Re: [PATCH 1/1] mpi3mr: Fix compilation errors observed on i386 arch

Guenter Roeck <linux@xxxxxxxxxxxx> · Sat, 16 Jul 2022 07:03:44 -0700

On 7/16/22 06:35, Sreekanth Reddy wrote:
Hi Guenter,

Please check the changes below. I hope this change will work with
32-bit pointers as well.  If it looks good then I will post this
change as a patch.

diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 0901bc932d5c..0bba19c0f984 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -386,7 +386,7 @@ static void mpi3mr_queue_qd_reduction_event(struct
mpi3mr_ioc *mrioc,
                 ioc_warn(mrioc, "failed to queue TG QD reduction event\n");
                 return;
         }
-       *(__le64 *)fwevt->event_data = (__le64)tg;
+       memcpy(fwevt->event_data, (char *)&tg, sizeof(void *)); >          fwevt->mrioc = mrioc;
         fwevt->event_id = MPI3MR_DRIVER_EVENT_TG_QD_REDUCTION;
         fwevt->send_ack = 0;
@@ -1660,8 +1660,7 @@ static void mpi3mr_fwevt_bh(struct mpi3mr_ioc *mrioc,
         {
                 struct mpi3mr_throttle_group_info *tg;

-               tg = (struct mpi3mr_throttle_group_info *)
-                   (*(__le64 *)fwevt->event_data);
+               memcpy((char *)&tg, fwevt->event_data, sizeof(void *));
                 dprint_event_bh(mrioc,
                     "qd reduction event processed for tg_id(%d)
reduction_needed(%d)\n",
                     tg->id, tg->need_qd_reduction);


If I understand correctly, you want to pass the pointer to tg along. If so,
the following seems cleaner and less confusing to me.

diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 6a47f8c77256..f581c07c2665 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -386,7 +386,7 @@ static void mpi3mr_queue_qd_reduction_event(struct mpi3mr_ioc *mrioc,
                ioc_warn(mrioc, "failed to queue TG QD reduction event\n");
                return;
        }
-       *(__le64 *)fwevt->event_data = (__le64)tg;
+       *(struct mpi3mr_throttle_group_info **)fwevt->event_data = tg;
        fwevt->mrioc = mrioc;
        fwevt->event_id = MPI3MR_DRIVER_EVENT_TG_QD_REDUCTION;
        fwevt->send_ack = 0;
@@ -1652,8 +1652,7 @@ static void mpi3mr_fwevt_bh(struct mpi3mr_ioc *mrioc,
        {
                struct mpi3mr_throttle_group_info *tg;

-               tg = (struct mpi3mr_throttle_group_info *)
-                   (*(__le64 *)fwevt->event_data);
+               tg = *(struct mpi3mr_throttle_group_info **)fwevt->event_data;
                dprint_event_bh(mrioc,
                    "qd reduction event processed for tg_id(%d) reduction_needed(%d)\n",
                    tg->id, tg->need_qd_reduction);

or simply

diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 6a47f8c77256..cc93b41dd428 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -386,7 +386,7 @@ static void mpi3mr_queue_qd_reduction_event(struct mpi3mr_ioc *mrioc,
                ioc_warn(mrioc, "failed to queue TG QD reduction event\n");
                return;
        }
-       *(__le64 *)fwevt->event_data = (__le64)tg;
+       *(void **)fwevt->event_data = tg;
        fwevt->mrioc = mrioc;
        fwevt->event_id = MPI3MR_DRIVER_EVENT_TG_QD_REDUCTION;
        fwevt->send_ack = 0;
@@ -1652,8 +1652,7 @@ static void mpi3mr_fwevt_bh(struct mpi3mr_ioc *mrioc,
        {
                struct mpi3mr_throttle_group_info *tg;

-               tg = (struct mpi3mr_throttle_group_info *)
-                   (*(__le64 *)fwevt->event_data);
+               tg = *(void **)fwevt->event_data;
                dprint_event_bh(mrioc,
                    "qd reduction event processed for tg_id(%d) reduction_needed(%d)\n",
                    tg->id, tg->need_qd_reduction);

Thanks,
Guenter

Thanks,
Sreekanth

On Fri, Jul 15, 2022 at 10:19 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:

On 7/15/22 08:02, Sreekanth Reddy wrote:
Fix below compilation errors observed on i386 ARCH,

cast from pointer to integer of different size
[-Werror=pointer-to-int-cast]

Fixes: c196bc4dce ("scsi: mpi3mr: Reduce VD queue depth on detecting throttling")
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx>
---
   drivers/scsi/mpi3mr/mpi3mr_os.c | 5 ++---
   1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 0901bc932d5c..d8013576d863 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -386,7 +386,7 @@ static void mpi3mr_queue_qd_reduction_event(struct mpi3mr_ioc *mrioc,
               ioc_warn(mrioc, "failed to queue TG QD reduction event\n");
               return;
       }
-     *(__le64 *)fwevt->event_data = (__le64)tg;
+     memcpy(fwevt->event_data, (char *)&tg, sizeof(u64));
       fwevt->mrioc = mrioc;
       fwevt->event_id = MPI3MR_DRIVER_EVENT_TG_QD_REDUCTION;
       fwevt->send_ack = 0;
@@ -1660,8 +1660,7 @@ static void mpi3mr_fwevt_bh(struct mpi3mr_ioc *mrioc,
       {
               struct mpi3mr_throttle_group_info *tg;

-             tg = (struct mpi3mr_throttle_group_info *)
-                 (*(__le64 *)fwevt->event_data);
+             memcpy((char *)&tg, fwevt->event_data, sizeof(u64));

How is this expected to work on a system with 32-bit pointers ?

Guenter

               dprint_event_bh(mrioc,
                   "qd reduction event processed for tg_id(%d) reduction_needed(%d)\n",
                   tg->id, tg->need_qd_reduction);








