Merge ../linux-2.6

[pandora-kernel.git] / arch / powerpc / kernel / head_64.S

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 8cfd040..6ff3cf5 100644 (file)
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -21,7 +21,6 @@
  *  2 of the License, or (at your option) any later version.
  */
 
-#include <linux/config.h>
 #include <linux/threads.h>
 #include <asm/reg.h>
 #include <asm/page.h>
@@ -192,6 +191,37 @@ exception_marker:
        ori     reg,reg,(label)@l;      /* virt addr of handler ... */
 #endif
 
+/*
+ * Equal to EXCEPTION_PROLOG_PSERIES, except that it forces 64bit mode.
+ * The firmware calls the registered system_reset_fwnmi and
+ * machine_check_fwnmi handlers in 32bit mode if the cpu happens to run
+ * a 32bit application at the time of the event.
+ * This firmware bug is present on POWER4 and JS20.
+ */
+#define EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(area, label)              \
+       mfspr   r13,SPRN_SPRG3;         /* get paca address into r13 */ \
+       std     r9,area+EX_R9(r13);     /* save r9 - r12 */             \
+       std     r10,area+EX_R10(r13);                                   \
+       std     r11,area+EX_R11(r13);                                   \
+       std     r12,area+EX_R12(r13);                                   \
+       mfspr   r9,SPRN_SPRG1;                                          \
+       std     r9,area+EX_R13(r13);                                    \
+       mfcr    r9;                                                     \
+       clrrdi  r12,r13,32;             /* get high part of &label */   \
+       mfmsr   r10;                                                    \
+       /* force 64bit mode */                                          \
+       li      r11,5;                  /* MSR_SF_LG|MSR_ISF_LG */      \
+       rldimi  r10,r11,61,0;           /* insert into top 3 bits */    \
+       /* done 64bit mode */                                           \
+       mfspr   r11,SPRN_SRR0;          /* save SRR0 */                 \
+       LOAD_HANDLER(r12,label)                                         \
+       ori     r10,r10,MSR_IR|MSR_DR|MSR_RI;                           \
+       mtspr   SPRN_SRR0,r12;                                          \
+       mfspr   r12,SPRN_SRR1;          /* and SRR1 */                  \
+       mtspr   SPRN_SRR1,r10;                                          \
+       rfid;                                                           \
+       b       .       /* prevent speculative execution */
+
 #define EXCEPTION_PROLOG_PSERIES(area, label)                          \
        mfspr   r13,SPRN_SPRG3;         /* get paca address into r13 */ \
        std     r9,area+EX_R9(r13);     /* save r9 - r12 */             \
@@ -605,14 +635,14 @@ slb_miss_user_pseries:
 system_reset_fwnmi:
        HMT_MEDIUM
        mtspr   SPRN_SPRG1,r13          /* save r13 */
-       EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)
+       EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXGEN, system_reset_common)
 
        .globl machine_check_fwnmi
       .align 7
 machine_check_fwnmi:
        HMT_MEDIUM
        mtspr   SPRN_SPRG1,r13          /* save r13 */
-       EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
+       EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXMC, machine_check_common)
 
 #ifdef CONFIG_PPC_ISERIES
 /***  ISeries-LPAR interrupt handlers ***/