[PATCH] x86: fix the irqbalance quirk for E7320/E7520/E7525

Move the irqbalance quirks for E7320/E7520/E7525(Errata 23 in
http://download.intel.com/design/chipsets/specupdt/30304203.pdf) to early
quirks.

And add a PCI quirk for these platforms to check(which happens very late
during the boot) if the APIC routing is indeed set to default flat mode.

This fixes the breakage(in x86_64) of this quirk due to cpu hotplug which
selects physical mode instead of the logical flat(as needed for this errata
workaround).

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

3 files changed, 63 insertions, 11 deletions

diff --git a/arch/i386/kernel/acpi/earlyquirk.c b/arch/i386/kernel/acpi/earlyquirk.c
index c9841692bb7..4b60af7f91d 100644
--- a/arch/i386/kernel/acpi/earlyquirk.c
+++ b/arch/i386/kernel/acpi/earlyquirk.c
@@ -10,6 +10,7 @@
 #include <asm/pci-direct.h>
 #include <asm/acpi.h>
 #include <asm/apic.h>
+#include <asm/irq.h>
 
 #ifdef CONFIG_ACPI
 
@@ -49,6 +50,24 @@ static int __init check_bridge(int vendor, int device)
 	return 0;
 }
 
+static void check_intel(void)
+{
+	u16 vendor, device;
+
+	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
+
+	if (vendor != PCI_VENDOR_ID_INTEL)
+		return;
+
+	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
+#ifdef CONFIG_SMP
+	if (device == PCI_DEVICE_ID_INTEL_E7320_MCH ||
+	    device == PCI_DEVICE_ID_INTEL_E7520_MCH ||
+	    device == PCI_DEVICE_ID_INTEL_E7525_MCH)
+		quirk_intel_irqbalance();
+#endif
+}
+
 void __init check_acpi_pci(void)
 {
 	int num, slot, func;
@@ -60,6 +79,8 @@ void __init check_acpi_pci(void)
 	if (!early_pci_allowed())
 		return;
 
+	check_intel();
+
 	/* Poor man's PCI discovery */
 	for (num = 0; num < 32; num++) {
 		for (slot = 0; slot < 32; slot++) {
diff --git a/arch/i386/kernel/quirks.c b/arch/i386/kernel/quirks.c
index 9f6ab1789bb..a01320a7b63 100644
--- a/arch/i386/kernel/quirks.c
+++ b/arch/i386/kernel/quirks.c
@@ -3,10 +3,23 @@
  */
 #include <linux/pci.h>
 #include <linux/irq.h>
+#include <asm/pci-direct.h>
+#include <asm/genapic.h>
+#include <asm/cpu.h>
 
 #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
+static void __devinit verify_quirk_intel_irqbalance(struct pci_dev *dev)
+{
+#ifdef CONFIG_X86_64
+	if (genapic !=  &apic_flat)
+		panic("APIC mode must be flat on this system\n");
+#elif defined(CONFIG_X86_GENERICARCH)
+	if (genapic != &apic_default)
+		panic("APIC mode must be default(flat) on this system. Use apic=default\n");
+#endif
+}
 
-static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
+void __init quirk_intel_irqbalance(void)
 {
 	u8 config, rev;
 	u32 word;
@@ -16,18 +29,18 @@ static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
 	 * based platforms.
 	 * Disable SW irqbalance/affinity on those platforms.
 	 */
-	pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
+	rev = read_pci_config_byte(0, 0, 0, PCI_CLASS_REVISION);
 	if (rev > 0x9)
 		return;
 
 	printk(KERN_INFO "Intel E7520/7320/7525 detected.");
 
-	/* enable access to config space*/
-	pci_read_config_byte(dev, 0xf4, &config);
-	pci_write_config_byte(dev, 0xf4, config|0x2);
+	/* enable access to config space */
+	config = read_pci_config_byte(0, 0, 0, 0xf4);
+	write_pci_config_byte(0, 0, 0, 0xf4, config|0x2);
 
 	/* read xTPR register */
-	raw_pci_ops->read(0, 0, 0x40, 0x4c, 2, &word);
+	word = read_pci_config_16(0, 0, 0x40, 0x4c);
 
 	if (!(word & (1 << 13))) {
 		printk(KERN_INFO "Disabling irq balancing and affinity\n");
@@ -38,13 +51,24 @@ static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
 #ifdef CONFIG_PROC_FS
 		no_irq_affinity = 1;
 #endif
+#ifdef CONFIG_HOTPLUG_CPU
+		printk(KERN_INFO "Disabling cpu hotplug control\n");
+		enable_cpu_hotplug = 0;
+#endif
+#ifdef CONFIG_X86_64
+		/* force the genapic selection to flat mode so that
+		 * interrupts can be redirected to more than one CPU.
+		 */
+		genapic_force = &apic_flat;
+#endif
 	}
 
-	/* put back the original value for config space*/
+	/* put back the original value for config space */
 	if (!(config & 0x2))
-		pci_write_config_byte(dev, 0xf4, config);
+		write_pci_config_byte(0, 0, 0, 0xf4, config);
 }
-DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_E7320_MCH,	quirk_intel_irqbalance);
-DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_E7525_MCH,	quirk_intel_irqbalance);
-DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_E7520_MCH,	quirk_intel_irqbalance);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_E7320_MCH,  verify_quirk_intel_irqbalance);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_E7525_MCH,  verify_quirk_intel_irqbalance);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_E7520_MCH,  verify_quirk_intel_irqbalance);
+
 #endif
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index cd7de9c9654..346f27f4c79 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -58,6 +58,7 @@
 #include <asm/arch_hooks.h>
 #include <asm/nmi.h>
 #include <asm/pda.h>
+#include <asm/genapic.h>
 
 #include <mach_apic.h>
 #include <mach_wakecpu.h>
@@ -1482,6 +1483,12 @@ int __devinit __cpu_up(unsigned int cpu)
 	cpu_set(cpu, smp_commenced_mask);
 	while (!cpu_isset(cpu, cpu_online_map))
 		cpu_relax();
+
+#ifdef CONFIG_X86_GENERICARCH
+	if (num_online_cpus() > 8 && genapic == &apic_default)
+		panic("Default flat APIC routing can't be used with > 8 cpus\n");
+#endif
+
 	return 0;
 }