Author: mav
Date: Thu Nov 17 21:07:56 2011
New Revision: 227637
URL: http://svn.freebsd.org/changeset/base/227637
Log:
Introduce CAM_SIM_POLLED SIM flag, indicating that it works in polling mode.
It blocks CAM SWI usage on requests completion, unneeded because of polling
and denied during kernel dumping because of blocked scheduler.
Before r198899 there was periph flag CAM_PERIPH_POLLED, but that was wrong,
because there is whole SIM is polled or handled by SWI, not a single periph.
Tested by: kib
MFC after: 1 month
Modified:
head/sys/cam/cam_sim.h
head/sys/cam/cam_xpt.c
Modified: head/sys/cam/cam_sim.h
==============================================================================
--- head/sys/cam/cam_sim.h Thu Nov 17 21:06:53 2011 (r227636)
+++ head/sys/cam/cam_sim.h Thu Nov 17 21:07:56 2011 (r227637)
@@ -104,7 +104,8 @@ struct cam_sim {
u_int32_t flags;
#define CAM_SIM_REL_TIMEOUT_PENDING 0x01
#define CAM_SIM_MPSAFE 0x02
-#define CAM_SIM_ON_DONEQ 0x04
+#define CAM_SIM_ON_DONEQ 0x04
+#define CAM_SIM_POLLED 0x08
struct callout callout;
struct cam_devq *devq; /* Device Queue to use for this SIM */
int refcount; /* References to the SIM. */
Modified: head/sys/cam/cam_xpt.c
==============================================================================
--- head/sys/cam/cam_xpt.c Thu Nov 17 21:06:53 2011 (r227636)
+++ head/sys/cam/cam_xpt.c Thu Nov 17 21:07:56 2011 (r227637)
@@ -2957,6 +2957,9 @@ xpt_polled_action(union ccb *start_ccb)
mtx_assert(sim->mtx, MA_OWNED);
+ /* Don't use ISR for this SIM while polling. */
+ sim->flags |= CAM_SIM_POLLED;
+
/*
* Steal an opening so that no other queued requests
* can get it before us while we simulate interrupts.
@@ -2996,6 +2999,9 @@ xpt_polled_action(union ccb *start_ccb)
} else {
start_ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
}
+
+ /* We will use CAM ISR for this SIM again. */
+ sim->flags &= ~CAM_SIM_POLLED;
}
/*
@@ -4224,7 +4230,7 @@ xpt_done(union ccb *done_ccb)
TAILQ_INSERT_TAIL(&sim->sim_doneq, &done_ccb->ccb_h,
sim_links.tqe);
done_ccb->ccb_h.pinfo.index = CAM_DONEQ_INDEX;
- if ((sim->flags & CAM_SIM_ON_DONEQ) == 0) {
+ if ((sim->flags & (CAM_SIM_ON_DONEQ | CAM_SIM_POLLED)) == 0) {
mtx_lock(&cam_simq_lock);
first = TAILQ_EMPTY(&cam_simq);
TAILQ_INSERT_TAIL(&cam_simq, sim, links);
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