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Copy and clear the reply descriptor atomically. This prevents concurrency

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in the interrupt handlers (usually due to timeout/error recovery) from
seeing and processing the same descriptor twice.
This commit is contained in:
Scott Long 2018-12-09 06:10:11 +00:00
parent 44f299a3cc
commit 617e85f387
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=341755
2 changed files with 32 additions and 13 deletions
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22
sys/dev/mpr/mpr.c
View File

@ -2493,12 +2493,13 @@ void
mpr_intr_locked(void *data)
{
MPI2_REPLY_DESCRIPTORS_UNION *desc;
MPI2_DIAG_RELEASE_REPLY *rel_rep;
mpr_fw_diagnostic_buffer_t *pBuffer;
struct mpr_softc *sc;
uint64_t tdesc;
struct mpr_command *cm = NULL;
uint8_t flags;
u_int pq;
MPI2_DIAG_RELEASE_REPLY *rel_rep;
mpr_fw_diagnostic_buffer_t *pBuffer;
sc = (struct mpr_softc *)data;
@ -2510,6 +2511,17 @@ mpr_intr_locked(void *data)
for ( ;; ) {
cm = NULL;
desc = &sc->post_queue[sc->replypostindex];
/*
* Copy and clear out the descriptor so that any reentry will
* immediately know that this descriptor has already been
* looked at. There is unfortunate casting magic because the
* MPI API doesn't have a cardinal 64bit type.
*/
tdesc = 0xffffffffffffffff;
tdesc = atomic_swap_64((uint64_t *)desc, tdesc);
desc = (MPI2_REPLY_DESCRIPTORS_UNION *)&tdesc;
flags = desc->Default.ReplyFlags &
MPI2_RPY_DESCRIPT_FLAGS_TYPE_MASK;
if ((flags == MPI2_RPY_DESCRIPT_FLAGS_UNUSED) ||
@ -2604,7 +2616,8 @@ mpr_intr_locked(void *data)
cm = &sc->commands[
le16toh(desc->AddressReply.SMID)];
KASSERT(cm->cm_state == MPR_CM_STATE_INQUEUE,
("command not inqueue\n"));
("command SMID %d not inqueue\n",
desc->AddressReply.SMID));
cm->cm_state = MPR_CM_STATE_BUSY;
cm->cm_reply = reply;
cm->cm_reply_data =
@ -2630,9 +2643,6 @@ mpr_intr_locked(void *data)
mpr_display_reply_info(sc,cm->cm_reply);
mpr_complete_command(sc, cm);
}
desc->Words.Low = 0xffffffff;
desc->Words.High = 0xffffffff;
}
if (pq != sc->replypostindex) {

23
sys/dev/mps/mps.c
View File

@ -2361,12 +2361,13 @@ void
mps_intr_locked(void *data)
{
MPI2_REPLY_DESCRIPTORS_UNION *desc;
struct mps_softc *sc;
struct mps_command *cm = NULL;
uint8_t flags;
u_int pq;
MPI2_DIAG_RELEASE_REPLY *rel_rep;
mps_fw_diagnostic_buffer_t *pBuffer;
struct mps_softc *sc;
struct mps_command *cm = NULL;
uint64_t tdesc;
uint8_t flags;
u_int pq;
sc = (struct mps_softc *)data;
@ -2378,6 +2379,17 @@ mps_intr_locked(void *data)
for ( ;; ) {
cm = NULL;
desc = &sc->post_queue[sc->replypostindex];
/*
* Copy and clear out the descriptor so that any reentry will
* immediately know that this descriptor has already been
* looked at. There is unfortunate casting magic because the
* MPI API doesn't have a cardinal 64bit type.
*/
tdesc = 0xffffffffffffffff;
tdesc = atomic_swap_64((uint64_t *)desc, tdesc);
desc = (MPI2_REPLY_DESCRIPTORS_UNION *)&tdesc;
flags = desc->Default.ReplyFlags &
MPI2_RPY_DESCRIPT_FLAGS_TYPE_MASK;
if ((flags == MPI2_RPY_DESCRIPT_FLAGS_UNUSED)
@ -2496,9 +2508,6 @@ mps_intr_locked(void *data)
mps_display_reply_info(sc,cm->cm_reply);
mps_complete_command(sc, cm);
}
desc->Words.Low = 0xffffffff;
desc->Words.High = 0xffffffff;
}
if (pq != sc->replypostindex) {