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Diffstat (limited to 'arch/powerpc/kernel/process.c')
-rw-r--r--arch/powerpc/kernel/process.c111
1 files changed, 68 insertions, 43 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 794b754deec2..016bd831908e 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -471,49 +471,58 @@ EXPORT_SYMBOL(giveup_all);
#ifdef CONFIG_PPC_BOOK3S_64
#ifdef CONFIG_PPC_FPU
-static int restore_fp(struct task_struct *tsk)
+static bool should_restore_fp(void)
{
- if (tsk->thread.load_fp) {
- load_fp_state(&current->thread.fp_state);
+ if (current->thread.load_fp) {
current->thread.load_fp++;
- return 1;
+ return true;
}
- return 0;
+ return false;
+}
+
+static void do_restore_fp(void)
+{
+ load_fp_state(&current->thread.fp_state);
}
#else
-static int restore_fp(struct task_struct *tsk) { return 0; }
+static bool should_restore_fp(void) { return false; }
+static void do_restore_fp(void) { }
#endif /* CONFIG_PPC_FPU */
#ifdef CONFIG_ALTIVEC
-#define loadvec(thr) ((thr).load_vec)
-static int restore_altivec(struct task_struct *tsk)
+static bool should_restore_altivec(void)
{
- if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) {
- load_vr_state(&tsk->thread.vr_state);
- tsk->thread.used_vr = 1;
- tsk->thread.load_vec++;
-
- return 1;
+ if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) {
+ current->thread.load_vec++;
+ return true;
}
- return 0;
+ return false;
+}
+
+static void do_restore_altivec(void)
+{
+ load_vr_state(&current->thread.vr_state);
+ current->thread.used_vr = 1;
}
#else
-#define loadvec(thr) 0
-static inline int restore_altivec(struct task_struct *tsk) { return 0; }
+static bool should_restore_altivec(void) { return false; }
+static void do_restore_altivec(void) { }
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
-static int restore_vsx(struct task_struct *tsk)
+static bool should_restore_vsx(void)
{
- if (cpu_has_feature(CPU_FTR_VSX)) {
- tsk->thread.used_vsr = 1;
- return 1;
- }
-
- return 0;
+ if (cpu_has_feature(CPU_FTR_VSX))
+ return true;
+ return false;
+}
+static void do_restore_vsx(void)
+{
+ current->thread.used_vsr = 1;
}
#else
-static inline int restore_vsx(struct task_struct *tsk) { return 0; }
+static bool should_restore_vsx(void) { return false; }
+static void do_restore_vsx(void) { }
#endif /* CONFIG_VSX */
/*
@@ -529,32 +538,42 @@ static inline int restore_vsx(struct task_struct *tsk) { return 0; }
void notrace restore_math(struct pt_regs *regs)
{
unsigned long msr;
-
- if (!MSR_TM_ACTIVE(regs->msr) &&
- !current->thread.load_fp && !loadvec(current->thread))
- return;
+ unsigned long new_msr = 0;
msr = regs->msr;
- msr_check_and_set(msr_all_available);
/*
- * Only reload if the bit is not set in the user MSR, the bit BEING set
- * indicates that the registers are hot
+ * new_msr tracks the facilities that are to be restored. Only reload
+ * if the bit is not set in the user MSR (if it is set, the registers
+ * are live for the user thread).
*/
- if ((!(msr & MSR_FP)) && restore_fp(current))
- msr |= MSR_FP | current->thread.fpexc_mode;
+ if ((!(msr & MSR_FP)) && should_restore_fp())
+ new_msr |= MSR_FP | current->thread.fpexc_mode;
- if ((!(msr & MSR_VEC)) && restore_altivec(current))
- msr |= MSR_VEC;
+ if ((!(msr & MSR_VEC)) && should_restore_altivec())
+ new_msr |= MSR_VEC;
- if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) &&
- restore_vsx(current)) {
- msr |= MSR_VSX;
+ if ((!(msr & MSR_VSX)) && should_restore_vsx()) {
+ if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC))
+ new_msr |= MSR_VSX;
}
- msr_check_and_clear(msr_all_available);
+ if (new_msr) {
+ msr_check_and_set(new_msr);
+
+ if (new_msr & MSR_FP)
+ do_restore_fp();
+
+ if (new_msr & MSR_VEC)
+ do_restore_altivec();
+
+ if (new_msr & MSR_VSX)
+ do_restore_vsx();
- regs->msr = msr;
+ msr_check_and_clear(new_msr);
+
+ regs->msr |= new_msr;
+ }
}
#endif
@@ -1599,6 +1618,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
{
struct pt_regs *childregs, *kregs;
extern void ret_from_fork(void);
+ extern void ret_from_fork_scv(void);
extern void ret_from_kernel_thread(void);
void (*f)(void);
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
@@ -1635,7 +1655,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
if (usp)
childregs->gpr[1] = usp;
p->thread.regs = childregs;
- childregs->gpr[3] = 0; /* Result from fork() */
+ /* 64s sets this in ret_from_fork */
+ if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+ childregs->gpr[3] = 0; /* Result from fork() */
if (clone_flags & CLONE_SETTLS) {
if (!is_32bit_task())
childregs->gpr[13] = tls;
@@ -1643,7 +1665,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
childregs->gpr[2] = tls;
}
- f = ret_from_fork;
+ if (trap_is_scv(regs))
+ f = ret_from_fork_scv;
+ else
+ f = ret_from_fork;
}
childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
sp -= STACK_FRAME_OVERHEAD;