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| author | James Morse <james.morse@arm.com> | 2016-04-27 17:47:02 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-04-28 12:05:46 +0100 |
| commit | 00a44cdaba0900c63a003e0c431f506f49376a90 (patch) | |
| tree | 98dbb48f951a2ecab7a0ee09e89bf09a4d754a36 /arch/arm64/kvm/hyp.S | |
| parent | e7227d0e528f9a96d4a866f43e20dd9b33f0e782 (diff) | |
| download | linux-00a44cdaba0900c63a003e0c431f506f49376a90.tar.bz2 | |
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>
Diffstat (limited to 'arch/arm64/kvm/hyp.S')
| -rw-r--r-- | arch/arm64/kvm/hyp.S | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 48f19a37b3df..4ee5612f43ea 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -38,13 +38,18 @@ * 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) |