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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>
This commit is contained in:
James Hogan 2016-05-06 14:36:22 +01:00 committed by Ralf Baechle
parent 1300fcd5e1
commit f1b711c638
1 changed files with 5 additions and 11 deletions
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16
arch/mips/kvm/locore.S
View File

@ -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 */