The patch titled
ipmi: run to completion fixes
has been added to the -mm tree. Its filename is
ipmi-run-to-completion-fixes.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: ipmi: run to completion fixes
From: Corey Minyard <cminyard@xxxxxxxxxx>
The "run_to_completion" mode was somewhat broken. Locks need to be avoided in
run_to_completion mode, and it shouldn't be used by normal users, just
internally for panic situations.
This patch removes locks in run_to_completion mode and removes the user call
for setting the mode. The only user was the poweroff code, but it was easily
converted to use the polling interface.
Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/ipmi/ipmi_msghandler.c | 8 ----
drivers/char/ipmi/ipmi_poweroff.c | 20 +++++++++---
drivers/char/ipmi/ipmi_si_intf.c | 42 +++++++++++---------------
include/linux/ipmi.h | 11 +-----
4 files changed, 37 insertions(+), 44 deletions(-)
diff -puN drivers/char/ipmi/ipmi_msghandler.c~ipmi-run-to-completion-fixes drivers/char/ipmi/ipmi_msghandler.c
--- a/drivers/char/ipmi/ipmi_msghandler.c~ipmi-run-to-completion-fixes
+++ a/drivers/char/ipmi/ipmi_msghandler.c
@@ -1197,13 +1197,6 @@ int ipmi_unregister_for_cmd(ipmi_user_t
return rv;
}
-void ipmi_user_set_run_to_completion(ipmi_user_t user, int val)
-{
- ipmi_smi_t intf = user->intf;
- if (intf->handlers)
- intf->handlers->set_run_to_completion(intf->send_info, val);
-}
-
static unsigned char
ipmb_checksum(unsigned char *data, int size)
{
@@ -4190,5 +4183,4 @@ EXPORT_SYMBOL(ipmi_get_my_address);
EXPORT_SYMBOL(ipmi_set_my_LUN);
EXPORT_SYMBOL(ipmi_get_my_LUN);
EXPORT_SYMBOL(ipmi_smi_add_proc_entry);
-EXPORT_SYMBOL(ipmi_user_set_run_to_completion);
EXPORT_SYMBOL(ipmi_free_recv_msg);
diff -puN drivers/char/ipmi/ipmi_poweroff.c~ipmi-run-to-completion-fixes drivers/char/ipmi/ipmi_poweroff.c
--- a/drivers/char/ipmi/ipmi_poweroff.c~ipmi-run-to-completion-fixes
+++ a/drivers/char/ipmi/ipmi_poweroff.c
@@ -99,11 +99,14 @@ static unsigned char ipmi_version;
allocate them, since we may be in a panic situation. The whole
thing is single-threaded, anyway, so multiple messages are not
required. */
+static atomic_t dummy_count = ATOMIC_INIT(0);
static void dummy_smi_free(struct ipmi_smi_msg *msg)
{
+ atomic_dec(&dummy_count);
}
static void dummy_recv_free(struct ipmi_recv_msg *msg)
{
+ atomic_dec(&dummy_count);
}
static struct ipmi_smi_msg halt_smi_msg =
{
@@ -152,17 +155,28 @@ static int ipmi_request_wait_for_respons
return halt_recv_msg.msg.data[0];
}
-/* We are in run-to-completion mode, no completion is desired. */
+/* Wait for message to complete, spinning. */
static int ipmi_request_in_rc_mode(ipmi_user_t user,
struct ipmi_addr *addr,
struct kernel_ipmi_msg *send_msg)
{
int rv;
+ atomic_set(&dummy_count, 2);
rv = ipmi_request_supply_msgs(user, addr, 0, send_msg, NULL,
&halt_smi_msg, &halt_recv_msg, 0);
- if (rv)
+ if (rv) {
+ atomic_set(&dummy_count, 0);
return rv;
+ }
+
+ /*
+ * Spin until our message is done.
+ */
+ while (atomic_read(&dummy_count) > 0) {
+ ipmi_poll_interface(user);
+ barrier();
+ }
return halt_recv_msg.msg.data[0];
}
@@ -531,9 +545,7 @@ static void ipmi_poweroff_function (void
return;
/* Use run-to-completion mode, since interrupts may be off. */
- ipmi_user_set_run_to_completion(ipmi_user, 1);
specific_poweroff_func(ipmi_user);
- ipmi_user_set_run_to_completion(ipmi_user, 0);
}
/* Wait for an IPMI interface to be installed, the first one installed
diff -puN drivers/char/ipmi/ipmi_si_intf.c~ipmi-run-to-completion-fixes drivers/char/ipmi/ipmi_si_intf.c
--- a/drivers/char/ipmi/ipmi_si_intf.c~ipmi-run-to-completion-fixes
+++ a/drivers/char/ipmi/ipmi_si_intf.c
@@ -806,56 +806,54 @@ static void sender(void *
return;
}
- spin_lock_irqsave(&(smi_info->msg_lock), flags);
#ifdef DEBUG_TIMING
do_gettimeofday(&t);
printk("**Enqueue: %d.%9.9d\n", t.tv_sec, t.tv_usec);
#endif
if (smi_info->run_to_completion) {
- /* If we are running to completion, then throw it in
- the list and run transactions until everything is
- clear. Priority doesn't matter here. */
+ /*
+ * If we are running to completion, then throw it in
+ * the list and run transactions until everything is
+ * clear. Priority doesn't matter here.
+ */
+
+ /*
+ * Run to completion means we are single-threaded, no
+ * need for locks.
+ */
list_add_tail(&(msg->link), &(smi_info->xmit_msgs));
- /* We have to release the msg lock and claim the smi
- lock in this case, because of race conditions. */
- spin_unlock_irqrestore(&(smi_info->msg_lock), flags);
-
- spin_lock_irqsave(&(smi_info->si_lock), flags);
result = smi_event_handler(smi_info, 0);
while (result != SI_SM_IDLE) {
udelay(SI_SHORT_TIMEOUT_USEC);
result = smi_event_handler(smi_info,
SI_SHORT_TIMEOUT_USEC);
}
- spin_unlock_irqrestore(&(smi_info->si_lock), flags);
return;
+ }
+
+ spin_lock_irqsave(&smi_info->msg_lock, flags);
+ if (priority > 0) {
+ list_add_tail(&msg->link, &smi_info->hp_xmit_msgs);
} else {
- if (priority > 0) {
- list_add_tail(&(msg->link), &(smi_info->hp_xmit_msgs));
- } else {
- list_add_tail(&(msg->link), &(smi_info->xmit_msgs));
- }
+ list_add_tail(&msg->link, &smi_info->xmit_msgs);
}
- spin_unlock_irqrestore(&(smi_info->msg_lock), flags);
+ spin_unlock_irqrestore(&smi_info->msg_lock, flags);
- spin_lock_irqsave(&(smi_info->si_lock), flags);
+ spin_lock_irqsave(&smi_info->si_lock, flags);
if ((smi_info->si_state == SI_NORMAL)
&& (smi_info->curr_msg == NULL))
{
start_next_msg(smi_info);
}
- spin_unlock_irqrestore(&(smi_info->si_lock), flags);
+ spin_unlock_irqrestore(&smi_info->si_lock, flags);
}
static void set_run_to_completion(void *send_info, int i_run_to_completion)
{
struct smi_info *smi_info = send_info;
enum si_sm_result result;
- unsigned long flags;
-
- spin_lock_irqsave(&(smi_info->si_lock), flags);
smi_info->run_to_completion = i_run_to_completion;
if (i_run_to_completion) {
@@ -866,8 +864,6 @@ static void set_run_to_completion(void *
SI_SHORT_TIMEOUT_USEC);
}
}
-
- spin_unlock_irqrestore(&(smi_info->si_lock), flags);
}
static int ipmi_thread(void *data)
diff -puN include/linux/ipmi.h~ipmi-run-to-completion-fixes include/linux/ipmi.h
--- a/include/linux/ipmi.h~ipmi-run-to-completion-fixes
+++ a/include/linux/ipmi.h
@@ -368,9 +368,8 @@ int ipmi_request_supply_msgs(ipmi_user_t
* Poll the IPMI interface for the user. This causes the IPMI code to
* do an immediate check for information from the driver and handle
* anything that is immediately pending. This will not block in any
- * way. This is useful if you need to implement polling from the user
- * for things like modifying the watchdog timeout when a panic occurs
- * or disabling the watchdog timer on a reboot.
+ * way. This is useful if you need to spin waiting for something to
+ * happen in the IPMI driver.
*/
void ipmi_poll_interface(ipmi_user_t user);
@@ -422,12 +421,6 @@ int ipmi_get_maintenance_mode(ipmi_user_
int ipmi_set_maintenance_mode(ipmi_user_t user, int mode);
/*
- * Allow run-to-completion mode to be set for the interface of
- * a specific user.
- */
-void ipmi_user_set_run_to_completion(ipmi_user_t user, int val);
-
-/*
* When the user is created, it will not receive IPMI events by
* default. The user must set this to TRUE to get incoming events.
* The first user that sets this to TRUE will receive all events that
_
Patches currently in -mm which might be from cminyard@xxxxxxxxxx are
git-watchdog.patch
ipmi-hold-attn-until-upper-layer-ready.patch
ipmi-change-device-node-ordering-to-reflect-probe-order.patch
ipmi-run-to-completion-fixes.patch
ipmi-dont-grab-locks-in-run-to-completion-mode.patch
ipmi-dont-print-event-queue-full-on-every-event.patch
ipmi-update-driver-version.patch
ipmi-convert-locked-counters-to-atomics.patch
ipmi-convert-locked-counters-to-atomics-in-the-system-interface.patch
-
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