Patch to get cpqphp working with IOAPIC (2.6.0-test5)

Patch to get cpqphp working with IOAPIC (2.6.0-test5)

[Dely Sy]

Hi,

Here is a patch for 2.6.0-test5 to get cpqphp working with IOAPIC. 
My earlier statement that a kernel patch is not needed for 2.6 is 
true only when ACPI is enabled.  A similar patch is needed in 
pcibios_enable_irq() for 2.4 kernel and I will send it out 
later.

The fix is in pirq_enable_irq().  This function is called indirectly
by pci_enable_device().  For device present during boot up, it should 
get the proper dev->irq for pcibios_fixup_irqs() has been called to 
get the dev->irq from MP table. If the value is still zero, then 
this is properly caused by "buggy MP table".  For hot-plug device, 
its dev->irq is 0 when the pci_enable_device() is called for it hasn't 
gone through the fixup.  Therefore, the code (similiar to the code 
in pcibios_fixup_irqs) is needed here.

Thanks,
Dely          


diff -Naur linux-2.6.0-test5/arch/i386/pci/irq.c linux-2.6.0-test5php/arch/i386/pci/irq.c
--- linux-2.6.0-test5/arch/i386/pci/irq.c	2003-09-08 12:50:43.000000000 -0700
+++ linux-2.6.0-test5php/arch/i386/pci/irq.c	2003-09-16 01:00:13.000000000 -0700
@@ -812,9 +812,36 @@
 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 	if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
 		char *msg;
-		if (io_apic_assign_pci_irqs)
-			msg = " Probably buggy MP table.";
-		else if (pci_probe & PCI_BIOS_IRQ_SCAN)
+		if (io_apic_assign_pci_irqs) {
+			int irq;
+			
+			pin--;		/* interrupt pins are numbered starting from 1 */
+			irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
+			/*
+			 * Busses behind bridges are typically not listed in the MP-table.
+			 * In this case we have to look up the IRQ based on the parent bus,
+			 * parent slot, and pin number. The SMP code detects such bridged
+			 * busses itself so we should get into this branch reliably.
+			 */
+			if (irq < 0 && dev->bus->parent) { /* go back to the bridge */
+				struct pci_dev * bridge = dev->bus->self;
+
+				pin = (pin + PCI_SLOT(dev->devfn)) % 4;
+				irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number, 
+						PCI_SLOT(bridge->devfn), pin);
+				if (irq >= 0) {
+					printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n", 
+						bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
+				}	
+			}
+			if (irq >= 0) {
+				printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
+					dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
+				dev->irq = irq;
+				return 0;
+			} else
+				msg = " Probably buggy MP table.";
+		} else if (pci_probe & PCI_BIOS_IRQ_SCAN)
 			msg = "";
 		else
 			msg = " Please try using pci=biosirq.";
diff -Naur linux-2.6.0-test5/drivers/pci/hotplug/cpqphp_ctrl.c linux-2.6.0-test5php/drivers/pci/hotplug/cpqphp_ctrl.c
--- linux-2.6.0-test5/drivers/pci/hotplug/cpqphp_ctrl.c	2003-09-08 12:50:01.000000000 -0700
+++ linux-2.6.0-test5php/drivers/pci/hotplug/cpqphp_ctrl.c	2003-09-15 14:37:41.000000000 -0700
@@ -2446,7 +2446,7 @@
 				   u8 behind_bridge, struct resource_lists * resources)
 {
 	int cloop;
-	u8 IRQ;
+	u8 IRQ = 0;
 	u8 temp_byte;
 	u8 device;
 	u8 class_code;
@@ -3021,6 +3021,7 @@
 			}
 		}		// End of base register loop
 
+#if !defined(CONFIG_X86_IO_APIC)
 		// Figure out which interrupt pin this function uses
 		rc = pci_bus_read_config_byte (pci_bus, devfn, PCI_INTERRUPT_PIN, &temp_byte);
 
@@ -3045,6 +3046,7 @@
 
 		// IRQ Line
 		rc = pci_bus_write_config_byte (pci_bus, devfn, PCI_INTERRUPT_LINE, IRQ);
+#endif
 
 		if (!behind_bridge) {
 			rc = cpqhp_set_irq(func->bus, func->device, temp_byte + 0x09, IRQ);
diff -Naur linux-2.6.0-test5/drivers/pci/hotplug/cpqphp_pci.c linux-2.6.0-test5php/drivers/pci/hotplug/cpqphp_pci.c
--- linux-2.6.0-test5/drivers/pci/hotplug/cpqphp_pci.c	2003-09-08 12:50:29.000000000 -0700
+++ linux-2.6.0-test5php/drivers/pci/hotplug/cpqphp_pci.c	2003-09-15 14:38:27.000000000 -0700
@@ -151,6 +151,7 @@
  */
 int cpqhp_set_irq (u8 bus_num, u8 dev_num, u8 int_pin, u8 irq_num)
 {
+#if !defined(CONFIG_X86_IO_APIC)	
 	int rc;
 	u16 temp_word;
 	struct pci_dev fakedev;
@@ -175,6 +176,7 @@
 	// This should only be for x86 as it sets the Edge Level Control Register
 	outb((u8) (temp_word & 0xFF), 0x4d0);
 	outb((u8) ((temp_word & 0xFF00) >> 8), 0x4d1);
+#endif
 
 	return 0;
 }

Re: Patch to get cpqphp working with IOAPIC (2.6.0-test5)

[Greg KH]

On Tue, Sep 16, 2003 at 08:50:24AM -0700, Dely Sy wrote:
> Hi,
> 
> Here is a patch for 2.6.0-test5 to get cpqphp working with IOAPIC. 
> My earlier statement that a kernel patch is not needed for 2.6 is 
> true only when ACPI is enabled.  A similar patch is needed in 
> pcibios_enable_irq() for 2.4 kernel and I will send it out 
> later.
> 
> The fix is in pirq_enable_irq().  This function is called indirectly
> by pci_enable_device().  For device present during boot up, it should 
> get the proper dev->irq for pcibios_fixup_irqs() has been called to 
> get the dev->irq from MP table. If the value is still zero, then 
> this is properly caused by "buggy MP table".  For hot-plug device, 
> its dev->irq is 0 when the pci_enable_device() is called for it hasn't 
> gone through the fixup.  Therefore, the code (similiar to the code 
> in pcibios_fixup_irqs) is needed here.

Wow, very sorry for the long delay here.  I took the patch you sent me
for the irq.c file in your previous big SHPC patch and added it to the
rest of the cpqphp changes you made here, and applied it to my trees.

thanks,

greg k-h