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| author | Yinghai Lu <yhlu.kernel@gmail.com> | 2008-08-19 20:50:03 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-16 16:52:08 +0200 |
| commit | 71f521bbaf375b685aeea20c6b0ed8600cd6edfe (patch) | |
| tree | a18b8e8284ff7a68c341de8b1342866b9821ae7f /arch/x86/kernel | |
| parent | a84488c213a8cfc29200344a6fb6357d48c8ed85 (diff) | |
| download | linux-71f521bbaf375b685aeea20c6b0ed8600cd6edfe.tar.gz linux-71f521bbaf375b685aeea20c6b0ed8600cd6edfe.tar.bz2 linux-71f521bbaf375b685aeea20c6b0ed8600cd6edfe.zip | |
x86, irq: get nr_irqs from madt
Until now, NR_IRQS was derived from black magic defines that had to
be "large enough" to both accomodate NR_CPUS and MAX_NR_IO_APICs.
This resulted in a way too large irq_desc[] array on most x86 systems.
Especially with larger CPU masks, the size of irq_desc can spiral out
of control quickly.
So be smarter about it and use precise allocation instead: determine the
default maximum possible IRQ number from the ACPI MADT. Use a minimum limit
of at least 32 IRQs for broken BIOSes.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/acpi/boot.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index eb875cdc7367..3e9d163fd92f 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -957,6 +957,29 @@ void __init mp_register_ioapic(int id, u32 address, u32 gsi_base) nr_ioapics++; } +int get_nr_irqs_via_madt(void) +{ + int idx; + int nr = 0; + + for (idx = 0; idx < nr_ioapics; idx++) { + if (mp_ioapic_routing[idx].gsi_end > nr) + nr = mp_ioapic_routing[idx].gsi_end; + } + + nr++; + + /* double it for hotplug and msi and nmi */ + nr <<= 1; + + /* something wrong ? */ + if (nr < 32) + nr = 32; + + return nr; + +} + static void assign_to_mp_irq(struct mp_config_intsrc *m, struct mp_config_intsrc *mp_irq) { @@ -1254,9 +1277,12 @@ static int __init acpi_parse_madt_ioapic_entries(void) return count; } + + nr_irqs = get_nr_irqs_via_madt(); + count = acpi_table_parse_madt(ACPI_MADT_TYPE_INTERRUPT_OVERRIDE, acpi_parse_int_src_ovr, - NR_IRQ_VECTORS); + nr_irqs); if (count < 0) { printk(KERN_ERR PREFIX "Error parsing interrupt source overrides entry\n"); @@ -1276,7 +1302,7 @@ static int __init acpi_parse_madt_ioapic_entries(void) count = acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE, acpi_parse_nmi_src, - NR_IRQ_VECTORS); + nr_irqs); if (count < 0) { printk(KERN_ERR PREFIX "Error parsing NMI SRC entry\n"); /* TBD: Cleanup to allow fallback to MPS */ |