On 2021-10-21 10:06, Christoph Hellwig wrote:
Add a helper to check if a potentially blocking operation should
dip into the atomic pools.
Reviewed-by: Robin Murphy <robin.mur...@arm.com>
Signed-off-by: Christoph Hellwig <h...@lst.de>
---
kernel/dma/direct.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index f2ec40f5733fc..babf79c16c041 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -151,6 +151,15 @@ static struct page *__dma_direct_alloc_pages(struct device
*dev, size_t size,
return page;
}
+/*
+ * Check if a potentially blocking operations needs to dip into the atomic
+ * pools for the given device/gfp.
+ */
+static bool dma_direct_use_pool(struct device *dev, gfp_t gfp)
+{
+ return gfpflags_allow_blocking(gfp) && !is_swiotlb_for_alloc(dev);
+}
+
static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp)
{
@@ -229,8 +238,7 @@ void *dma_direct_alloc(struct device *dev, size_t size,
* instead have to dip into the atomic pools.
*/
if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP)) {
- if (!gfpflags_allow_blocking(gfp) &&
- !is_swiotlb_for_alloc(dev))
+ if (dma_direct_use_pool(dev, gfp))
return dma_direct_alloc_from_pool(dev, size,
dma_handle, gfp);
remap = true;
@@ -241,8 +249,7 @@ void *dma_direct_alloc(struct device *dev, size_t size,
* Decrypting memory may block, so allocate the memory from the atomic
* pools if we can't block.
*/
- if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
- !is_swiotlb_for_alloc(dev))
+ if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp))
return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
/* we always manually zero the memory once we are done */
@@ -359,8 +366,7 @@ struct page *dma_direct_alloc_pages(struct device *dev,
size_t size,
struct page *page;
void *ret;
- if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
- !is_swiotlb_for_alloc(dev))
+ if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp))
return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
page = __dma_direct_alloc_pages(dev, size, gfp);
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