[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/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;
}