[PATCH] powerpc: Create a trampoline for the fwnmi vectors
The fwnmi vectors can be anywhere < 32 MB, so we need to use a trampoline
for them. The kdump kernel will register the trampoline addresses, which will
then jump up to the real code above 32 MB.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 65aedc9..f4194f5 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -553,6 +553,7 @@
* Vectors for the FWNMI option. Share common code.
*/
.globl system_reset_fwnmi
+ .align 7
system_reset_fwnmi:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13 /* save r13 */
@@ -560,6 +561,7 @@
EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)
.globl machine_check_fwnmi
+ .align 7
machine_check_fwnmi:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13 /* save r13 */
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index fbd214d..49b305f 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -49,14 +49,12 @@
#include <asm/machdep.h>
#include <asm/rtas.h>
#include <asm/udbg.h>
+#include <asm/firmware.h>
static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
static DEFINE_SPINLOCK(ras_log_buf_lock);
-char mce_data_buf[RTAS_ERROR_LOG_MAX]
-;
-/* This is true if we are using the firmware NMI handler (typically LPAR) */
-extern int fwnmi_active;
+char mce_data_buf[RTAS_ERROR_LOG_MAX];
static int ras_get_sensor_state_token;
static int ras_check_exception_token;
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 8828dc3..d678f22 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -77,8 +77,6 @@
#endif
extern void find_udbg_vterm(void);
-extern void system_reset_fwnmi(void); /* from head.S */
-extern void machine_check_fwnmi(void); /* from head.S */
int fwnmi_active; /* TRUE if an FWNMI handler is present */
@@ -104,18 +102,22 @@
/* Initialize firmware assisted non-maskable interrupts if
* the firmware supports this feature.
- *
*/
static void __init fwnmi_init(void)
{
- int ret;
+ unsigned long system_reset_addr, machine_check_addr;
+
int ibm_nmi_register = rtas_token("ibm,nmi-register");
if (ibm_nmi_register == RTAS_UNKNOWN_SERVICE)
return;
- ret = rtas_call(ibm_nmi_register, 2, 1, NULL,
- __pa((unsigned long)system_reset_fwnmi),
- __pa((unsigned long)machine_check_fwnmi));
- if (ret == 0)
+
+ /* If the kernel's not linked at zero we point the firmware at low
+ * addresses anyway, and use a trampoline to get to the real code. */
+ system_reset_addr = __pa(system_reset_fwnmi) - PHYSICAL_START;
+ machine_check_addr = __pa(machine_check_fwnmi) - PHYSICAL_START;
+
+ if (0 == rtas_call(ibm_nmi_register, 2, 1, NULL, system_reset_addr,
+ machine_check_addr))
fwnmi_active = 1;
}
diff --git a/include/asm-powerpc/firmware.h b/include/asm-powerpc/firmware.h
index 12fabbc..f804b34 100644
--- a/include/asm-powerpc/firmware.h
+++ b/include/asm-powerpc/firmware.h
@@ -98,6 +98,12 @@
extern firmware_feature_t firmware_features_table[];
#endif
+extern void system_reset_fwnmi(void);
+extern void machine_check_fwnmi(void);
+
+/* This is true if we are using the firmware NMI handler (typically LPAR) */
+extern int fwnmi_active;
+
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_FIRMWARE_H */