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authorRatheesh Kannoth <rkannoth@marvell.com>2026-09-16 07:51:11 +0530
committerJakub Kicinski <kuba@kernel.org>2026-09-21 16:17:10 -0700
commitd06f2ebf67ff2962fe00d687e4f0d4703eb41a12 (patch)
tree054e8f647d7644eca7548c6bc441401efb00abe0
parentMerge tag 'nf-26-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf (diff)
octeontx2-af: Fix memory scaling limitation in SR-IOV mode
The original code used DMA_ATTR_FORCE_CONTIGUOUS, which could exhaust the CMA pool when a large number of VFs were requested. Fix this by switching to the DMA streaming API. This is equivalent on Octeon platforms, which provide full I/O coherency via the SMMU. Cc: Leon Romanovsky <leon@kernel.org> Fixes: 73d33dbc0723 ("octeontx2-af: Use DMA_ATTR_FORCE_CONTIGUOUS attribute in DMA alloc") Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com> Reviewed-by: Leon Romanovsky <leon@kernel.org> Link: https://patch.msgid.link/20260916022111.1083017-1-rkannoth@marvell.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--drivers/net/ethernet/marvell/octeontx2/af/common.h45
1 files changed, 39 insertions, 6 deletions
diff --git a/drivers/net/ethernet/marvell/octeontx2/af/common.h b/drivers/net/ethernet/marvell/octeontx2/af/common.h
index 779413a383b7..78e42549d990 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/common.h
+++ b/drivers/net/ethernet/marvell/octeontx2/af/common.h
@@ -7,6 +7,10 @@
#ifndef COMMON_H
#define COMMON_H
+#include <linux/dma-mapping.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+
#include "rvu_struct.h"
#define OTX2_ALIGN 128 /* Align to cacheline */
@@ -44,6 +48,33 @@ struct qmem {
u32 qsize;
};
+static inline void *otx2_dma_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle)
+{
+ dma_addr_t dma_addr;
+ void *vaddr;
+
+ vaddr = kzalloc(size, GFP_KERNEL);
+ if (!vaddr)
+ return NULL;
+
+ dma_addr = dma_map_single(dev, vaddr, size, DMA_BIDIRECTIONAL);
+ if (dma_mapping_error(dev, dma_addr)) {
+ kfree(vaddr);
+ return NULL;
+ }
+
+ *dma_handle = dma_addr;
+ return vaddr;
+}
+
+static inline void otx2_dma_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle)
+{
+ dma_unmap_single(dev, dma_handle, size, DMA_BIDIRECTIONAL);
+ kfree(vaddr);
+}
+
static inline int qmem_alloc(struct device *dev, struct qmem **q,
int qsize, int entry_sz)
{
@@ -60,8 +91,11 @@ static inline int qmem_alloc(struct device *dev, struct qmem **q,
qmem->entry_sz = entry_sz;
qmem->alloc_sz = (qsize * entry_sz) + OTX2_ALIGN;
- qmem->base = dma_alloc_attrs(dev, qmem->alloc_sz, &qmem->iova,
- GFP_KERNEL, DMA_ATTR_FORCE_CONTIGUOUS);
+
+ if (get_order(PAGE_ALIGN(qmem->alloc_sz)) > MAX_PAGE_ORDER)
+ return -ENOMEM;
+
+ qmem->base = otx2_dma_alloc_coherent(dev, qmem->alloc_sz, &qmem->iova);
if (!qmem->base)
return -ENOMEM;
@@ -80,10 +114,9 @@ static inline void qmem_free(struct device *dev, struct qmem *qmem)
return;
if (qmem->base)
- dma_free_attrs(dev, qmem->alloc_sz,
- qmem->base - qmem->align,
- qmem->iova - qmem->align,
- DMA_ATTR_FORCE_CONTIGUOUS);
+ otx2_dma_free_coherent(dev, qmem->alloc_sz,
+ qmem->base - qmem->align,
+ qmem->iova - qmem->align);
devm_kfree(dev, qmem);
}