From dfbe0d3b6be52596b5694b1bb75b19562e769021 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Tue, 15 Jan 2008 17:29:33 +1100 Subject: [PATCH] [POWERPC] Fix boot failure on POWER6 Commit 473980a99316c0e788bca50996375a2815124ce1 added a call to clear the SLB shadow buffer before registering it. Unfortunately this means that we clear out the entries that slb_initialize has previously set in there. On POWER6, the hypervisor uses the SLB shadow buffer when doing partition switches, and that means that after the next partition switch, each non-boot CPU has no SLB entries to map the kernel text and data, which causes it to crash. This fixes it by reverting most of 473980a9 and instead clearing the 3rd entry explicitly in slb_initialize. This fixes the problem that 473980a9 was trying to solve, but without breaking POWER6. Signed-off-by: Paul Mackerras --- arch/powerpc/mm/slb.c | 10 ++-------- arch/powerpc/platforms/pseries/lpar.c | 1 - include/asm-powerpc/mmu-hash64.h | 1 - 3 files changed, 2 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c index a282bc212e80..50d7372bc2ce 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -82,14 +82,6 @@ static inline void slb_shadow_clear(unsigned long entry) get_slb_shadow()->save_area[entry].esid = 0; } -void slb_shadow_clear_all(void) -{ - int i; - - for (i = 0; i < SLB_NUM_BOLTED; i++) - slb_shadow_clear(i); -} - static inline void create_shadowed_slbe(unsigned long ea, int ssize, unsigned long flags, unsigned long entry) @@ -300,6 +292,8 @@ void slb_initialize(void) create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, 1); + slb_shadow_clear(2); + /* We don't bolt the stack for the time being - we're in boot, * so the stack is in the bolted segment. By the time it goes * elsewhere, we'll call _switch() which will bolt in the new diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 34317aa148a8..9a455d46379d 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -272,7 +272,6 @@ void vpa_init(int cpu) */ addr = __pa(&slb_shadow[cpu]); if (firmware_has_feature(FW_FEATURE_SPLPAR)) { - slb_shadow_clear_all(); ret = register_slb_shadow(hwcpu, addr); if (ret) printk(KERN_ERR diff --git a/include/asm-powerpc/mmu-hash64.h b/include/asm-powerpc/mmu-hash64.h index 951e2487aa69..82328dec2b52 100644 --- a/include/asm-powerpc/mmu-hash64.h +++ b/include/asm-powerpc/mmu-hash64.h @@ -286,7 +286,6 @@ extern void hpte_init_iSeries(void); extern void hpte_init_beat(void); extern void hpte_init_beat_v3(void); -extern void slb_shadow_clear_all(void); extern void stabs_alloc(void); extern void slb_initialize(void); extern void slb_flush_and_rebolt(void); -- 2.20.1