From: peterm@redhat.com <peterm@redhat.com>
Date: Fri, 17 Apr 2009 12:09:25 -0400
Subject: [ipmi] allow shared interrupts
Message-id: 200904171609.n3HG9PVD013418@dhcp-100-18-167.bos.redhat.com
O-Subject: [Patch RHEL 5.4][Part 1/4]IPMI: Allow shared interrupts
Bugzilla: 475536
RH-Acked-by: Brian Maly <bmaly@redhat.com>
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>

Hello,

This is a patch set of four changes requested by the hw
partners for inclusion in RHEL 5.4.  All of the patches are from
upstream.  Kernels were built in brew and partners are testing.
Still waiting on test results but I wanted to post ahead of next
weeks code freeze rush.

This first patch drops the use of enable/diable_irq and instead
send messages to the BMC to control the IRQ operations.  The
proper flags are set on request_irq, and the shut down code
has been cleaned up.

commit ee6cd5f8f573ad11f270a07fb201822c2862474d

Kernels were built in brew, all archs.
Task info: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1757755

Testing:  IBM and HP are testing the kernels.  Still waiting on test
results.

This resolves:

Bug 475536 -  [LTC 5.4 FEAT] OpenIPMI driver update [201263]

Regards,

Peter

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index c482726..506fc70 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -81,6 +81,12 @@
 #define SI_SHORT_TIMEOUT_USEC  250 /* .25ms when the SM request a
                                        short timeout */
 
+/* Bit for BMC global enables. */
+#define IPMI_BMC_RCV_MSG_INTR     0x01
+#define IPMI_BMC_EVT_MSG_INTR     0x02
+#define IPMI_BMC_EVT_MSG_BUFF     0x04
+#define IPMI_BMC_SYS_LOG          0x08
+
 enum si_intf_state {
 	SI_NORMAL,
 	SI_GETTING_FLAGS,
@@ -89,7 +95,9 @@ enum si_intf_state {
 	SI_CLEARING_FLAGS_THEN_SET_IRQ,
 	SI_GETTING_MESSAGES,
 	SI_ENABLE_INTERRUPTS1,
-	SI_ENABLE_INTERRUPTS2
+	SI_ENABLE_INTERRUPTS2,
+	SI_DISABLE_INTERRUPTS1,
+	SI_DISABLE_INTERRUPTS2
 	/* FIXME - add watchdog stuff. */
 };
 
@@ -338,6 +346,17 @@ static void start_enable_irq(struct smi_info *smi_info)
 	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;
+}
+
 static void start_clear_flags(struct smi_info *smi_info)
 {
 	unsigned char msg[3];
@@ -358,7 +377,7 @@ static void start_clear_flags(struct smi_info *smi_info)
 static inline void disable_si_irq(struct smi_info *smi_info)
 {
 	if ((smi_info->irq) && (!smi_info->interrupt_disabled)) {
-		disable_irq_nosync(smi_info->irq);
+		start_disable_irq(smi_info);
 		smi_info->interrupt_disabled = 1;
 	}
 }
@@ -366,7 +385,7 @@ static inline void disable_si_irq(struct smi_info *smi_info)
 static inline void enable_si_irq(struct smi_info *smi_info)
 {
 	if ((smi_info->irq) && (smi_info->interrupt_disabled)) {
-		enable_irq(smi_info->irq);
+		start_enable_irq(smi_info);
 		smi_info->interrupt_disabled = 0;
 	}
 }
@@ -588,7 +607,9 @@ static void handle_transaction_done(struct smi_info *smi_info)
 		} else {
 			msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 			msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
-			msg[2] = msg[3] | 1; /* enable msg queue int */
+			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_ENABLE_INTERRUPTS2;
@@ -610,6 +631,45 @@ static void handle_transaction_done(struct smi_info *smi_info)
 		smi_info->si_state = SI_NORMAL;
 		break;
 	}
+
+	case SI_DISABLE_INTERRUPTS1:
+	{
+		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) {
+			printk(KERN_WARNING
+			       "ipmi_si: Could not disable interrupts"
+			       ", failed get.\n");
+			smi_info->si_state = SI_NORMAL;
+		} 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) {
+			printk(KERN_WARNING
+			       "ipmi_si: Could not disable interrupts"
+			       ", failed set.\n");
+		}
+		smi_info->si_state = SI_NORMAL;
+		break;
+	}
 	}
 }
 
@@ -863,9 +923,6 @@ static void smi_timeout(unsigned long data)
 	struct timeval    t;
 #endif
 
-	if (atomic_read(&smi_info->stop_operation))
-		return;
-
 	spin_lock_irqsave(&(smi_info->si_lock), flags);
 #ifdef DEBUG_TIMING
 	do_gettimeofday(&t);
@@ -921,15 +978,11 @@ static irqreturn_t si_irq_handler(int irq, void *data, struct pt_regs *regs)
 	smi_info->interrupts++;
 	spin_unlock(&smi_info->count_lock);
 
-	if (atomic_read(&smi_info->stop_operation))
-		goto out;
-
 #ifdef DEBUG_TIMING
 	do_gettimeofday(&t);
 	printk("**Interrupt: %d.%9.9d\n", t.tv_sec, t.tv_usec);
 #endif
 	smi_event_handler(smi_info, 0);
- out:
 	spin_unlock_irqrestore(&(smi_info->si_lock), flags);
 	return IRQ_HANDLED;
 }
@@ -1121,7 +1174,7 @@ static int std_irq_setup(struct smi_info *info)
 	if (info->si_type == SI_BT) {
 		rv = request_irq(info->irq,
 				 si_bt_irq_handler,
-				 IRQF_DISABLED,
+				 IRQF_SHARED | IRQF_DISABLED,
 				 DEVICE_NAME,
 				 info);
 		if (!rv)
@@ -1131,7 +1184,7 @@ static int std_irq_setup(struct smi_info *info)
 	} else
 		rv = request_irq(info->irq,
 				 si_irq_handler,
-				 IRQF_DISABLED,
+				 IRQF_SHARED | IRQF_DISABLED,
 				 DEVICE_NAME,
 				 info);
 	if (rv) {
@@ -1711,15 +1764,11 @@ static u32 ipmi_acpi_gpe(void *context)
 	smi_info->interrupts++;
 	spin_unlock(&smi_info->count_lock);
 
-	if (atomic_read(&smi_info->stop_operation))
-		goto out;
-
 #ifdef DEBUG_TIMING
 	do_gettimeofday(&t);
 	printk("**ACPI_GPE: %d.%9.9d\n", t.tv_sec, t.tv_usec);
 #endif
 	smi_event_handler(smi_info, 0);
- out:
 	spin_unlock_irqrestore(&(smi_info->si_lock), flags);
 
 	return ACPI_INTERRUPT_HANDLED;
@@ -2950,28 +2999,36 @@ static void cleanup_one_si(struct smi_info *to_clean)
 
 	list_del(&to_clean->link);
 
-	/* Tell the timer and interrupt handlers that we are shutting
-	   down. */
-	spin_lock_irqsave(&(to_clean->si_lock), flags);
-	spin_lock(&(to_clean->msg_lock));
-
+	/* Tell the driver that we are shutting down. */
 	atomic_inc(&to_clean->stop_operation);
 
-	if (to_clean->irq_cleanup)
-		to_clean->irq_cleanup(to_clean);
-
-	spin_unlock(&(to_clean->msg_lock));
-	spin_unlock_irqrestore(&(to_clean->si_lock), flags);
-
-	/* Wait until we know that we are out of any interrupt
-	   handlers might have been running before we freed the
-	   interrupt. */
-	synchronize_sched();
-
+	/*
+	 * Make sure the timer and thread are stopped and will not run
+	 * again.
+	 */
 	wait_for_timer_and_thread(to_clean);
+	/*
+	 * Timeouts are stopped, now make sure the interrupts are off
+	 * for the device.  A little tricky with locks to make sure
+	 * there are no races.
+	 */
+	spin_lock_irqsave(&to_clean->si_lock, flags);
+	while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
+		spin_unlock_irqrestore(&to_clean->si_lock, flags);
+		poll(to_clean);
+		schedule_timeout_uninterruptible(1);
+		spin_lock_irqsave(&to_clean->si_lock, flags);
+	}
+	disable_si_irq(to_clean);
+	spin_unlock_irqrestore(&to_clean->si_lock, flags);
+	while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
+		poll(to_clean);
+		schedule_timeout_uninterruptible(1);
+	}
 
-	/* Interrupts and timeouts are stopped, now make sure the
-	   interface is in a clean state. */
+	/* Clean up interrupts and make sure that everything is done. */
+	if (to_clean->irq_cleanup)
+		to_clean->irq_cleanup(to_clean);
 	while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
 		poll(to_clean);
 		schedule_timeout_uninterruptible(1);