KVM: PPC: elide struct thread_struct instances from stack

[pandora-kernel.git] / arch / powerpc / kvm / book3s.c

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index f6eac2f..801d9f3 100644 (file)
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1293,12 +1293,17 @@ extern int __kvmppc_vcpu_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
 int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 {
        int ret;
-       struct thread_struct ext_bkp;
+       double fpr[32][TS_FPRWIDTH];
+       unsigned int fpscr;
+       int fpexc_mode;
 #ifdef CONFIG_ALTIVEC
-       bool save_vec = current->thread.used_vr;
+       vector128 vr[32];
+       vector128 vscr;
+       unsigned long uninitialized_var(vrsave);
+       int used_vr;
 #endif
 #ifdef CONFIG_VSX
-       bool save_vsx = current->thread.used_vsr;
+       int used_vsr;
 #endif
        ulong ext_msr;
 
@@ -1311,27 +1316,27 @@ int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
        /* Save FPU state in stack */
        if (current->thread.regs->msr & MSR_FP)
                giveup_fpu(current);
-       memcpy(ext_bkp.fpr, current->thread.fpr, sizeof(current->thread.fpr));
-       ext_bkp.fpscr = current->thread.fpscr;
-       ext_bkp.fpexc_mode = current->thread.fpexc_mode;
+       memcpy(fpr, current->thread.fpr, sizeof(current->thread.fpr));
+       fpscr = current->thread.fpscr.val;
+       fpexc_mode = current->thread.fpexc_mode;
 
 #ifdef CONFIG_ALTIVEC
        /* Save Altivec state in stack */
-       if (save_vec) {
+       used_vr = current->thread.used_vr;
+       if (used_vr) {
                if (current->thread.regs->msr & MSR_VEC)
                        giveup_altivec(current);
-               memcpy(ext_bkp.vr, current->thread.vr, sizeof(ext_bkp.vr));
-               ext_bkp.vscr = current->thread.vscr;
-               ext_bkp.vrsave = current->thread.vrsave;
+               memcpy(vr, current->thread.vr, sizeof(current->thread.vr));
+               vscr = current->thread.vscr;
+               vrsave = current->thread.vrsave;
        }
-       ext_bkp.used_vr = current->thread.used_vr;
 #endif
 
 #ifdef CONFIG_VSX
        /* Save VSX state in stack */
-       if (save_vsx && (current->thread.regs->msr & MSR_VSX))
+       used_vsr = current->thread.used_vsr;
+       if (used_vsr && (current->thread.regs->msr & MSR_VSX))
                        __giveup_vsx(current);
-       ext_bkp.used_vsr = current->thread.used_vsr;
 #endif
 
        /* Remember the MSR with disabled extensions */
@@ -1356,22 +1361,22 @@ int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
        kvmppc_giveup_ext(vcpu, MSR_VSX);
 
        /* Restore FPU state from stack */
-       memcpy(current->thread.fpr, ext_bkp.fpr, sizeof(ext_bkp.fpr));
-       current->thread.fpscr = ext_bkp.fpscr;
-       current->thread.fpexc_mode = ext_bkp.fpexc_mode;
+       memcpy(current->thread.fpr, fpr, sizeof(current->thread.fpr));
+       current->thread.fpscr.val = fpscr;
+       current->thread.fpexc_mode = fpexc_mode;
 
 #ifdef CONFIG_ALTIVEC
        /* Restore Altivec state from stack */
-       if (save_vec && current->thread.used_vr) {
-               memcpy(current->thread.vr, ext_bkp.vr, sizeof(ext_bkp.vr));
-               current->thread.vscr = ext_bkp.vscr;
-               current->thread.vrsave= ext_bkp.vrsave;
+       if (used_vr && current->thread.used_vr) {
+               memcpy(current->thread.vr, vr, sizeof(current->thread.vr));
+               current->thread.vscr = vscr;
+               current->thread.vrsave = vrsave;
        }
-       current->thread.used_vr = ext_bkp.used_vr;
+       current->thread.used_vr = used_vr;
 #endif
 
 #ifdef CONFIG_VSX
-       current->thread.used_vsr = ext_bkp.used_vsr;
+       current->thread.used_vsr = used_vsr;
 #endif
 
        return ret;