[patch 11/13] ioapic: Fix non atomic allocation with interrupts disabled

Suresh Siddha
2009-03-17T00:29:59Z

[-- Attachment #1: fix_kmalloc_with_irqs_disabled.patch --]
[-- Type: text/plain, Size: 3233 bytes --]

save_mask_IO_APIC_setup() was using non atomic memory allocation while getting
called with interrupts disabled. Fix this by splitting this into two different
function. Allocation part save_IO_APIC_setup() now happens before
disabling interrupts.

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

Index: tip/arch/x86/kernel/apic/apic.c
===================================================================
--- tip.orig/arch/x86/kernel/apic/apic.c
+++ tip/arch/x86/kernel/apic/apic.c
@@ -1338,15 +1338,16 @@ void __init enable_IR_x2apic(void)
return;
}

- local_irq_save(flags);
- mask_8259A();
-
- ret = save_mask_IO_APIC_setup();
+ ret = save_IO_APIC_setup();
if (ret) {
pr_info("Saving IO-APIC state failed: %d\n", ret);
goto end;
}

+ local_irq_save(flags);
+ mask_IO_APIC_setup();
+ mask_8259A();
+
ret = enable_intr_remapping(1);

if (ret && x2apic_preenabled) {
@@ -1371,10 +1372,10 @@ end_restore:
else
reinit_intr_remapped_IO_APIC(x2apic_preenabled);

-end:
unmask_8259A();
local_irq_restore(flags);

+end:
if (!ret) {
if (!x2apic_preenabled)
pr_info("Enabled x2apic and interrupt-remapping\n");
Index: tip/arch/x86/kernel/apic/io_apic.c
===================================================================
--- tip.orig/arch/x86/kernel/apic/io_apic.c
+++ tip/arch/x86/kernel/apic/io_apic.c
@@ -853,9 +853,9 @@ __setup("pirq=", ioapic_pirq_setup);
static struct IO_APIC_route_entry *early_ioapic_entries[MAX_IO_APICS];

/*
- * Saves and masks all the unmasked IO-APIC RTE's
+ * Saves all the IO-APIC RTE's
*/
-int save_mask_IO_APIC_setup(void)
+int save_IO_APIC_setup(void)
{
union IO_APIC_reg_01 reg_01;
unsigned long flags;
@@ -880,16 +880,9 @@ int save_mask_IO_APIC_setup(void)
}

for (apic = 0; apic < nr_ioapics; apic++)
- for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
- struct IO_APIC_route_entry entry;
-
- entry = early_ioapic_entries[apic][pin] =
+ for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
+ early_ioapic_entries[apic][pin] =
ioapic_read_entry(apic, pin);
- if (!entry.mask) {
- entry.mask = 1;
- ioapic_write_entry(apic, pin, entry);
- }
- }

return 0;

@@ -902,6 +895,25 @@ nomem:
return -ENOMEM;
}

+void mask_IO_APIC_setup(void)
+{
+ int apic, pin;
+
+ for (apic = 0; apic < nr_ioapics; apic++) {
+ if (!early_ioapic_entries[apic])
+ break;
+ for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
+ struct IO_APIC_route_entry entry;
+
+ entry = early_ioapic_entries[apic][pin];
+ if (!entry.mask) {
+ entry.mask = 1;
+ ioapic_write_entry(apic, pin, entry);
+ }
+ }
+ }
+}
+
void restore_IO_APIC_setup(void)
{
int apic, pin;
Index: tip/arch/x86/include/asm/io_apic.h
===================================================================
--- tip.orig/arch/x86/include/asm/io_apic.h
+++ tip/arch/x86/include/asm/io_apic.h
@@ -162,7 +162,8 @@ extern int (*ioapic_renumber_irq)(int io
extern void ioapic_init_mappings(void);

#ifdef CONFIG_X86_64
-extern int save_mask_IO_APIC_setup(void);
+extern int save_IO_APIC_setup(void);
+extern void mask_IO_APIC_setup(void);
extern void restore_IO_APIC_setup(void);
extern void reinit_intr_remapped_IO_APIC(int);
#endif

--