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MIPS: KVM: Omit FPU handling entry code if possible 

The FPU handling code on entry from guest is unnecessary if no FPU is
present, so allow it to be dropped at uasm assembly time.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
James Hogan 2016-06-23 17:34:42 +01:00 committed by Paolo Bonzini
parent 9c98865840
commit d37f4038d1
1 changed files with 15 additions and 12 deletions
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27
arch/mips/kvm/entry.c
View File

@ -393,18 +393,21 @@ void *kvm_mips_build_exit(void *addr)
UASM_i_LW(&p, K0, uasm_rel_lo((long)&ebase), K0);
uasm_i_mtc0(&p, K0, C0_EBASE);
/*
* If FPU is enabled, save FCR31 and clear it so that later ctc1's don't
* trigger FPE for pending exceptions.
*/
uasm_i_lui(&p, AT, ST0_CU1 >> 16);
uasm_i_and(&p, V1, V0, AT);
uasm_il_beqz(&p, &r, V1, label_fpu_1);
uasm_i_nop(&p);
uasm_i_cfc1(&p, T0, 31);
uasm_i_sw(&p, T0, offsetof(struct kvm_vcpu_arch, fpu.fcr31), K1);
uasm_i_ctc1(&p, ZERO, 31);
uasm_l_fpu_1(&l, p);
if (raw_cpu_has_fpu) {
/*
* If FPU is enabled, save FCR31 and clear it so that later
* ctc1's don't trigger FPE for pending exceptions.
*/
uasm_i_lui(&p, AT, ST0_CU1 >> 16);
uasm_i_and(&p, V1, V0, AT);
uasm_il_beqz(&p, &r, V1, label_fpu_1);
uasm_i_nop(&p);
uasm_i_cfc1(&p, T0, 31);
uasm_i_sw(&p, T0, offsetof(struct kvm_vcpu_arch, fpu.fcr31),
K1);
uasm_i_ctc1(&p, ZERO, 31);
uasm_l_fpu_1(&l, p);
}
#ifdef CONFIG_CPU_HAS_MSA
/*