This is a note to let you know that I've just added the patch titled
scsi: libsas: Align SMP request allocation to ARCH_DMA_MINALIGN
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-libsas-align-smp-request-allocation-to-arch_dma.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c3d533e28fa759235c21a5f7c0919977a43e31c6
Author: Yihang Li <liyihang9@xxxxxxxxxx>
Date: Thu Mar 28 17:06:26 2024 +0800
scsi: libsas: Align SMP request allocation to ARCH_DMA_MINALIGN
[ Upstream commit e675a4fd6d1f8990d3bed5dada3d20edfa000423 ]
This series [1] reduced the kmalloc() minimum alignment on arm64 to 8 bytes
(from 128). In libsas, this will cause SMP requests to be 8-byte aligned
through kmalloc() allocation. However, for hisi_sas hardware, all command
addresses must be 16-byte-aligned. Otherwise, the commands fail to be
executed.
ARCH_DMA_MINALIGN represents the minimum (static) alignment for safe DMA
operations, so use ARCH_DMA_MINALIGN as the alignment for SMP request.
Link: https://lkml.kernel.org/r/20230612153201.554742-1-catalin.marinas@xxxxxxx [1]
Signed-off-by: Yihang Li <liyihang9@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240328090626.621147-1-liyihang9@xxxxxxxxxx
Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Reviewed-by: John Garry <john.g.garry@xxxxxxxxxx>
Reviewed-by: Jason Yan <yanaijie@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 5c261005b74e4..f6e6db8b8aba9 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -135,7 +135,7 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
static inline void *alloc_smp_req(int size)
{
- u8 *p = kzalloc(size, GFP_KERNEL);
+ u8 *p = kzalloc(ALIGN(size, ARCH_DMA_MINALIGN), GFP_KERNEL);
if (p)
p[0] = SMP_REQUEST;
return p;
