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| author | Marc Zyngier <maz@kernel.org> | 2021-02-08 09:57:14 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-02-09 13:47:07 +0000 |
| commit | 0c93df9622d4d921bcd0dc83f71fed9e98f5119f (patch) | |
| tree | 73019ad94842d05353ba18096698a48be9e38631 /arch/arm64/kernel/hyp-stub.S | |
| parent | f359182291c757cdf77bcd014c025d1ed6b87662 (diff) | |
| download | linux-0c93df9622d4d921bcd0dc83f71fed9e98f5119f.tar.bz2 | |
arm64: Initialise as nVHE before switching to VHE
As we are aiming to be able to control whether we enable VHE or
not, let's always drop down to EL1 first, and only then upgrade
to VHE if at all possible.
This means that if the kernel is booted at EL2, we always start
with a nVHE init, drop to EL1 to initialise the the kernel, and
only then upgrade the kernel EL to EL2 if possible (the process
is obviously shortened for secondary CPUs).
The resume path is handled similarly to a secondary CPU boot.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-6-maz@kernel.org
[will: Avoid calling switch_to_vhe twice on kaslr path]
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/hyp-stub.S')
| -rw-r--r-- | arch/arm64/kernel/hyp-stub.S | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 3f3dbbe8914d..373ed2213e1d 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -190,3 +190,27 @@ SYM_FUNC_START(__hyp_reset_vectors) hvc #0 ret SYM_FUNC_END(__hyp_reset_vectors) + +/* + * Entry point to switch to VHE if deemed capable + */ +SYM_FUNC_START(switch_to_vhe) +#ifdef CONFIG_ARM64_VHE + // Need to have booted at EL2 + adr_l x1, __boot_cpu_mode + ldr w0, [x1] + cmp w0, #BOOT_CPU_MODE_EL2 + b.ne 1f + + // and still be at EL1 + mrs x0, CurrentEL + cmp x0, #CurrentEL_EL1 + b.ne 1f + + // Turn the world upside down + mov x0, #HVC_VHE_RESTART + hvc #0 +1: +#endif + ret +SYM_FUNC_END(switch_to_vhe) |