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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2015-03-17 10:59:53 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-03-19 22:46:02 +0300 |
| commit | 8b0a95753a34b5c8b2e483e0e5b1d67761e32c5f (patch) | |
| tree | b94cad9ea7b18ad3b28b56d76c6fb6093a2bbd68 /arch/arm64/kernel/head.S | |
| parent | b1c98297fe0c6e2899ede03fc3b831f36e19fb76 (diff) | |
| download | linux-8b0a95753a34b5c8b2e483e0e5b1d67761e32c5f.tar.xz | |
arm64: merge __enable_mmu and __turn_mmu_on
Enabling of the MMU is split into two functions, with an align and
a branch in the middle. On arm64, the entire kernel Image is ID mapped
so this is really not necessary, and we can just merge it into a
single function.
Also replaces an open coded adrp/add reference to __enable_mmu pair
with adr_l.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/head.S')
| -rw-r--r-- | arch/arm64/kernel/head.S | 33 |
1 files changed, 7 insertions, 26 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 818213186dac..750403c62928 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -255,8 +255,7 @@ ENTRY(stext) */ ldr x27, =__mmap_switched // address to jump to after // MMU has been enabled - adrp lr, __enable_mmu // return (PIC) address - add lr, lr, #:lo12:__enable_mmu + adr_l lr, __enable_mmu // return (PIC) address b __cpu_setup // initialise processor ENDPROC(stext) @@ -615,11 +614,12 @@ ENDPROC(__secondary_switched) #endif /* CONFIG_SMP */ /* - * Setup common bits before finally enabling the MMU. Essentially this is just - * loading the page table pointer and vector base registers. + * Enable the MMU. * - * On entry to this code, x0 must contain the SCTLR_EL1 value for turning on - * the MMU. + * x0 = SCTLR_EL1 value for turning on the MMU. + * x27 = *virtual* address to jump to upon completion + * + * other registers depend on the function called upon completion */ __enable_mmu: ldr x5, =vectors @@ -627,29 +627,10 @@ __enable_mmu: msr ttbr0_el1, x25 // load TTBR0 msr ttbr1_el1, x26 // load TTBR1 isb - b __turn_mmu_on -ENDPROC(__enable_mmu) - -/* - * Enable the MMU. This completely changes the structure of the visible memory - * space. You will not be able to trace execution through this. - * - * x0 = system control register - * x27 = *virtual* address to jump to upon completion - * - * other registers depend on the function called upon completion - * - * We align the entire function to the smallest power of two larger than it to - * ensure it fits within a single block map entry. Otherwise were PHYS_OFFSET - * close to the end of a 512MB or 1GB block we might require an additional - * table to map the entire function. - */ - .align 4 -__turn_mmu_on: msr sctlr_el1, x0 isb br x27 -ENDPROC(__turn_mmu_on) +ENDPROC(__enable_mmu) /* * Calculate the start of physical memory. |