[PATCH] ppc64: VMX (Altivec) support & signal32 rework, from Ben Herrenschmidt

From: Anton Blanchard <anton@samba.org>

VMX (Altivec) support & signal32 rework, from Ben Herrenschmidt

1 files changed, 93 insertions, 12 deletions

diff --git a/arch/ppc64/kernel/process.c b/arch/ppc64/kernel/process.c
index 0b16f7615ad5..041827788def 100644
--- a/arch/ppc64/kernel/process.c
+++ b/arch/ppc64/kernel/process.c
@@ -50,7 +50,10 @@
 #include <asm/cputable.h>
 #include <asm/sections.h>
 
+#ifndef CONFIG_SMP
 struct task_struct *last_task_used_math = NULL;
+struct task_struct *last_task_used_altivec = NULL;
+#endif
 
 struct mm_struct ioremap_mm = { pgd             : ioremap_dir  
                                ,page_table_lock : SPIN_LOCK_UNLOCKED };
@@ -58,8 +61,7 @@ struct mm_struct ioremap_mm = { pgd             : ioremap_dir
 char *sysmap = NULL;
 unsigned long sysmap_size = 0;
 
-void
-enable_kernel_fp(void)
+void enable_kernel_fp(void)
 {
 #ifdef CONFIG_SMP
 	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
@@ -70,6 +72,7 @@ enable_kernel_fp(void)
 	giveup_fpu(last_task_used_math);
 #endif /* CONFIG_SMP */
 }
+EXPORT_SYMBOL(enable_kernel_fp);
 
 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
 {
@@ -85,6 +88,31 @@ int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
 	return 1;
 }
 
+#ifdef CONFIG_ALTIVEC
+
+void enable_kernel_altivec(void)
+{
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
+		giveup_altivec(current);
+	else
+		giveup_altivec(NULL);	/* just enables FP for kernel */
+#else
+	giveup_altivec(last_task_used_altivec);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_altivec);
+
+int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
+{
+	if (regs->msr & MSR_VEC)
+		giveup_altivec(current);
+	memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
+	return 1;
+}
+
+#endif /* CONFIG_ALTIVEC */
+
 struct task_struct *__switch_to(struct task_struct *prev,
 				struct task_struct *new)
 {
@@ -104,8 +132,20 @@ struct task_struct *__switch_to(struct task_struct *prev,
 	 */
 	if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
 		giveup_fpu(prev);
+#ifdef CONFIG_ALTIVEC
+	if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
+		giveup_altivec(prev);
+#endif /* CONFIG_ALTIVEC */
 #endif /* CONFIG_SMP */
 
+#if defined(CONFIG_ALTIVEC) && !defined(CONFIG_SMP)
+	/* Avoid the trap.  On smp this this never happens since
+	 * we don't set last_task_used_altivec -- Cort
+	 */
+	if (new->thread.regs && last_task_used_altivec == new)
+		new->thread.regs->msr |= MSR_VEC;
+#endif /* CONFIG_ALTIVEC */
+
 	new_thread = &new->thread;
 	old_thread = &current->thread;
 
@@ -158,8 +198,14 @@ void show_regs(struct pt_regs * regs)
 
 void exit_thread(void)
 {
+#ifndef CONFIG_SMP
 	if (last_task_used_math == current)
 		last_task_used_math = NULL;
+#ifdef CONFIG_ALTIVEC
+	if (last_task_used_altivec == current)
+		last_task_used_altivec = NULL;
+#endif /* CONFIG_ALTIVEC */
+#endif /* CONFIG_SMP */
 }
 
 void flush_thread(void)
@@ -169,8 +215,14 @@ void flush_thread(void)
 	if (t->flags & _TIF_ABI_PENDING)
 		t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
 
+#ifndef CONFIG_SMP
 	if (last_task_used_math == current)
 		last_task_used_math = NULL;
+#ifdef CONFIG_ALTIVEC
+	if (last_task_used_altivec == current)
+		last_task_used_altivec = NULL;
+#endif /* CONFIG_ALTIVEC */
+#endif /* CONFIG_SMP */
 }
 
 void
@@ -178,6 +230,25 @@ release_thread(struct task_struct *t)
 {
 }
 
+
+/*
+ * This gets called before we allocate a new thread and copy
+ * the current task into it.
+ */
+void prepare_to_copy(struct task_struct *tsk)
+{
+	struct pt_regs *regs = tsk->thread.regs;
+
+	if (regs == NULL)
+		return;
+	if (regs->msr & MSR_FP)
+		giveup_fpu(current);
+#ifdef CONFIG_ALTIVEC
+	if (regs->msr & MSR_VEC)
+		giveup_altivec(current);
+#endif /* CONFIG_ALTIVEC */
+}
+
 /*
  * Copy a thread..
  */
@@ -268,9 +339,25 @@ void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp)
 	regs->gpr[1] = sp;
 	regs->gpr[2] = toc;
 	regs->msr = MSR_USER64;
+#ifndef CONFIG_SMP
 	if (last_task_used_math == current)
 		last_task_used_math = 0;
+#endif /* CONFIG_SMP */
+	memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
 	current->thread.fpscr = 0;
+#ifdef CONFIG_ALTIVEC
+#ifndef CONFIG_SMP
+	if (last_task_used_altivec == current)
+		last_task_used_altivec = 0;
+#endif /* CONFIG_SMP */
+	memset(current->thread.vr, 0, sizeof(current->thread.vr));
+	current->thread.vscr.u[0] = 0;
+	current->thread.vscr.u[1] = 0;
+	current->thread.vscr.u[2] = 0;
+	current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
+	current->thread.vrsave = 0;
+	current->thread.used_vr = 0;
+#endif /* CONFIG_ALTIVEC */
 }
 
 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
@@ -314,9 +401,6 @@ int sys_clone(unsigned long clone_flags, unsigned long p2, unsigned long p3,
 		}
 	}
 
-	if (regs->msr & MSR_FP)
-		giveup_fpu(current);
-
 	return do_fork(clone_flags & ~CLONE_IDLETASK, p2, regs, 0,
 		    (int *)parent_tidptr, (int *)child_tidptr);
 }
@@ -325,9 +409,6 @@ int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
 	     unsigned long p4, unsigned long p5, unsigned long p6,
 	     struct pt_regs *regs)
 {
-	if (regs->msr & MSR_FP)
-		giveup_fpu(current);
-
 	return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
 }
 
@@ -335,9 +416,6 @@ int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
 	      unsigned long p4, unsigned long p5, unsigned long p6,
 	      struct pt_regs *regs)
 {
-	if (regs->msr & MSR_FP)
-		giveup_fpu(current);
-
 	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], regs, 0,
 	            NULL, NULL);
 }
@@ -355,7 +433,10 @@ int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
 		goto out;
 	if (regs->msr & MSR_FP)
 		giveup_fpu(current);
-  
+#ifdef CONFIG_ALTIVEC
+	if (regs->msr & MSR_VEC)
+		giveup_altivec(current);
+#endif /* CONFIG_ALTIVEC */
 	error = do_execve(filename, (char **) a1, (char **) a2, regs);
   
 	if (error == 0)