x86, ioapic: Use ioapic_saved_data while enabling intr-remapping

Code flow for enabling interrupt-remapping was
allocating/freeing buffers for saving/restoring io-apic RTE's.
ioapic suspend/resume code uses boot time allocated
ioapic_saved_data that is a perfect match for reuse here.

This will remove the unnecessary allocation/free of the
temporary buffers during suspend/resume of interrupt-remapping
enabled platforms aswell as paving the way for further code
consolidation.

Tested-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/20110518233157.574469296@sbsiddha-MOBL3.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 18 insertions, 62 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 8e771d32ada1..08b794d07a52 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -101,7 +101,7 @@ int mp_irq_entries;
 static int nr_irqs_gsi = NR_IRQS_LEGACY;
 
 /*
- * Saved I/O APIC state during suspend/resume.
+ * Saved I/O APIC state during suspend/resume, or while enabling intr-remap.
 */
 static struct IO_APIC_route_entry *ioapic_saved_data[MAX_IO_APICS];
 
@@ -628,74 +628,43 @@ static int __init ioapic_pirq_setup(char *str)
 __setup("pirq=", ioapic_pirq_setup);
 #endif /* CONFIG_X86_32 */
 
-struct IO_APIC_route_entry **alloc_ioapic_entries(void)
-{
-	int apic;
-	struct IO_APIC_route_entry **ioapic_entries;
-
-	ioapic_entries = kzalloc(sizeof(*ioapic_entries) * nr_ioapics,
-				GFP_ATOMIC);
-	if (!ioapic_entries)
-		return 0;
-
-	for (apic = 0; apic < nr_ioapics; apic++) {
-		ioapic_entries[apic] =
-			kzalloc(sizeof(struct IO_APIC_route_entry) *
-				nr_ioapic_registers[apic], GFP_ATOMIC);
-		if (!ioapic_entries[apic])
-			goto nomem;
-	}
-
-	return ioapic_entries;
-
-nomem:
-	while (--apic >= 0)
-		kfree(ioapic_entries[apic]);
-	kfree(ioapic_entries);
-
-	return 0;
-}
-
 /*
  * Saves all the IO-APIC RTE's
  */
-int save_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
+int save_ioapic_entries(void)
 {
 	int apic, pin;
-
-	if (!ioapic_entries)
-		return -ENOMEM;
+	int err = 0;
 
 	for (apic = 0; apic < nr_ioapics; apic++) {
-		if (!ioapic_entries[apic])
-			return -ENOMEM;
+		if (!ioapic_saved_data[apic]) {
+			err = -ENOMEM;
+			continue;
+		}
 
 		for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
-			ioapic_entries[apic][pin] =
+			ioapic_saved_data[apic][pin] =
 				ioapic_read_entry(apic, pin);
 	}
 
-	return 0;
+	return err;
 }
 
 /*
  * Mask all IO APIC entries.
  */
-void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
+void mask_ioapic_entries(void)
 {
 	int apic, pin;
 
-	if (!ioapic_entries)
-		return;
-
 	for (apic = 0; apic < nr_ioapics; apic++) {
-		if (!ioapic_entries[apic])
-			break;
+		if (!ioapic_saved_data[apic])
+			continue;
 
 		for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
 			struct IO_APIC_route_entry entry;
 
-			entry = ioapic_entries[apic][pin];
+			entry = ioapic_saved_data[apic][pin];
 			if (!entry.mask) {
 				entry.mask = 1;
 				ioapic_write_entry(apic, pin, entry);
@@ -705,36 +674,23 @@ void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
 }
 
 /*
- * Restore IO APIC entries which was saved in ioapic_entries.
+ * Restore IO APIC entries which was saved in ioapic_saved_data
  */
-int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
+int restore_ioapic_entries(void)
 {
 	int apic, pin;
 
-	if (!ioapic_entries)
-		return -ENOMEM;
-
 	for (apic = 0; apic < nr_ioapics; apic++) {
-		if (!ioapic_entries[apic])
-			return -ENOMEM;
+		if (!ioapic_saved_data[apic])
+			continue;
 
 		for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
 			ioapic_write_entry(apic, pin,
-					ioapic_entries[apic][pin]);
+					   ioapic_saved_data[apic][pin]);
 	}
 	return 0;
 }
 
-void free_ioapic_entries(struct IO_APIC_route_entry **ioapic_entries)
-{
-	int apic;
-
-	for (apic = 0; apic < nr_ioapics; apic++)
-		kfree(ioapic_entries[apic]);
-
-	kfree(ioapic_entries);
-}
-
 /*
  * Find the IRQ entry number of a certain pin.
  */