[PATCH] ppc32: support hotplug cpu on powermacs
This allows cpus to be off-lined on 32-bit SMP powermacs. When a cpu
is off-lined, it is put into sleep mode with interrupts disabled. It
can be on-lined again by asserting its soft-reset pin, which is
connected to a GPIO pin.
With this I can off-line the second cpu in my dual G4 powermac, which
means that I can then suspend the machine (the suspend/resume code
refuses to suspend if more than one cpu is online, and making it cope
with multiple cpus is surprisingly messy).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/ppc/kernel/head.S b/arch/ppc/kernel/head.S
index 55daf12..1960fb8 100644
--- a/arch/ppc/kernel/head.S
+++ b/arch/ppc/kernel/head.S
@@ -1023,23 +1023,21 @@
andc r4,r4,r3
mtspr SPRN_HID0,r4
sync
- bl gemini_prom_init
b __secondary_start
#endif /* CONFIG_GEMINI */
- .globl __secondary_start_psurge
-__secondary_start_psurge:
- li r24,1 /* cpu # */
- b __secondary_start_psurge99
- .globl __secondary_start_psurge2
-__secondary_start_psurge2:
- li r24,2 /* cpu # */
- b __secondary_start_psurge99
- .globl __secondary_start_psurge3
-__secondary_start_psurge3:
- li r24,3 /* cpu # */
- b __secondary_start_psurge99
-__secondary_start_psurge99:
- /* we come in here with IR=0 and DR=1, and DBAT 0
+
+ .globl __secondary_start_pmac_0
+__secondary_start_pmac_0:
+ /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
+ li r24,0
+ b 1f
+ li r24,1
+ b 1f
+ li r24,2
+ b 1f
+ li r24,3
+1:
+ /* on powersurge, we come in here with IR=0 and DR=1, and DBAT 0
set to map the 0xf0000000 - 0xffffffff region */
mfmsr r0
rlwinm r0,r0,0,28,26 /* clear DR (0x10) */