i)
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
+ for_each_sg(sgl, sg, nelems, i) {
+ dma_addr_t dma = sg->dma_address;
+ phys_addr_t phys = swiotlb_dma_to_phys(dev, dma);
+
+ __dma_unmap_area(phys_to_virt(phys), sg->length, dir);
+ }
swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
}
@@ -258,8 +269,11 @@ static void __swiotlb_sync_single_for_cpu(struct device *dev,
dma_addr_t dev_addr, size_t size,
enum dma_data_direction dir)
{
- if (!is_device_dma_coherent(dev))
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+ if (!is_device_dma_coherent(dev)) {
+ phys_addr_t phys = swiotlb_dma_to_phys(dev, dev_addr);
+
+ __dma_unmap_area(phys_to_virt(phys), size, dir);
+ }
swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
}
@@ -269,7 +283,8 @@ static void __swiotlb_sync_single_for_device(struct device *dev,
{
swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
if (!is_device_dma_coherent(dev))
- __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+ __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)),
+ size, dir);
}
static void __swiotlb_sync_sg_for_cpu(struct device *dev,
@@ -280,9 +295,12 @@ static void __swiotlb_sync_sg_for_cpu(struct device *dev,
int i;
if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, nelems, i)
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
+ for_each_sg(sgl, sg, nelems, i) {
+ dma_addr_t dma = sg->dma_address;
+ phys_addr_t phys = swiotlb_dma_to_phys(dev, dma);
+
+ __dma_unmap_area(phys_to_virt(phys), sg->length, dir);
+ }
swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
}
@@ -295,9 +313,12 @@ static void __swiotlb_sync_sg_for_device(struct device *dev,
swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, nelems, i)
- __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
+ for_each_sg(sgl, sg, nelems, i) {
+ dma_addr_t dma = sg->dma_address;
+ phys_addr_t phys = swiotlb_dma_to_phys(dev, dma);
+
+ __dma_map_area(phys_to_virt(phys), sg->length, dir);
+ }
}
static int __swiotlb_mmap(struct device *dev,
@@ -309,7 +330,7 @@ static int __swiotlb_mmap(struct device *dev,
unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
PAGE_SHIFT;
unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
+ unsigned long pfn = swiotlb_dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
@@ -334,9 +355,11 @@ static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
{
int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
- if (!ret)
- sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)),
- PAGE_ALIGN(size), 0);
+ if (!ret) {
+ phys_addr_t phys = swiotlb_dma_to_phys(dev, handle);
+
+ sg_set_page(sgt->sgl, phys_to_page(phys), PAGE_ALIGN(size), 0);
+ }
return ret;
}
Since we know for sure that swiotlb_to_phys is a no-op on arm64, it
might be cleaner to simply not reference it at all. I suppose we could
have some private local wrappers, e.g.:
#define swiotlb_to_virt(addr) phys_to_virt((phys_addr_t)(addr))
to keep the intent of the code clear (and just in case anyone ever
builds a system mad enough to warrant switching out that definition, but
I'd hope that never happens).
Otherwise, looks good - thanks for doing this!
Robin.