Author: mav
Date: Tue Mar 21 09:12:41 2017
New Revision: 315673
URL: https://svnweb.freebsd.org/changeset/base/315673
Log:
Make CAM SIM lock optional.
For three years now CAM does not use SIM lock, but still enforces SIM to
use it. Remove this requirement, allowing SIMs to have any locking they
prefer, if they pass no mutex to cam_sim_alloc().
MFC after: 2 weeks
Modified:
head/sys/cam/cam_sim.c
head/sys/cam/cam_xpt.c
head/sys/sys/param.h
Modified: head/sys/cam/cam_sim.c
==============================================================================
--- head/sys/cam/cam_sim.c Tue Mar 21 09:07:05 2017 (r315672)
+++ head/sys/cam/cam_sim.c Tue Mar 21 09:12:41 2017 (r315673)
@@ -46,6 +46,9 @@ __FBSDID("$FreeBSD$");
static MALLOC_DEFINE(M_CAMSIM, "CAM SIM", "CAM SIM buffers");
+static struct mtx cam_sim_free_mtx;
+MTX_SYSINIT(cam_sim_free_init, &cam_sim_free_mtx, "CAM SIM free lock",
MTX_DEF);
+
struct cam_devq *
cam_simq_alloc(u_int32_t max_sim_transactions)
{
@@ -66,9 +69,6 @@ cam_sim_alloc(sim_action_func sim_action
{
struct cam_sim *sim;
- if (mtx == NULL)
- return (NULL);
-
sim = (struct cam_sim *)malloc(sizeof(struct cam_sim),
M_CAMSIM, M_ZERO | M_NOWAIT);
@@ -101,16 +101,23 @@ cam_sim_alloc(sim_action_func sim_action
void
cam_sim_free(struct cam_sim *sim, int free_devq)
{
+ struct mtx *mtx = sim->mtx;
int error;
- mtx_assert(sim->mtx, MA_OWNED);
+ if (mtx) {
+ mtx_assert(mtx, MA_OWNED);
+ } else {
+ mtx = &cam_sim_free_mtx;
+ mtx_lock(mtx);
+ }
sim->refcount--;
if (sim->refcount > 0) {
- error = msleep(sim, sim->mtx, PRIBIO, "simfree", 0);
+ error = msleep(sim, mtx, PRIBIO, "simfree", 0);
KASSERT(error == 0, ("invalid error value for msleep(9)"));
}
-
KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
+ if (sim->mtx == NULL)
+ mtx_unlock(mtx);
if (free_devq)
cam_simq_free(sim->devq);
@@ -120,31 +127,43 @@ cam_sim_free(struct cam_sim *sim, int fr
void
cam_sim_release(struct cam_sim *sim)
{
- int lock;
+ struct mtx *mtx = sim->mtx;
- lock = (mtx_owned(sim->mtx) == 0);
- if (lock)
- CAM_SIM_LOCK(sim);
+ if (mtx) {
+ if (!mtx_owned(mtx))
+ mtx_lock(mtx);
+ else
+ mtx = NULL;
+ } else {
+ mtx = &cam_sim_free_mtx;
+ mtx_lock(mtx);
+ }
KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
sim->refcount--;
if (sim->refcount == 0)
wakeup(sim);
- if (lock)
- CAM_SIM_UNLOCK(sim);
+ if (mtx)
+ mtx_unlock(mtx);
}
void
cam_sim_hold(struct cam_sim *sim)
{
- int lock;
+ struct mtx *mtx = sim->mtx;
- lock = (mtx_owned(sim->mtx) == 0);
- if (lock)
- CAM_SIM_LOCK(sim);
+ if (mtx) {
+ if (!mtx_owned(mtx))
+ mtx_lock(mtx);
+ else
+ mtx = NULL;
+ } else {
+ mtx = &cam_sim_free_mtx;
+ mtx_lock(mtx);
+ }
KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
sim->refcount++;
- if (lock)
- CAM_SIM_UNLOCK(sim);
+ if (mtx)
+ mtx_unlock(mtx);
}
void
Modified: head/sys/cam/cam_xpt.c
==============================================================================
--- head/sys/cam/cam_xpt.c Tue Mar 21 09:07:05 2017 (r315672)
+++ head/sys/cam/cam_xpt.c Tue Mar 21 09:12:41 2017 (r315673)
@@ -2523,7 +2523,7 @@ xpt_action_default(union ccb *start_ccb)
{
struct cam_path *path;
struct cam_sim *sim;
- int lock;
+ struct mtx *mtx;
path = start_ccb->ccb_h.path;
CAM_DEBUG(path, CAM_DEBUG_TRACE,
@@ -2681,16 +2681,18 @@ xpt_action_default(union ccb *start_ccb)
case XPT_PATH_INQ:
call_sim:
sim = path->bus->sim;
- lock = (mtx_owned(sim->mtx) == 0);
- if (lock)
- CAM_SIM_LOCK(sim);
+ mtx = sim->mtx;
+ if (mtx && !mtx_owned(mtx))
+ mtx_lock(mtx);
+ else
+ mtx = NULL;
CAM_DEBUG(path, CAM_DEBUG_TRACE,
("sim->sim_action: func=%#x\n",
start_ccb->ccb_h.func_code));
(*(sim->sim_action))(sim, start_ccb);
CAM_DEBUG(path, CAM_DEBUG_TRACE,
("sim->sim_action: status=%#x\n", start_ccb->ccb_h.status));
- if (lock)
- CAM_SIM_UNLOCK(sim);
+ if (mtx)
+ mtx_unlock(mtx);
break;
case XPT_PATH_STATS:
start_ccb->cpis.last_reset = path->bus->last_reset;
@@ -2914,8 +2916,8 @@ call_sim:
break;
}
cur_entry->event_enable = csa->event_enable;
- cur_entry->event_lock =
- mtx_owned(path->bus->sim->mtx) ? 1 : 0;
+ cur_entry->event_lock = (path->bus->sim->mtx &&
+ mtx_owned(path->bus->sim->mtx)) ? 1 : 0;
cur_entry->callback_arg = csa->callback_arg;
cur_entry->callback = csa->callback;
SLIST_INSERT_HEAD(async_head, cur_entry, links);
@@ -3082,10 +3084,12 @@ xpt_polled_action(union ccb *start_ccb)
struct cam_sim *sim;
struct cam_devq *devq;
struct cam_ed *dev;
+ struct mtx *mtx;
timeout = start_ccb->ccb_h.timeout * 10;
sim = start_ccb->ccb_h.path->bus->sim;
devq = sim->devq;
+ mtx = sim->mtx;
dev = start_ccb->ccb_h.path->device;
mtx_unlock(&dev->device_mtx);
@@ -3100,9 +3104,11 @@ xpt_polled_action(union ccb *start_ccb)
(--timeout > 0)) {
mtx_unlock(&devq->send_mtx);
DELAY(100);
- CAM_SIM_LOCK(sim);
+ if (mtx)
+ mtx_lock(mtx);
(*(sim->sim_poll))(sim);
- CAM_SIM_UNLOCK(sim);
+ if (mtx)
+ mtx_unlock(mtx);
camisr_runqueue();
mtx_lock(&devq->send_mtx);
}
@@ -3112,9 +3118,11 @@ xpt_polled_action(union ccb *start_ccb)
if (timeout != 0) {
xpt_action(start_ccb);
while(--timeout > 0) {
- CAM_SIM_LOCK(sim);
+ if (mtx)
+ mtx_lock(mtx);
(*(sim->sim_poll))(sim);
- CAM_SIM_UNLOCK(sim);
+ if (mtx)
+ mtx_unlock(mtx);
camisr_runqueue();
if ((start_ccb->ccb_h.status & CAM_STATUS_MASK)
!= CAM_REQ_INPROG)
@@ -3271,7 +3279,7 @@ restart:
static void
xpt_run_devq(struct cam_devq *devq)
{
- int lock;
+ struct mtx *mtx;
CAM_DEBUG_PRINT(CAM_DEBUG_XPT, ("xpt_run_devq\n"));
@@ -3361,13 +3369,15 @@ xpt_run_devq(struct cam_devq *devq)
* queued device, rather than the one from the calling bus.
*/
sim = device->sim;
- lock = (mtx_owned(sim->mtx) == 0);
- if (lock)
- CAM_SIM_LOCK(sim);
+ mtx = sim->mtx;
+ if (mtx && !mtx_owned(mtx))
+ mtx_lock(mtx);
+ else
+ mtx = NULL;
work_ccb->ccb_h.qos.sim_data = sbinuptime(); // xxx uintprt_t
too small 32bit platforms
(*(sim->sim_action))(sim, work_ccb);
- if (lock)
- CAM_SIM_UNLOCK(sim);
+ if (mtx)
+ mtx_unlock(mtx);
mtx_lock(&devq->send_mtx);
}
devq->send_queue.qfrozen_cnt--;
@@ -3878,8 +3888,6 @@ xpt_bus_register(struct cam_sim *sim, de
struct cam_path *path;
cam_status status;
- mtx_assert(sim->mtx, MA_OWNED);
-
sim->bus_id = bus;
new_bus = (struct cam_eb *)malloc(sizeof(*new_bus),
M_CAMXPT, M_NOWAIT|M_ZERO);
Modified: head/sys/sys/param.h
==============================================================================
--- head/sys/sys/param.h Tue Mar 21 09:07:05 2017 (r315672)
+++ head/sys/sys/param.h Tue Mar 21 09:12:41 2017 (r315673)
@@ -58,7 +58,7 @@
* in the range 5 to 9.
*/
#undef __FreeBSD_version
-#define __FreeBSD_version 1200026 /* Master, propagated to newvers */
+#define __FreeBSD_version 1200027 /* Master, propagated to newvers */
/*
* __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
