Currently all iSeries secondary CPU's spin directly on the cpu_start in thier
paca. Make them spin on the global __secondary_hold_spinloop, until after the
pacas have been initialised.
As sfr points out this works because __secondary_hold_spinloop is being set
already, but iSeries isn't looking at it :)
Signed-off-by: Tony Breeds <[EMAIL PROTECTED]>
Acked-by: Stephen Rothwell <[EMAIL PROTECTED]>
---
Changes since v1:
- Updated commit message.
Changes since v2:
- Fixed my brain damage, and split out the code that should be in 3/3
arch/powerpc/platforms/iseries/exception.S | 27 ++++++++++++++++++++++++++-
1 files changed, 26 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/platforms/iseries/exception.S
b/arch/powerpc/platforms/iseries/exception.S
index c775cd4..8ff330d 100644
--- a/arch/powerpc/platforms/iseries/exception.S
+++ b/arch/powerpc/platforms/iseries/exception.S
@@ -59,8 +59,33 @@ system_reset_iSeries:
andc r4,r4,r5
mtspr SPRN_CTRLT,r4
+/* Spin on __secondary_hold_spinloop until it is updated by the boot cpu. */
+/* In the UP case we'll yeild() later, and we will not access the paca anyway
*/
+#ifdef CONFIG_SMP
1:
HMT_LOW
+ LOAD_REG_IMMEDIATE(r23, __secondary_hold_spinloop)
+ ld r23,0(r23)
+ sync
+ LOAD_REG_IMMEDIATE(r3,current_set)
+ sldi r28,r24,3 /* get current_set[cpu#] */
+ ldx r3,r3,r28
+ addi r1,r3,THREAD_SIZE
+ subi r1,r1,STACK_FRAME_OVERHEAD
+
+ cmpwi 0,r23,0 /* Keep poking the Hypervisor until */
+ bne 2f /* we're released */
+ /* Let the Hypervisor know we are alive */
+ /* 8002 is a call to HvCallCfg::getLps, a harmless Hypervisor function
*/
+ lis r3,0x8002
+ rldicr r3,r3,32,15 /* r0 = (r3 << 32) & 0xffff000000000000
*/
+ li r0,-1 /* r0=-1 indicates a Hypervisor call */
+ sc /* Invoke the hypervisor via a system
call */
+ b 1b
+#endif
+
+2:
+ HMT_LOW
#ifdef CONFIG_SMP
lbz r23,PACAPROCSTART(r13) /* Test if this processor
* should start */
@@ -91,7 +116,7 @@ iSeries_secondary_smp_loop:
li r0,-1 /* r0=-1 indicates a Hypervisor call */
sc /* Invoke the hypervisor via a system
call */
mfspr r13,SPRN_SPRG3 /* Put r13 back ???? */
- b 1b /* If SMP not configured, secondaries
+ b 2b /* If SMP not configured, secondaries
* loop forever */
/*** ISeries-LPAR interrupt handlers ***/
--
1.5.5.1
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