Date: Sun, 21 Aug 2005 17:13:32 GMT From: Scott Long <scottl@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 82377 for review Message-ID: <200508211713.j7LHDWnZ056624@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=82377 Change 82377 by scottl@scottl-junior on 2005/08/21 17:13:18 Introduce the topology lock. It covers the reference counting of path components so that peripherals and sims can use path objects without having to lock them. Affected files ... .. //depot/projects/scottl-camlock/src/sys/cam/cam_xpt.c#16 edit Differences ... ==== //depot/projects/scottl-camlock/src/sys/cam/cam_xpt.c#16 (text+ko) ==== @@ -619,6 +619,7 @@ typedef TAILQ_HEAD(cam_isrq, ccb_hdr) cam_isrq_t; static cam_isrq_t cam_bioq; static struct mtx cam_bioq_lock; +static struct mtx cam_topo_lock; /* "Pool" of inactive ccbs managed by xpt_alloc_ccb and xpt_free_ccb */ static SLIST_HEAD(,ccb_hdr) ccb_freeq; @@ -1390,6 +1391,7 @@ STAILQ_INIT(&highpowerq); mtx_init(&cam_bioq_lock, "CAM BIOQ lock", NULL, MTX_DEF); + mtx_init(&cam_topo_lock, "XPT Topology lock", NULL, MTX_DEF); /* * The xpt layer is, itself, the equivelent of a SIM. @@ -3301,7 +3303,6 @@ } case XPT_DEV_MATCH: { - int s; dev_pos_type position_type; struct ccb_dev_match *cdm; @@ -3310,7 +3311,7 @@ /* * Prevent EDT changes while we traverse it. */ - s = splcam(); + mtx_lock(&cam_topo_lock); /* * There are two ways of getting at information in the EDT. * The first way is via the primary EDT tree. It starts @@ -3358,7 +3359,7 @@ break; } - splx(s); + mtx_unlock(&cam_topo_lock); if (cdm->status == CAM_DEV_MATCH_ERROR) start_ccb->ccb_h.status = CAM_REQ_CMP_ERR; @@ -3421,6 +3422,7 @@ csa->ccb_h.path->device->refcount++; } + mtx_lock(&cam_topo_lock); if ((added & AC_FOUND_DEVICE) != 0) { /* * Get this peripheral up to date with all @@ -3435,6 +3437,7 @@ */ xpt_for_all_busses(xptsetasyncbusfunc, cur_entry); } + mtx_unlock(&cam_topo_lock); splx(s); start_ccb->ccb_h.status = CAM_REQ_CMP; break; @@ -3969,7 +3972,6 @@ void xpt_merge_ccb(union ccb *master_ccb, union ccb *slave_ccb) { - GIANT_REQUIRED; /* * Pull fields that are valid for peripheral drivers to set @@ -3986,7 +3988,6 @@ void xpt_setup_ccb(struct ccb_hdr *ccb_h, struct cam_path *path, u_int32_t priority) { - GIANT_REQUIRED; CAM_DEBUG(path, CAM_DEBUG_TRACE, ("xpt_setup_ccb\n")); ccb_h->pinfo.priority = priority; @@ -3998,7 +3999,7 @@ ccb_h->target_id = CAM_TARGET_WILDCARD; if (path->device) { ccb_h->target_lun = path->device->lun_id; - ccb_h->pinfo.generation = ++path->device->ccbq.queue.generation; + atomic_add_int(&ccb_h->pinfo.generation, 1); } else { ccb_h->target_lun = CAM_TARGET_WILDCARD; } @@ -4014,8 +4015,6 @@ struct cam_path *path; cam_status status; - GIANT_REQUIRED; - path = (struct cam_path *)malloc(sizeof(*path), M_CAMXPT, M_NOWAIT); if (path == NULL) { @@ -4032,6 +4031,33 @@ } static cam_status +xpt_clone_path(struct cam_path *old_path_ptr, struct cam_path **new_path_ptr) +{ + struct cam_path *path; + + path = (struct cam_path *)malloc(sizeof(*path), M_CAMXPT, M_NOWAIT); + + if (path == NULL) + return (CAM_RESRC_UNAVAIL); + + mtx_lock(&cam_topo_lock); + path->periph = old_path_ptr->periph; + path->bus = old_path_ptr->bus; + path->target = old_path_ptr->target; + path->device = old_path_ptr->device; + if (path->bus != NULL) + path->bus->refcount++; + if (path->target != NULL) + path->target->refcount++; + if (path->device != NULL) + path->device->refcount++; + mtx_unlock(&cam_topo_lock); + + *new_path_ptr = path; + return (CAM_REQ_CMP); +} + +static cam_status xpt_compile_path(struct cam_path *new_path, struct cam_periph *perph, path_id_t path_id, target_id_t target_id, lun_id_t lun_id) { @@ -4039,7 +4065,6 @@ struct cam_et *target; struct cam_ed *device; cam_status status; - int s; status = CAM_REQ_CMP; /* Completed without error */ target = NULL; /* Wildcarded */ @@ -4049,7 +4074,7 @@ * We will potentially modify the EDT, so block interrupts * that may attempt to create cam paths. */ - s = splcam(); + mtx_lock(&cam_topo_lock); bus = xpt_find_bus(path_id); if (bus == NULL) { status = CAM_PATH_INVALID; @@ -4083,7 +4108,7 @@ } } } - splx(s); + mtx_unlock(&cam_topo_lock); /* * Only touch the user's data if we are successful. @@ -4095,12 +4120,14 @@ new_path->device = device; CAM_DEBUG(new_path, CAM_DEBUG_TRACE, ("xpt_compile_path\n")); } else { + mtx_lock(&cam_topo_lock); if (device != NULL) xpt_release_device(bus, target, device); if (target != NULL) xpt_release_target(bus, target); if (bus != NULL) xpt_release_bus(bus); + mtx_unlock(&cam_topo_lock); } return (status); } @@ -4109,6 +4136,8 @@ xpt_release_path(struct cam_path *path) { CAM_DEBUG(path, CAM_DEBUG_TRACE, ("xpt_release_path\n")); + + mtx_lock(&cam_topo_lock); if (path->device != NULL) { xpt_release_device(path->bus, path->target, path->device); path->device = NULL; @@ -4121,12 +4150,12 @@ xpt_release_bus(path->bus); path->bus = NULL; } + mtx_unlock(&cam_topo_lock); } void xpt_free_path(struct cam_path *path) { - GIANT_REQUIRED; CAM_DEBUG(path, CAM_DEBUG_TRACE, ("xpt_free_path\n")); xpt_release_path(path); @@ -4141,7 +4170,6 @@ int xpt_path_comp(struct cam_path *path1, struct cam_path *path2) { - GIANT_REQUIRED; int retval = 0; @@ -4177,7 +4205,6 @@ void xpt_print_path(struct cam_path *path) { - GIANT_REQUIRED; if (path == NULL) printf("(nopath): "); @@ -4212,8 +4239,6 @@ { struct sbuf sb; - GIANT_REQUIRED; - sbuf_new(&sb, str, str_len, 0); if (path == NULL) @@ -4250,7 +4275,6 @@ path_id_t xpt_path_path_id(struct cam_path *path) { - GIANT_REQUIRED; return(path->bus->path_id); } @@ -4258,7 +4282,6 @@ target_id_t xpt_path_target_id(struct cam_path *path) { - GIANT_REQUIRED; if (path->target != NULL) return (path->target->target_id); @@ -4269,7 +4292,6 @@ lun_id_t xpt_path_lun_id(struct cam_path *path) { - GIANT_REQUIRED; if (path->device != NULL) return (path->device->lun_id); @@ -4280,7 +4302,6 @@ struct cam_sim * xpt_path_sim(struct cam_path *path) { - GIANT_REQUIRED; return (path->bus->sim); } @@ -4288,7 +4309,6 @@ struct cam_periph* xpt_path_periph(struct cam_path *path) { - GIANT_REQUIRED; return (path->periph); } @@ -4419,7 +4439,9 @@ xpt_async(AC_PATH_DEREGISTERED, &bus_path, NULL); /* Release the reference count held while registered. */ + mtx_lock(&cam_topo_lock); xpt_release_bus(bus_path.bus); + mtx_unlock(&cam_topo_lock); xpt_release_path(&bus_path); return (CAM_REQ_CMP); @@ -4499,8 +4521,9 @@ } void -xpt_async(u_int32_t async_code, struct cam_path *path, void *async_arg) +xpt_async(u_int32_t async_code, struct cam_path *opath, void *async_arg) { + struct cam_path *path; struct cam_eb *bus; struct cam_et *target, *next_target; struct cam_ed *device, *next_device; @@ -4511,6 +4534,13 @@ CAM_DEBUG(path, CAM_DEBUG_TRACE, ("xpt_async\n")); /* + * The caller owns the path object that was passed in. Clone + * it so that we don't risk having it disappear on us. + */ + if (xpt_clone_path(opath, &path) != CAM_REQ_CMP) + return; + + /* * Most async events come from a CAM interrupt context. In * a few cases, the error recovery code at the peripheral layer, * which may run from our SWI or a process context, may signal @@ -4577,6 +4607,7 @@ xpt_async_bcast(&xpt_periph->path->device->asyncs, async_code, path, async_arg); splx(s); + xpt_free_path(path); } static void @@ -4808,6 +4839,7 @@ sim->c_handle); sim->flags &= ~CAM_SIM_REL_TIMEOUT_PENDING; } + mtx_lock(&cam_topo_lock); bus = xpt_find_bus(sim->path_id); splx(s); @@ -4815,9 +4847,12 @@ /* * Now that we are unfrozen run the send queue. */ + mtx_unlock(&cam_topo_lock); xpt_run_dev_sendq(bus); + mtx_lock(&cam_topo_lock); } xpt_release_bus(bus); + mtx_unlock(&cam_topo_lock); } else splx(s); } else @@ -4868,8 +4903,6 @@ { union ccb *new_ccb; - GIANT_REQUIRED; - new_ccb = malloc(sizeof(*new_ccb), M_CAMXPT, M_WAITOK); return (new_ccb); } @@ -4879,8 +4912,6 @@ { union ccb *new_ccb; - GIANT_REQUIRED; - new_ccb = malloc(sizeof(*new_ccb), M_CAMXPT, M_NOWAIT); return (new_ccb); } @@ -4929,17 +4960,14 @@ static void xpt_release_bus(struct cam_eb *bus) { - int s; - s = splcam(); + mtx_assert(&cam_topo_lock, MA_OWNED); if ((--bus->refcount == 0) && (TAILQ_FIRST(&bus->et_entries) == NULL)) { TAILQ_REMOVE(&xpt_busses, bus, links); bus_generation++; - splx(s); free(bus, M_CAMXPT); - } else - splx(s); + } } static struct cam_et * @@ -4947,6 +4975,7 @@ { struct cam_et *target; + mtx_assert(&cam_topo_lock, MA_OWNED); target = (struct cam_et *)malloc(sizeof(*target), M_CAMXPT, M_NOWAIT); if (target != NULL) { struct cam_et *cur_target; @@ -4981,18 +5010,15 @@ static void xpt_release_target(struct cam_eb *bus, struct cam_et *target) { - int s; - s = splcam(); + mtx_assert(&cam_topo_lock, MA_OWNED); if ((--target->refcount == 0) && (TAILQ_FIRST(&target->ed_entries) == NULL)) { TAILQ_REMOVE(&bus->et_entries, target, links); bus->generation++; - splx(s); free(target, M_CAMXPT); xpt_release_bus(bus); - } else - splx(s); + } } static struct cam_ed * @@ -5005,6 +5031,7 @@ struct cam_devq *devq; cam_status status; + mtx_assert(&cam_topo_lock, MA_OWNED); /* Make space for us in the device queue on our bus */ devq = bus->sim->devq; status = cam_devq_resize(devq, devq->alloc_queue.array_size + 1); @@ -5097,9 +5124,8 @@ xpt_release_device(struct cam_eb *bus, struct cam_et *target, struct cam_ed *device) { - int s; - s = splcam(); + mtx_assert(&cam_topo_lock, MA_OWNED); if ((--device->refcount == 0) && ((device->flags & CAM_DEV_UNCONFIGURED) != 0)) { struct cam_devq *devq; @@ -5118,13 +5144,11 @@ /* Release our slot in the devq */ devq = bus->sim->devq; cam_devq_resize(devq, devq->alloc_queue.array_size - 1); - splx(s); camq_fini(&device->drvq); camq_fini(&device->ccbq.queue); free(device, M_CAMXPT); xpt_release_target(bus, target); - } else - splx(s); + } } static u_int32_t @@ -5157,6 +5181,7 @@ { struct cam_eb *bus; + mtx_assert(&cam_topo_lock, MA_OWNED); for (bus = TAILQ_FIRST(&xpt_busses); bus != NULL; bus = TAILQ_NEXT(bus, links)) { @@ -5173,6 +5198,7 @@ { struct cam_et *target; + mtx_assert(&cam_topo_lock, MA_OWNED); for (target = TAILQ_FIRST(&bus->et_entries); target != NULL; target = TAILQ_NEXT(target, links)) { @@ -5189,6 +5215,7 @@ { struct cam_ed *device; + mtx_assert(&cam_topo_lock, MA_OWNED); for (device = TAILQ_FIRST(&target->ed_entries); device != NULL; device = TAILQ_NEXT(device, links)) { @@ -6861,10 +6888,12 @@ /* * Scan all installed busses. */ + mtx_lock(&cam_topo_lock); xpt_for_all_busses(xptconfigbuscountfunc, NULL); if (busses_to_config == 0) { /* Call manually because we don't have any busses */ + mtx_unlock(&cam_topo_lock); xpt_finishconfig(xpt_periph, NULL); } else { if (busses_to_reset > 0 && scsi_delay >= 2000) { @@ -6872,6 +6901,7 @@ "devices to settle\n", scsi_delay/1000); } xpt_for_all_busses(xptconfigfunc, NULL); + mtx_unlock(&cam_topo_lock); } } @@ -6937,7 +6967,9 @@ * attached. For any devices like that, announce the * passthrough driver so the user will see something. */ + mtx_lock(&cam_topo_lock); xpt_for_all_devices(xptpassannouncefunc, NULL); + mtx_unlock(&cam_topo_lock); /* Release our hook so that the boot can continue. */ config_intrhook_disestablish(xpt_config_hook);
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