Re: oops in ioapic_write_entry

[Yinghai Lu <yinghai@kernel.org>]

On 08/03/2010 04:08 AM, Eric W. Biederman wrote:
> 
> For the common case I think we still do the right thing, even now, for
> these broken bios tables.  There is likely an uncommon case for which
> something like your shared_legacy_irq deserves to be used, especially
> at it preserves our well tested historical behavior.

Dave, Irnna, Gary:

can you check this patch on your systems?

Thanks

Yinghai

[PATCH] x86: check if apic/pin is shared with legacy one

fix system that external device that have io apic on apic0/pin(0-15)

also
for the io apic out of order system:
<6>ACPI: IOAPIC (id[0x10] address[0xfecff000] gsi_base[0])
<6>IOAPIC[0]: apic_id 16, version 0, address 0xfecff000, GSI 0-2
<6>ACPI: IOAPIC (id[0x0f] address[0xfec00000] gsi_base[3])
<6>IOAPIC[1]: apic_id 15, version 0, address 0xfec00000, GSI 3-38
<6>ACPI: IOAPIC (id[0x0e] address[0xfec01000] gsi_base[39])
<6>IOAPIC[2]: apic_id 14, version 0, address 0xfec01000, GSI 39-74
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 1 global_irq 4 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 5 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 3 global_irq 6 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 4 global_irq 7 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 6 global_irq 9 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 7 global_irq 10 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 8 global_irq 11 low edge)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 12 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 12 global_irq 15 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 13 global_irq 16 dfl dfl)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 14 global_irq 17 low edge)
<6>ACPI: INT_SRC_OVR (bus 0 bus_irq 15 global_irq 18 dfl dfl)

after this patch will get

apic0, pin0, GSI 0: irq 0+75
apic0, pin1, GSI 1: irq 1+75
apic0, pin2, GSI 2: irq 2
apic1, pin0, GSI 3: irq 3+75
apic1, pin5, GSI 8: irq 8+75
apic1, pin10,GSI 13: irq 13+75
apic1, pin11,GSI 14: irq 14+75

because mp_config_acpi_legacy_irqs will put apic0, pin2, irq2 in mp_irqs...
so pin_2_irq_legacy will report 2.
irq_to_gsi will still report 2. so it is right.
gsi_to_irq will report 2.

for GSI 0, 1, 3, 8, 13, 14: still right as before.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 arch/x86/kernel/apic/io_apic.c |   31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

Index: linux-2.6/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6/arch/x86/kernel/apic/io_apic.c
@@ -1013,6 +1013,28 @@ static inline int irq_trigger(int idx)
 	return MPBIOS_trigger(idx);
 }
 
+static int pin_2_irq_leagcy(int apic, int pin)
+{
+	int i;
+
+	for (i = 0; i < mp_irq_entries; i++) {
+		int bus = mp_irqs[i].srcbus;
+
+		if (!test_bit(bus, mp_bus_not_pci))
+			continue;
+
+		if (mp_ioapics[apic].apicid != mp_irqs[i].dstapic)
+			continue;
+
+		if (mp_irqs[i].dstirq != pin)
+			continue;
+
+		return mp_irqs[i].srcbusirq;
+	}
+
+	return -1;
+}
+
 static int pin_2_irq(int idx, int apic, int pin)
 {
 	int irq;
@@ -1029,10 +1051,13 @@ static int pin_2_irq(int idx, int apic,
 	} else {
 		u32 gsi = mp_gsi_routing[apic].gsi_base + pin;
 
-		if (gsi >= NR_IRQS_LEGACY)
+		if (gsi >= NR_IRQS_LEGACY) {
 			irq = gsi;
-		else
-			irq = gsi_top + gsi;
+		} else {
+			irq = pin_2_irq_legacy(apic, pin);
+			if (irq < 0)
+				irq = gsi_top + gsi;
+		}
 	}
 
 #ifdef CONFIG_X86_32