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authorJames Hogan <james.hogan@imgtec.com>2016-05-06 16:36:22 +0300
committerRalf Baechle <ralf@linux-mips.org>2016-05-13 15:02:19 +0300
commitf1b711c638c7df56112eff8e9661c91202782516 (patch)
tree499012a7401da027907354e8ede36b3fbc65a7f1 /arch/mips
parent1300fcd5e1754b654954717410c7035c0daac605 (diff)
downloadlinux-f1b711c638c7df56112eff8e9661c91202782516.tar.xz
MIPS: KVM/locore.S: Relax noat
Now that the at register ($1) is no longer saved by __kvm_mips_vcpu_run(), relax the noat assembler directive so that it only applies around code where at is restored before entering guest, and saved after exiting guest. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13209/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/kvm/locore.S16
1 files changed, 5 insertions, 11 deletions
diff --git a/arch/mips/kvm/locore.S b/arch/mips/kvm/locore.S
index 3ea522e4954b..1f2167bc847d 100644
--- a/arch/mips/kvm/locore.S
+++ b/arch/mips/kvm/locore.S
@@ -48,7 +48,6 @@
* a1: vcpu
*/
.set noreorder
- .set noat
FEXPORT(__kvm_mips_vcpu_run)
/* k0/k1 not being used in host kernel context */
@@ -145,6 +144,7 @@ FEXPORT(__kvm_mips_load_asid)
/* Disable RDHWR access */
mtc0 zero, CP0_HWRENA
+ .set noat
/* Now load up the Guest Context from VCPU */
LONG_L $1, VCPU_R1(k1)
LONG_L $2, VCPU_R2(k1)
@@ -256,6 +256,8 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra)
LONG_S $30, VCPU_R30(k1)
LONG_S $31, VCPU_R31(k1)
+ .set at
+
/* We need to save hi/lo and restore them on the way out */
mfhi t0
LONG_S t0, VCPU_HI(k1)
@@ -307,9 +309,7 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra)
/* load up the host EBASE */
mfc0 v0, CP0_STATUS
- .set at
or k0, v0, ST0_BEV
- .set noat
mtc0 k0, CP0_STATUS
ehb
@@ -321,7 +321,6 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra)
* If FPU is enabled, save FCR31 and clear it so that later ctc1's don't
* trigger FPE for pending exceptions.
*/
- .set at
and v1, v0, ST0_CU1
beqz v1, 1f
nop
@@ -331,7 +330,6 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra)
sw t0, VCPU_FCR31(k1)
ctc1 zero,fcr31
.set pop
- .set noat
1:
#ifdef CONFIG_CPU_HAS_MSA
@@ -354,10 +352,8 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra)
#endif
/* Now that the new EBASE has been loaded, unset BEV and KSU_USER */
- .set at
and v0, v0, ~(ST0_EXL | KSU_USER | ST0_IE)
or v0, v0, ST0_CU0
- .set noat
mtc0 v0, CP0_STATUS
ehb
@@ -424,18 +420,14 @@ __kvm_mips_return_to_guest:
/* Switch EBASE back to the one used by KVM */
mfc0 v1, CP0_STATUS
- .set at
or k0, v1, ST0_BEV
- .set noat
mtc0 k0, CP0_STATUS
ehb
mtc0 t0, CP0_EBASE
/* Setup status register for running guest in UM */
- .set at
or v1, v1, (ST0_EXL | KSU_USER | ST0_IE)
and v1, v1, ~(ST0_CU0 | ST0_MX)
- .set noat
mtc0 v1, CP0_STATUS
ehb
@@ -464,6 +456,7 @@ __kvm_mips_return_to_guest:
/* Disable RDHWR access */
mtc0 zero, CP0_HWRENA
+ .set noat
/* load the guest context from VCPU and return */
LONG_L $0, VCPU_R0(k1)
LONG_L $1, VCPU_R1(k1)
@@ -509,6 +502,7 @@ FEXPORT(__kvm_mips_skip_guest_restore)
LONG_L k1, VCPU_R27(k1)
eret
+ .set at
__kvm_mips_return_to_host:
/* EBASE is already pointing to Linux */