diff options
| author |   Nicholas Piggin <npiggin@gmail.com> | 2016-12-22 04:29:25 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2017-01-27 15:41:20 +1100 |
| commit | d3918e7fd4a27564f93ec46d0359a9739c5deb8d (patch) | |
| tree | 92569d562aaba206de93259e989c0e9bac8a566e /arch/powerpc/kvm/book3s_segment.S | |
| parent | Linux 4.10-rc4 (diff) | |
| download | linux-dev-d3918e7fd4a27564f93ec46d0359a9739c5deb8d.tar.xz linux-dev-d3918e7fd4a27564f93ec46d0359a9739c5deb8d.zip | |
KVM: PPC: Book3S: Change interrupt call to reduce scratch space use on HV
Change the calling convention to put the trap number together with
CR in two halves of r12, which frees up HSTATE_SCRATCH2 in the HV
handler.
The 64-bit PR handler entry translates the calling convention back
to match the previous call convention (i.e., shared with 32-bit), for
simplicity.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kvm/book3s_segment.S')
| -rw-r--r-- | arch/powerpc/kvm/book3s_segment.S | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S index ca8f174289bb..68e45080cf93 100644 --- a/arch/powerpc/kvm/book3s_segment.S +++ b/arch/powerpc/kvm/book3s_segment.S @@ -167,20 +167,31 @@ kvmppc_handler_trampoline_enter_end: * * *****************************************************************************/ -.global kvmppc_handler_trampoline_exit -kvmppc_handler_trampoline_exit: - .global kvmppc_interrupt_pr kvmppc_interrupt_pr: + /* 64-bit entry. Register usage at this point: + * + * SPRG_SCRATCH0 = guest R13 + * R12 = (guest CR << 32) | exit handler id + * R13 = PACA + * HSTATE.SCRATCH0 = guest R12 + */ +#ifdef CONFIG_PPC64 + /* Match 32-bit entry */ + rotldi r12, r12, 32 /* Flip R12 halves for stw */ + stw r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */ + srdi r12, r12, 32 /* shift trap into low half */ +#endif +.global kvmppc_handler_trampoline_exit +kvmppc_handler_trampoline_exit: /* Register usage at this point: * - * SPRG_SCRATCH0 = guest R13 - * R12 = exit handler id - * R13 = shadow vcpu (32-bit) or PACA (64-bit) + * SPRG_SCRATCH0 = guest R13 + * R12 = exit handler id + * R13 = shadow vcpu (32-bit) or PACA (64-bit) * HSTATE.SCRATCH0 = guest R12 * HSTATE.SCRATCH1 = guest CR - * */ /* Save registers */ |