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, 37 insertions, 35 deletions

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index bebdf1a1a540..ea25e45ea959 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -265,27 +265,27 @@ struct rt_sigframe {
 unsigned long copy_fpr_to_user(void __user *to,
 			       struct task_struct *task)
 {
-	double buf[ELF_NFPREG];
+	u64 buf[ELF_NFPREG];
 	int i;
 
 	/* save FPR copy to local buffer then write to the thread_struct */
 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
 		buf[i] = task->thread.TS_FPR(i);
-	memcpy(&buf[i], &task->thread.fpscr, sizeof(double));
+	buf[i] = task->thread.fp_state.fpscr;
 	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
 }
 
 unsigned long copy_fpr_from_user(struct task_struct *task,
 				 void __user *from)
 {
-	double buf[ELF_NFPREG];
+	u64 buf[ELF_NFPREG];
 	int i;
 
 	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
 		return 1;
 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
 		task->thread.TS_FPR(i) = buf[i];
-	memcpy(&task->thread.fpscr, &buf[i], sizeof(double));
+	task->thread.fp_state.fpscr = buf[i];
 
 	return 0;
 }
@@ -293,25 +293,25 @@ unsigned long copy_fpr_from_user(struct task_struct *task,
 unsigned long copy_vsx_to_user(void __user *to,
 			       struct task_struct *task)
 {
-	double buf[ELF_NVSRHALFREG];
+	u64 buf[ELF_NVSRHALFREG];
 	int i;
 
 	/* save FPR copy to local buffer then write to the thread_struct */
 	for (i = 0; i < ELF_NVSRHALFREG; i++)
-		buf[i] = task->thread.fpr[i][TS_VSRLOWOFFSET];
+		buf[i] = task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET];
 	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
 }
 
 unsigned long copy_vsx_from_user(struct task_struct *task,
 				 void __user *from)
 {
-	double buf[ELF_NVSRHALFREG];
+	u64 buf[ELF_NVSRHALFREG];
 	int i;
 
 	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
 		return 1;
 	for (i = 0; i < ELF_NVSRHALFREG ; i++)
-		task->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];
+		task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
 	return 0;
 }
 
@@ -319,27 +319,27 @@ unsigned long copy_vsx_from_user(struct task_struct *task,
 unsigned long copy_transact_fpr_to_user(void __user *to,
 				  struct task_struct *task)
 {
-	double buf[ELF_NFPREG];
+	u64 buf[ELF_NFPREG];
 	int i;
 
 	/* save FPR copy to local buffer then write to the thread_struct */
 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
 		buf[i] = task->thread.TS_TRANS_FPR(i);
-	memcpy(&buf[i], &task->thread.transact_fpscr, sizeof(double));
+	buf[i] = task->thread.transact_fp.fpscr;
 	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
 }
 
 unsigned long copy_transact_fpr_from_user(struct task_struct *task,
 					  void __user *from)
 {
-	double buf[ELF_NFPREG];
+	u64 buf[ELF_NFPREG];
 	int i;
 
 	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
 		return 1;
 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
 		task->thread.TS_TRANS_FPR(i) = buf[i];
-	memcpy(&task->thread.transact_fpscr, &buf[i], sizeof(double));
+	task->thread.transact_fp.fpscr = buf[i];
 
 	return 0;
 }
@@ -347,25 +347,25 @@ unsigned long copy_transact_fpr_from_user(struct task_struct *task,
 unsigned long copy_transact_vsx_to_user(void __user *to,
 				  struct task_struct *task)
 {
-	double buf[ELF_NVSRHALFREG];
+	u64 buf[ELF_NVSRHALFREG];
 	int i;
 
 	/* save FPR copy to local buffer then write to the thread_struct */
 	for (i = 0; i < ELF_NVSRHALFREG; i++)
-		buf[i] = task->thread.transact_fpr[i][TS_VSRLOWOFFSET];
+		buf[i] = task->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET];
 	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
 }
 
 unsigned long copy_transact_vsx_from_user(struct task_struct *task,
 					  void __user *from)
 {
-	double buf[ELF_NVSRHALFREG];
+	u64 buf[ELF_NVSRHALFREG];
 	int i;
 
 	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
 		return 1;
 	for (i = 0; i < ELF_NVSRHALFREG ; i++)
-		task->thread.transact_fpr[i][TS_VSRLOWOFFSET] = buf[i];
+		task->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = buf[i];
 	return 0;
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
@@ -373,14 +373,14 @@ unsigned long copy_transact_vsx_from_user(struct task_struct *task,
 inline unsigned long copy_fpr_to_user(void __user *to,
 				      struct task_struct *task)
 {
-	return __copy_to_user(to, task->thread.fpr,
+	return __copy_to_user(to, task->thread.fp_state.fpr,
 			      ELF_NFPREG * sizeof(double));
 }
 
 inline unsigned long copy_fpr_from_user(struct task_struct *task,
 					void __user *from)
 {
-	return __copy_from_user(task->thread.fpr, from,
+	return __copy_from_user(task->thread.fp_state.fpr, from,
 			      ELF_NFPREG * sizeof(double));
 }
 
@@ -388,14 +388,14 @@ inline unsigned long copy_fpr_from_user(struct task_struct *task,
 inline unsigned long copy_transact_fpr_to_user(void __user *to,
 					 struct task_struct *task)
 {
-	return __copy_to_user(to, task->thread.transact_fpr,
+	return __copy_to_user(to, task->thread.transact_fp.fpr,
 			      ELF_NFPREG * sizeof(double));
 }
 
 inline unsigned long copy_transact_fpr_from_user(struct task_struct *task,
 						 void __user *from)
 {
-	return __copy_from_user(task->thread.transact_fpr, from,
+	return __copy_from_user(task->thread.transact_fp.fpr, from,
 				ELF_NFPREG * sizeof(double));
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
@@ -423,7 +423,7 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 	/* save altivec registers */
 	if (current->thread.used_vr) {
 		flush_altivec_to_thread(current);
-		if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
+		if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
 				   ELF_NVRREG * sizeof(vector128)))
 			return 1;
 		/* set MSR_VEC in the saved MSR value to indicate that
@@ -534,17 +534,17 @@ static int save_tm_user_regs(struct pt_regs *regs,
 	/* save altivec registers */
 	if (current->thread.used_vr) {
 		flush_altivec_to_thread(current);
-		if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
+		if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,
 				   ELF_NVRREG * sizeof(vector128)))
 			return 1;
 		if (msr & MSR_VEC) {
 			if (__copy_to_user(&tm_frame->mc_vregs,
-					   current->thread.transact_vr,
+					   &current->thread.transact_vr,
 					   ELF_NVRREG * sizeof(vector128)))
 				return 1;
 		} else {
 			if (__copy_to_user(&tm_frame->mc_vregs,
-					   current->thread.vr,
+					   &current->thread.vr_state,
 					   ELF_NVRREG * sizeof(vector128)))
 				return 1;
 		}
@@ -692,11 +692,12 @@ static long restore_user_regs(struct pt_regs *regs,
 	regs->msr &= ~MSR_VEC;
 	if (msr & MSR_VEC) {
 		/* restore altivec registers from the stack */
-		if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
+		if (__copy_from_user(&current->thread.vr_state, &sr->mc_vregs,
 				     sizeof(sr->mc_vregs)))
 			return 1;
 	} else if (current->thread.used_vr)
-		memset(current->thread.vr, 0, ELF_NVRREG * sizeof(vector128));
+		memset(&current->thread.vr_state, 0,
+		       ELF_NVRREG * sizeof(vector128));
 
 	/* Always get VRSAVE back */
 	if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
@@ -722,7 +723,7 @@ static long restore_user_regs(struct pt_regs *regs,
 			return 1;
 	} else if (current->thread.used_vsr)
 		for (i = 0; i < 32 ; i++)
-			current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
+			current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 #endif /* CONFIG_VSX */
 	/*
 	 * force the process to reload the FP registers from
@@ -798,15 +799,16 @@ static long restore_tm_user_regs(struct pt_regs *regs,
 	regs->msr &= ~MSR_VEC;
 	if (msr & MSR_VEC) {
 		/* restore altivec registers from the stack */
-		if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
+		if (__copy_from_user(&current->thread.vr_state, &sr->mc_vregs,
 				     sizeof(sr->mc_vregs)) ||
-		    __copy_from_user(current->thread.transact_vr,
+		    __copy_from_user(&current->thread.transact_vr,
 				     &tm_sr->mc_vregs,
 				     sizeof(sr->mc_vregs)))
 			return 1;
 	} else if (current->thread.used_vr) {
-		memset(current->thread.vr, 0, ELF_NVRREG * sizeof(vector128));
-		memset(current->thread.transact_vr, 0,
+		memset(&current->thread.vr_state, 0,
+		       ELF_NVRREG * sizeof(vector128));
+		memset(&current->thread.transact_vr, 0,
 		       ELF_NVRREG * sizeof(vector128));
 	}
 
@@ -838,8 +840,8 @@ static long restore_tm_user_regs(struct pt_regs *regs,
 			return 1;
 	} else if (current->thread.used_vsr)
 		for (i = 0; i < 32 ; i++) {
-			current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
-			current->thread.transact_fpr[i][TS_VSRLOWOFFSET] = 0;
+			current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+			current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
 		}
 #endif /* CONFIG_VSX */
 
@@ -1030,7 +1032,7 @@ int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
 		if (__put_user(0, &rt_sf->uc.uc_link))
 			goto badframe;
 
-	current->thread.fpscr.val = 0;	/* turn off all fp exceptions */
+	current->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
@@ -1462,7 +1464,7 @@ int handle_signal32(unsigned long sig, struct k_sigaction *ka,
 
 	regs->link = tramp;
 
-	current->thread.fpscr.val = 0;	/* turn off all fp exceptions */
+	current->thread.fp_state.fpscr = 0;	/* turn off all fp exceptions */
 
 	/* create a stack frame for the caller of the handler */
 	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;