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-rw-r--r--arch/sh/kernel/cpu/fpu.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/fpu.c b/arch/sh/kernel/cpu/fpu.c
new file mode 100644
index 000000000..fd6db0ab1
--- /dev/null
+++ b/arch/sh/kernel/cpu/fpu.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/sched/signal.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/slab.h>
+#include <asm/processor.h>
+#include <asm/fpu.h>
+#include <asm/traps.h>
+#include <asm/ptrace.h>
+
+int init_fpu(struct task_struct *tsk)
+{
+ if (tsk_used_math(tsk)) {
+ if ((boot_cpu_data.flags & CPU_HAS_FPU) && tsk == current)
+ unlazy_fpu(tsk, task_pt_regs(tsk));
+ return 0;
+ }
+
+ /*
+ * Memory allocation at the first usage of the FPU and other state.
+ */
+ if (!tsk->thread.xstate) {
+ tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
+ GFP_KERNEL);
+ if (!tsk->thread.xstate)
+ return -ENOMEM;
+ }
+
+ if (boot_cpu_data.flags & CPU_HAS_FPU) {
+ struct sh_fpu_hard_struct *fp = &tsk->thread.xstate->hardfpu;
+ memset(fp, 0, xstate_size);
+ fp->fpscr = FPSCR_INIT;
+ } else {
+ struct sh_fpu_soft_struct *fp = &tsk->thread.xstate->softfpu;
+ memset(fp, 0, xstate_size);
+ fp->fpscr = FPSCR_INIT;
+ }
+
+ set_stopped_child_used_math(tsk);
+ return 0;
+}
+
+#ifdef CONFIG_SH_FPU
+void __fpu_state_restore(void)
+{
+ struct task_struct *tsk = current;
+
+ restore_fpu(tsk);
+
+ task_thread_info(tsk)->status |= TS_USEDFPU;
+ tsk->thread.fpu_counter++;
+}
+
+void fpu_state_restore(struct pt_regs *regs)
+{
+ struct task_struct *tsk = current;
+
+ if (unlikely(!user_mode(regs))) {
+ printk(KERN_ERR "BUG: FPU is used in kernel mode.\n");
+ BUG();
+ return;
+ }
+
+ if (!tsk_used_math(tsk)) {
+ int ret;
+ /*
+ * does a slab alloc which can sleep
+ */
+ local_irq_enable();
+ ret = init_fpu(tsk);
+ local_irq_disable();
+ if (ret) {
+ /*
+ * ran out of memory!
+ */
+ force_sig(SIGKILL);
+ return;
+ }
+ }
+
+ grab_fpu(regs);
+
+ __fpu_state_restore();
+}
+
+BUILD_TRAP_HANDLER(fpu_state_restore)
+{
+ TRAP_HANDLER_DECL;
+
+ fpu_state_restore(regs);
+}
+#endif /* CONFIG_SH_FPU */