ipmi: Periodically check to see if irqs and messages are set right

The BMC can be reset while we are running; that means the interrupt
and event message buffer settings may be wrong.  So periodically
check to see if these values are correct, and fix them if they
are wrong.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Tony Rex <tony.rex@ericsson.com>
Tested-by: Magnus Johansson E <magnus.e.johansson@ericsson.com>

1 files changed, 101 insertions, 96 deletions

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 4f11301a0c42..2952d2dcc855 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -92,12 +92,9 @@ enum si_intf_state {
         SI_GETTING_FLAGS,
         SI_GETTING_EVENTS,
         SI_CLEARING_FLAGS,
-        SI_CLEARING_FLAGS_THEN_SET_IRQ,
         SI_GETTING_MESSAGES,
-        SI_ENABLE_INTERRUPTS1,
-        SI_ENABLE_INTERRUPTS2,
-        SI_DISABLE_INTERRUPTS1,
-        SI_DISABLE_INTERRUPTS2
+        SI_CHECKING_ENABLES,
+        SI_SETTING_ENABLES
         /* FIXME - add watchdog stuff. */
 };
 
@@ -260,6 +257,11 @@ struct smi_info {
          */
         bool interrupt_disabled;
 
+        /*
+         * Does the BMC support events?
+         */
+        bool supports_event_msg_buff;
+
         /* From the get device id response... */
         struct ipmi_device_id device_id;
 
@@ -386,30 +388,15 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info)
         return rv;
 }
 
-static void start_enable_irq(struct smi_info *smi_info)
+static void start_check_enables(struct smi_info *smi_info)
 {
         unsigned char msg[2];
 
-        /*
-         * If we are enabling interrupts, we have to tell the
-         * BMC to use them.
-         */
         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
 
         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
-        smi_info->si_state = SI_ENABLE_INTERRUPTS1;
-}
-
-static void start_disable_irq(struct smi_info *smi_info)
-{
-        unsigned char msg[2];
-
-        msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
-        msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
-
-        smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
-        smi_info->si_state = SI_DISABLE_INTERRUPTS1;
+        smi_info->si_state = SI_CHECKING_ENABLES;
 }
 
 static void start_clear_flags(struct smi_info *smi_info)
@@ -467,8 +454,8 @@ static void smi_mod_timer(struct smi_info *smi_info, unsigned long new_val)
 static inline bool disable_si_irq(struct smi_info *smi_info)
 {
         if ((smi_info->irq) && (!smi_info->interrupt_disabled)) {
-                start_disable_irq(smi_info);
                 smi_info->interrupt_disabled = true;
+                start_check_enables(smi_info);
                 return true;
         }
         return false;
@@ -477,8 +464,8 @@ static inline bool disable_si_irq(struct smi_info *smi_info)
 static inline bool enable_si_irq(struct smi_info *smi_info)
 {
         if ((smi_info->irq) && (smi_info->interrupt_disabled)) {
-                start_enable_irq(smi_info);
                 smi_info->interrupt_disabled = false;
+                start_check_enables(smi_info);
                 return true;
         }
         return false;
@@ -538,6 +525,36 @@ static void handle_flags(struct smi_info *smi_info)
                 smi_info->si_state = SI_NORMAL;
 }
 
+/*
+ * Global enables we care about.
+ */
+#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
+                             IPMI_BMC_EVT_MSG_INTR)
+
+static u8 current_global_enables(struct smi_info *smi_info, u8 base)
+{
+        u8 enables = 0;
+
+        if (smi_info->supports_event_msg_buff)
+                enables |= IPMI_BMC_EVT_MSG_BUFF;
+        else
+                enables &= ~IPMI_BMC_EVT_MSG_BUFF;
+
+        if (smi_info->irq && !smi_info->interrupt_disabled)
+                enables |= IPMI_BMC_RCV_MSG_INTR;
+        else
+                enables &= ~IPMI_BMC_RCV_MSG_INTR;
+
+        if (smi_info->supports_event_msg_buff &&
+            smi_info->irq && !smi_info->interrupt_disabled)
+
+                enables |= IPMI_BMC_EVT_MSG_INTR;
+        else
+                enables &= ~IPMI_BMC_EVT_MSG_INTR;
+
+        return enables;
+}
+
 static void handle_transaction_done(struct smi_info *smi_info)
 {
         struct ipmi_smi_msg *msg;
@@ -592,7 +609,6 @@ static void handle_transaction_done(struct smi_info *smi_info)
         }
 
         case SI_CLEARING_FLAGS:
-        case SI_CLEARING_FLAGS_THEN_SET_IRQ:
         {
                 unsigned char msg[3];
 
@@ -603,10 +619,7 @@ static void handle_transaction_done(struct smi_info *smi_info)
                         dev_warn(smi_info->dev,
                                  "Error clearing flags: %2.2x\n", msg[2]);
                 }
-                if (smi_info->si_state == SI_CLEARING_FLAGS_THEN_SET_IRQ)
-                        start_enable_irq(smi_info);
-                else
-                        smi_info->si_state = SI_NORMAL;
+                smi_info->si_state = SI_NORMAL;
                 break;
         }
 
@@ -686,9 +699,10 @@ static void handle_transaction_done(struct smi_info *smi_info)
                 break;
         }
 
-        case SI_ENABLE_INTERRUPTS1:
+        case SI_CHECKING_ENABLES:
         {
                 unsigned char msg[4];
+                u8 enables;
 
                 /* We got the flags from the SMI, now handle them. */
                 smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
@@ -698,72 +712,50 @@ static void handle_transaction_done(struct smi_info *smi_info)
                         dev_warn(smi_info->dev,
                                  "Maybe ok, but ipmi might run very slowly.\n");
                         smi_info->si_state = SI_NORMAL;
-                } else {
+                        break;
+                }
+                enables = current_global_enables(smi_info, 0);
+                if (enables != (msg[3] & GLOBAL_ENABLES_MASK)) {
+                        /* Enables are not correct, fix them. */
                         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
                         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
-                        msg[2] = (msg[3] |
-                                  IPMI_BMC_RCV_MSG_INTR |
-                                  IPMI_BMC_EVT_MSG_INTR);
+                        msg[2] = enables | (msg[3] & ~GLOBAL_ENABLES_MASK);
                         smi_info->handlers->start_transaction(
                                 smi_info->si_sm, msg, 3);
-                        smi_info->si_state = SI_ENABLE_INTERRUPTS2;
+                        smi_info->si_state = SI_SETTING_ENABLES;
+                } else if (smi_info->supports_event_msg_buff) {
+                        smi_info->curr_msg = ipmi_alloc_smi_msg();
+                        if (!smi_info->curr_msg) {
+                                smi_info->si_state = SI_NORMAL;
+                                break;
+                        }
+                        start_getting_msg_queue(smi_info);
+                } else {
+                        smi_info->si_state = SI_NORMAL;
                 }
                 break;
         }
 
-        case SI_ENABLE_INTERRUPTS2:
+        case SI_SETTING_ENABLES:
         {
                 unsigned char msg[4];
 
-                /* We got the flags from the SMI, now handle them. */
                 smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
-                if (msg[2] != 0) {
+                if (msg[2] != 0)
                         dev_warn(smi_info->dev,
-                                 "Couldn't set irq info: %x.\n", msg[2]);
-                        dev_warn(smi_info->dev,
-                                 "Maybe ok, but ipmi might run very slowly.\n");
-                } else
-                        smi_info->interrupt_disabled = false;
-
-                /* We enabled interrupts, flags may be pending. */
-                handle_flags(smi_info);
-                break;
-        }
-
-        case SI_DISABLE_INTERRUPTS1:
-        {
-                unsigned char msg[4];
+                                 "Could not set the global enables: 0x%x.\n",
+                                 msg[2]);
 
-                /* We got the flags from the SMI, now handle them. */
-                smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
-                if (msg[2] != 0) {
-                        dev_warn(smi_info->dev, "Could not disable interrupts"
-                                 ", failed get.\n");
-                        smi_info->si_state = SI_NORMAL;
+                if (smi_info->supports_event_msg_buff) {
+                        smi_info->curr_msg = ipmi_alloc_smi_msg();
+                        if (!smi_info->curr_msg) {
+                                smi_info->si_state = SI_NORMAL;
+                                break;
+                        }
+                        start_getting_msg_queue(smi_info);
                 } else {
-                        msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
-                        msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
-                        msg[2] = (msg[3] &
-                                  ~(IPMI_BMC_RCV_MSG_INTR |
-                                    IPMI_BMC_EVT_MSG_INTR));
-                        smi_info->handlers->start_transaction(
-                                smi_info->si_sm, msg, 3);
-                        smi_info->si_state = SI_DISABLE_INTERRUPTS2;
-                }
-                break;
-        }
-
-        case SI_DISABLE_INTERRUPTS2:
-        {
-                unsigned char msg[4];
-
-                /* We got the flags from the SMI, now handle them. */
-                smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
-                if (msg[2] != 0) {
-                        dev_warn(smi_info->dev, "Could not disable interrupts"
-                                 ", failed set.\n");
+                        smi_info->si_state = SI_NORMAL;
                 }
-                smi_info->si_state = SI_NORMAL;
                 break;
         }
         }
@@ -859,19 +851,21 @@ static enum si_sm_result smi_event_handler(struct smi_info *smi_info,
                  */
                 atomic_set(&smi_info->req_events, 0);
 
-                smi_info->curr_msg = ipmi_alloc_smi_msg();
-                if (!smi_info->curr_msg)
-                        goto out;
-
-                smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
-                smi_info->curr_msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
-                smi_info->curr_msg->data_size = 2;
+                /*
+                 * Take this opportunity to check the interrupt and
+                 * message enable state for the BMC.  The BMC can be
+                 * asynchronously reset, and may thus get interrupts
+                 * disable and messages disabled.
+                 */
+                if (smi_info->supports_event_msg_buff || smi_info->irq) {
+                        start_check_enables(smi_info);
+                } else {
+                        smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
+                        if (!smi_info->curr_msg)
+                                goto out;
 
-                smi_info->handlers->start_transaction(
-                        smi_info->si_sm,
-                        smi_info->curr_msg->data,
-                        smi_info->curr_msg->data_size);
-                smi_info->si_state = SI_GETTING_EVENTS;
+                        start_getting_events(smi_info);
+                }
                 goto restart;
         }
  out:
@@ -2918,9 +2912,11 @@ static int try_enable_event_buffer(struct smi_info *smi_info)
                 goto out;
         }
 
-        if (resp[3] & IPMI_BMC_EVT_MSG_BUFF)
+        if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
                 /* buffer is already enabled, nothing to do. */
+                smi_info->supports_event_msg_buff = true;
                 goto out;
+        }
 
         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
@@ -2953,6 +2949,9 @@ static int try_enable_event_buffer(struct smi_info *smi_info)
                  * that the event buffer is not supported.
                  */
                 rv = -ENOENT;
+        else
+                smi_info->supports_event_msg_buff = true;
+
  out:
         kfree(resp);
         return rv;
@@ -3392,9 +3391,15 @@ static int try_smi_init(struct smi_info *new_smi)
          * timer to avoid racing with the timer.
          */
         start_clear_flags(new_smi);
-        /* IRQ is defined to be set when non-zero. */
-        if (new_smi->irq)
-                new_smi->si_state = SI_CLEARING_FLAGS_THEN_SET_IRQ;
+
+        /*
+         * IRQ is defined to be set when non-zero.  req_events will
+         * cause a global flags check that will enable interrupts.
+         */
+        if (new_smi->irq) {
+                new_smi->interrupt_disabled = false;
+                atomic_set(&new_smi->req_events, 1);
+        }
 
         if (!new_smi->dev) {
                 /*