6 files changed, 47 insertions, 17 deletions

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 7e06b43720d3..a6ca6da1430b 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -31,6 +31,10 @@
 #define KEXEC_ARCH KEXEC_ARCH_PPC
 #endif
 
+#define KEXEC_STATE_NONE 0
+#define KEXEC_STATE_IRQS_OFF 1
+#define KEXEC_STATE_REAL_MODE 2
+
 #ifndef __ASSEMBLY__
 #include <linux/cpumask.h>
 #include <asm/reg.h>
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index a011603d4079..971dfa4815f0 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -82,6 +82,7 @@ struct paca_struct {
         s16 hw_cpu_id;                  /* Physical processor number */
         u8 cpu_start;                   /* At startup, processor spins until */
                                         /* this becomes non-zero. */
+        u8 kexec_state;         /* set when kexec down has irqs off */
 #ifdef CONFIG_PPC_STD_MMU_64
         struct slb_shadow *slb_shadow_ptr;
 
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 0271b58ec31e..1b784ff92d9d 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -184,6 +184,7 @@ int main(void)
 #endif /* CONFIG_PPC_STD_MMU_64 */
         DEFINE(PACAEMERGSP, offsetof(struct paca_struct, emergency_sp));
         DEFINE(PACAHWCPUID, offsetof(struct paca_struct, hw_cpu_id));
+        DEFINE(PACAKEXECSTATE, offsetof(struct paca_struct, kexec_state));
         DEFINE(PACA_STARTPURR, offsetof(struct paca_struct, startpurr));
         DEFINE(PACA_STARTSPURR, offsetof(struct paca_struct, startspurr));
         DEFINE(PACA_USER_TIME, offsetof(struct paca_struct, user_time));
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 040bd1de8d99..26f9900f773c 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -155,33 +155,38 @@ void kexec_copy_flush(struct kimage *image)
 
 #ifdef CONFIG_SMP
 
-/* FIXME: we should schedule this function to be called on all cpus based
- * on calling the interrupts, but we would like to call it off irq level
- * so that the interrupt controller is clean.
- */
+static int kexec_all_irq_disabled = 0;
+
 static void kexec_smp_down(void *arg)
 {
+        local_irq_disable();
+        mb(); /* make sure our irqs are disabled before we say they are */
+        get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;
+        while(kexec_all_irq_disabled == 0)
+                cpu_relax();
+        mb(); /* make sure all irqs are disabled before this */
+        /*
+         * Now every CPU has IRQs off, we can clear out any pending
+         * IPIs and be sure that no more will come in after this.
+         */
         if (ppc_md.kexec_cpu_down)
                 ppc_md.kexec_cpu_down(0, 1);
 
-        local_irq_disable();
         kexec_smp_wait();
         /* NOTREACHED */
 }
 
-static void kexec_prepare_cpus(void)
+static void kexec_prepare_cpus_wait(int wait_state)
 {
         int my_cpu, i, notified=-1;
 
-        smp_call_function(kexec_smp_down, NULL, /* wait */0);
         my_cpu = get_cpu();
-
-        /* check the others cpus are now down (via paca hw cpu id == -1) */
+        /* Make sure each CPU has atleast made it to the state we need */
         for (i=0; i < NR_CPUS; i++) {
                 if (i == my_cpu)
                         continue;
 
-                while (paca[i].hw_cpu_id != -1) {
+                while (paca[i].kexec_state < wait_state) {
                         barrier();
                         if (!cpu_possible(i)) {
                                 printk("kexec: cpu %d hw_cpu_id %d is not"
@@ -201,20 +206,35 @@ static void kexec_prepare_cpus(void)
                         }
                         if (i != notified) {
                                 printk( "kexec: waiting for cpu %d (physical"
-                                                " %d) to go down\n",
-                                                i, paca[i].hw_cpu_id);
+                                                " %d) to enter %i state\n",
+                                        i, paca[i].hw_cpu_id, wait_state);
                                 notified = i;
                         }
                 }
         }
+        mb();
+}
+
+static void kexec_prepare_cpus(void)
+{
+
+        smp_call_function(kexec_smp_down, NULL, /* wait */0);
+        local_irq_disable();
+        mb(); /* make sure IRQs are disabled before we say they are */
+        get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;
+
+        kexec_prepare_cpus_wait(KEXEC_STATE_IRQS_OFF);
+        /* we are sure every CPU has IRQs off at this point */
+        kexec_all_irq_disabled = 1;
 
         /* after we tell the others to go down */
         if (ppc_md.kexec_cpu_down)
                 ppc_md.kexec_cpu_down(0, 0);
 
-        put_cpu();
+        /* Before removing MMU mapings make sure all CPUs have entered real mode */
+        kexec_prepare_cpus_wait(KEXEC_STATE_REAL_MODE);
 
-        local_irq_disable();
+        put_cpu();
 }
 
 #else /* ! SMP */
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index a5cf9c1356a6..a2b18dffa03e 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -24,6 +24,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/cputable.h>
 #include <asm/thread_info.h>
+#include <asm/kexec.h>
 
         .text
 
@@ -471,6 +472,10 @@ _GLOBAL(kexec_wait)
 1:      mflr    r5
         addi    r5,r5,kexec_flag-1b
 
+        li      r4,KEXEC_STATE_REAL_MODE
+        stb     r4,PACAKEXECSTATE(r13)
+        SYNC
+
 99:     HMT_LOW
 #ifdef CONFIG_KEXEC             /* use no memory without kexec */
         lwz     r4,0(r5)
@@ -494,14 +499,11 @@ kexec_flag:
  * note: this is a terminal routine, it does not save lr
  *
  * get phys id from paca
- * set paca id to -1 to say we got here
  * switch to real mode
  * join other cpus in kexec_wait(phys_id)
  */
 _GLOBAL(kexec_smp_wait)
         lhz     r3,PACAHWCPUID(r13)
-        li      r4,-1
-        sth     r4,PACAHWCPUID(r13)     /* let others know we left */
         bl      real_mode
         b       .kexec_wait
 
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 0c40c6f476fe..f88acf0218db 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -18,6 +18,7 @@
 #include <asm/pgtable.h>
 #include <asm/iseries/lpar_map.h>
 #include <asm/iseries/hv_types.h>
+#include <asm/kexec.h>
 
 /* This symbol is provided by the linker - let it fill in the paca
  * field correctly */
@@ -97,6 +98,7 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu)
         new_paca->kernelbase = (unsigned long) _stext;
         new_paca->kernel_msr = MSR_KERNEL;
         new_paca->hw_cpu_id = 0xffff;
+        new_paca->kexec_state = KEXEC_STATE_NONE;
         new_paca->__current = &init_task;
 #ifdef CONFIG_PPC_STD_MMU_64
         new_paca->slb_shadow_ptr = &slb_shadow[cpu];