2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Brian King commit 46db2f86a3b2a94e0b33e0b4548fb7b7b6bdff66 upstream. The SLB can change sizes across a live migration, which was not being handled, resulting in possible machine crashes during migration if migrating to a machine which has a smaller max SLB size than the source machine. Fix this by first reducing the SLB size to the minimum possible value, which is 32, prior to migration. Then during the device tree update which occurs after migration, we make the call to ensure the SLB gets updated. Also add the slb_size to the lparcfg output so that the migration tools can check to make sure the kernel has this capability before allowing migration in scenarios where the SLB size will change. BenH: Fixed #include -> to avoid breaking ppc32 build Signed-off-by: Brian King Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/mmu-hash64.h | 2 ++ arch/powerpc/kernel/lparcfg.c | 3 +++ arch/powerpc/kernel/rtas.c | 7 ++++++- arch/powerpc/mm/slb.c | 16 ++++++++++++---- arch/powerpc/platforms/pseries/reconfig.c | 9 ++++++++- 5 files changed, 31 insertions(+), 6 deletions(-) --- a/arch/powerpc/include/asm/mmu-hash64.h +++ b/arch/powerpc/include/asm/mmu-hash64.h @@ -41,6 +41,7 @@ extern char initial_stab[]; #define SLB_NUM_BOLTED 3 #define SLB_CACHE_ENTRIES 8 +#define SLB_MIN_SIZE 32 /* Bits in the SLB ESID word */ #define SLB_ESID_V ASM_CONST(0x0000000008000000) /* valid */ @@ -296,6 +297,7 @@ extern void slb_flush_and_rebolt(void); extern void stab_initialize(unsigned long stab); extern void slb_vmalloc_update(void); +extern void slb_set_size(u16 size); #endif /* __ASSEMBLY__ */ /* --- a/arch/powerpc/kernel/lparcfg.c +++ b/arch/powerpc/kernel/lparcfg.c @@ -35,6 +35,7 @@ #include #include #include +#include #define MODULE_VERS "1.8" #define MODULE_NAME "lparcfg" @@ -537,6 +538,8 @@ static int pseries_lparcfg_data(struct s seq_printf(m, "shared_processor_mode=%d\n", lppaca[0].shared_proc); + seq_printf(m, "slb_size=%d\n", mmu_slb_size); + return 0; } --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -39,6 +39,7 @@ #include #include #include +#include struct rtas_t rtas = { .lock = __RAW_SPIN_LOCK_UNLOCKED @@ -713,6 +714,7 @@ static void rtas_percpu_suspend_me(void { long rc = H_SUCCESS; unsigned long msr_save; + u16 slb_size = mmu_slb_size; int cpu; struct rtas_suspend_me_data *data = (struct rtas_suspend_me_data *)info; @@ -735,13 +737,16 @@ static void rtas_percpu_suspend_me(void /* All other cpus are in H_JOIN, this cpu does * the suspend. */ + slb_set_size(SLB_MIN_SIZE); printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id()); data->error = rtas_call(data->token, 0, 1, NULL); - if (data->error) + if (data->error) { printk(KERN_DEBUG "ibm,suspend-me returned %d\n", data->error); + slb_set_size(slb_size); + } } else { printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n", smp_processor_id(), rc); --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -240,14 +240,22 @@ void switch_slb(struct task_struct *tsk, static inline void patch_slb_encoding(unsigned int *insn_addr, unsigned int immed) { - /* Assume the instruction had a "0" immediate value, just - * "or" in the new value - */ - *insn_addr |= immed; + *insn_addr = (*insn_addr & 0xffff0000) | immed; flush_icache_range((unsigned long)insn_addr, 4+ (unsigned long)insn_addr); } +void slb_set_size(u16 size) +{ + extern unsigned int *slb_compare_rr_to_size; + + if (mmu_slb_size == size) + return; + + mmu_slb_size = size; + patch_slb_encoding(slb_compare_rr_to_size, mmu_slb_size); +} + void slb_initialize(void) { unsigned long linear_llp, vmalloc_llp, io_llp; --- a/arch/powerpc/platforms/pseries/reconfig.c +++ b/arch/powerpc/platforms/pseries/reconfig.c @@ -20,6 +20,7 @@ #include #include #include +#include @@ -439,9 +440,15 @@ static int do_update_property(char *buf, if (!newprop) return -ENOMEM; + if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size")) + slb_set_size(*(int *)value); + oldprop = of_find_property(np, name,NULL); - if (!oldprop) + if (!oldprop) { + if (strlen(name)) + return prom_add_property(np, newprop); return -ENODEV; + } rc = prom_update_property(np, newprop, oldprop); if (rc) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/