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Commit b9e0353f authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
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x86/acpi: remove irq-compression trick on 32-bit 

We already have a per cpu vector on 32-bit via recent changes, and
don't need this trick any more (which trick obfuscates the real GSI
mappings and which only triggers on larger systems to begin with):

On 3 ioapic system (24 per ioapic) before patch I got:

ACPI: PCI Interrupt Link [ILSB] enabled at IRQ 71
IOAPIC[2]: Set routing entry (10-23 -> 0xa9 -> IRQ 64 Mode:1 Active:1)
pci 0000:80:01.1: PCI INT A -> Link[ILSB] -> GSI 71 (level, low) -> IRQ 64
ACPI: PCI Interrupt Link [LE5B] enabled at IRQ 67
IOAPIC[2]: Set routing entry (10-19 -> 0xb1 -> IRQ 65 Mode:1 Active:1)
pci 0000:83:00.0: PCI INT B -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 65
ACPI: PCI Interrupt Link [LE5A] enabled at IRQ 66
IOAPIC[2]: Set routing entry (10-18 -> 0xb9 -> IRQ 66 Mode:1 Active:1)
pci 0000:83:00.1: PCI INT A -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
ACPI: PCI Interrupt Link [LE5D] enabled at IRQ 65
IOAPIC[2]: Set routing entry (10-17 -> 0xc1 -> IRQ 67 Mode:1 Active:1)
pci 0000:84:00.0: PCI INT B -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 67
ACPI: PCI Interrupt Link [LE5C] enabled at IRQ 64
IOAPIC[2]: Set routing entry (10-16 -> 0xc9 -> IRQ 68 Mode:1 Active:1)
pci 0000:84:00.1: PCI INT A -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 68
pci 0000:87:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
pci 0000:87:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 67
pci 0000:88:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 68
pci 0000:88:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 65
pci 0000:8b:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
pci 0000:8b:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 67
pci 0000:8c:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 68
pci 0000:8c:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 65

after the patch we get:

ACPI: PCI Interrupt Link [ILSB] enabled at IRQ 71
IOAPIC[2]: Set routing entry (10-23 -> 0xa9 -> IRQ 71 Mode:1 Active:1)
pci 0000:80:01.1: PCI INT A -> Link[ILSB] -> GSI 71 (level, low) -> IRQ 71
ACPI: PCI Interrupt Link [LE5B] enabled at IRQ 67
IOAPIC[2]: Set routing entry (10-19 -> 0xb1 -> IRQ 67 Mode:1 Active:1)
pci 0000:83:00.0: PCI INT B -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 67
ACPI: PCI Interrupt Link [LE5A] enabled at IRQ 66
IOAPIC[2]: Set routing entry (10-18 -> 0xb9 -> IRQ 66 Mode:1 Active:1)
pci 0000:83:00.1: PCI INT A -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
ACPI: PCI Interrupt Link [LE5D] enabled at IRQ 65
IOAPIC[2]: Set routing entry (10-17 -> 0xc1 -> IRQ 65 Mode:1 Active:1)
pci 0000:84:00.0: PCI INT B -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 65
ACPI: PCI Interrupt Link [LE5C] enabled at IRQ 64
IOAPIC[2]: Set routing entry (10-16 -> 0xc9 -> IRQ 64 Mode:1 Active:1)
pci 0000:84:00.1: PCI INT A -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 64
pci 0000:87:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
pci 0000:87:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 65
pci 0000:88:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 64
pci 0000:88:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 67
pci 0000:8b:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
pci 0000:8b:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 65
pci 0000:8c:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 64
pci 0000:8c:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 67

As it can be seen that GSIs now get mapped lineary.

[ Impact: simplify irq number mapping on bigger 32-bit systems ]
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Len Brown <lenb@kernel.org>
LKML-Reference: <4A01C35C.7060207@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b2e5d858
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Showing with 7 additions and 58 deletions
arch/x86/kernel/acpi/boot.c
View file @ b9e0353f
......@@ -1162,22 +1162,9 @@ int mp_register_gsi(struct device *dev, u32 gsi, int triggering, int polarity)
{
int ioapic;
int ioapic_pin;
#ifdef CONFIG_X86_32
#define MAX_GSI_NUM 4096
#define IRQ_COMPRESSION_START 64
static int pci_irq = IRQ_COMPRESSION_START;
/*
* Mapping between Global System Interrupts, which
* represent all possible interrupts, and IRQs
* assigned to actual devices.
*/
static int gsi_to_irq[MAX_GSI_NUM];
#else
if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC)
return gsi;
#endif
/* Don't set up the ACPI SCI because it's already set up */
if (acpi_gbl_FADT.sci_interrupt == gsi)
......@@ -1196,66 +1183,28 @@ int mp_register_gsi(struct device *dev, u32 gsi, int triggering, int polarity)
gsi = ioapic_renumber_irq(ioapic, gsi);
#endif
/*
* Avoid pin reprogramming. PRTs typically include entries
* with redundant pin->gsi mappings (but unique PCI devices);
* we only program the IOAPIC on the first.
*/
if (ioapic_pin > MP_MAX_IOAPIC_PIN) {
printk(KERN_ERR "Invalid reference to IOAPIC pin "
"%d-%d\n", mp_ioapic_routing[ioapic].apic_id,
ioapic_pin);
return gsi;
}
/*
* Avoid pin reprogramming. PRTs typically include entries
* with redundant pin->gsi mappings (but unique PCI devices);
* we only program the IOAPIC on the first.
*/
if (test_bit(ioapic_pin, mp_ioapic_routing[ioapic].pin_programmed)) {
pr_debug("Pin %d-%d already programmed\n",
mp_ioapic_routing[ioapic].apic_id, ioapic_pin);
#ifdef CONFIG_X86_32
return (gsi < IRQ_COMPRESSION_START ? gsi : gsi_to_irq[gsi]);
#else
return gsi;
#endif
}
set_bit(ioapic_pin, mp_ioapic_routing[ioapic].pin_programmed);
#ifdef CONFIG_X86_32
/*
* For GSI >= 64, use IRQ compression
*/
if ((gsi >= IRQ_COMPRESSION_START)
&& (triggering == ACPI_LEVEL_SENSITIVE)) {
/*
* For PCI devices assign IRQs in order, avoiding gaps
* due to unused I/O APIC pins.
*/
int irq = gsi;
if (gsi < MAX_GSI_NUM) {
/*
* Retain the VIA chipset work-around (gsi > 15), but
* avoid a problem where the 8254 timer (IRQ0) is setup
* via an override (so it's not on pin 0 of the ioapic),
* and at the same time, the pin 0 interrupt is a PCI
* type. The gsi > 15 test could cause these two pins
* to be shared as IRQ0, and they are not shareable.
* So test for this condition, and if necessary, avoid
* the pin collision.
*/
gsi = pci_irq++;
/*
* Don't assign IRQ used by ACPI SCI
*/
if (gsi == acpi_gbl_FADT.sci_interrupt)
gsi = pci_irq++;
gsi_to_irq[irq] = gsi;
} else {
printk(KERN_ERR "GSI %u is too high\n", gsi);
return gsi;
}
}
#endif
io_apic_set_pci_routing(dev, ioapic, ioapic_pin, gsi,
triggering == ACPI_EDGE_SENSITIVE ? 0 : 1,
polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
return gsi;
}
......
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