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authorRabin Vincent <rabin@rab.in>2016-03-03 15:58:00 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2016-03-04 23:35:17 +0000
commit19e6e5e5392bd646c93d9e2c7b2b58c8558cb041 (patch)
tree58faab0da010a9828e2670cf68619adbc0732e77 /arch/arm/mm
parentf57deb0be5c25fcf2d30dce113f0a6a985c227bb (diff)
ARM: 8547/1: dma-mapping: store buffer information
Keep a list of allocated DMA buffers so that we can store metadata in alloc() which we later need in free(). Signed-off-by: Rabin Vincent <rabin.vincent@axis.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/dma-mapping.c49
1 files changed, 48 insertions, 1 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 9f996a3d79f7..696f6ee259ee 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -42,6 +42,31 @@
#include "dma.h"
#include "mm.h"
+struct arm_dma_buffer {
+ struct list_head list;
+ void *virt;
+};
+
+static LIST_HEAD(arm_dma_bufs);
+static DEFINE_SPINLOCK(arm_dma_bufs_lock);
+
+static struct arm_dma_buffer *arm_dma_buffer_find(void *virt)
+{
+ struct arm_dma_buffer *buf, *found = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&arm_dma_bufs_lock, flags);
+ list_for_each_entry(buf, &arm_dma_bufs, list) {
+ if (buf->virt == virt) {
+ list_del(&buf->list);
+ found = buf;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
+ return found;
+}
+
/*
* The DMA API is built upon the notion of "buffer ownership". A buffer
* is either exclusively owned by the CPU (and therefore may be accessed
@@ -620,6 +645,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
struct page *page = NULL;
void *addr;
bool want_vaddr;
+ struct arm_dma_buffer *buf;
#ifdef CONFIG_DMA_API_DEBUG
u64 limit = (mask + 1) & ~mask;
@@ -633,6 +659,10 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
if (!mask)
return NULL;
+ buf = kzalloc(sizeof(*buf), gfp);
+ if (!buf)
+ return NULL;
+
if (mask < 0xffffffffULL)
gfp |= GFP_DMA;
@@ -662,8 +692,18 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
addr = __alloc_remap_buffer(dev, size, gfp, prot, &page,
caller, want_vaddr);
- if (page)
+ if (page) {
+ unsigned long flags;
+
*handle = pfn_to_dma(dev, page_to_pfn(page));
+ buf->virt = want_vaddr ? addr : page;
+
+ spin_lock_irqsave(&arm_dma_bufs_lock, flags);
+ list_add(&buf->list, &arm_dma_bufs);
+ spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
+ } else {
+ kfree(buf);
+ }
return want_vaddr ? addr : page;
}
@@ -742,6 +782,11 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
{
struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
bool want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs);
+ struct arm_dma_buffer *buf;
+
+ buf = arm_dma_buffer_find(cpu_addr);
+ if (WARN(!buf, "Freeing invalid buffer %p\n", cpu_addr))
+ return;
size = PAGE_ALIGN(size);
@@ -760,6 +805,8 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
WARN_ON(irqs_disabled());
__free_from_contiguous(dev, page, cpu_addr, size, want_vaddr);
}
+
+ kfree(buf);
}
void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,