[PATCH] genirq: x86_64 irq: Remove the msi assumption that irq == vector

This patch removes the change in behavior of the irq allocation code when
CONFIG_PCI_MSI is defined.  Removing all instances of the assumption that irq
== vector.

create_irq is rewritten to first allocate a free irq and then to assign that
irq a vector.

assign_irq_vector is made static and the AUTO_ASSIGN case which allocates an
vector not bound to an irq is removed.

The ioapic vector methods are removed, and everything now works with irqs.

The definition of NR_IRQS no longer depends on CONFIG_PCI_MSI

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 47 insertions, 100 deletions

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 437b6f96cc80..bb16f3790f09 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -44,6 +44,8 @@
 #include <asm/nmi.h>
 #include <asm/msidef.h>
 
+static int assign_irq_vector(int irq);
+
 #define __apicdebuginit  __init
 
 int sis_apic_bug; /* not actually supported, dummy for compile */
@@ -83,14 +85,6 @@ static struct irq_pin_list {
         short apic, pin, next;
 } irq_2_pin[PIN_MAP_SIZE];
 
-int vector_irq[NR_VECTORS] __read_mostly = { [0 ... NR_VECTORS - 1] = -1};
-#ifdef CONFIG_PCI_MSI
-#define vector_to_irq(vector)   \
-        (platform_legacy_irq(vector) ? vector : vector_irq[vector])
-#else
-#define vector_to_irq(vector)   (vector)
-#endif
-
 #define __DO_ACTION(R, ACTION, FINAL)                                   \
                                                                         \
 {                                                                       \
@@ -162,7 +156,7 @@ static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t mask)
 
         spin_lock_irqsave(&ioapic_lock, flags);
         __DO_ACTION(1, = dest, )
-        set_irq_info(irq, mask);
+        set_native_irq_info(irq, mask);
         spin_unlock_irqrestore(&ioapic_lock, flags);
 }
 #endif
@@ -599,18 +593,14 @@ static inline int IO_APIC_irq_trigger(int irq)
 /* irq_vectors is indexed by the sum of all RTEs in all I/O APICs. */
 u8 irq_vector[NR_IRQ_VECTORS] __read_mostly = { FIRST_DEVICE_VECTOR , 0 };
 
-int assign_irq_vector(int irq)
+static int __assign_irq_vector(int irq)
 {
         static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
-        unsigned long flags;
         int vector;
 
-        BUG_ON(irq != AUTO_ASSIGN && (unsigned)irq >= NR_IRQ_VECTORS);
-
-        spin_lock_irqsave(&vector_lock, flags);
+        BUG_ON((unsigned)irq >= NR_IRQ_VECTORS);
 
-        if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) {
-                spin_unlock_irqrestore(&vector_lock, flags);
+        if (IO_APIC_VECTOR(irq) > 0) {
                 return IO_APIC_VECTOR(irq);
         }
 next:
@@ -625,10 +615,18 @@ next:
         }
 
         vector = current_vector;
-        vector_irq[vector] = irq;
-        if (irq != AUTO_ASSIGN)
-                IO_APIC_VECTOR(irq) = vector;
+        IO_APIC_VECTOR(irq) = vector;
+
+        return vector;
+}
+
+static int assign_irq_vector(int irq)
+{
+        int vector;
+        unsigned long flags;
 
+        spin_lock_irqsave(&vector_lock, flags);
+        vector = __assign_irq_vector(irq);
         spin_unlock_irqrestore(&vector_lock, flags);
 
         return vector;
@@ -644,18 +642,14 @@ static struct irq_chip ioapic_chip;
 
 static void ioapic_register_intr(int irq, int vector, unsigned long trigger)
 {
-        unsigned idx;
-
-        idx = use_pci_vector() && !platform_legacy_irq(irq) ? vector : irq;
-
         if ((trigger == IOAPIC_AUTO && IO_APIC_irq_trigger(irq)) ||
                         trigger == IOAPIC_LEVEL)
-                set_irq_chip_and_handler(idx, &ioapic_chip,
+                set_irq_chip_and_handler(irq, &ioapic_chip,
                                          handle_fasteoi_irq);
         else
-                set_irq_chip_and_handler(idx, &ioapic_chip,
+                set_irq_chip_and_handler(irq, &ioapic_chip,
                                          handle_edge_irq);
-        set_intr_gate(vector, interrupt[idx]);
+        set_intr_gate(vector, interrupt[irq]);
 }
 
 static void __init setup_IO_APIC_irqs(void)
@@ -872,17 +866,12 @@ void __apicdebuginit print_IO_APIC(void)
                 );
         }
         }
-        if (use_pci_vector())
-                printk(KERN_INFO "Using vector-based indexing\n");
         printk(KERN_DEBUG "IRQ to pin mappings:\n");
         for (i = 0; i < NR_IRQS; i++) {
                 struct irq_pin_list *entry = irq_2_pin + i;
                 if (entry->pin < 0)
                         continue;
-                if (use_pci_vector() && !platform_legacy_irq(i))
-                        printk(KERN_DEBUG "IRQ%d ", IO_APIC_VECTOR(i));
-                else
-                        printk(KERN_DEBUG "IRQ%d ", i);
+                printk(KERN_DEBUG "IRQ%d ", i);
                 for (;;) {
                         printk("-> %d:%d", entry->apic, entry->pin);
                         if (!entry->next)
@@ -1206,42 +1195,8 @@ static unsigned int startup_ioapic_irq(unsigned int irq)
         return was_pending;
 }
 
-static unsigned int startup_ioapic_vector(unsigned int vector)
-{
-        int irq = vector_to_irq(vector);
-
-        return startup_ioapic_irq(irq);
-}
-
-static void mask_ioapic_vector (unsigned int vector)
-{
-        int irq = vector_to_irq(vector);
-
-        mask_IO_APIC_irq(irq);
-}
-
-static void unmask_ioapic_vector (unsigned int vector)
-{
-        int irq = vector_to_irq(vector);
-
-        unmask_IO_APIC_irq(irq);
-}
-
-#ifdef CONFIG_SMP
-static void set_ioapic_affinity_vector (unsigned int vector,
-                                        cpumask_t cpu_mask)
-{
-        int irq = vector_to_irq(vector);
-
-        set_native_irq_info(vector, cpu_mask);
-        set_ioapic_affinity_irq(irq, cpu_mask);
-}
-#endif // CONFIG_SMP
-
-static int ioapic_retrigger_vector(unsigned int vector)
+static int ioapic_retrigger_irq(unsigned int irq)
 {
-        int irq = vector_to_irq(vector);
-
         send_IPI_self(IO_APIC_VECTOR(irq));
 
         return 1;
@@ -1288,15 +1243,15 @@ static void ack_apic_level(unsigned int irq)
 
 static struct irq_chip ioapic_chip __read_mostly = {
         .name           = "IO-APIC",
-        .startup        = startup_ioapic_vector,
-        .mask           = mask_ioapic_vector,
-        .unmask         = unmask_ioapic_vector,
+        .startup        = startup_ioapic_irq,
+        .mask           = mask_IO_APIC_irq,
+        .unmask         = unmask_IO_APIC_irq,
         .ack            = ack_apic_edge,
         .eoi            = ack_apic_level,
 #ifdef CONFIG_SMP
-        .set_affinity   = set_ioapic_affinity_vector,
+        .set_affinity   = set_ioapic_affinity_irq,
 #endif
-        .retrigger      = ioapic_retrigger_vector,
+        .retrigger      = ioapic_retrigger_irq,
 };
 
 static inline void init_IO_APIC_traps(void)
@@ -1316,11 +1271,6 @@ static inline void init_IO_APIC_traps(void)
          */
         for (irq = 0; irq < NR_IRQS ; irq++) {
                 int tmp = irq;
-                if (use_pci_vector()) {
-                        if (!platform_legacy_irq(tmp))
-                                if ((tmp = vector_to_irq(tmp)) == -1)
-                                        continue;
-                }
                 if (IO_APIC_IRQ(tmp) && !IO_APIC_VECTOR(tmp)) {
                         /*
                          * Hmm.. We don't have an entry for this,
@@ -1695,32 +1645,33 @@ static int __init ioapic_init_sysfs(void)
 
 device_initcall(ioapic_init_sysfs);
 
-#ifdef CONFIG_PCI_MSI
 /*
- * Dynamic irq allocate and deallocation for MSI
+ * Dynamic irq allocate and deallocation
  */
 int create_irq(void)
 {
-        /* Hack of the day: irq == vector.
-         *
-         * Ultimately this will be be more general,
-         * and not depend on the irq to vector identity mapping.
-         * But this version is needed until msi.c can cope with
-         * the more general form.
-         */
-        int irq, vector;
+        /* Allocate an unused irq */
+        int irq;
+        int new;
+        int vector = 0;
         unsigned long flags;
-        vector = assign_irq_vector(AUTO_ASSIGN);
-        irq = vector;
 
-        if (vector >= 0) {
-                spin_lock_irqsave(&vector_lock, flags);
-                vector_irq[vector] = irq;
-                irq_vector[irq] = vector;
-                spin_unlock_irqrestore(&vector_lock, flags);
+        irq = -ENOSPC;
+        spin_lock_irqsave(&vector_lock, flags);
+        for (new = (NR_IRQS - 1); new >= 0; new--) {
+                if (platform_legacy_irq(new))
+                        continue;
+                if (irq_vector[new] != 0)
+                        continue;
+                vector = __assign_irq_vector(new);
+                if (likely(vector > 0))
+                        irq = new;
+                break;
+        }
+        spin_unlock_irqrestore(&vector_lock, flags);
 
+        if (irq >= 0) {
                 set_intr_gate(vector, interrupt[irq]);
-
                 dynamic_irq_init(irq);
         }
         return irq;
@@ -1729,17 +1680,13 @@ int create_irq(void)
 void destroy_irq(unsigned int irq)
 {
         unsigned long flags;
-        unsigned int vector;
 
         dynamic_irq_cleanup(irq);
 
         spin_lock_irqsave(&vector_lock, flags);
-        vector = irq_vector[irq];
-        vector_irq[vector] = -1;
         irq_vector[irq] = 0;
         spin_unlock_irqrestore(&vector_lock, flags);
 }
-#endif
 
 /*
  * MSI mesage composition
@@ -1882,7 +1829,7 @@ int io_apic_set_pci_routing (int ioapic, int pin, int irq, int triggering, int p
         ioapic_write_entry(ioapic, pin, entry);
 
         spin_lock_irqsave(&ioapic_lock, flags);
-        set_native_irq_info(use_pci_vector() ? entry.vector : irq, TARGET_CPUS);
+        set_native_irq_info(irq, TARGET_CPUS);
         spin_unlock_irqrestore(&ioapic_lock, flags);
 
         return 0;