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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
commitd635711daa98be86d4c7fd01499c34f566b54ccb (patch)
treeaa5cc3760a27c3d57146498cb82fa549547de06c /arch/powerpc/kernel/process.c
parentc91265cd0efb83778f015b4d4b1129bd2cfd075e (diff)
Linux-libre 4.6.2-gnu
Diffstat (limited to 'arch/powerpc/kernel/process.c')
-rw-r--r--arch/powerpc/kernel/process.c168
1 files changed, 151 insertions, 17 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 54ed9c766..b8500b4ac 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -133,6 +133,16 @@ void __msr_check_and_clear(unsigned long bits)
EXPORT_SYMBOL(__msr_check_and_clear);
#ifdef CONFIG_PPC_FPU
+void __giveup_fpu(struct task_struct *tsk)
+{
+ save_fpu(tsk);
+ tsk->thread.regs->msr &= ~MSR_FP;
+#ifdef CONFIG_VSX
+ if (cpu_has_feature(CPU_FTR_VSX))
+ tsk->thread.regs->msr &= ~MSR_VSX;
+#endif
+}
+
void giveup_fpu(struct task_struct *tsk)
{
check_if_tm_restore_required(tsk);
@@ -187,9 +197,32 @@ void enable_kernel_fp(void)
}
}
EXPORT_SYMBOL(enable_kernel_fp);
+
+static int restore_fp(struct task_struct *tsk) {
+ if (tsk->thread.load_fp) {
+ load_fp_state(&current->thread.fp_state);
+ current->thread.load_fp++;
+ return 1;
+ }
+ return 0;
+}
+#else
+static int restore_fp(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_PPC_FPU */
#ifdef CONFIG_ALTIVEC
+#define loadvec(thr) ((thr).load_vec)
+
+static void __giveup_altivec(struct task_struct *tsk)
+{
+ save_altivec(tsk);
+ tsk->thread.regs->msr &= ~MSR_VEC;
+#ifdef CONFIG_VSX
+ if (cpu_has_feature(CPU_FTR_VSX))
+ tsk->thread.regs->msr &= ~MSR_VSX;
+#endif
+}
+
void giveup_altivec(struct task_struct *tsk)
{
check_if_tm_restore_required(tsk);
@@ -229,22 +262,49 @@ void flush_altivec_to_thread(struct task_struct *tsk)
}
}
EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
+
+static int restore_altivec(struct task_struct *tsk)
+{
+ 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;
+ }
+ return 0;
+}
+#else
+#define loadvec(thr) 0
+static inline int restore_altivec(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
-void giveup_vsx(struct task_struct *tsk)
+static void __giveup_vsx(struct task_struct *tsk)
{
- check_if_tm_restore_required(tsk);
-
- msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
if (tsk->thread.regs->msr & MSR_FP)
__giveup_fpu(tsk);
if (tsk->thread.regs->msr & MSR_VEC)
__giveup_altivec(tsk);
+ tsk->thread.regs->msr &= ~MSR_VSX;
+}
+
+static void giveup_vsx(struct task_struct *tsk)
+{
+ check_if_tm_restore_required(tsk);
+
+ msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
__giveup_vsx(tsk);
msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
}
-EXPORT_SYMBOL(giveup_vsx);
+
+static void save_vsx(struct task_struct *tsk)
+{
+ if (tsk->thread.regs->msr & MSR_FP)
+ save_fpu(tsk);
+ if (tsk->thread.regs->msr & MSR_VEC)
+ save_altivec(tsk);
+}
void enable_kernel_vsx(void)
{
@@ -275,6 +335,19 @@ void flush_vsx_to_thread(struct task_struct *tsk)
}
}
EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
+
+static int restore_vsx(struct task_struct *tsk)
+{
+ if (cpu_has_feature(CPU_FTR_VSX)) {
+ tsk->thread.used_vsr = 1;
+ return 1;
+ }
+
+ return 0;
+}
+#else
+static inline int restore_vsx(struct task_struct *tsk) { return 0; }
+static inline void save_vsx(struct task_struct *tsk) { }
#endif /* CONFIG_VSX */
#ifdef CONFIG_SPE
@@ -374,12 +447,76 @@ void giveup_all(struct task_struct *tsk)
}
EXPORT_SYMBOL(giveup_all);
+void restore_math(struct pt_regs *regs)
+{
+ unsigned long msr;
+
+ if (!current->thread.load_fp && !loadvec(current->thread))
+ return;
+
+ 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
+ */
+ if ((!(msr & MSR_FP)) && restore_fp(current))
+ msr |= MSR_FP | current->thread.fpexc_mode;
+
+ if ((!(msr & MSR_VEC)) && restore_altivec(current))
+ msr |= MSR_VEC;
+
+ if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) &&
+ restore_vsx(current)) {
+ msr |= MSR_VSX;
+ }
+
+ msr_check_and_clear(msr_all_available);
+
+ regs->msr = msr;
+}
+
+void save_all(struct task_struct *tsk)
+{
+ unsigned long usermsr;
+
+ if (!tsk->thread.regs)
+ return;
+
+ usermsr = tsk->thread.regs->msr;
+
+ if ((usermsr & msr_all_available) == 0)
+ return;
+
+ msr_check_and_set(msr_all_available);
+
+ /*
+ * Saving the way the register space is in hardware, save_vsx boils
+ * down to a save_fpu() and save_altivec()
+ */
+ if (usermsr & MSR_VSX) {
+ save_vsx(tsk);
+ } else {
+ if (usermsr & MSR_FP)
+ save_fpu(tsk);
+
+ if (usermsr & MSR_VEC)
+ save_altivec(tsk);
+ }
+
+ if (usermsr & MSR_SPE)
+ __giveup_spe(tsk);
+
+ msr_check_and_clear(msr_all_available);
+}
+
void flush_all_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
BUG_ON(tsk != current);
- giveup_all(tsk);
+ save_all(tsk);
#ifdef CONFIG_SPE
if (tsk->thread.regs->msr & MSR_SPE)
@@ -832,17 +969,9 @@ void restore_tm_state(struct pt_regs *regs)
msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
- if (msr_diff & MSR_FP) {
- msr_check_and_set(MSR_FP);
- load_fp_state(&current->thread.fp_state);
- msr_check_and_clear(MSR_FP);
- regs->msr |= current->thread.fpexc_mode;
- }
- if (msr_diff & MSR_VEC) {
- msr_check_and_set(MSR_VEC);
- load_vr_state(&current->thread.vr_state);
- msr_check_and_clear(MSR_VEC);
- }
+
+ restore_math(regs);
+
regs->msr |= msr_diff;
}
@@ -1006,6 +1135,10 @@ struct task_struct *__switch_to(struct task_struct *prev,
batch = this_cpu_ptr(&ppc64_tlb_batch);
batch->active = 1;
}
+
+ if (current_thread_info()->task->thread.regs)
+ restore_math(current_thread_info()->task->thread.regs);
+
#endif /* CONFIG_PPC_BOOK3S_64 */
return last;
@@ -1307,6 +1440,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
f = ret_from_fork;
}
+ childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
sp -= STACK_FRAME_OVERHEAD;
/*