lkml.org 
[lkml]   [2019]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 11/21] dma-iommu: refactor page array remap helpers
Date
Move the call to dma_common_pages_remap / dma_common_free_remap  into
__iommu_dma_alloc / __iommu_dma_free and rename those functions to
better describe what they do. This keeps the functionality that
allocates and remaps a non-contigous array of pages nicely abstracted
out from the calling code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/dma-iommu.c | 75 +++++++++++++++++++--------------------
1 file changed, 36 insertions(+), 39 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4d46beeea5b7..2013c650718a 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -524,51 +524,57 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev,
}

/**
- * iommu_dma_free - Free a buffer allocated by __iommu_dma_alloc()
+ * iommu_dma_free_remap - Free a buffer allocated by iommu_dma_alloc_remap
* @dev: Device which owns this buffer
- * @pages: Array of buffer pages as returned by __iommu_dma_alloc()
* @size: Size of buffer in bytes
+ * @cpu_address: Virtual address of the buffer
* @handle: DMA address of buffer
*
* Frees both the pages associated with the buffer, and the array
* describing them
*/
-static void __iommu_dma_free(struct device *dev, struct page **pages,
- size_t size, dma_addr_t *handle)
+static void iommu_dma_free_remap(struct device *dev, size_t size,
+ void *cpu_addr, dma_addr_t dma_handle)
{
- __iommu_dma_unmap(iommu_get_dma_domain(dev), *handle, size);
- __iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
- *handle = DMA_MAPPING_ERROR;
+ struct vm_struct *area = find_vm_area(cpu_addr);
+
+ if (WARN_ON(!area || !area->pages))
+ return;
+ __iommu_dma_unmap(iommu_get_dma_domain(dev), dma_handle, size);
+ __iommu_dma_free_pages(area->pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
+ dma_common_free_remap(cpu_addr, PAGE_ALIGN(size), VM_USERMAP);
}

/**
- * __iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
+ * iommu_dma_alloc_remap - Allocate and map a buffer contiguous in IOVA space
* @dev: Device to allocate memory for. Must be a real device
* attached to an iommu_dma_domain
* @size: Size of buffer in bytes
+ * @dma_handle: Out argument for allocated DMA handle
* @gfp: Allocation flags
* @attrs: DMA attributes for this allocation
- * @prot: IOMMU mapping flags
- * @handle: Out argument for allocated DMA handle
*
* If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
* but an IOMMU which supports smaller pages might not map the whole thing.
*
- * Return: Array of struct page pointers describing the buffer,
- * or NULL on failure.
+ * Return: Mapped virtual address, or NULL on failure.
*/
-static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
- gfp_t gfp, unsigned long attrs, int prot, dma_addr_t *handle)
+static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
struct iommu_domain *domain = iommu_get_dma_domain(dev);
struct iommu_dma_cookie *cookie = domain->iova_cookie;
struct iova_domain *iovad = &cookie->iovad;
+ bool coherent = dev_is_dma_coherent(dev);
+ int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
+ pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
+ unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
struct page **pages;
struct sg_table sgt;
dma_addr_t iova;
- unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
+ void *vaddr;

- *handle = DMA_MAPPING_ERROR;
+ *dma_handle = DMA_MAPPING_ERROR;

min_size = alloc_sizes & -alloc_sizes;
if (min_size < PAGE_SIZE) {
@@ -594,7 +600,7 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
goto out_free_iova;

- if (!(prot & IOMMU_CACHE)) {
+ if (!(ioprot & IOMMU_CACHE)) {
struct scatterlist *sg;
int i;

@@ -602,14 +608,21 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
arch_dma_prep_coherent(sg_page(sg), sg->length);
}

- if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot)
+ if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, ioprot)
< size)
goto out_free_sg;

- *handle = iova;
+ vaddr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
+ __builtin_return_address(0));
+ if (!vaddr)
+ goto out_unmap;
+
+ *dma_handle = iova;
sg_free_table(&sgt);
- return pages;
+ return vaddr;

+out_unmap:
+ __iommu_dma_unmap(domain, iova, size);
out_free_sg:
sg_free_table(&sgt);
out_free_iova:
@@ -1013,18 +1026,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
size >> PAGE_SHIFT);
}
} else {
- pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
- struct page **pages;
-
- pages = __iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
- handle);
- if (!pages)
- return NULL;
-
- addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
- __builtin_return_address(0));
- if (!addr)
- __iommu_dma_free(dev, pages, iosize, handle);
+ addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
}
return addr;
}
@@ -1038,7 +1040,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
/*
* @cpu_addr will be one of 4 things depending on how it was allocated:
* - A remapped array of pages for contiguous allocations.
- * - A remapped array of pages from __iommu_dma_alloc(), for all
+ * - A remapped array of pages from iommu_dma_alloc_remap(), for all
* non-atomic allocations.
* - A non-cacheable alias from the atomic pool, for atomic
* allocations by non-coherent devices.
@@ -1056,12 +1058,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
dma_common_free_remap(cpu_addr, size, VM_USERMAP);
} else if (is_vmalloc_addr(cpu_addr)){
- struct vm_struct *area = find_vm_area(cpu_addr);
-
- if (WARN_ON(!area || !area->pages))
- return;
- __iommu_dma_free(dev, area->pages, iosize, &handle);
- dma_common_free_remap(cpu_addr, size, VM_USERMAP);
+ 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));
--
2.20.1
\
 
 \ /
  Last update: 2019-03-27 09:06    [W:0.232 / U:10.192 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site