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-rw-r--r--asm/head.S29
-rw-r--r--core/init.c15
-rw-r--r--include/skiboot.h2
3 files changed, 46 insertions, 0 deletions
diff --git a/asm/head.S b/asm/head.S
index 264899b..e2ddc91 100644
--- a/asm/head.S
+++ b/asm/head.S
@@ -479,6 +479,35 @@ call_relocate:
.long 0xa6037b7d; /* mtsrr1 r11 */ \
.long 0x2400004c /* rfid */
+.global enable_machine_check
+enable_machine_check:
+ mflr %r0
+ bcl 20,31,$+4
+0: mflr %r3
+ addi %r3,%r3,(1f - 0b)
+ mtspr SPR_HSRR0,%r3
+ mfmsr %r3
+ ori %r3,%r3,MSR_ME
+ mtspr SPR_HSRR1,%r3
+ hrfid
+1: mtlr %r0
+ blr
+
+.global disable_machine_check
+disable_machine_check:
+ mflr %r0
+ bcl 20,31,$+4
+0: mflr %r3
+ addi %r3,%r3,(1f - 0b)
+ mtspr SPR_HSRR0,%r3
+ mfmsr %r3
+ li %r4,MSR_ME
+ andc %r3,%r3,%r4
+ mtspr SPR_HSRR1,%r3
+ hrfid
+1: mtlr %r0
+ blr
+
pm_save_regs:
SAVE_GPR(2,%r1)
SAVE_GPR(14,%r1)
diff --git a/core/init.c b/core/init.c
index 36cf28d..5736d33 100644
--- a/core/init.c
+++ b/core/init.c
@@ -809,9 +809,24 @@ void __noreturn __nomcount main_cpu_entry(const void *fdt)
*/
clear_console();
+ /*
+ * Some boot firmwares enter OPAL with MSR[ME]=1, as they presumably
+ * handle machine checks until we take over. As we overwrite the
+ * previous exception vectors with our own handlers, disable MSR[ME].
+ * This could be done atomically by patching in a branch then patching
+ * it out last, but that's a lot of effort.
+ */
+ disable_machine_check();
+
/* Copy all vectors down to 0 */
copy_exception_vectors();
+ /*
+ * Enable MSR[ME] bit so we can take MCEs. We don't currently
+ * recover, but we print some useful information.
+ */
+ enable_machine_check();
+
/* Setup a NULL catcher to catch accidental NULL ptr calls */
setup_branch_null_catcher();
diff --git a/include/skiboot.h b/include/skiboot.h
index fd751dc..d1de10a 100644
--- a/include/skiboot.h
+++ b/include/skiboot.h
@@ -332,6 +332,8 @@ extern void fast_sleep_exit(void);
extern void fake_rtc_init(void);
/* Assembly in head.S */
+extern void disable_machine_check(void);
+extern void enable_machine_check(void);
extern void enter_p8_pm_state(bool winkle);
extern void enter_p9_pm_state(uint64_t psscr);
extern void enter_p9_pm_lite_state(uint64_t psscr);