[PATCH 1/4] MIPS: sgi-ip32: Mask MACE PCI interrupts in CRIME only

[Imre Kaloz]

Masking PCI interrupts in the MACE PCI control register overwrites the
error and arbitration enables set at init, and a read-modify-write can
hang CRIME 1.1 machines under DMA load. Enable the slot interrupts once
and mask them in CRIME.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Imre Kaloz <kaloz@xxxxxxxxxx>
---
 arch/mips/pci/pci-ip32.c      |  7 ++++--
 arch/mips/sgi-ip32/ip32-irq.c | 45 +++--------------------------------
 2 files changed, 8 insertions(+), 44 deletions(-)

diff --git a/arch/mips/pci/pci-ip32.c b/arch/mips/pci/pci-ip32.c
index 7ae89d0c7099..30aca6f76563 100644
--- a/arch/mips/pci/pci-ip32.c
+++ b/arch/mips/pci/pci-ip32.c
@@ -125,10 +125,13 @@ static int __init mace_init(void)
 {
 	PCIBIOS_MIN_IO = 0x1000;
 
-	/* Clear any outstanding errors and enable interrupts */
+	/*
+	 * Clear any outstanding errors and enable interrupts.  PCI interrupts
+	 * are masked in CRIME, so the per-slot enables stay on.
+	 */
 	mace->pci.error_addr = 0;
 	mace->pci.error = 0;
-	mace->pci.control = 0xff008500;
+	mace->pci.control = 0xff0085ff;
 
 	printk("MACE PCI rev %d\n", mace->pci.rev);
 
diff --git a/arch/mips/sgi-ip32/ip32-irq.c b/arch/mips/sgi-ip32/ip32-irq.c
index 29d04468a06b..b9c72af481ed 100644
--- a/arch/mips/sgi-ip32/ip32-irq.c
+++ b/arch/mips/sgi-ip32/ip32-irq.c
@@ -160,38 +160,6 @@ static struct irq_chip crime_edge_interrupt = {
 	.irq_unmask	= crime_enable_irq,
 };
 
-/*
- * This is for MACE PCI interrupts.  We can decrease bus traffic by masking
- * as close to the source as possible.	This also means we can take the
- * next chunk of the CRIME register in one piece.
- */
-
-static unsigned long macepci_mask;
-
-static void enable_macepci_irq(struct irq_data *d)
-{
-	macepci_mask |= MACEPCI_CONTROL_INT(d->irq - MACEPCI_SCSI0_IRQ);
-	mace->pci.control = macepci_mask;
-	crime_mask |= 1 << (d->irq - CRIME_IRQ_BASE);
-	crime->imask = crime_mask;
-}
-
-static void disable_macepci_irq(struct irq_data *d)
-{
-	crime_mask &= ~(1 << (d->irq - CRIME_IRQ_BASE));
-	crime->imask = crime_mask;
-	flush_crime_bus();
-	macepci_mask &= ~MACEPCI_CONTROL_INT(d->irq - MACEPCI_SCSI0_IRQ);
-	mace->pci.control = macepci_mask;
-	flush_mace_bus();
-}
-
-static struct irq_chip ip32_macepci_interrupt = {
-	.name = "IP32 MACE PCI",
-	.irq_mask = disable_macepci_irq,
-	.irq_unmask = enable_macepci_irq,
-};
-
 /* This is used for MACE ISA interrupts.  That means bits 4-6 in the
  * CRIME register.
  */
@@ -299,8 +267,8 @@ static struct irq_chip ip32_maceisa_edge_interrupt = {
 	.irq_unmask	= enable_maceisa_irq,
 };
 
-/* This is used for regular non-ISA, non-PCI MACE interrupts.  That means
- * bits 0-3 and 7 in the CRIME register.
+/* This is used for regular non-ISA MACE interrupts.  That means bits 0-3
+ * and 7-15 in the CRIME register.
  */
 
 static void enable_mace_irq(struct irq_data *d)
@@ -436,20 +404,13 @@ void __init arch_init_irq(void)
 	mips_cpu_irq_init();
 	for (irq = CRIME_IRQ_BASE; irq <= IP32_IRQ_MAX; irq++) {
 		switch (irq) {
-		case MACE_VID_IN1_IRQ ... MACE_PCI_BRIDGE_IRQ:
+		case MACE_VID_IN1_IRQ ... MACEPCI_SHARED2_IRQ:
 			irq_set_chip_and_handler_name(irq,
 						      &ip32_mace_interrupt,
 						      handle_level_irq,
 						      "level");
 			break;
 
-		case MACEPCI_SCSI0_IRQ ...  MACEPCI_SHARED2_IRQ:
-			irq_set_chip_and_handler_name(irq,
-						      &ip32_macepci_interrupt,
-						      handle_level_irq,
-						      "level");
-			break;
-
 		case CRIME_CPUERR_IRQ:
 		case CRIME_MEMERR_IRQ:
 			irq_set_chip_and_handler_name(irq,
-- 
2.47.3