1 files changed, 26 insertions, 16 deletions

diff --git a/arch/x86_64/kernel/genapic_flat.c b/arch/x86_64/kernel/genapic_flat.c
index b4cbbad04226..00f3fa6df714 100644
--- a/arch/x86_64/kernel/genapic_flat.c
+++ b/arch/x86_64/kernel/genapic_flat.c
@@ -7,6 +7,8 @@
  * Hacked for x86-64 by James Cleverdon from i386 architecture code by
  * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
  * James Cleverdon.
+ * Ashok Raj <ashok.raj@intel.com>
+ *      Removed IPI broadcast shortcut to support CPU hotplug
  */
 #include <linux/config.h>
 #include <linux/threads.h>
@@ -45,22 +47,6 @@ static void flat_init_apic_ldr(void)
         apic_write_around(APIC_LDR, val);
 }
 
-static void flat_send_IPI_allbutself(int vector)
-{
-        /*
-         * if there are no other CPUs in the system then
-         * we get an APIC send error if we try to broadcast.
-         * thus we have to avoid sending IPIs in this case.
-         */
-        if (num_online_cpus() > 1)
-                __send_IPI_shortcut(APIC_DEST_ALLBUT, vector, APIC_DEST_LOGICAL);
-}
-
-static void flat_send_IPI_all(int vector)
-{
-        __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
-}
-
 static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
 {
         unsigned long mask = cpus_addr(cpumask)[0];
@@ -93,6 +79,30 @@ static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
         local_irq_restore(flags);
 }
 
+static void flat_send_IPI_allbutself(int vector)
+{
+        cpumask_t mask;
+        /*
+         * if there are no other CPUs in the system then
+         * we get an APIC send error if we try to broadcast.
+         * thus we have to avoid sending IPIs in this case.
+         */
+        int this_cpu = get_cpu();
+
+        mask = cpu_online_map;
+        cpu_clear(this_cpu, mask);
+
+        if (cpus_weight(mask) >= 1)
+                flat_send_IPI_mask(mask, vector);
+
+        put_cpu();
+}
+
+static void flat_send_IPI_all(int vector)
+{
+        flat_send_IPI_mask(cpu_online_map, vector);
+}
+
 static int flat_apic_id_registered(void)
 {
         return physid_isset(GET_APIC_ID(apic_read(APIC_ID)), phys_cpu_present_map);