On 2025-08-06 17:41:08, Alexandra Winter wrote:
>smcd_buf_free() calls smc_ism_unregister_dmb(lgr->smcd, buf_desc) and
>then unconditionally frees buf_desc.
>
>Remove the cleaning up of fields of buf_desc in
>smc_ism_unregister_dmb(), because it is not helpful.
>
>This removes the only usage of ISM_ERROR from the smc module. So move it
>to drivers/s390/net/ism.h.
>
>Signed-off-by: Alexandra Winter <wintera@xxxxxxxxxxxxx>
>Reviewed-by: Mahanta Jambigi <mjambigi@xxxxxxxxxxxxx>
>---
> drivers/s390/net/ism.h | 1 +
> include/net/smc.h | 2 --
> net/smc/smc_ism.c | 14 +++++---------
> net/smc/smc_ism.h | 3 ++-
> 4 files changed, 8 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/s390/net/ism.h b/drivers/s390/net/ism.h
>index 047fa6101555..b5b03db52fce 100644
>--- a/drivers/s390/net/ism.h
>+++ b/drivers/s390/net/ism.h
>@@ -10,6 +10,7 @@
> #include <asm/pci_insn.h>
>
> #define UTIL_STR_LEN 16
>+#define ISM_ERROR 0xFFFF
>
> /*
> * Do not use the first word of the DMB bits to ensure 8 byte aligned access.
>diff --git a/include/net/smc.h b/include/net/smc.h
>index db84e4e35080..a9c023dd1380 100644
>--- a/include/net/smc.h
>+++ b/include/net/smc.h
>@@ -44,8 +44,6 @@ struct smcd_dmb {
>
> #define ISM_RESERVED_VLANID 0x1FFF
>
>-#define ISM_ERROR 0xFFFF
>-
> struct smcd_dev;
>
> struct smcd_gid {
>diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
>index 84f98e18c7db..a94e1450d095 100644
>--- a/net/smc/smc_ism.c
>+++ b/net/smc/smc_ism.c
>@@ -205,13 +205,13 @@ int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
> return rc;
> }
>
>-int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
>+void smc_ism_unregister_dmb(struct smcd_dev *smcd,
>+ struct smc_buf_desc *dmb_desc)
> {
> struct smcd_dmb dmb;
>- int rc = 0;
>
> if (!dmb_desc->dma_addr)
>- return rc;
>+ return;
>
> memset(&dmb, 0, sizeof(dmb));
> dmb.dmb_tok = dmb_desc->token;
>@@ -219,13 +219,9 @@ int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
> dmb.cpu_addr = dmb_desc->cpu_addr;
> dmb.dma_addr = dmb_desc->dma_addr;
> dmb.dmb_len = dmb_desc->len;
>- rc = smcd->ops->unregister_dmb(smcd, &dmb);
>- if (!rc || rc == ISM_ERROR) {
>- dmb_desc->cpu_addr = NULL;
>- dmb_desc->dma_addr = 0;
>- }
>+ smcd->ops->unregister_dmb(smcd, &dmb);
Hmm, I think the old way of handling error here is certainly not good.
But completely ignoring error handling here would make bugs harder
to detect.
What about adding a WARN_ON_ONCE(rc) ?
Also, I think we can just remove the rc == ISM_ERROR to remove
the dependency of ISM_ERROR in smc.
Best regards,
Dust
