[PATCH 5.10 04/57] net: octeontx2: Make sure the buffer is 128 byte aligned

From: Greg Kroah-Hartman
Date: Fri Feb 05 2021 - 13:56:45 EST


From: Kevin Hao <haokexin@xxxxxxxxx>

commit db2805150a0f27c00ad286a29109397a7723adad upstream.

The octeontx2 hardware needs the buffer to be 128 byte aligned.
But in the current implementation of napi_alloc_frag(), it can't
guarantee the return address is 128 byte aligned even the request size
is a multiple of 128 bytes, so we have to request an extra 128 bytes and
use the PTR_ALIGN() to make sure that the buffer is aligned correctly.

Fixes: 7a36e4918e30 ("octeontx2-pf: Use the napi_alloc_frag() to alloc the pool buffers")
Reported-by: Subbaraya Sundeep <sbhatta@xxxxxxxxxxx>
Signed-off-by: Kevin Hao <haokexin@xxxxxxxxx>
Tested-by: Subbaraya Sundeep <sbhatta@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210121070906.25380-1-haokexin@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
@@ -473,10 +473,11 @@ dma_addr_t __otx2_alloc_rbuf(struct otx2
dma_addr_t iova;
u8 *buf;

- buf = napi_alloc_frag(pool->rbsize);
+ buf = napi_alloc_frag(pool->rbsize + OTX2_ALIGN);
if (unlikely(!buf))
return -ENOMEM;

+ buf = PTR_ALIGN(buf, OTX2_ALIGN);
iova = dma_map_single_attrs(pfvf->dev, buf, pool->rbsize,
DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
if (unlikely(dma_mapping_error(pfvf->dev, iova))) {