v4.19.13 snapshot.
diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
new file mode 100644
index 0000000..ee2abe9
--- /dev/null
+++ b/arch/sh/kernel/process_64.c
@@ -0,0 +1,464 @@
+/*
+ * arch/sh/kernel/process_64.c
+ *
+ * This file handles the architecture-dependent parts of process handling..
+ *
+ * Copyright (C) 2000, 2001  Paolo Alberelli
+ * Copyright (C) 2003 - 2007  Paul Mundt
+ * Copyright (C) 2003, 2004 Richard Curnow
+ *
+ * Started from SH3/4 version:
+ *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
+ *
+ *   In turn started from i386 version:
+ *     Copyright (C) 1995  Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/ptrace.h>
+#include <linux/reboot.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <asm/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/mmu_context.h>
+#include <asm/fpu.h>
+#include <asm/switch_to.h>
+
+struct task_struct *last_task_used_math = NULL;
+struct pt_regs fake_swapper_regs = { 0, };
+
+void show_regs(struct pt_regs *regs)
+{
+	unsigned long long ah, al, bh, bl, ch, cl;
+
+	printk("\n");
+	show_regs_print_info(KERN_DEFAULT);
+
+	ah = (regs->pc) >> 32;
+	al = (regs->pc) & 0xffffffff;
+	bh = (regs->regs[18]) >> 32;
+	bl = (regs->regs[18]) & 0xffffffff;
+	ch = (regs->regs[15]) >> 32;
+	cl = (regs->regs[15]) & 0xffffffff;
+	printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->sr) >> 32;
+	al = (regs->sr) & 0xffffffff;
+        asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
+        asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
+	bh = (bh) >> 32;
+	bl = (bl) & 0xffffffff;
+        asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
+        asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
+	ch = (ch) >> 32;
+	cl = (cl) & 0xffffffff;
+	printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[0]) >> 32;
+	al = (regs->regs[0]) & 0xffffffff;
+	bh = (regs->regs[1]) >> 32;
+	bl = (regs->regs[1]) & 0xffffffff;
+	ch = (regs->regs[2]) >> 32;
+	cl = (regs->regs[2]) & 0xffffffff;
+	printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[3]) >> 32;
+	al = (regs->regs[3]) & 0xffffffff;
+	bh = (regs->regs[4]) >> 32;
+	bl = (regs->regs[4]) & 0xffffffff;
+	ch = (regs->regs[5]) >> 32;
+	cl = (regs->regs[5]) & 0xffffffff;
+	printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[6]) >> 32;
+	al = (regs->regs[6]) & 0xffffffff;
+	bh = (regs->regs[7]) >> 32;
+	bl = (regs->regs[7]) & 0xffffffff;
+	ch = (regs->regs[8]) >> 32;
+	cl = (regs->regs[8]) & 0xffffffff;
+	printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[9]) >> 32;
+	al = (regs->regs[9]) & 0xffffffff;
+	bh = (regs->regs[10]) >> 32;
+	bl = (regs->regs[10]) & 0xffffffff;
+	ch = (regs->regs[11]) >> 32;
+	cl = (regs->regs[11]) & 0xffffffff;
+	printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[12]) >> 32;
+	al = (regs->regs[12]) & 0xffffffff;
+	bh = (regs->regs[13]) >> 32;
+	bl = (regs->regs[13]) & 0xffffffff;
+	ch = (regs->regs[14]) >> 32;
+	cl = (regs->regs[14]) & 0xffffffff;
+	printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[16]) >> 32;
+	al = (regs->regs[16]) & 0xffffffff;
+	bh = (regs->regs[17]) >> 32;
+	bl = (regs->regs[17]) & 0xffffffff;
+	ch = (regs->regs[19]) >> 32;
+	cl = (regs->regs[19]) & 0xffffffff;
+	printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[20]) >> 32;
+	al = (regs->regs[20]) & 0xffffffff;
+	bh = (regs->regs[21]) >> 32;
+	bl = (regs->regs[21]) & 0xffffffff;
+	ch = (regs->regs[22]) >> 32;
+	cl = (regs->regs[22]) & 0xffffffff;
+	printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[23]) >> 32;
+	al = (regs->regs[23]) & 0xffffffff;
+	bh = (regs->regs[24]) >> 32;
+	bl = (regs->regs[24]) & 0xffffffff;
+	ch = (regs->regs[25]) >> 32;
+	cl = (regs->regs[25]) & 0xffffffff;
+	printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[26]) >> 32;
+	al = (regs->regs[26]) & 0xffffffff;
+	bh = (regs->regs[27]) >> 32;
+	bl = (regs->regs[27]) & 0xffffffff;
+	ch = (regs->regs[28]) >> 32;
+	cl = (regs->regs[28]) & 0xffffffff;
+	printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[29]) >> 32;
+	al = (regs->regs[29]) & 0xffffffff;
+	bh = (regs->regs[30]) >> 32;
+	bl = (regs->regs[30]) & 0xffffffff;
+	ch = (regs->regs[31]) >> 32;
+	cl = (regs->regs[31]) & 0xffffffff;
+	printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[32]) >> 32;
+	al = (regs->regs[32]) & 0xffffffff;
+	bh = (regs->regs[33]) >> 32;
+	bl = (regs->regs[33]) & 0xffffffff;
+	ch = (regs->regs[34]) >> 32;
+	cl = (regs->regs[34]) & 0xffffffff;
+	printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[35]) >> 32;
+	al = (regs->regs[35]) & 0xffffffff;
+	bh = (regs->regs[36]) >> 32;
+	bl = (regs->regs[36]) & 0xffffffff;
+	ch = (regs->regs[37]) >> 32;
+	cl = (regs->regs[37]) & 0xffffffff;
+	printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[38]) >> 32;
+	al = (regs->regs[38]) & 0xffffffff;
+	bh = (regs->regs[39]) >> 32;
+	bl = (regs->regs[39]) & 0xffffffff;
+	ch = (regs->regs[40]) >> 32;
+	cl = (regs->regs[40]) & 0xffffffff;
+	printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[41]) >> 32;
+	al = (regs->regs[41]) & 0xffffffff;
+	bh = (regs->regs[42]) >> 32;
+	bl = (regs->regs[42]) & 0xffffffff;
+	ch = (regs->regs[43]) >> 32;
+	cl = (regs->regs[43]) & 0xffffffff;
+	printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[44]) >> 32;
+	al = (regs->regs[44]) & 0xffffffff;
+	bh = (regs->regs[45]) >> 32;
+	bl = (regs->regs[45]) & 0xffffffff;
+	ch = (regs->regs[46]) >> 32;
+	cl = (regs->regs[46]) & 0xffffffff;
+	printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[47]) >> 32;
+	al = (regs->regs[47]) & 0xffffffff;
+	bh = (regs->regs[48]) >> 32;
+	bl = (regs->regs[48]) & 0xffffffff;
+	ch = (regs->regs[49]) >> 32;
+	cl = (regs->regs[49]) & 0xffffffff;
+	printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[50]) >> 32;
+	al = (regs->regs[50]) & 0xffffffff;
+	bh = (regs->regs[51]) >> 32;
+	bl = (regs->regs[51]) & 0xffffffff;
+	ch = (regs->regs[52]) >> 32;
+	cl = (regs->regs[52]) & 0xffffffff;
+	printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[53]) >> 32;
+	al = (regs->regs[53]) & 0xffffffff;
+	bh = (regs->regs[54]) >> 32;
+	bl = (regs->regs[54]) & 0xffffffff;
+	ch = (regs->regs[55]) >> 32;
+	cl = (regs->regs[55]) & 0xffffffff;
+	printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[56]) >> 32;
+	al = (regs->regs[56]) & 0xffffffff;
+	bh = (regs->regs[57]) >> 32;
+	bl = (regs->regs[57]) & 0xffffffff;
+	ch = (regs->regs[58]) >> 32;
+	cl = (regs->regs[58]) & 0xffffffff;
+	printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[59]) >> 32;
+	al = (regs->regs[59]) & 0xffffffff;
+	bh = (regs->regs[60]) >> 32;
+	bl = (regs->regs[60]) & 0xffffffff;
+	ch = (regs->regs[61]) >> 32;
+	cl = (regs->regs[61]) & 0xffffffff;
+	printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->regs[62]) >> 32;
+	al = (regs->regs[62]) & 0xffffffff;
+	bh = (regs->tregs[0]) >> 32;
+	bl = (regs->tregs[0]) & 0xffffffff;
+	ch = (regs->tregs[1]) >> 32;
+	cl = (regs->tregs[1]) & 0xffffffff;
+	printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->tregs[2]) >> 32;
+	al = (regs->tregs[2]) & 0xffffffff;
+	bh = (regs->tregs[3]) >> 32;
+	bl = (regs->tregs[3]) & 0xffffffff;
+	ch = (regs->tregs[4]) >> 32;
+	cl = (regs->tregs[4]) & 0xffffffff;
+	printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	ah = (regs->tregs[5]) >> 32;
+	al = (regs->tregs[5]) & 0xffffffff;
+	bh = (regs->tregs[6]) >> 32;
+	bl = (regs->tregs[6]) & 0xffffffff;
+	ch = (regs->tregs[7]) >> 32;
+	cl = (regs->tregs[7]) & 0xffffffff;
+	printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx\n",
+	       ah, al, bh, bl, ch, cl);
+
+	/*
+	 * If we're in kernel mode, dump the stack too..
+	 */
+	if (!user_mode(regs)) {
+		void show_stack(struct task_struct *tsk, unsigned long *sp);
+		unsigned long sp = regs->regs[15] & 0xffffffff;
+		struct task_struct *tsk = get_current();
+
+		tsk->thread.kregs = regs;
+
+		show_stack(tsk, (unsigned long *)sp);
+	}
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(struct task_struct *tsk)
+{
+	/*
+	 * See arch/sparc/kernel/process.c for the precedent for doing
+	 * this -- RPC.
+	 *
+	 * The SH-5 FPU save/restore approach relies on
+	 * last_task_used_math pointing to a live task_struct.  When
+	 * another task tries to use the FPU for the 1st time, the FPUDIS
+	 * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
+	 * existing FPU state to the FP regs field within
+	 * last_task_used_math before re-loading the new task's FPU state
+	 * (or initialising it if the FPU has been used before).  So if
+	 * last_task_used_math is stale, and its page has already been
+	 * re-allocated for another use, the consequences are rather
+	 * grim. Unless we null it here, there is no other path through
+	 * which it would get safely nulled.
+	 */
+#ifdef CONFIG_SH_FPU
+	if (last_task_used_math == tsk)
+		last_task_used_math = NULL;
+#endif
+}
+
+void flush_thread(void)
+{
+
+	/* Called by fs/exec.c (setup_new_exec) to remove traces of a
+	 * previously running executable. */
+#ifdef CONFIG_SH_FPU
+	if (last_task_used_math == current) {
+		last_task_used_math = NULL;
+	}
+	/* Force FPU state to be reinitialised after exec */
+	clear_used_math();
+#endif
+
+	/* if we are a kernel thread, about to change to user thread,
+         * update kreg
+         */
+	if(current->thread.kregs==&fake_swapper_regs) {
+          current->thread.kregs =
+             ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
+	  current->thread.uregs = current->thread.kregs;
+	}
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+	/* do nothing */
+}
+
+/* Fill in the fpu structure for a core dump.. */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
+{
+#ifdef CONFIG_SH_FPU
+	int fpvalid;
+	struct task_struct *tsk = current;
+
+	fpvalid = !!tsk_used_math(tsk);
+	if (fpvalid) {
+		if (current == last_task_used_math) {
+			enable_fpu();
+			save_fpu(tsk);
+			disable_fpu();
+			last_task_used_math = 0;
+			regs->sr |= SR_FD;
+		}
+
+		memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));
+	}
+
+	return fpvalid;
+#else
+	return 0; /* Task didn't use the fpu at all. */
+#endif
+}
+EXPORT_SYMBOL(dump_fpu);
+
+asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
+
+int copy_thread(unsigned long clone_flags, unsigned long usp,
+		unsigned long arg, struct task_struct *p)
+{
+	struct pt_regs *childregs;
+
+#ifdef CONFIG_SH_FPU
+	/* can't happen for a kernel thread */
+	if (last_task_used_math == current) {
+		enable_fpu();
+		save_fpu(current);
+		disable_fpu();
+		last_task_used_math = NULL;
+		current_pt_regs()->sr |= SR_FD;
+	}
+#endif
+	/* Copy from sh version */
+	childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
+	p->thread.sp = (unsigned long) childregs;
+
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->regs[2] = (unsigned long)arg;
+		childregs->regs[3] = (unsigned long)usp;
+		childregs->sr = (1 << 30); /* not user_mode */
+		childregs->sr |= SR_FD; /* Invalidate FPU flag */
+		p->thread.pc = (unsigned long) ret_from_kernel_thread;
+		return 0;
+	}
+	*childregs = *current_pt_regs();
+
+	/*
+	 * Sign extend the edited stack.
+	 * Note that thread.pc and thread.pc will stay
+	 * 32-bit wide and context switch must take care
+	 * of NEFF sign extension.
+	 */
+	if (usp)
+		childregs->regs[15] = neff_sign_extend(usp);
+	p->thread.uregs = childregs;
+
+	childregs->regs[9] = 0; /* Set return value for child */
+	childregs->sr |= SR_FD; /* Invalidate FPU flag */
+
+	p->thread.pc = (unsigned long) ret_from_fork;
+
+	return 0;
+}
+
+#ifdef CONFIG_FRAME_POINTER
+static int in_sh64_switch_to(unsigned long pc)
+{
+	extern char __sh64_switch_to_end;
+	/* For a sleeping task, the PC is somewhere in the middle of the function,
+	   so we don't have to worry about masking the LSB off */
+	return (pc >= (unsigned long) sh64_switch_to) &&
+	       (pc < (unsigned long) &__sh64_switch_to_end);
+}
+#endif
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	unsigned long pc;
+
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+
+	/*
+	 * The same comment as on the Alpha applies here, too ...
+	 */
+	pc = thread_saved_pc(p);
+
+#ifdef CONFIG_FRAME_POINTER
+	if (in_sh64_switch_to(pc)) {
+		unsigned long schedule_fp;
+		unsigned long sh64_switch_to_fp;
+		unsigned long schedule_caller_pc;
+
+		sh64_switch_to_fp = (long) p->thread.sp;
+		/* r14 is saved at offset 4 in the sh64_switch_to frame */
+		schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
+
+		/* and the caller of 'schedule' is (currently!) saved at offset 24
+		   in the frame of schedule (from disasm) */
+		schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
+		return schedule_caller_pc;
+	}
+#endif
+	return pc;
+}