1 files changed, 71 insertions, 124 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 7d52343356e8..78ca97fffa94 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -66,6 +66,8 @@
 #include <asm/apic.h>
 
 #define __apicdebuginit(type) static type __init
+#define for_each_irq_pin(entry, head) \
+	for (entry = head; entry; entry = entry->next)
 
 /*
  *      Is the SiS APIC rmw bug present ?
@@ -116,15 +118,6 @@ static int __init parse_noapic(char *str)
 }
 early_param("noapic", parse_noapic);
 
-struct irq_pin_list;
-
-/*
- * This is performance-critical, we want to do it O(1)
- *
- * the indexing order of this array favors 1:1 mappings
- * between pins and IRQs.
- */
-
 struct irq_pin_list {
 	int apic, pin;
 	struct irq_pin_list *next;
@@ -139,6 +132,11 @@ static struct irq_pin_list *get_one_free_irq_2_pin(int node)
 	return pin;
 }
 
+/*
+ * This is performance-critical, we want to do it O(1)
+ *
+ * Most irqs are mapped 1:1 with pins.
+ */
 struct irq_cfg {
 	struct irq_pin_list *irq_2_pin;
 	cpumask_var_t domain;
@@ -411,13 +409,10 @@ static bool io_apic_level_ack_pending(struct irq_cfg *cfg)
 	unsigned long flags;
 
 	spin_lock_irqsave(&ioapic_lock, flags);
-	entry = cfg->irq_2_pin;
-	for (;;) {
+	for_each_irq_pin(entry, cfg->irq_2_pin) {
 		unsigned int reg;
 		int pin;
 
-		if (!entry)
-			break;
 		pin = entry->pin;
 		reg = io_apic_read(entry->apic, 0x10 + pin*2);
 		/* Is the remote IRR bit set? */
@@ -425,9 +420,6 @@ static bool io_apic_level_ack_pending(struct irq_cfg *cfg)
 			spin_unlock_irqrestore(&ioapic_lock, flags);
 			return true;
 		}
-		if (!entry->next)
-			break;
-		entry = entry->next;
 	}
 	spin_unlock_irqrestore(&ioapic_lock, flags);
 
@@ -495,72 +487,68 @@ static void ioapic_mask_entry(int apic, int pin)
  * shared ISA-space IRQs, so we have to support them. We are super
  * fast in the common case, and fast for shared ISA-space IRQs.
  */
-static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
+static int
+add_pin_to_irq_node_nopanic(struct irq_cfg *cfg, int node, int apic, int pin)
 {
-	struct irq_pin_list *entry;
-
-	entry = cfg->irq_2_pin;
-	if (!entry) {
-		entry = get_one_free_irq_2_pin(node);
-		if (!entry) {
-			printk(KERN_ERR "can not alloc irq_2_pin to add %d - %d\n",
-					apic, pin);
-			return;
-		}
-		cfg->irq_2_pin = entry;
-		entry->apic = apic;
-		entry->pin = pin;
-		return;
-	}
+	struct irq_pin_list **last, *entry;
 
-	while (entry->next) {
-		/* not again, please */
+	/* don't allow duplicates */
+	last = &cfg->irq_2_pin;
+	for_each_irq_pin(entry, cfg->irq_2_pin) {
 		if (entry->apic == apic && entry->pin == pin)
-			return;
-
-		entry = entry->next;
+			return 0;
+		last = &entry->next;
 	}
 
-	entry->next = get_one_free_irq_2_pin(node);
-	entry = entry->next;
+	entry = get_one_free_irq_2_pin(node);
+	if (!entry) {
+		printk(KERN_ERR "can not alloc irq_pin_list (%d,%d,%d)\n",
+				node, apic, pin);
+		return -ENOMEM;
+	}
 	entry->apic = apic;
 	entry->pin = pin;
+
+	*last = entry;
+	return 0;
+}
+
+static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
+{
+	if (add_pin_to_irq_node_nopanic(cfg, node, apic, pin))
+		panic("IO-APIC: failed to add irq-pin. Can not proceed\n");
 }
 
 /*
  * Reroute an IRQ to a different pin.
  */
 static void __init replace_pin_at_irq_node(struct irq_cfg *cfg, int node,
-				      int oldapic, int oldpin,
-				      int newapic, int newpin)
+					   int oldapic, int oldpin,
+					   int newapic, int newpin)
 {
-	struct irq_pin_list *entry = cfg->irq_2_pin;
-	int replaced = 0;
+	struct irq_pin_list *entry;
 
-	while (entry) {
+	for_each_irq_pin(entry, cfg->irq_2_pin) {
 		if (entry->apic == oldapic && entry->pin == oldpin) {
 			entry->apic = newapic;
 			entry->pin = newpin;
-			replaced = 1;
 			/* every one is different, right? */
-			break;
+			return;
 		}
-		entry = entry->next;
 	}
 
-	/* why? call replace before add? */
-	if (!replaced)
-		add_pin_to_irq_node(cfg, node, newapic, newpin);
+	/* old apic/pin didn't exist, so just add new ones */
+	add_pin_to_irq_node(cfg, node, newapic, newpin);
 }
 
-static inline void io_apic_modify_irq(struct irq_cfg *cfg,
-				int mask_and, int mask_or,
-				void (*final)(struct irq_pin_list *entry))
+static void io_apic_modify_irq(struct irq_cfg *cfg,
+			       int mask_and, int mask_or,
+			       void (*final)(struct irq_pin_list *entry))
 {
 	int pin;
 	struct irq_pin_list *entry;
 
-	for (entry = cfg->irq_2_pin; entry != NULL; entry = entry->next) {
+	for_each_irq_pin(entry, cfg->irq_2_pin) {
 		unsigned int reg;
 		pin = entry->pin;
 		reg = io_apic_read(entry->apic, 0x10 + pin * 2);
@@ -577,7 +565,6 @@ static void __unmask_IO_APIC_irq(struct irq_cfg *cfg)
 	io_apic_modify_irq(cfg, ~IO_APIC_REDIR_MASKED, 0, NULL);
 }
 
-#ifdef CONFIG_X86_64
 static void io_apic_sync(struct irq_pin_list *entry)
 {
 	/*
@@ -593,11 +580,6 @@ static void __mask_IO_APIC_irq(struct irq_cfg *cfg)
 {
 	io_apic_modify_irq(cfg, ~0, IO_APIC_REDIR_MASKED, &io_apic_sync);
 }
-#else /* CONFIG_X86_32 */
-static void __mask_IO_APIC_irq(struct irq_cfg *cfg)
-{
-	io_apic_modify_irq(cfg, ~0, IO_APIC_REDIR_MASKED, NULL);
-}
 
 static void __mask_and_edge_IO_APIC_irq(struct irq_cfg *cfg)
 {
@@ -610,7 +592,6 @@ static void __unmask_and_level_IO_APIC_irq(struct irq_cfg *cfg)
 	io_apic_modify_irq(cfg, ~IO_APIC_REDIR_MASKED,
 			IO_APIC_REDIR_LEVEL_TRIGGER, NULL);
 }
-#endif /* CONFIG_X86_32 */
 
 static void mask_IO_APIC_irq_desc(struct irq_desc *desc)
 {
@@ -1699,12 +1680,8 @@ __apicdebuginit(void) print_IO_APIC(void)
 		if (!entry)
 			continue;
 		printk(KERN_DEBUG "IRQ%d ", irq);
-		for (;;) {
+		for_each_irq_pin(entry, cfg->irq_2_pin)
 			printk("-> %d:%d", entry->apic, entry->pin);
-			if (!entry->next)
-				break;
-			entry = entry->next;
-		}
 		printk("\n");
 	}
 
@@ -2208,7 +2185,6 @@ static unsigned int startup_ioapic_irq(unsigned int irq)
 	return was_pending;
 }
 
-#ifdef CONFIG_X86_64
 static int ioapic_retrigger_irq(unsigned int irq)
 {
 
@@ -2221,14 +2197,6 @@ static int ioapic_retrigger_irq(unsigned int irq)
 
 	return 1;
 }
-#else
-static int ioapic_retrigger_irq(unsigned int irq)
-{
-	apic->send_IPI_self(irq_cfg(irq)->vector);
-
-	return 1;
-}
-#endif
 
 /*
  * Level and edge triggered IO-APIC interrupts need different handling,
@@ -2266,13 +2234,9 @@ static void __target_IO_APIC_irq(unsigned int irq, unsigned int dest, struct irq
 	struct irq_pin_list *entry;
 	u8 vector = cfg->vector;
 
-	entry = cfg->irq_2_pin;
-	for (;;) {
+	for_each_irq_pin(entry, cfg->irq_2_pin) {
 		unsigned int reg;
 
-		if (!entry)
-			break;
-
 		apic = entry->apic;
 		pin = entry->pin;
 		/*
@@ -2285,9 +2249,6 @@ static void __target_IO_APIC_irq(unsigned int irq, unsigned int dest, struct irq
 		reg &= ~IO_APIC_REDIR_VECTOR_MASK;
 		reg |= vector;
 		io_apic_modify(apic, 0x10 + pin*2, reg);
-		if (!entry->next)
-			break;
-		entry = entry->next;
 	}
 }
 
@@ -2512,11 +2473,8 @@ atomic_t irq_mis_count;
 static void ack_apic_level(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
-
-#ifdef CONFIG_X86_32
 	unsigned long v;
 	int i;
-#endif
 	struct irq_cfg *cfg;
 	int do_unmask_irq = 0;
 
@@ -2529,31 +2487,28 @@ static void ack_apic_level(unsigned int irq)
 	}
 #endif
 
-#ifdef CONFIG_X86_32
 	/*
-	* It appears there is an erratum which affects at least version 0x11
-	* of I/O APIC (that's the 82093AA and cores integrated into various
-	* chipsets).  Under certain conditions a level-triggered interrupt is
-	* erroneously delivered as edge-triggered one but the respective IRR
-	* bit gets set nevertheless.  As a result the I/O unit expects an EOI
-	* message but it will never arrive and further interrupts are blocked
-	* from the source.  The exact reason is so far unknown, but the
-	* phenomenon was observed when two consecutive interrupt requests
-	* from a given source get delivered to the same CPU and the source is
-	* temporarily disabled in between.
-	*
-	* A workaround is to simulate an EOI message manually.  We achieve it
-	* by setting the trigger mode to edge and then to level when the edge
-	* trigger mode gets detected in the TMR of a local APIC for a
-	* level-triggered interrupt.  We mask the source for the time of the
-	* operation to prevent an edge-triggered interrupt escaping meanwhile.
-	* The idea is from Manfred Spraul.  --macro
-	*/
+	 * It appears there is an erratum which affects at least version 0x11
+	 * of I/O APIC (that's the 82093AA and cores integrated into various
+	 * chipsets).  Under certain conditions a level-triggered interrupt is
+	 * erroneously delivered as edge-triggered one but the respective IRR
+	 * bit gets set nevertheless.  As a result the I/O unit expects an EOI
+	 * message but it will never arrive and further interrupts are blocked
+	 * from the source.  The exact reason is so far unknown, but the
+	 * phenomenon was observed when two consecutive interrupt requests
+	 * from a given source get delivered to the same CPU and the source is
+	 * temporarily disabled in between.
+	 *
+	 * A workaround is to simulate an EOI message manually.  We achieve it
+	 * by setting the trigger mode to edge and then to level when the edge
+	 * trigger mode gets detected in the TMR of a local APIC for a
+	 * level-triggered interrupt.  We mask the source for the time of the
+	 * operation to prevent an edge-triggered interrupt escaping meanwhile.
+	 * The idea is from Manfred Spraul.  --macro
+	 */
 	cfg = desc->chip_data;
 	i = cfg->vector;
-
 	v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
-#endif
 
 	/*
 	 * We must acknowledge the irq before we move it or the acknowledge will
@@ -2595,7 +2550,7 @@ static void ack_apic_level(unsigned int irq)
 		unmask_IO_APIC_irq_desc(desc);
 	}
 
-#ifdef CONFIG_X86_32
+	/* Tail end of version 0x11 I/O APIC bug workaround */
 	if (!(v & (1 << (i & 0x1f)))) {
 		atomic_inc(&irq_mis_count);
 		spin_lock(&ioapic_lock);
@@ -2603,26 +2558,15 @@ static void ack_apic_level(unsigned int irq)
 		__unmask_and_level_IO_APIC_irq(cfg);
 		spin_unlock(&ioapic_lock);
 	}
-#endif
 }
 
 #ifdef CONFIG_INTR_REMAP
 static void __eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg)
 {
-	int apic, pin;
 	struct irq_pin_list *entry;
 
-	entry = cfg->irq_2_pin;
-	for (;;) {
-
-		if (!entry)
-			break;
-
-		apic = entry->apic;
-		pin = entry->pin;
-		io_apic_eoi(apic, pin);
-		entry = entry->next;
-	}
+	for_each_irq_pin(entry, cfg->irq_2_pin)
+		io_apic_eoi(entry->apic, entry->pin);
 }
 
 static void
@@ -3238,8 +3182,7 @@ void destroy_irq(unsigned int irq)
 	cfg = desc->chip_data;
 	dynamic_irq_cleanup(irq);
 	/* connect back irq_cfg */
-	if (desc)
-		desc->chip_data = cfg;
+	desc->chip_data = cfg;
 
 	free_irte(irq);
 	spin_lock_irqsave(&vector_lock, flags);
@@ -3909,7 +3852,11 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq,
 	 */
 	if (irq >= NR_IRQS_LEGACY) {
 		cfg = desc->chip_data;
-		add_pin_to_irq_node(cfg, node, ioapic, pin);
+		if (add_pin_to_irq_node_nopanic(cfg, node, ioapic, pin)) {
+			printk(KERN_INFO "can not add pin %d for irq %d\n",
+				pin, irq);
+			return 0;
+		}
 	}
 
 	setup_IO_APIC_irq(ioapic, pin, irq, desc, trigger, polarity);