x86, apic: Use .apicdrivers section for the apic drivers list

This will eliminate the need for apic_probe[], as the probing
now will happen based on the apic drivers order in the
.apcidrivers section.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: steiner@sgi.com
Cc: gorcunov@openvz.org
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/20110521005526.164277071@sbsiddha-MOBL3.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 36 insertions, 31 deletions

diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index a319b33cfc14..8796e1d25f0c 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -206,14 +206,14 @@ static struct apic *apic_probe[] __initdata = {
 static int cmdline_apic __initdata;
 static int __init parse_apic(char *arg)
 {
-        int i;
+        struct apic **drv;
 
         if (!arg)
                 return -EINVAL;
 
-        for (i = 0; apic_probe[i]; i++) {
-                if (!strcmp(apic_probe[i]->name, arg)) {
-                        apic = apic_probe[i];
+        for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+                if (!strcmp((*drv)->name, arg)) {
+                        apic = *drv;
                         cmdline_apic = 1;
                         return 0;
                 }
@@ -247,15 +247,16 @@ void __init generic_bigsmp_probe(void)
 void __init generic_apic_probe(void)
 {
         if (!cmdline_apic) {
-                int i;
-                for (i = 0; apic_probe[i]; i++) {
-                        if (apic_probe[i]->probe()) {
-                                apic = apic_probe[i];
+                struct apic **drv;
+
+                for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+                        if ((*drv)->probe()) {
+                                apic = *drv;
                                 break;
                         }
                 }
                 /* Not visible without early console */
-                if (!apic_probe[i])
+                if (drv == __apicdrivers_end)
                         panic("Didn't find an APIC driver");
         }
         printk(KERN_INFO "Using APIC driver %s\n", apic->name);
@@ -266,16 +267,16 @@ void __init generic_apic_probe(void)
 int __init
 generic_mps_oem_check(struct mpc_table *mpc, char *oem, char *productid)
 {
-        int i;
+        struct apic **drv;
 
-        for (i = 0; apic_probe[i]; ++i) {
-                if (!apic_probe[i]->mps_oem_check)
+        for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+                if (!((*drv)->mps_oem_check))
                         continue;
-                if (!apic_probe[i]->mps_oem_check(mpc, oem, productid))
+                if (!(*drv)->mps_oem_check(mpc, oem, productid))
                         continue;
 
                 if (!cmdline_apic) {
-                        apic = apic_probe[i];
+                        apic = *drv;
                         printk(KERN_INFO "Switched to APIC driver `%s'.\n",
                                apic->name);
                 }
@@ -286,16 +287,16 @@ generic_mps_oem_check(struct mpc_table *mpc, char *oem, char *productid)
 
 int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
-        int i;
+        struct apic **drv;
 
-        for (i = 0; apic_probe[i]; ++i) {
-                if (!apic_probe[i]->acpi_madt_oem_check)
+        for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+                if (!(*drv)->acpi_madt_oem_check)
                         continue;
-                if (!apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id))
+                if (!(*drv)->acpi_madt_oem_check(oem_id, oem_table_id))
                         continue;
 
                 if (!cmdline_apic) {
-                        apic = apic_probe[i];
+                        apic = *drv;
                         printk(KERN_INFO "Switched to APIC driver `%s'.\n",
                                apic->name);
                 }
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index 39fb42b51f6a..e2c361d0fb96 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -54,19 +54,21 @@ static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
  */
 void __init default_setup_apic_routing(void)
 {
-        int i;
+        struct apic **drv;
 
         enable_IR_x2apic();
 
-        for (i = 0; apic_probe[i]; ++i) {
-                if (apic_probe[i]->probe()) {
-                        apic = apic_probe[i];
+        for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+                if ((*drv)->probe && (*drv)->probe()) {
+                        if (apic != *drv) {
+                                apic = *drv;
+                                pr_info("Switched APIC routing to %s.\n",
+                                        apic->name);
+                        }
                         break;
                 }
         }
 
-        printk(KERN_INFO "APIC routing finalized to %s.\n", apic->name);
-
         if (is_vsmp_box()) {
                 /* need to update phys_pkg_id */
                 apic->phys_pkg_id = apicid_phys_pkg_id;
@@ -82,13 +84,15 @@ void apic_send_IPI_self(int vector)
 
 int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
-        int i;
+        struct apic **drv;
 
-        for (i = 0; apic_probe[i]; ++i) {
-                if (apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id)) {
-                        apic = apic_probe[i];
-                        printk(KERN_INFO "Setting APIC routing to %s.\n",
-                                apic->name);
+        for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+                if ((*drv)->acpi_madt_oem_check(oem_id, oem_table_id)) {
+                        if (apic != *drv) {
+                                apic = *drv;
+                                pr_info("Setting APIC routing to %s.\n",
+                                        apic->name);
+                        }
                         return 1;
                 }
         }