diff options
author | Will Deacon <will.deacon@arm.com> | 2011-11-23 07:26:25 -0500 |
---|---|---|
committer | Will Deacon <will.deacon@arm.com> | 2011-12-06 09:04:15 -0500 |
commit | 4e8ee7de227e3ab9a72040b448ad728c5428a042 (patch) | |
tree | ffaf8492fd359d3281a55ff6e751504e905cc27c /arch/arm/kernel/head.S | |
parent | 72662e01088394577be4a3f14da94cf87bea2591 (diff) |
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 <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm/kernel/head.S')
-rw-r--r-- | arch/arm/kernel/head.S | 4 |
1 files changed, 3 insertions, 1 deletions
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) | |||
398 | * other registers depend on the function called upon completion | 398 | * other registers depend on the function called upon completion |
399 | */ | 399 | */ |
400 | .align 5 | 400 | .align 5 |
401 | __turn_mmu_on: | 401 | .pushsection .idmap.text, "ax" |
402 | ENTRY(__turn_mmu_on) | ||
402 | mov r0, r0 | 403 | mov r0, r0 |
403 | mcr p15, 0, r0, c1, c0, 0 @ write control reg | 404 | mcr p15, 0, r0, c1, c0, 0 @ write control reg |
404 | mrc p15, 0, r3, c0, c0, 0 @ read id reg | 405 | mrc p15, 0, r3, c0, c0, 0 @ read id reg |
@@ -407,6 +408,7 @@ __turn_mmu_on: | |||
407 | mov pc, r3 | 408 | mov pc, r3 |
408 | __turn_mmu_on_end: | 409 | __turn_mmu_on_end: |
409 | ENDPROC(__turn_mmu_on) | 410 | ENDPROC(__turn_mmu_on) |
411 | .popsection | ||
410 | 412 | ||
411 | 413 | ||
412 | #ifdef CONFIG_SMP_ON_UP | 414 | #ifdef CONFIG_SMP_ON_UP |