| Message ID | 20240328062657.581460-1-liyihang9@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3] scsi: libsas: Allocation SMP request is aligned to 16B | expand |
On 3/28/24 15:26, Yihang Li wrote: > This series [1] reducing the kmalloc() minimum alignment on arm64 to 8 > (from 128). In libsas, this will cause SMP requests to be 8-byte-aligned > through kmalloc() allocation. However, for the hisi_sas hardware, all > commands address must be 16-byte-aligned. Otherwise, the commands fail to > be executed. > > So use 16B as the alignment for SMP request. > > Link: https://lkml.kernel.org/r/20230612153201.554742-1-catalin.marinas@arm.com [1] > Signed-off-by: Yihang Li <liyihang9@huawei.com> Looks OK to me. Reviewed-by: Damien Le Moal <dlemoal@kernel.org> > --- > Changes since v2: > - Use 16B as alignment for SMP requests instead of ARCH_DMA_MINALIGN. > > Changes since v1: > - Directly modify alloc_smp_req() instead of using handler callback. > --- > drivers/scsi/libsas/sas_expander.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c > index a2204674b680..5ddbd00d5c76 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, 16), GFP_KERNEL); > if (p) > p[0] = SMP_REQUEST; > return p;
> + u8 *p = kzalloc(ALIGN(size, 16), GFP_KERNEL);
No, a magic undocumented 16 here max no sense at all. See the
discussion on the previous iteration.
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c index a2204674b680..5ddbd00d5c76 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, 16), GFP_KERNEL); if (p) p[0] = SMP_REQUEST; return p;
This series [1] reducing the kmalloc() minimum alignment on arm64 to 8 (from 128). In libsas, this will cause SMP requests to be 8-byte-aligned through kmalloc() allocation. However, for the hisi_sas hardware, all commands address must be 16-byte-aligned. Otherwise, the commands fail to be executed. So use 16B as the alignment for SMP request. Link: https://lkml.kernel.org/r/20230612153201.554742-1-catalin.marinas@arm.com [1] Signed-off-by: Yihang Li <liyihang9@huawei.com> --- Changes since v2: - Use 16B as alignment for SMP requests instead of ARCH_DMA_MINALIGN. Changes since v1: - Directly modify alloc_smp_req() instead of using handler callback. --- drivers/scsi/libsas/sas_expander.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)