diff options
| author | Alex Shi <alex.shi@linaro.org> | 2016-05-24 16:58:26 +0800 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2016-05-24 17:15:06 +0800 |
| commit | 8411a7b227dac86913d60ee360a5283402b5c50f (patch) | |
| tree | 03440b16c77a765372621006d1c031577f99d279 /arch/arm64 | |
| parent | 3200bf6148648ea42c77c908416ba8fdd097b39f (diff) | |
arm64: kvm: Move lr save/restore from do_el2_call into EL1
Today the 'hvc' calling KVM or the hyp-stub is expected to preserve all
registers. KVM saves/restores the registers it needs on the EL2 stack using
do_el2_call(). The hyp-stub has no stack, later patches need to be able to
be able to clobber the link register.
Move the link register save/restore to the the call sites.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit 00a44cdaba0900c63a003e0c431f506f49376a90)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
arch/arm64/kvm/hyp.S
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/hyp-stub.S | 10 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp.S | 7 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/hyp-entry.S | 6 |
3 files changed, 16 insertions, 7 deletions
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index a272f335c289..7eab8acbbbd9 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -101,10 +101,16 @@ ENDPROC(\label) */ ENTRY(__hyp_get_vectors) + str lr, [sp, #-16]! mov x0, xzr - // fall through -ENTRY(__hyp_set_vectors) hvc #0 + ldr lr, [sp], #16 ret ENDPROC(__hyp_get_vectors) + +ENTRY(__hyp_set_vectors) + str lr, [sp, #-16]! + hvc #0 + ldr lr, [sp], #16 + ret ENDPROC(__hyp_set_vectors) diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index bfd019ba0cb9..b8fe4d1f1c1e 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -38,14 +38,19 @@ * A function pointer with a value of 0 has a special meaning, and is * used to implement __hyp_get_vectors in the same way as in * arch/arm64/kernel/hyp_stub.S. + * HVC behaves as a 'bl' call and will clobber lr. */ ENTRY(kvm_call_hyp) -alternative_if_not ARM64_HAS_VIRT_HOST_EXTN +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN + str lr, [sp, #-16]! hvc #0 + ldr lr, [sp], #16 ret alternative_else b __vhe_hyp_call nop + nop + nop alternative_endif ENDPROC(kvm_call_hyp) diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 8950cdb1174b..f4e6e0f4b8fa 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -43,19 +43,17 @@ * Shuffle the parameters before calling the function * pointed to in x0. Assumes parameters in x[1,2,3]. */ - sub sp, sp, #16 - str lr, [sp] mov lr, x0 mov x0, x1 mov x1, x2 mov x2, x3 blr lr - ldr lr, [sp] - add sp, sp, #16 .endm ENTRY(__vhe_hyp_call) + str lr, [sp, #-16]! do_el2_call + ldr lr, [sp], #16 /* * We used to rely on having an exception return to get * an implicit isb. In the E2H case, we don't have it anymore. |