From 4e8ee7de227e3ab9a72040b448ad728c5428a042 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 23 Nov 2011 12:26:25 +0000 Subject: ARM: SMP: use idmap_pgd for mapping MMU enable during secondary booting The ARM SMP booting code allocates a temporary set of page tables containing an identity mapping of the kernel image and provides this to secondary CPUs for initial booting. In reality, we only need to include the __turn_mmu_on function in the identity mapping since the rest of the kernel is executing from virtual addresses after this point. This patch adds __turn_mmu_on to the .idmap.text section, allowing the SMP booting code to use the idmap_pgd directly and not have to populate its own set of page table. As a result of this patch, we can make the identity_mapping_add function static (since it is only used within mm/idmap.c) and also remove the identity_mapping_del function. The identity map population is moved to an early initcall so that it is setup in time for secondary CPU bringup. Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm/mm/idmap.c | 34 ++-------------------------------- 1 file changed, 2 insertions(+), 32 deletions(-) (limited to 'arch/arm/mm/idmap.c') diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c index b01760e6da18..660f1bc68f99 100644 --- a/arch/arm/mm/idmap.c +++ b/arch/arm/mm/idmap.c @@ -32,7 +32,7 @@ static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end, } while (pud++, addr = next, addr != end); } -void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) +static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) { unsigned long prot, next; @@ -47,36 +47,6 @@ void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) } while (pgd++, addr = next, addr != end); } -#ifdef CONFIG_SMP -static void idmap_del_pmd(pud_t *pud, unsigned long addr, unsigned long end) -{ - pmd_t *pmd = pmd_offset(pud, addr); - pmd_clear(pmd); -} - -static void idmap_del_pud(pgd_t *pgd, unsigned long addr, unsigned long end) -{ - pud_t *pud = pud_offset(pgd, addr); - unsigned long next; - - do { - next = pud_addr_end(addr, end); - idmap_del_pmd(pud, addr, next); - } while (pud++, addr = next, addr != end); -} - -void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end) -{ - unsigned long next; - - pgd += pgd_index(addr); - do { - next = pgd_addr_end(addr, end); - idmap_del_pud(pgd, addr, next); - } while (pgd++, addr = next, addr != end); -} -#endif - extern char __idmap_text_start[], __idmap_text_end[]; static int __init init_static_idmap(void) @@ -97,7 +67,7 @@ static int __init init_static_idmap(void) return 0; } -arch_initcall(init_static_idmap); +early_initcall(init_static_idmap); /* * In order to soft-boot, we need to switch to a 1:1 mapping for the -- cgit