[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 <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/ds.c b/arch/sparc64/kernel/ds.c
index 1c58710..ba01533 100644
--- a/arch/sparc64/kernel/ds.c
+++ b/arch/sparc64/kernel/ds.c
@@ -228,7 +228,7 @@
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 @@
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 @@
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 @@
pkt.res.result = DS_OK;
ds_send(lp, &pkt, sizeof(pkt));
-
- mdesc_update();
}
struct ds_shutdown_req {
@@ -391,18 +403,6 @@
__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 @@
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 @@
}
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 @@
}
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 @@
return 0;
}
-static void process_dr_cpu_list(struct ds_cap_state *cp)
-{
- struct dr_cpu_queue_entry *qp, *tmp;
- unsigned long flags;
- LIST_HEAD(todo);
- cpumask_t mask;
-
- 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);
-
-next:
- list_del(&qp->list);
- kfree(qp);
- }
-}
-
-static int dr_cpu_thread(void *__unused)
-{
- struct ds_cap_state *cp;
- DEFINE_WAIT(wait);
-
- 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;
-
- process_dr_cpu_list(cp);
- }
-
- return 0;
-}
-
static void dr_cpu_data(struct ldc_channel *lp,
- struct ds_cap_state *dp,
+ struct ds_cap_state *cp,
void *buf, int len)
{
- struct dr_cpu_queue_entry *qp;
- struct ds_data *dpkt = buf;
- struct dr_cpu_tag *rp;
+ 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;
- rp = (struct dr_cpu_tag *) (dpkt + 1);
+ switch (tag->type) {
+ case DR_CPU_CONFIGURE:
+ case DR_CPU_UNCONFIGURE:
+ case DR_CPU_FORCE_UNCONFIGURE:
+ break;
- 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);
+ default:
+ dr_cpu_send_error(cp, data);
+ return;
}
+
+ 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);
}
-#endif
+#endif /* CONFIG_HOTPLUG_CPU */
struct ds_pri_msg {
__u64 req_num;
@@ -820,7 +762,7 @@
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 @@
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 @@
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);
+ struct ds_queue_entry *qp;
- 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));
+ 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 @@
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 @@
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 62a3897..de5310f 100644
--- a/arch/sparc64/kernel/mdesc.c
+++ b/arch/sparc64/kernel/mdesc.c
@@ -214,7 +214,7 @@
}
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 @@
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 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;
