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[v3,1/3] dma-mapping: improve DMA zone selection

Message ID fe2e245ba534fc3cee9890ba12d1da13084e67a5.1722249878.git.baruch@tkos.co.il (mailing list archive)
State New, archived
Headers show
Series dma: support DMA zone starting above 4GB | expand

Commit Message

Baruch Siach July 29, 2024, 10:51 a.m. UTC 
When device DMA limit does not fit in DMA32 zone it should use DMA zone,
even when DMA zone is stricter than needed.

Same goes for devices that can't allocate from the entire normal zone.
Limit to DMA32 in that case.

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
 kernel/dma/direct.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 4480a3cd92e0..3b4be4ca3b08 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -4,7 +4,7 @@ 
  *
  * DMA operations that map physical memory directly without using an IOMMU.
  */
-#include <linux/memblock.h> /* for max_pfn */
+#include <linux/memblock.h>
 #include <linux/export.h>
 #include <linux/mm.h>
 #include <linux/dma-map-ops.h>
@@ -59,9 +59,9 @@  static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 *phys_limit)
 	 * zones.
 	 */
 	*phys_limit = dma_to_phys(dev, dma_limit);
-	if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits))
+	if (*phys_limit < DMA_BIT_MASK(32))
 		return GFP_DMA;
-	if (*phys_limit <= DMA_BIT_MASK(32))
+	if (*phys_limit < memblock_end_of_DRAM())
 		return GFP_DMA32;
 	return 0;
 }