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>

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 4f11301a0c4283ec1a693514d9ff9375d233a168..2952d2dcc85509cff33ccd0be84ef829fd694190 100644 (file)
--- 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) {
                /*