diff options
Diffstat (limited to 'arch/x86_64/mm/init.c')
| -rw-r--r-- | arch/x86_64/mm/init.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c index 2b1d6c38239..be483a1d7b5 100644 --- a/arch/x86_64/mm/init.c +++ b/arch/x86_64/mm/init.c @@ -312,12 +312,19 @@ void __init init_memory_mapping(unsigned long start, unsigned long end) extern struct x8664_pda cpu_pda[NR_CPUS]; -/* Assumes all CPUs still execute in init_mm */ -void zap_low_mappings(void) +void __cpuinit zap_low_mappings(int cpu) { - pgd_t *pgd = pgd_offset_k(0UL); - pgd_clear(pgd); - flush_tlb_all(); + if (cpu == 0) { + pgd_t *pgd = pgd_offset_k(0UL); + pgd_clear(pgd); + } else { + /* + * For AP's, zap the low identity mappings by changing the cr3 + * to init_level4_pgt and doing local flush tlb all + */ + asm volatile("movq %0,%%cr3" :: "r" (__pa_symbol(&init_level4_pgt))); + } + __flush_tlb_all(); } /* Compute zone sizes for the DMA and DMA32 zones in a node. */ @@ -474,14 +481,13 @@ void __init mem_init(void) datasize >> 10, initsize >> 10); +#ifdef CONFIG_SMP /* - * Subtle. SMP is doing its boot stuff late (because it has to - * fork idle threads) - but it also needs low mappings for the - * protected-mode entry to work. We zap these entries only after - * the WP-bit has been tested. + * Sync boot_level4_pgt mappings with the init_level4_pgt + * except for the low identity mappings which are already zapped + * in init_level4_pgt. This sync-up is essential for AP's bringup */ -#ifndef CONFIG_SMP - zap_low_mappings(); + memcpy(boot_level4_pgt+1, init_level4_pgt+1, (PTRS_PER_PGD-1)*sizeof(pgd_t)); #endif } |