1 files changed, 36 insertions, 13 deletions

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index 6fcfa12e5c56..148c2f2d9780 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -128,6 +128,19 @@ static void __cpuinit smp_85xx_mach_cpu_die(void)
 }
 #endif
 
+static inline void flush_spin_table(void *spin_table)
+{
+        flush_dcache_range((ulong)spin_table,
+                (ulong)spin_table + sizeof(struct epapr_spin_table));
+}
+
+static inline u32 read_spin_table_addr_l(void *spin_table)
+{
+        flush_dcache_range((ulong)spin_table,
+                (ulong)spin_table + sizeof(struct epapr_spin_table));
+        return in_be32(&((struct epapr_spin_table *)spin_table)->addr_l);
+}
+
 static int __cpuinit smp_85xx_kick_cpu(int nr)
 {
         unsigned long flags;
@@ -161,8 +174,8 @@ static int __cpuinit smp_85xx_kick_cpu(int nr)
 
         /* Map the spin table */
         if (ioremappable)
-                spin_table = ioremap(*cpu_rel_addr,
-                                sizeof(struct epapr_spin_table));
+                spin_table = ioremap_prot(*cpu_rel_addr,
+                        sizeof(struct epapr_spin_table), _PAGE_COHERENT);
         else
                 spin_table = phys_to_virt(*cpu_rel_addr);
 
@@ -173,7 +186,16 @@ static int __cpuinit smp_85xx_kick_cpu(int nr)
         generic_set_cpu_up(nr);
 
         if (system_state == SYSTEM_RUNNING) {
+                /*
+                 * To keep it compatible with old boot program which uses
+                 * cache-inhibit spin table, we need to flush the cache
+                 * before accessing spin table to invalidate any staled data.
+                 * We also need to flush the cache after writing to spin
+                 * table to push data out.
+                 */
+                flush_spin_table(spin_table);
                 out_be32(&spin_table->addr_l, 0);
+                flush_spin_table(spin_table);
 
                 /*
                  * We don't set the BPTR register here since it already points
@@ -181,9 +203,14 @@ static int __cpuinit smp_85xx_kick_cpu(int nr)
                  */
                 mpic_reset_core(hw_cpu);
 
-                /* wait until core is ready... */
-                if (!spin_event_timeout(in_be32(&spin_table->addr_l) == 1,
-                                                10000, 100)) {
+                /*
+                 * wait until core is ready...
+                 * We need to invalidate the stale data, in case the boot
+                 * loader uses a cache-inhibited spin table.
+                 */
+                if (!spin_event_timeout(
+                                read_spin_table_addr_l(spin_table) == 1,
+                                10000, 100)) {
                         pr_err("%s: timeout waiting for core %d to reset\n",
                                                         __func__, hw_cpu);
                         ret = -ENOENT;
@@ -194,12 +221,10 @@ static int __cpuinit smp_85xx_kick_cpu(int nr)
                 __secondary_hold_acknowledge = -1;
         }
 #endif
+        flush_spin_table(spin_table);
         out_be32(&spin_table->pir, hw_cpu);
         out_be32(&spin_table->addr_l, __pa(__early_start));
-
-        if (!ioremappable)
-                flush_dcache_range((ulong)spin_table,
-                        (ulong)spin_table + sizeof(struct epapr_spin_table));
+        flush_spin_table(spin_table);
 
         /* Wait a bit for the CPU to ack. */
         if (!spin_event_timeout(__secondary_hold_acknowledge == hw_cpu,
@@ -213,13 +238,11 @@ out:
 #else
         smp_generic_kick_cpu(nr);
 
+        flush_spin_table(spin_table);
         out_be32(&spin_table->pir, hw_cpu);
         out_be64((u64 *)(&spin_table->addr_h),
           __pa((u64)*((unsigned long long *)generic_secondary_smp_init)));
-
-        if (!ioremappable)
-                flush_dcache_range((ulong)spin_table,
-                        (ulong)spin_table + sizeof(struct epapr_spin_table));
+        flush_spin_table(spin_table);
 #endif
 
         local_irq_restore(flags);