powerpc: Put FP/VSX and VR state into structures

This creates new 'thread_fp_state' and 'thread_vr_state' structures
to store FP/VSX state (including FPSCR) and Altivec/VSX state
(including VSCR), and uses them in the thread_struct.  In the
thread_fp_state, the FPRs and VSRs are represented as u64 rather
than double, since we rarely perform floating-point computations
on the values, and this will enable the structures to be used
in KVM code as well.  Similarly FPSCR is now a u64 rather than
a structure of two 32-bit values.

This takes the offsets out of the macros such as SAVE_32FPRS,
REST_32FPRS, etc.  This enables the same macros to be used for normal
and transactional state, enabling us to delete the transactional
versions of the macros.   This also removes the unused do_load_up_fpu
and do_load_up_altivec, which were in fact buggy since they didn't
create large enough stack frames to account for the fact that
load_up_fpu and load_up_altivec are not designed to be called from C
and assume that their caller's stack frame is an interrupt frame.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 15 insertions, 21 deletions

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 27db1e665959..c0b48f96a91c 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -444,7 +444,7 @@ void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr)
 #ifdef CONFIG_VSX
 	u64 *vcpu_vsx = vcpu->arch.vsr;
 #endif
-	u64 *thread_fpr = (u64*)t->fpr;
+	u64 *thread_fpr = &t->fp_state.fpr[0][0];
 	int i;
 
 	/*
@@ -466,14 +466,14 @@ void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr)
 		/*
 		 * Note that on CPUs with VSX, giveup_fpu stores
 		 * both the traditional FP registers and the added VSX
-		 * registers into thread.fpr[].
+		 * registers into thread.fp_state.fpr[].
 		 */
 		if (current->thread.regs->msr & MSR_FP)
 			giveup_fpu(current);
 		for (i = 0; i < ARRAY_SIZE(vcpu->arch.fpr); i++)
 			vcpu_fpr[i] = thread_fpr[get_fpr_index(i)];
 
-		vcpu->arch.fpscr = t->fpscr.val;
+		vcpu->arch.fpscr = t->fp_state.fpscr;
 
 #ifdef CONFIG_VSX
 		if (cpu_has_feature(CPU_FTR_VSX))
@@ -486,8 +486,8 @@ void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr)
 	if (msr & MSR_VEC) {
 		if (current->thread.regs->msr & MSR_VEC)
 			giveup_altivec(current);
-		memcpy(vcpu->arch.vr, t->vr, sizeof(vcpu->arch.vr));
-		vcpu->arch.vscr = t->vscr;
+		memcpy(vcpu->arch.vr, t->vr_state.vr, sizeof(vcpu->arch.vr));
+		vcpu->arch.vscr = t->vr_state.vscr;
 	}
 #endif
 
@@ -539,7 +539,7 @@ static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
 #ifdef CONFIG_VSX
 	u64 *vcpu_vsx = vcpu->arch.vsr;
 #endif
-	u64 *thread_fpr = (u64*)t->fpr;
+	u64 *thread_fpr = &t->fp_state.fpr[0][0];
 	int i;
 
 	/* When we have paired singles, we emulate in software */
@@ -584,15 +584,15 @@ static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
 		for (i = 0; i < ARRAY_SIZE(vcpu->arch.vsr) / 2; i++)
 			thread_fpr[get_fpr_index(i) + 1] = vcpu_vsx[i];
 #endif
-		t->fpscr.val = vcpu->arch.fpscr;
+		t->fp_state.fpscr = vcpu->arch.fpscr;
 		t->fpexc_mode = 0;
 		kvmppc_load_up_fpu();
 	}
 
 	if (msr & MSR_VEC) {
 #ifdef CONFIG_ALTIVEC
-		memcpy(t->vr, vcpu->arch.vr, sizeof(vcpu->arch.vr));
-		t->vscr = vcpu->arch.vscr;
+		memcpy(t->vr_state.vr, vcpu->arch.vr, sizeof(vcpu->arch.vr));
+		t->vr_state.vscr = vcpu->arch.vscr;
 		t->vrsave = -1;
 		kvmppc_load_up_altivec();
 #endif
@@ -1116,12 +1116,10 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
 int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 {
 	int ret;
-	double fpr[32][TS_FPRWIDTH];
-	unsigned int fpscr;
+	struct thread_fp_state fp;
 	int fpexc_mode;
 #ifdef CONFIG_ALTIVEC
-	vector128 vr[32];
-	vector128 vscr;
+	struct thread_vr_state vr;
 	unsigned long uninitialized_var(vrsave);
 	int used_vr;
 #endif
@@ -1153,8 +1151,7 @@ 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(fpr, current->thread.fpr, sizeof(current->thread.fpr));
-	fpscr = current->thread.fpscr.val;
+	fp = current->thread.fp_state;
 	fpexc_mode = current->thread.fpexc_mode;
 
 #ifdef CONFIG_ALTIVEC
@@ -1163,8 +1160,7 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 	if (used_vr) {
 		if (current->thread.regs->msr & MSR_VEC)
 			giveup_altivec(current);
-		memcpy(vr, current->thread.vr, sizeof(current->thread.vr));
-		vscr = current->thread.vscr;
+		vr = current->thread.vr_state;
 		vrsave = current->thread.vrsave;
 	}
 #endif
@@ -1196,15 +1192,13 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 	current->thread.regs->msr = ext_msr;
 
 	/* Restore FPU/VSX state from stack */
-	memcpy(current->thread.fpr, fpr, sizeof(current->thread.fpr));
-	current->thread.fpscr.val = fpscr;
+	current->thread.fp_state = fp;
 	current->thread.fpexc_mode = fpexc_mode;
 
 #ifdef CONFIG_ALTIVEC
 	/* Restore Altivec state from stack */
 	if (used_vr && current->thread.used_vr) {
-		memcpy(current->thread.vr, vr, sizeof(current->thread.vr));
-		current->thread.vscr = vscr;
+		current->thread.vr_state = vr;
 		current->thread.vrsave = vrsave;
 	}
 	current->thread.used_vr = used_vr;