From: David S. Miller Date: Mon, 16 Jul 2007 23:50:36 +0000 (-0700) Subject: [SPARC64]: Fix race between MD update and dr-cpu add. X-Git-Tag: v2.6.23-rc1~769^2~1 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=778feeb4757daef5d7118feab2319142367910dd;p=linux-2.6-omap-h63xx.git [SPARC64]: Fix race between MD update and dr-cpu add. We need to make sure the MD update occurs before we try to process dr-cpu configure requests. MD update and dr-cpu were being processed by seperate threads so that did not happen occaisionally. Fix this by executing all domain services data packets from a single thread, in order. This will help simplify some other things as well. Signed-off-by: David S. Miller --- diff --git a/arch/sparc64/kernel/ds.c b/arch/sparc64/kernel/ds.c index 1c587107cef..ba01533f4e0 100644 --- a/arch/sparc64/kernel/ds.c +++ b/arch/sparc64/kernel/ds.c @@ -228,7 +228,7 @@ static struct ds_cap_state *find_cap_by_string(const char *name) return NULL; } -static int ds_send(struct ldc_channel *lp, void *data, int len) +static int __ds_send(struct ldc_channel *lp, void *data, int len) { int err, limit = 1000; @@ -243,6 +243,18 @@ static int ds_send(struct ldc_channel *lp, void *data, int len) return err; } +static int ds_send(struct ldc_channel *lp, void *data, int len) +{ + unsigned long flags; + int err; + + spin_lock_irqsave(&ds_lock, flags); + err = __ds_send(lp, data, len); + spin_unlock_irqrestore(&ds_lock, flags); + + return err; +} + struct ds_md_update_req { __u64 req_num; }; @@ -267,6 +279,8 @@ static void md_update_data(struct ldc_channel *lp, printk(KERN_INFO PFX "Machine description update.\n"); + mdesc_update(); + memset(&pkt, 0, sizeof(pkt)); pkt.data.tag.type = DS_DATA; pkt.data.tag.len = sizeof(pkt) - sizeof(struct ds_msg_tag); @@ -275,8 +289,6 @@ static void md_update_data(struct ldc_channel *lp, pkt.res.result = DS_OK; ds_send(lp, &pkt, sizeof(pkt)); - - mdesc_update(); } struct ds_shutdown_req { @@ -391,18 +403,6 @@ struct dr_cpu_resp_entry { __u32 str_off; }; -/* DR cpu requests get queued onto the work list by the - * dr_cpu_data() callback. The list is protected by - * ds_lock, and processed by dr_cpu_process() in order. - */ -static LIST_HEAD(dr_cpu_work_list); -static DECLARE_WAIT_QUEUE_HEAD(dr_cpu_wait); - -struct dr_cpu_queue_entry { - struct list_head list; - char req[0]; -}; - static void __dr_cpu_send_error(struct ds_cap_state *cp, struct ds_data *data) { struct dr_cpu_tag *tag = (struct dr_cpu_tag *) (data + 1); @@ -425,7 +425,7 @@ static void __dr_cpu_send_error(struct ds_cap_state *cp, struct ds_data *data) pkt.data.tag.len = msg_len - sizeof(struct ds_msg_tag); - ds_send(dp->lp, &pkt, msg_len); + __ds_send(dp->lp, &pkt, msg_len); } static void dr_cpu_send_error(struct ds_cap_state *cp, struct ds_data *data) @@ -555,7 +555,7 @@ static int dr_cpu_configure(struct ds_cap_state *cp, u64 req_num, } spin_lock_irqsave(&ds_lock, flags); - ds_send(ds_info->lp, resp, resp_len); + __ds_send(ds_info->lp, resp, resp_len); spin_unlock_irqrestore(&ds_lock, flags); kfree(resp); @@ -596,7 +596,7 @@ static int dr_cpu_unconfigure(struct ds_cap_state *cp, u64 req_num, } spin_lock_irqsave(&ds_lock, flags); - ds_send(ds_info->lp, resp, resp_len); + __ds_send(ds_info->lp, resp, resp_len); spin_unlock_irqrestore(&ds_lock, flags); kfree(resp); @@ -604,107 +604,49 @@ static int dr_cpu_unconfigure(struct ds_cap_state *cp, u64 req_num, return 0; } -static void process_dr_cpu_list(struct ds_cap_state *cp) +static void dr_cpu_data(struct ldc_channel *lp, + struct ds_cap_state *cp, + void *buf, int len) { - struct dr_cpu_queue_entry *qp, *tmp; - unsigned long flags; - LIST_HEAD(todo); + struct ds_data *data = buf; + struct dr_cpu_tag *tag = (struct dr_cpu_tag *) (data + 1); + u32 *cpu_list = (u32 *) (tag + 1); + u64 req_num = tag->req_num; cpumask_t mask; + unsigned int i; + int err; - spin_lock_irqsave(&ds_lock, flags); - list_splice(&dr_cpu_work_list, &todo); - INIT_LIST_HEAD(&dr_cpu_work_list); - spin_unlock_irqrestore(&ds_lock, flags); - - list_for_each_entry_safe(qp, tmp, &todo, list) { - struct ds_data *data = (struct ds_data *) qp->req; - struct dr_cpu_tag *tag = (struct dr_cpu_tag *) (data + 1); - u32 *cpu_list = (u32 *) (tag + 1); - u64 req_num = tag->req_num; - unsigned int i; - int err; - - switch (tag->type) { - case DR_CPU_CONFIGURE: - case DR_CPU_UNCONFIGURE: - case DR_CPU_FORCE_UNCONFIGURE: - break; - - default: - dr_cpu_send_error(cp, data); - goto next; - } - - purge_dups(cpu_list, tag->num_records); - - cpus_clear(mask); - for (i = 0; i < tag->num_records; i++) { - if (cpu_list[i] == CPU_SENTINEL) - continue; - - if (cpu_list[i] < NR_CPUS) - cpu_set(cpu_list[i], mask); - } - - if (tag->type == DR_CPU_CONFIGURE) - err = dr_cpu_configure(cp, req_num, &mask); - else - err = dr_cpu_unconfigure(cp, req_num, &mask); - - if (err) - dr_cpu_send_error(cp, data); + switch (tag->type) { + case DR_CPU_CONFIGURE: + case DR_CPU_UNCONFIGURE: + case DR_CPU_FORCE_UNCONFIGURE: + break; -next: - list_del(&qp->list); - kfree(qp); + default: + dr_cpu_send_error(cp, data); + return; } -} -static int dr_cpu_thread(void *__unused) -{ - struct ds_cap_state *cp; - DEFINE_WAIT(wait); + purge_dups(cpu_list, tag->num_records); - cp = find_cap_by_string("dr-cpu"); - - while (1) { - prepare_to_wait(&dr_cpu_wait, &wait, TASK_INTERRUPTIBLE); - if (list_empty(&dr_cpu_work_list)) - schedule(); - finish_wait(&dr_cpu_wait, &wait); - - if (kthread_should_stop()) - break; + cpus_clear(mask); + for (i = 0; i < tag->num_records; i++) { + if (cpu_list[i] == CPU_SENTINEL) + continue; - process_dr_cpu_list(cp); + if (cpu_list[i] < NR_CPUS) + cpu_set(cpu_list[i], mask); } - return 0; -} - -static void dr_cpu_data(struct ldc_channel *lp, - struct ds_cap_state *dp, - void *buf, int len) -{ - struct dr_cpu_queue_entry *qp; - struct ds_data *dpkt = buf; - struct dr_cpu_tag *rp; + if (tag->type == DR_CPU_CONFIGURE) + err = dr_cpu_configure(cp, req_num, &mask); + else + err = dr_cpu_unconfigure(cp, req_num, &mask); - rp = (struct dr_cpu_tag *) (dpkt + 1); - - qp = kmalloc(sizeof(struct dr_cpu_queue_entry) + len, GFP_ATOMIC); - if (!qp) { - struct ds_cap_state *cp; - - cp = find_cap_by_string("dr-cpu"); - __dr_cpu_send_error(cp, dpkt); - } else { - memcpy(&qp->req, buf, len); - list_add_tail(&qp->list, &dr_cpu_work_list); - wake_up(&dr_cpu_wait); - } + if (err) + dr_cpu_send_error(cp, data); } -#endif +#endif /* CONFIG_HOTPLUG_CPU */ struct ds_pri_msg { __u64 req_num; @@ -820,7 +762,7 @@ void ldom_set_var(const char *var, const char *value) ds_var_doorbell = 0; ds_var_response = -1; - ds_send(dp->lp, &pkt, msg_len); + __ds_send(dp->lp, &pkt, msg_len); spin_unlock_irqrestore(&ds_lock, flags); loops = 1000; @@ -904,7 +846,7 @@ static int register_services(struct ds_info *dp) pbuf.req.minor = 0; strcpy(pbuf.req.svc_id, cp->service_id); - err = ds_send(lp, &pbuf, msg_len); + err = __ds_send(lp, &pbuf, msg_len); if (err > 0) cp->state = CAP_STATE_REG_SENT; } @@ -960,27 +902,97 @@ conn_reset: return -ECONNRESET; } +static void __send_ds_nack(struct ds_info *dp, u64 handle) +{ + struct ds_data_nack nack = { + .tag = { + .type = DS_NACK, + .len = (sizeof(struct ds_data_nack) - + sizeof(struct ds_msg_tag)), + }, + .handle = handle, + .result = DS_INV_HDL, + }; + + __ds_send(dp->lp, &nack, sizeof(nack)); +} + +static LIST_HEAD(ds_work_list); +static DECLARE_WAIT_QUEUE_HEAD(ds_wait); + +struct ds_queue_entry { + struct list_head list; + int req_len; + int __pad; + u64 req[0]; +}; + +static void process_ds_work(void) +{ + struct ds_queue_entry *qp, *tmp; + static struct ds_info *dp; + unsigned long flags; + LIST_HEAD(todo); + + spin_lock_irqsave(&ds_lock, flags); + list_splice(&ds_work_list, &todo); + INIT_LIST_HEAD(&ds_work_list); + spin_unlock_irqrestore(&ds_lock, flags); + + dp = ds_info; + + list_for_each_entry_safe(qp, tmp, &todo, list) { + struct ds_data *dpkt = (struct ds_data *) qp->req; + struct ds_cap_state *cp = find_cap(dpkt->handle); + int req_len = qp->req_len; + + if (!cp) { + printk(KERN_ERR PFX "Data for unknown handle %lu\n", + dpkt->handle); + + spin_lock_irqsave(&ds_lock, flags); + __send_ds_nack(dp, dpkt->handle); + spin_unlock_irqrestore(&ds_lock, flags); + } else { + cp->data(dp->lp, cp, dpkt, req_len); + } + + list_del(&qp->list); + kfree(qp); + } +} + +static int ds_thread(void *__unused) +{ + DEFINE_WAIT(wait); + + while (1) { + prepare_to_wait(&ds_wait, &wait, TASK_INTERRUPTIBLE); + if (list_empty(&ds_work_list)) + schedule(); + finish_wait(&ds_wait, &wait); + + if (kthread_should_stop()) + break; + + process_ds_work(); + } + + return 0; +} + static int ds_data(struct ds_info *dp, struct ds_msg_tag *pkt, int len) { struct ds_data *dpkt = (struct ds_data *) pkt; - struct ds_cap_state *cp = find_cap(dpkt->handle); - - if (!cp) { - struct ds_data_nack nack = { - .tag = { - .type = DS_NACK, - .len = (sizeof(struct ds_data_nack) - - sizeof(struct ds_msg_tag)), - }, - .handle = dpkt->handle, - .result = DS_INV_HDL, - }; - - printk(KERN_ERR PFX "Data for unknown handle %lu\n", - dpkt->handle); - ds_send(dp->lp, &nack, sizeof(nack)); + struct ds_queue_entry *qp; + + qp = kmalloc(sizeof(struct ds_queue_entry) + len, GFP_ATOMIC); + if (!qp) { + __send_ds_nack(dp, dpkt->handle); } else { - cp->data(dp->lp, cp, dpkt, len); + memcpy(&qp->req, pkt, len); + list_add_tail(&qp->list, &ds_work_list); + wake_up(&ds_wait); } return 0; } @@ -996,7 +1008,7 @@ static void ds_up(struct ds_info *dp) req.ver.major = 1; req.ver.minor = 0; - err = ds_send(lp, &req, sizeof(req)); + err = __ds_send(lp, &req, sizeof(req)); if (err > 0) dp->hs_state = DS_HS_START; } @@ -1148,9 +1160,7 @@ static int __init ds_init(void) for (i = 0; i < ARRAY_SIZE(ds_states); i++) ds_states[i].handle = ((u64)i << 32); -#ifdef CONFIG_HOTPLUG_CPU - kthread_run(dr_cpu_thread, NULL, "kdrcpud"); -#endif + kthread_run(ds_thread, NULL, "kldomd"); return vio_register_driver(&ds_driver); } diff --git a/arch/sparc64/kernel/mdesc.c b/arch/sparc64/kernel/mdesc.c index 62a38979394..de5310ffdb4 100644 --- a/arch/sparc64/kernel/mdesc.c +++ b/arch/sparc64/kernel/mdesc.c @@ -214,7 +214,7 @@ void mdesc_release(struct mdesc_handle *hp) } EXPORT_SYMBOL(mdesc_release); -static void do_mdesc_update(struct work_struct *work) +void mdesc_update(void) { unsigned long len, real_len, status; struct mdesc_handle *hp, *orig_hp; @@ -248,13 +248,6 @@ static void do_mdesc_update(struct work_struct *work) spin_unlock_irqrestore(&mdesc_lock, flags); } -static DECLARE_WORK(mdesc_update_work, do_mdesc_update); - -void mdesc_update(void) -{ - schedule_work(&mdesc_update_work); -} - static struct mdesc_elem *node_block(struct mdesc_hdr *mdesc) { return (struct mdesc_elem *) (mdesc + 1); @@ -278,13 +271,14 @@ u64 mdesc_node_by_name(struct mdesc_handle *hp, u64 last_node = hp->mdesc.node_sz / 16; u64 ret; - if (from_node == MDESC_NODE_NULL) - from_node = 0; - - if (from_node >= last_node) + if (from_node == MDESC_NODE_NULL) { + ret = from_node = 0; + } else if (from_node >= last_node) { return MDESC_NODE_NULL; + } else { + ret = ep[from_node].d.val; + } - ret = ep[from_node].d.val; while (ret < last_node) { if (ep[ret].tag != MD_NODE) return MDESC_NODE_NULL;