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authorYinghai Lu <yinghai@kernel.org>2008-12-05 18:58:33 -0800
committerIngo Molnar <mingo@elte.hu>2008-12-08 14:31:54 +0100
commitbe5d5350a937cd8513b258739f1099420129e96f (patch)
tree9864a69da06dff2b4e0973d41d440c9d73fbc117 /arch
parent99d093d12897562a253540a902bbf65ec16042ac (diff)
x86: MSI start irq numbering from nr_irqs_gsi
Impact: sanitize MSI irq number ordering from top-down to bottom-up Increase new MSI IRQs starting from nr_irqs_gsi (which is somewhere below 256), instead of decreasing from NR_IRQS. (The latter method can result in confusingly high IRQ numbers - if NR_CPUS is set to a high value and NR_IRQS scales up to a high value.) Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/io_apic.h2
-rw-r--r--arch/x86/kernel/io_apic.c24
-rw-r--r--arch/x86/kernel/setup.c2
3 files changed, 19 insertions, 9 deletions
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 6afd9933a7d..b35e94c2d6d 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -188,7 +188,7 @@ extern void restore_IO_APIC_setup(void);
extern void reinit_intr_remapped_IO_APIC(int);
#endif
-extern int probe_nr_irqs(void);
+extern void probe_nr_irqs_gsi(void);
#else /* !CONFIG_X86_IO_APIC */
#define io_apic_assign_pci_irqs 0
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index 9870461ae93..0dcde74abd1 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -2973,7 +2973,7 @@ unsigned int create_irq_nr(unsigned int irq_want)
irq = 0;
spin_lock_irqsave(&vector_lock, flags);
- for (new = irq_want; new > 0; new--) {
+ for (new = irq_want; new < NR_IRQS; new++) {
if (platform_legacy_irq(new))
continue;
@@ -3001,11 +3001,14 @@ unsigned int create_irq_nr(unsigned int irq_want)
return irq;
}
+static int nr_irqs_gsi = NR_IRQS_LEGACY;
int create_irq(void)
{
+ unsigned int irq_want;
int irq;
- irq = create_irq_nr(nr_irqs - 1);
+ irq_want = nr_irqs_gsi;
+ irq = create_irq_nr(irq_want);
if (irq == 0)
irq = -1;
@@ -3281,7 +3284,7 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc)
int ret;
unsigned int irq_want;
- irq_want = nr_irqs - 1;
+ irq_want = nr_irqs_gsi;
irq = create_irq_nr(irq_want);
if (irq == 0)
return -1;
@@ -3321,11 +3324,11 @@ int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
int index = 0;
#endif
- irq_want = nr_irqs - 1;
+ irq_want = nr_irqs_gsi;
sub_handle = 0;
list_for_each_entry(msidesc, &dev->msi_list, list) {
irq = create_irq_nr(irq_want);
- irq_want--;
+ irq_want++;
if (irq == 0)
return -1;
#ifdef CONFIG_INTR_REMAP
@@ -3674,9 +3677,16 @@ int __init io_apic_get_redir_entries (int ioapic)
return reg_01.bits.entries;
}
-int __init probe_nr_irqs(void)
+void __init probe_nr_irqs_gsi(void)
{
- return NR_IRQS;
+ int idx;
+ int nr = 0;
+
+ for (idx = 0; idx < nr_ioapics; idx++)
+ nr += io_apic_get_redir_entries(idx) + 1;
+
+ if (nr > nr_irqs_gsi)
+ nr_irqs_gsi = nr;
}
/* --------------------------------------------------------------------------
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 9d5674f7b6c..a3834f12320 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1082,7 +1082,7 @@ void __init setup_arch(char **cmdline_p)
ioapic_init_mappings();
/* need to wait for io_apic is mapped */
- nr_irqs = probe_nr_irqs();
+ probe_nr_irqs_gsi();
kvm_guest_init();