Errata 4628 causes lockups during table walks that are recovered from
when a ptesync is received. So, issue a ptesync every timer interrupt,
and for CPUs that have not yet spun up, at regular intervals. This seems
sufficient to avoid hitting it.
Index: 2.6.21/arch/powerpc/kernel/head_64.S
===================================================================
--- 2.6.21.orig/arch/powerpc/kernel/head_64.S
+++ 2.6.21/arch/powerpc/kernel/head_64.S
@@ -123,10 +123,22 @@ _GLOBAL(__secondary_hold)
std r24,[EMAIL PROTECTED](0)
sync
+#ifdef CONFIG_SMP
/* All secondary cpus wait here until told to start. */
100: ld r4,[EMAIL PROTECTED](0)
cmpdi 0,r4,1
bne 100b
+#else
+ lis r3, 0x40
+ mtctr r3
+100: bdnz .
+ ptesync
+ ptesync
+ lis r3, 0x40
+ mtctr r3
+ b 100b
+
+#endif
#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
LOAD_REG_IMMEDIATE(r4, .generic_secondary_smp_init)
@@ -1582,16 +1594,32 @@ _GLOBAL(generic_secondary_smp_init)
2: mtspr SPRN_SPRG3,r13 /* Save vaddr of paca in SPRG3 */
/* From now on, r24 is expected to be logical cpuid */
mr r24,r5
+
+ lis r23, 0x40
+ mtctr r23
+
3: HMT_LOW
lbz r23,PACAPROCSTART(r13) /* Test if this processor should */
- /* start. */
- sync
#ifndef CONFIG_SMP
b 3b /* Never go on non-SMP */
#else
cmpwi 0,r23,0
- beq 3b /* Loop until told to go */
+ bne 5f /* Loop until told to go */
+ /* start. */
+ isync
+
+4: bdnz 3b
+ ptesync
+ isync
+ sync
+ ptesync
+ lis r23, 0x40
+ mtctr r23
+ b 3b
+
+5:
+
/* See if we need to call a cpu state restore handler */
LOAD_REG_IMMEDIATE(r23, cur_cpu_spec)
Index: 2.6.21/arch/powerpc/kernel/time.c
===================================================================
--- 2.6.21.orig/arch/powerpc/kernel/time.c
+++ 2.6.21/arch/powerpc/kernel/time.c
@@ -619,6 +619,8 @@ void timer_interrupt(struct pt_regs * re
unsigned long ticks;
u64 tb_next_jiffy;
+ asm("ptesync");
+
#ifdef CONFIG_PPC32
if (atomic_read(&ppc_n_lost_interrupts) != 0)
do_IRQ(regs);
--
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