Re: [Patch 0/2] Disable SW irqbalance/irqaffinity for E7520/E7320/E7525

From: Suresh Siddha
Date: Fri Sep 24 2004 - 17:24:20 EST


On Fri, Sep 24, 2004 at 04:24:47PM -0400, Jeff Garzik wrote:
> Zwane Mwaikambo wrote:
> > On Thu, 23 Sep 2004, Suresh Siddha wrote:
> >
> >
> >>As part of the workaround for the "Interrupt message re-ordering across
> >>hub interface" errata (page #16 in
> >>http://developer.intel.com/design/chipsets/specupdt/30288402.pdf),
> >>BIOS may enable hardware IRQ balancing for Lindenhurst/Tumwater based chipset
> >>platforms. Software based irq_balance/irq_affinity should be disabled if
> >>hardware IRQ balancing is enabled.
> >
> >
> > Can we avoid those tests? Like not starting the irq balancer code at all
> > with those chipsets?
>
>
> That's my preference.
>

Ok. How about this patch?

Add pci quirks to disable irqbalance/affinity for E7520/E7320/E7525
with revision ID 0x09 and below.

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>

diff -Nru linux-2.6.9-rc2/arch/i386/kernel/io_apic.c linux-irq/arch/i386/kernel/io_apic.c
--- linux-2.6.9-rc2/arch/i386/kernel/io_apic.c 2004-09-12 22:32:00.000000000 -0700
+++ linux-irq/arch/i386/kernel/io_apic.c 2004-09-04 12:12:42.499670496 -0700
@@ -31,6 +31,7 @@
#include <linux/mc146818rtc.h>
#include <linux/compiler.h>
#include <linux/acpi.h>
+#include <linux/pci.h>

#include <linux/sysdev.h>
#include <asm/io.h>
@@ -260,7 +261,7 @@
cpumask_t __cacheline_aligned pending_irq_balance_cpumask[NR_IRQS];

#define IRQBALANCE_CHECK_ARCH -999
-static int irqbalance_disabled = IRQBALANCE_CHECK_ARCH;
+int irqbalance_disabled = IRQBALANCE_CHECK_ARCH;
static int physical_balance = 0;

struct irq_cpu_info {
@@ -582,6 +583,30 @@
return 0;
}

+/* HW irqbalance may be enabled for E7520/E7320/E7525 with revision ID
+ * 0x09 and below. Disable sw irqbalance in that case
+ */
+static void check_hw_irqbalance(void)
+{
+ struct pci_dev *dev = NULL;
+ extern void quirk_intel_irqbalance(struct pci_dev *dev);
+
+ dev = pci_find_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SMCH,
+ dev);
+ if (!dev)
+ dev = pci_find_device(PCI_VENDOR_ID_INTEL,
+ PCI_DEVICE_ID_INTEL_E7320_MCH, dev);
+ if (!dev)
+ dev = pci_find_device(PCI_VENDOR_ID_INTEL,
+ PCI_DEVICE_ID_INTEL_E7525_MCH, dev);
+ if (!dev)
+ return;
+
+ quirk_intel_irqbalance(dev);
+
+ return;
+}
+
static int __init balanced_irq_init(void)
{
int i;
@@ -590,6 +615,8 @@

cpus_shift_right(tmp, cpu_online_map, 2);
c = &boot_cpu_data;
+
+ check_hw_irqbalance();
/* When not overwritten by the command line ask subarchitecture. */
if (irqbalance_disabled == IRQBALANCE_CHECK_ARCH)
irqbalance_disabled = NO_BALANCE_IRQ;
@@ -636,7 +663,7 @@
return 0;
}

-static int __init irqbalance_disable(char *str)
+int __init irqbalance_disable(char *str)
{
irqbalance_disabled = 1;
return 0;
diff -Nru linux-2.6.9-rc2/arch/i386/kernel/irq.c linux-irq/arch/i386/kernel/irq.c
--- linux-2.6.9-rc2/arch/i386/kernel/irq.c 2004-09-12 22:31:30.000000000 -0700
+++ linux-irq/arch/i386/kernel/irq.c 2004-09-04 11:48:21.000000000 -0700
@@ -272,7 +272,7 @@

static int noirqdebug;

-static int __init noirqdebug_setup(char *str)
+int __init noirqdebug_setup(char *str)
{
noirqdebug = 1;
printk("IRQ lockup detection disabled\n");
@@ -997,13 +997,15 @@
return len;
}

+int no_irq_affinity;
+
static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
unsigned long count, void *data)
{
int irq = (long)data, full_count = count, err;
cpumask_t new_value, tmp;

- if (!irq_desc[irq].handler->set_affinity)
+ if (!irq_desc[irq].handler->set_affinity || no_irq_affinity)
return -EIO;

err = cpumask_parse(buffer, count, new_value);
diff -Nru linux-2.6.9-rc2/arch/x86_64/kernel/irq.c linux-irq/arch/x86_64/kernel/irq.c
--- linux-2.6.9-rc2/arch/x86_64/kernel/irq.c 2004-09-12 22:32:26.000000000 -0700
+++ linux-irq/arch/x86_64/kernel/irq.c 2004-09-04 11:48:23.000000000 -0700
@@ -835,6 +835,8 @@
return len;
}

+int no_irq_affinity;
+
static int irq_affinity_write_proc (struct file *file,
const char __user *buffer,
unsigned long count, void *data)
@@ -842,7 +844,7 @@
int irq = (long) data, full_count = count, err;
cpumask_t tmp, new_value;

- if (!irq_desc[irq].handler->set_affinity)
+ if (!irq_desc[irq].handler->set_affinity || no_irq_affinity)
return -EIO;

err = cpumask_parse(buffer, count, new_value);
diff -Nru linux-2.6.9-rc2/drivers/pci/quirks.c linux-irq/drivers/pci/quirks.c
--- linux-2.6.9-rc2/drivers/pci/quirks.c 2004-09-12 22:31:27.000000000 -0700
+++ linux-irq/drivers/pci/quirks.c 2004-09-04 12:33:54.373316312 -0700
@@ -814,6 +814,64 @@
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_12, asus_hides_smbus_lpc );
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0, asus_hides_smbus_lpc );

+#ifdef CONFIG_X86_IO_APIC
+#include <asm/hw_irq.h>
+#ifdef CONFIG_IRQBALANCE
+extern int irqbalance_disable(char *str);
+#endif
+extern int no_irq_affinity;
+extern int noirqdebug_setup(char *str);
+
+
+void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
+{
+ u8 config, rev;
+ u32 word;
+ extern struct pci_raw_ops *raw_pci_ops;
+#ifdef CONFIG_IRQBALANCE
+ extern int irqbalance_disabled;
+
+ /* we might have come through check_hw_irqbalance()
+ * and enabled the workaround
+ */
+ if (irqbalance_disabled == 1 && no_irq_affinity)
+ return;
+#endif
+
+ pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
+ if (rev > 0x9)
+ return;
+
+ printk(KERN_INFO "Intel E7520/7320/7525 detected.");
+
+ /* enable access to config space*/
+ pci_read_config_byte(dev, 0xf4, &config);
+ config |= 0x2;
+ pci_write_config_byte(dev, 0xf4, config);
+
+ /* read xTPR register */
+ raw_pci_ops->read(0, 0, 0x40, 0x4c, 2, &word);
+
+ if (!(word & (1 << 13))) {
+ printk(KERN_INFO "Disabling irq balancing and affinity\n");
+#ifdef __i386__
+#ifdef CONFIG_IRQBALANCE
+ irqbalance_disable("");
+#endif
+ noirqdebug_setup("");
+#endif
+ no_irq_affinity = 1;
+ }
+
+ config &= ~0x2;
+ /* disable access to config space*/
+ pci_write_config_byte(dev, 0xf4, config);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SMCH, quirk_intel_irqbalance);
+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);
+#endif
+
/*
* SiS 96x south bridge: BIOS typically hides SMBus device...
*/
diff -Nru linux-2.6.9-rc2/include/linux/pci_ids.h linux-irq/include/linux/pci_ids.h
--- linux-2.6.9-rc2/include/linux/pci_ids.h 2004-09-12 22:33:54.000000000 -0700
+++ linux-irq/include/linux/pci_ids.h 2004-09-04 11:48:26.000000000 -0700
@@ -2204,6 +2204,8 @@
#define PCI_DEVICE_ID_INTEL_82855GM_HB 0x3580
#define PCI_DEVICE_ID_INTEL_82855GM_IG 0x3582
#define PCI_DEVICE_ID_INTEL_SMCH 0x3590
+#define PCI_DEVICE_ID_INTEL_E7320_MCH 0x3592
+#define PCI_DEVICE_ID_INTEL_E7525_MCH 0x359e
#define PCI_DEVICE_ID_INTEL_80310 0x530d
#define PCI_DEVICE_ID_INTEL_82371SB_0 0x7000
#define PCI_DEVICE_ID_INTEL_82371SB_1 0x7010
-
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