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| author | Marc Zyngier <maz@kernel.org> | 2022-06-30 19:04:54 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-07-01 17:22:51 +0300 |
| commit | ae4b7e38e9a94798f08f5d66b02077900ab92903 (patch) | |
| tree | 2e324759702d7bed7ea30b8f3e6c9755073f3d64 | |
| parent | b65e411d6cc2f12a728cabe66b930c63c527a340 (diff) | |
| download | linux-ae4b7e38e9a94798f08f5d66b02077900ab92903.tar.xz | |
arm64: Allow sticky E2H when entering EL1
For CPUs that have the unfortunate mis-feature to be stuck in
VHE mode, we perform a funny dance where we completely shortcut
the normal boot process to enable VHE and run the kernel at EL2,
and only then start booting the kernel.
Not only this is pretty ugly, but it means that the EL2 finalisation
occurs before we have processed the sysreg override.
Instead, start executing the kernel as if it was an EL1 guest and
rely on the normal EL2 finalisation to go back to EL2.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220630160500.1536744-4-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/kernel/head.S | 34 |
1 files changed, 10 insertions, 24 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 73eb7c96a245..29d641290293 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -511,6 +511,8 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL) msr vbar_el2, x0 isb + mov_q x1, INIT_SCTLR_EL1_MMU_OFF + /* * Fruity CPUs seem to have HCR_EL2.E2H set to RES1, * making it impossible to start in nVHE mode. Is that @@ -520,35 +522,19 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL) and x0, x0, #HCR_E2H cbz x0, 1f - /* Switching to VHE requires a sane SCTLR_EL1 as a start */ - mov_q x0, INIT_SCTLR_EL1_MMU_OFF - msr_s SYS_SCTLR_EL12, x0 - - /* - * Force an eret into a helper "function", and let it return - * to our original caller... This makes sure that we have - * initialised the basic PSTATE state. - */ - mov x0, #INIT_PSTATE_EL2 - msr spsr_el1, x0 - adr x0, __cpu_stick_to_vhe - msr elr_el1, x0 - eret + /* Set a sane SCTLR_EL1, the VHE way */ + msr_s SYS_SCTLR_EL12, x1 + mov x2, #BOOT_CPU_FLAG_E2H + b 2f 1: - mov_q x0, INIT_SCTLR_EL1_MMU_OFF - msr sctlr_el1, x0 - + msr sctlr_el1, x1 + mov x2, xzr +2: msr elr_el2, lr mov w0, #BOOT_CPU_MODE_EL2 + orr x0, x0, x2 eret - -__cpu_stick_to_vhe: - mov x0, #HVC_FINALISE_EL2 - hvc #0 - mov x0, #BOOT_CPU_MODE_EL2 - orr x0, x0, #BOOT_CPU_FLAG_E2H - ret SYM_FUNC_END(init_kernel_el) /* |