x86: add some pirq debugging

we use a few static mapping rules in our pirq routing functions,
and for example regression f3ac84324fd94 was due to the pirq
being out of range of the remapping array. Put in a few
WARN_ON_ONCE() lines so that we get notified about any such
out-of-bound incidents.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index 88d8f5c0ecb5..ee524ca5f8c0 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -200,6 +200,7 @@ static int pirq_ali_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
 {
         static const unsigned char irqmap[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 1, 11, 0, 12, 0, 14, 0, 15 };
 
+        WARN_ON_ONCE(pirq >= 16);
         return irqmap[read_config_nybble(router, 0x48, pirq-1)];
 }
 
@@ -207,7 +208,8 @@ static int pirq_ali_set(struct pci_dev *router, struct pci_dev *dev, int pirq, i
 {
         static const unsigned char irqmap[16] = { 0, 8, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 };
         unsigned int val = irqmap[irq];
-                
+
+        WARN_ON_ONCE(pirq >= 16);
         if (val) {
                 write_config_nybble(router, 0x48, pirq-1, val);
                 return 1;
@@ -257,12 +259,16 @@ static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, i
 static int pirq_via586_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
 {
         static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
+
+        WARN_ON_ONCE(pirq >= 5);
         return read_config_nybble(router, 0x55, pirqmap[pirq-1]);
 }
 
 static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
 {
         static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
+
+        WARN_ON_ONCE(pirq >= 5);
         write_config_nybble(router, 0x55, pirqmap[pirq-1], irq);
         return 1;
 }
@@ -275,12 +281,16 @@ static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq
 static int pirq_ite_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
 {
         static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
+
+        WARN_ON_ONCE(pirq >= 4);
         return read_config_nybble(router,0x43, pirqmap[pirq-1]);
 }
 
 static int pirq_ite_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
 {
         static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
+
+        WARN_ON_ONCE(pirq >= 4);
         write_config_nybble(router, 0x43, pirqmap[pirq-1], irq);
         return 1;
 }
@@ -419,6 +429,7 @@ static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, i
 
 static int pirq_vlsi_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
 {
+        WARN_ON_ONCE(pirq >= 9);
         if (pirq > 8) {
                 printk(KERN_INFO "VLSI router pirq escape (%d)\n", pirq);
                 return 0;
@@ -428,6 +439,7 @@ static int pirq_vlsi_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
 
 static int pirq_vlsi_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
 {
+        WARN_ON_ONCE(pirq >= 9);
         if (pirq > 8) {
                 printk(KERN_INFO "VLSI router pirq escape (%d)\n", pirq);
                 return 0;