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Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
-rw-r--r--arch/arm/mm/dma-mapping.c114
1 files changed, 104 insertions, 10 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4e7d1182e8a..051204fc461 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -267,17 +267,19 @@ static void __dma_free_remap(void *cpu_addr, size_t size)
vunmap(cpu_addr);
}
+#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
+
struct dma_pool {
size_t size;
spinlock_t lock;
unsigned long *bitmap;
unsigned long nr_pages;
void *vaddr;
- struct page *page;
+ struct page **pages;
};
static struct dma_pool atomic_pool = {
- .size = SZ_256K,
+ .size = DEFAULT_DMA_COHERENT_POOL_SIZE,
};
static int __init early_coherent_pool(char *p)
@@ -287,6 +289,21 @@ static int __init early_coherent_pool(char *p)
}
early_param("coherent_pool", early_coherent_pool);
+void __init init_dma_coherent_pool_size(unsigned long size)
+{
+ /*
+ * Catch any attempt to set the pool size too late.
+ */
+ BUG_ON(atomic_pool.vaddr);
+
+ /*
+ * Set architecture specific coherent pool size only if
+ * it has not been changed by kernel command line parameter.
+ */
+ if (atomic_pool.size == DEFAULT_DMA_COHERENT_POOL_SIZE)
+ atomic_pool.size = size;
+}
+
/*
* Initialise the coherent pool for atomic allocations.
*/
@@ -297,6 +314,7 @@ static int __init atomic_pool_init(void)
unsigned long nr_pages = pool->size >> PAGE_SHIFT;
unsigned long *bitmap;
struct page *page;
+ struct page **pages;
void *ptr;
int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);
@@ -304,21 +322,31 @@ static int __init atomic_pool_init(void)
if (!bitmap)
goto no_bitmap;
+ pages = kzalloc(nr_pages * sizeof(struct page *), GFP_KERNEL);
+ if (!pages)
+ goto no_pages;
+
if (IS_ENABLED(CONFIG_CMA))
ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page);
else
ptr = __alloc_remap_buffer(NULL, pool->size, GFP_KERNEL, prot,
&page, NULL);
if (ptr) {
+ int i;
+
+ for (i = 0; i < nr_pages; i++)
+ pages[i] = page + i;
+
spin_lock_init(&pool->lock);
pool->vaddr = ptr;
- pool->page = page;
+ pool->pages = pages;
pool->bitmap = bitmap;
pool->nr_pages = nr_pages;
pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n",
(unsigned)pool->size / 1024);
return 0;
}
+no_pages:
kfree(bitmap);
no_bitmap:
pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
@@ -443,27 +471,45 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page)
if (pageno < pool->nr_pages) {
bitmap_set(pool->bitmap, pageno, count);
ptr = pool->vaddr + PAGE_SIZE * pageno;
- *ret_page = pool->page + pageno;
+ *ret_page = pool->pages[pageno];
+ } else {
+ pr_err_once("ERROR: %u KiB atomic DMA coherent pool is too small!\n"
+ "Please increase it with coherent_pool= kernel parameter!\n",
+ (unsigned)pool->size / 1024);
}
spin_unlock_irqrestore(&pool->lock, flags);
return ptr;
}
+static bool __in_atomic_pool(void *start, size_t size)
+{
+ struct dma_pool *pool = &atomic_pool;
+ void *end = start + size;
+ void *pool_start = pool->vaddr;
+ void *pool_end = pool->vaddr + pool->size;
+
+ if (start < pool_start || start > pool_end)
+ return false;
+
+ if (end <= pool_end)
+ return true;
+
+ WARN(1, "Wrong coherent size(%p-%p) from atomic pool(%p-%p)\n",
+ start, end - 1, pool_start, pool_end - 1);
+
+ return false;
+}
+
static int __free_from_pool(void *start, size_t size)
{
struct dma_pool *pool = &atomic_pool;
unsigned long pageno, count;
unsigned long flags;
- if (start < pool->vaddr || start > pool->vaddr + pool->size)
+ if (!__in_atomic_pool(start, size))
return 0;
- if (start + size > pool->vaddr + pool->size) {
- WARN(1, "freeing wrong coherent size from pool\n");
- return 0;
- }
-
pageno = (start - pool->vaddr) >> PAGE_SHIFT;
count = size >> PAGE_SHIFT;
@@ -1090,10 +1136,22 @@ static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t si
return 0;
}
+static struct page **__atomic_get_pages(void *addr)
+{
+ struct dma_pool *pool = &atomic_pool;
+ struct page **pages = pool->pages;
+ int offs = (addr - pool->vaddr) >> PAGE_SHIFT;
+
+ return pages + offs;
+}
+
static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs)
{
struct vm_struct *area;
+ if (__in_atomic_pool(cpu_addr, PAGE_SIZE))
+ return __atomic_get_pages(cpu_addr);
+
if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs))
return cpu_addr;
@@ -1103,6 +1161,34 @@ static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs)
return NULL;
}
+static void *__iommu_alloc_atomic(struct device *dev, size_t size,
+ dma_addr_t *handle)
+{
+ struct page *page;
+ void *addr;
+
+ addr = __alloc_from_pool(size, &page);
+ if (!addr)
+ return NULL;
+
+ *handle = __iommu_create_mapping(dev, &page, size);
+ if (*handle == DMA_ERROR_CODE)
+ goto err_mapping;
+
+ return addr;
+
+err_mapping:
+ __free_from_pool(addr, size);
+ return NULL;
+}
+
+static void __iommu_free_atomic(struct device *dev, struct page **pages,
+ dma_addr_t handle, size_t size)
+{
+ __iommu_remove_mapping(dev, handle, size);
+ __free_from_pool(page_address(pages[0]), size);
+}
+
static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
{
@@ -1113,6 +1199,9 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
*handle = DMA_ERROR_CODE;
size = PAGE_ALIGN(size);
+ if (gfp & GFP_ATOMIC)
+ return __iommu_alloc_atomic(dev, size, handle);
+
pages = __iommu_alloc_buffer(dev, size, gfp);
if (!pages)
return NULL;
@@ -1179,6 +1268,11 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
return;
}
+ if (__in_atomic_pool(cpu_addr, size)) {
+ __iommu_free_atomic(dev, pages, handle, size);
+ return;
+ }
+
if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) {
unmap_kernel_range((unsigned long)cpu_addr, size);
vunmap(cpu_addr);