[PATCH 112/115] ion: fix bugs in cma heap

John Stultz
2013-12-14T03:28:00Z

From: Colin Cross <ccross@android.com>

Implement ion_cma_unmap_kernel, ion will call it unconditionally.
Use correct gfp flags when calling dma_alloc_coherent so it doesn't
try to use atomic DMA memory.
Check for invalid alignment when allocating.
Reject cached allocations - the cpu address returned by
dma_alloc_coherent is always going to be an uncached mapping, so
map_kernel will not see data written by a cached userspace mapping.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/staging/android/ion/ion_cma_heap.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index 3dcf9b4..f0f9889 100644
--- a/drivers/staging/android/ion/ion_cma_heap.c
+++ b/drivers/staging/android/ion/ion_cma_heap.c
@@ -69,13 +69,20 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,

dev_dbg(dev, "Request buffer allocation len %ld\n", len);

+ if (buffer->flags & ION_FLAG_CACHED)
+ return -EINVAL;
+
+ if (align > PAGE_SIZE)
+ return -EINVAL;
+
info = kzalloc(sizeof(struct ion_cma_buffer_info), GFP_KERNEL);
if (!info) {
dev_err(dev, "Can't allocate buffer info\n");
return ION_CMA_ALLOCATE_FAILED;
}

- info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle), 0);
+ info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle),
+ GFP_HIGHUSER | __GFP_ZERO);

if (!info->cpu_addr) {
dev_err(dev, "Fail to allocate buffer\n");
@@ -170,6 +177,11 @@ static void *ion_cma_map_kernel(struct ion_heap *heap,
return info->cpu_addr;
}

+static void ion_cma_unmap_kernel(struct ion_heap *heap,
+ struct ion_buffer *buffer)
+{
+}
+
static struct ion_heap_ops ion_cma_ops = {
.allocate = ion_cma_allocate,
.free = ion_cma_free,
@@ -178,6 +190,7 @@ static struct ion_heap_ops ion_cma_ops = {
.phys = ion_cma_phys,
.map_user = ion_cma_mmap,
.map_kernel = ion_cma_map_kernel,
+ .unmap_kernel = ion_cma_unmap_kernel,
};

struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data)
--
1.8.3.2