[PATCH 13/21] dma-iommu: factor contiguous allocations into helpers

From: Christoph Hellwig
Date: Wed Mar 27 2019 - 04:06:37 EST


This keeps the code together and will simplify using it in different
ways.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/iommu/dma-iommu.c | 110 ++++++++++++++++++++------------------
1 file changed, 59 insertions(+), 51 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 8ec69176673d..da2e0f4a63b6 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -458,6 +458,48 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
return iova + iova_off;
}

+static void iommu_dma_free_contiguous(struct device *dev, size_t size,
+ struct page *page, dma_addr_t dma_handle)
+{
+ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+ __iommu_dma_unmap(iommu_get_domain_for_dev(dev), dma_handle, size);
+ if (!dma_release_from_contiguous(dev, page, count))
+ __free_pages(page, get_order(size));
+}
+
+
+static void *iommu_dma_alloc_contiguous(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+ bool coherent = dev_is_dma_coherent(dev);
+ int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
+ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ unsigned int page_order = get_order(size);
+ struct page *page = NULL;
+
+ if (gfpflags_allow_blocking(gfp))
+ page = dma_alloc_from_contiguous(dev, count, page_order,
+ gfp & __GFP_NOWARN);
+
+ if (page)
+ memset(page_address(page), 0, PAGE_ALIGN(size));
+ else
+ page = alloc_pages(gfp, page_order);
+ if (!page)
+ return NULL;
+
+ *dma_handle = __iommu_dma_map(dev, page_to_phys(page), size, ioprot,
+ iommu_get_dma_domain(dev));
+ if (*dma_handle == DMA_MAPPING_ERROR) {
+ if (!dma_release_from_contiguous(dev, page, count))
+ __free_pages(page, page_order);
+ return NULL;
+ }
+
+ return page_address(page);
+}
+
static void __iommu_dma_free_pages(struct page **pages, int count)
{
while (count--)
@@ -754,19 +796,6 @@ static void iommu_dma_sync_sg_for_device(struct device *dev,
arch_sync_dma_for_device(dev, sg_phys(sg), sg->length, dir);
}

-static dma_addr_t __iommu_dma_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size, int prot)
-{
- return __iommu_dma_map(dev, page_to_phys(page) + offset, size, prot,
- iommu_get_dma_domain(dev));
-}
-
-static void __iommu_dma_unmap_page(struct device *dev, dma_addr_t handle,
- size_t size, enum dma_data_direction dir, unsigned long attrs)
-{
- __iommu_dma_unmap(iommu_get_dma_domain(dev), handle, size);
-}
-
static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
@@ -991,7 +1020,6 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
{
bool coherent = dev_is_dma_coherent(dev);
- int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
size_t iosize = size;
void *addr;

@@ -1004,7 +1032,6 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
gfp |= __GFP_ZERO;

if (!gfpflags_allow_blocking(gfp)) {
- struct page *page;
/*
* In atomic context we can't remap anything, so we'll only
* get the virtually contiguous buffer we need by way of a
@@ -1013,44 +1040,27 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
if (!coherent)
return iommu_dma_alloc_pool(dev, iosize, handle, gfp,
attrs);
-
- page = alloc_pages(gfp, get_order(size));
- if (!page)
- return NULL;
-
- addr = page_address(page);
- *handle = __iommu_dma_map_page(dev, page, 0, iosize, ioprot);
- if (*handle == DMA_MAPPING_ERROR) {
- __free_pages(page, get_order(size));
- addr = NULL;
- }
+ return iommu_dma_alloc_contiguous(dev, iosize, handle, gfp,
+ attrs);
} else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
struct page *page;

- page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
- get_order(size), gfp & __GFP_NOWARN);
- if (!page)
+ addr = iommu_dma_alloc_contiguous(dev, iosize, handle, gfp,
+ attrs);
+ if (!addr)
return NULL;
+ page = virt_to_page(addr);

- *handle = __iommu_dma_map_page(dev, page, 0, iosize, ioprot);
- if (*handle == DMA_MAPPING_ERROR) {
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
+ addr = dma_common_contiguous_remap(page, size, VM_USERMAP, prot,
+ __builtin_return_address(0));
+ if (!addr) {
+ iommu_dma_free_contiguous(dev, iosize, page, *handle);
return NULL;
}
- addr = dma_common_contiguous_remap(page, size, VM_USERMAP,
- prot,
- __builtin_return_address(0));
- if (addr) {
- if (!coherent)
- arch_dma_prep_coherent(page, iosize);
- memset(addr, 0, size);
- } else {
- __iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
- }
+
+ if (!coherent)
+ arch_dma_prep_coherent(page, iosize);
} else {
addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
}
@@ -1077,16 +1087,14 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
if (dma_in_atomic_pool(cpu_addr, size)) {
iommu_dma_free_pool(dev, size, cpu_addr, handle);
} else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- struct page *page = vmalloc_to_page(cpu_addr);
-
- __iommu_dma_unmap_page(dev, handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
+ iommu_dma_free_contiguous(dev, iosize,
+ vmalloc_to_page(cpu_addr), handle);
dma_common_free_remap(cpu_addr, size, VM_USERMAP);
} else if (is_vmalloc_addr(cpu_addr)){
iommu_dma_free_remap(dev, iosize, cpu_addr, handle);
} else {
- __iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
- __free_pages(virt_to_page(cpu_addr), get_order(size));
+ iommu_dma_free_contiguous(dev, iosize, virt_to_page(cpu_addr),
+ handle);
}
}

--
2.20.1