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| author | Will Deacon <will.deacon@arm.com> | 2011-11-23 12:26:25 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2011-12-06 14:04:15 +0000 |
| commit | 4e8ee7de227e3ab9a72040b448ad728c5428a042 (patch) | |
| tree | ffaf8492fd359d3281a55ff6e751504e905cc27c /arch/arm/kernel/head.S | |
| parent | 72662e01088394577be4a3f14da94cf87bea2591 (diff) | |
| download | linux-4e8ee7de227e3ab9a72040b448ad728c5428a042.tar.gz linux-4e8ee7de227e3ab9a72040b448ad728c5428a042.tar.bz2 linux-4e8ee7de227e3ab9a72040b448ad728c5428a042.zip | |
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) * 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 |