From 72662e01088394577be4a3f14da94cf87bea2591 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 23 Nov 2011 12:03:27 +0000 Subject: ARM: head.S: only include __turn_mmu_on in the initial identity mapping __create_page_tables identity maps the region of memory from __enable_mmu to the end of __turn_mmu_on. In preparation for including __turn_mmu_on in the .idmap.text section, this patch modifies the identity mapping so that it only includes the __turn_mmu_on code. Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm/kernel/head.S | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'arch/arm/kernel/head.S') diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 566c54c2a1fe..43e3aa3b0573 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -170,11 +170,11 @@ __create_page_tables: * Create identity mapping to cater for __enable_mmu. * This identity mapping will be removed by paging_init(). */ - adr r0, __enable_mmu_loc + adr r0, __turn_mmu_on_loc ldmia r0, {r3, r5, r6} sub r0, r0, r3 @ virt->phys offset - add r5, r5, r0 @ phys __enable_mmu - add r6, r6, r0 @ phys __enable_mmu_end + add r5, r5, r0 @ phys __turn_mmu_on + add r6, r6, r0 @ phys __turn_mmu_on_end mov r5, r5, lsr #SECTION_SHIFT mov r6, r6, lsr #SECTION_SHIFT @@ -287,10 +287,10 @@ __create_page_tables: ENDPROC(__create_page_tables) .ltorg .align -__enable_mmu_loc: +__turn_mmu_on_loc: .long . - .long __enable_mmu - .long __enable_mmu_end + .long __turn_mmu_on + .long __turn_mmu_on_end #if defined(CONFIG_SMP) __CPUINIT @@ -405,7 +405,7 @@ __turn_mmu_on: mov r3, r3 mov r3, r13 mov pc, r3 -__enable_mmu_end: +__turn_mmu_on_end: ENDPROC(__turn_mmu_on) -- cgit v1.2.3 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/kernel/head.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel/head.S') diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 43e3aa3b0573..64e9943ea4f0 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -398,7 +398,8 @@ ENDPROC(__enable_mmu) * other registers depend on the function called upon completion */ .align 5 -__turn_mmu_on: + .pushsection .idmap.text, "ax" +ENTRY(__turn_mmu_on) mov r0, r0 mcr p15, 0, r0, c1, c0, 0 @ write control reg mrc p15, 0, r3, c0, c0, 0 @ read id reg @@ -407,6 +408,7 @@ __turn_mmu_on: mov pc, r3 __turn_mmu_on_end: ENDPROC(__turn_mmu_on) + .popsection #ifdef CONFIG_SMP_ON_UP -- cgit v1.2.3