diff options
author | trasz <trasz@FreeBSD.org> | 2008-12-16 16:57:33 +0000 |
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committer | trasz <trasz@FreeBSD.org> | 2008-12-16 16:57:33 +0000 |
commit | 1aa4ea9cfb2dc8da2c82c6b4f27eee1e40c731be (patch) | |
tree | 4b0fd6e2cd5eb30999a8168d4c935eca7d284ac6 /sys/cam | |
parent | ebb77f64c32720fd23b448d19863ad50894b7919 (diff) | |
download | FreeBSD-src-1aa4ea9cfb2dc8da2c82c6b4f27eee1e40c731be.zip FreeBSD-src-1aa4ea9cfb2dc8da2c82c6b4f27eee1e40c731be.tar.gz |
Add SIM refcounting. This is slightly different from what DragonFly
does - in DragonFly, it's cam_sim_release() what actually frees the
SIM; cam_sim_free does nothing more than calling cam_sim_release().
Here, we drain in cam_sim_free, waiting for refcount to drop to zero.
We cannot do the same think DragonFly does, because after cam_sim_free
returns, client would destroy the sim->mtx, and CAM would trip over
an initialized mutex.
Reviewed by: scottl
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation
Diffstat (limited to 'sys/cam')
-rw-r--r-- | sys/cam/cam_sim.c | 29 | ||||
-rw-r--r-- | sys/cam/cam_sim.h | 3 | ||||
-rw-r--r-- | sys/cam/cam_xpt.c | 2 |
3 files changed, 34 insertions, 0 deletions
diff --git a/sys/cam/cam_sim.c b/sys/cam/cam_sim.c index cfc2044..d7fcaad 100644 --- a/sys/cam/cam_sim.c +++ b/sys/cam/cam_sim.c @@ -84,6 +84,7 @@ cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, sim->max_tagged_dev_openings = max_tagged_dev_transactions; sim->max_dev_openings = max_dev_transactions; sim->flags = 0; + sim->refcount = 1; sim->devq = queue; sim->mtx = mtx; if (mtx == &Giant) { @@ -103,12 +104,40 @@ cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, void cam_sim_free(struct cam_sim *sim, int free_devq) { + int error; + + sim->refcount--; + if (sim->refcount > 0) { + error = msleep(sim, sim->mtx, PRIBIO, "simfree", 0); + KASSERT(error == 0, ("invalid error value for msleep(9)")); + } + + KASSERT(sim->refcount == 0, ("sim->refcount == 0")); + if (free_devq) cam_simq_free(sim->devq); free(sim, M_CAMSIM); } void +cam_sim_release(struct cam_sim *sim) +{ + KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); + + sim->refcount--; + if (sim->refcount <= 1) + wakeup(sim); +} + +void +cam_sim_hold(struct cam_sim *sim) +{ + KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); + + sim->refcount++; +} + +void cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) { sim->path_id = path_id; diff --git a/sys/cam/cam_sim.h b/sys/cam/cam_sim.h index c2d3c5f..f37c5d5 100644 --- a/sys/cam/cam_sim.h +++ b/sys/cam/cam_sim.h @@ -61,6 +61,8 @@ struct cam_sim * cam_sim_alloc(sim_action_func sim_action, int max_tagged_dev_transactions, struct cam_devq *queue); void cam_sim_free(struct cam_sim *sim, int free_devq); +void cam_sim_hold(struct cam_sim *sim); +void cam_sim_release(struct cam_sim *sim); /* Optional sim attributes may be set with these. */ void cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id); @@ -105,6 +107,7 @@ struct cam_sim { #define CAM_SIM_ON_DONEQ 0x04 struct callout callout; struct cam_devq *devq; /* Device Queue to use for this SIM */ + int refcount; /* References to the SIM. */ /* "Pool" of inactive ccbs managed by xpt_alloc_ccb and xpt_free_ccb */ SLIST_HEAD(,ccb_hdr) ccb_freeq; diff --git a/sys/cam/cam_xpt.c b/sys/cam/cam_xpt.c index 60bfb99..cf3fa2c 100644 --- a/sys/cam/cam_xpt.c +++ b/sys/cam/cam_xpt.c @@ -4304,6 +4304,7 @@ xpt_bus_register(struct cam_sim *sim, device_t parent, u_int32_t bus) TAILQ_INIT(&new_bus->et_entries); new_bus->path_id = sim->path_id; + cam_sim_hold(sim); new_bus->sim = sim; timevalclear(&new_bus->last_reset); new_bus->flags = 0; @@ -4846,6 +4847,7 @@ xpt_release_bus(struct cam_eb *bus) TAILQ_REMOVE(&xsoftc.xpt_busses, bus, links); xsoftc.bus_generation++; mtx_unlock(&xsoftc.xpt_topo_lock); + cam_sim_release(bus->sim); free(bus, M_CAMXPT); } } |