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-rw-r--r--arch/m68k/kernel/process.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
new file mode 100644
index 000000000..2cb4a61bc
--- /dev/null
+++ b/arch/m68k/kernel/process.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/m68k/kernel/process.c
+ *
+ * Copyright (C) 1995 Hamish Macdonald
+ *
+ * 68060 fixes by Jesper Skov
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/reboot.h>
+#include <linux/init_task.h>
+#include <linux/mqueue.h>
+#include <linux/rcupdate.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+
+#include <asm/traps.h>
+#include <asm/machdep.h>
+#include <asm/setup.h>
+
+
+asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
+
+void arch_cpu_idle(void)
+{
+#if defined(MACH_ATARI_ONLY)
+ /* block out HSYNC on the atari (falcon) */
+ __asm__("stop #0x2200" : : : "cc");
+#else
+ __asm__("stop #0x2000" : : : "cc");
+#endif
+}
+
+void machine_restart(char * __unused)
+{
+ if (mach_reset)
+ mach_reset();
+ for (;;);
+}
+
+void machine_halt(void)
+{
+ if (mach_halt)
+ mach_halt();
+ for (;;);
+}
+
+void machine_power_off(void)
+{
+ do_kernel_power_off();
+ for (;;);
+}
+
+void (*pm_power_off)(void);
+EXPORT_SYMBOL(pm_power_off);
+
+void show_regs(struct pt_regs * regs)
+{
+ pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
+ regs->format, regs->vector, regs->pc, regs->sr,
+ print_tainted());
+ pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
+ regs->orig_d0, regs->d0, regs->a2, regs->a1);
+ pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5,
+ regs->d4);
+ pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2,
+ regs->d1);
+ if (!(regs->sr & PS_S))
+ pr_info("USP: %08lx\n", rdusp());
+}
+
+void flush_thread(void)
+{
+ current->thread.fc = USER_DATA;
+#ifdef CONFIG_FPU
+ if (!FPU_IS_EMU) {
+ unsigned long zero = 0;
+ asm volatile("frestore %0": :"m" (zero));
+ }
+#endif
+}
+
+/*
+ * Why not generic sys_clone, you ask? m68k passes all arguments on stack.
+ * And we need all registers saved, which means a bunch of stuff pushed
+ * on top of pt_regs, which means that sys_clone() arguments would be
+ * buried. We could, of course, copy them, but it's too costly for no
+ * good reason - generic clone() would have to copy them *again* for
+ * kernel_clone() anyway. So in this case it's actually better to pass pt_regs *
+ * and extract arguments for kernel_clone() from there. Eventually we might
+ * go for calling kernel_clone() directly from the wrapper, but only after we
+ * are finished with kernel_clone() prototype conversion.
+ */
+asmlinkage int m68k_clone(struct pt_regs *regs)
+{
+ /* regs will be equal to current_pt_regs() */
+ struct kernel_clone_args args = {
+ .flags = regs->d1 & ~CSIGNAL,
+ .pidfd = (int __user *)regs->d3,
+ .child_tid = (int __user *)regs->d4,
+ .parent_tid = (int __user *)regs->d3,
+ .exit_signal = regs->d1 & CSIGNAL,
+ .stack = regs->d2,
+ .tls = regs->d5,
+ };
+
+ return kernel_clone(&args);
+}
+
+/*
+ * Because extra registers are saved on the stack after the sys_clone3()
+ * arguments, this C wrapper extracts them from pt_regs * and then calls the
+ * generic sys_clone3() implementation.
+ */
+asmlinkage int m68k_clone3(struct pt_regs *regs)
+{
+ return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
+}
+
+int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
+{
+ unsigned long clone_flags = args->flags;
+ unsigned long usp = args->stack;
+ unsigned long tls = args->tls;
+ struct fork_frame {
+ struct switch_stack sw;
+ struct pt_regs regs;
+ } *frame;
+
+ frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
+
+ p->thread.ksp = (unsigned long)frame;
+ p->thread.esp0 = (unsigned long)&frame->regs;
+
+ /*
+ * Must save the current SFC/DFC value, NOT the value when
+ * the parent was last descheduled - RGH 10-08-96
+ */
+ p->thread.fc = USER_DATA;
+
+ if (unlikely(args->fn)) {
+ /* kernel thread */
+ memset(frame, 0, sizeof(struct fork_frame));
+ frame->regs.sr = PS_S;
+ frame->sw.a3 = (unsigned long)args->fn;
+ frame->sw.d7 = (unsigned long)args->fn_arg;
+ frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
+ p->thread.usp = 0;
+ return 0;
+ }
+ memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
+ sizeof(struct fork_frame));
+ frame->regs.d0 = 0;
+ frame->sw.retpc = (unsigned long)ret_from_fork;
+ p->thread.usp = usp ?: rdusp();
+
+ if (clone_flags & CLONE_SETTLS)
+ task_thread_info(p)->tp_value = tls;
+
+#ifdef CONFIG_FPU
+ if (!FPU_IS_EMU) {
+ /* Copy the current fpu state */
+ asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
+
+ if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
+ if (CPU_IS_COLDFIRE) {
+ asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
+ "fmovel %/fpiar,%1\n\t"
+ "fmovel %/fpcr,%2\n\t"
+ "fmovel %/fpsr,%3"
+ :
+ : "m" (p->thread.fp[0]),
+ "m" (p->thread.fpcntl[0]),
+ "m" (p->thread.fpcntl[1]),
+ "m" (p->thread.fpcntl[2])
+ : "memory");
+ } else {
+ asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
+ "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
+ :
+ : "m" (p->thread.fp[0]),
+ "m" (p->thread.fpcntl[0])
+ : "memory");
+ }
+ }
+
+ /* Restore the state in case the fpu was busy */
+ asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
+ }
+#endif /* CONFIG_FPU */
+
+ return 0;
+}
+
+/* Fill in the fpu structure for a core dump. */
+int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
+{
+ if (FPU_IS_EMU) {
+ int i;
+
+ memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
+ memcpy(fpu->fpregs, current->thread.fp, 96);
+ /* Convert internal fpu reg representation
+ * into long double format
+ */
+ for (i = 0; i < 24; i += 3)
+ fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
+ ((fpu->fpregs[i] & 0x0000ffff) << 16);
+ return 1;
+ }
+
+ if (IS_ENABLED(CONFIG_FPU)) {
+ char fpustate[216];
+
+ /* First dump the fpu context to avoid protocol violation. */
+ asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
+ if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
+ return 0;
+
+ if (CPU_IS_COLDFIRE) {
+ asm volatile ("fmovel %/fpiar,%0\n\t"
+ "fmovel %/fpcr,%1\n\t"
+ "fmovel %/fpsr,%2\n\t"
+ "fmovemd %/fp0-%/fp7,%3"
+ :
+ : "m" (fpu->fpcntl[0]),
+ "m" (fpu->fpcntl[1]),
+ "m" (fpu->fpcntl[2]),
+ "m" (fpu->fpregs[0])
+ : "memory");
+ } else {
+ asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
+ :
+ : "m" (fpu->fpcntl[0])
+ : "memory");
+ asm volatile ("fmovemx %/fp0-%/fp7,%0"
+ :
+ : "m" (fpu->fpregs[0])
+ : "memory");
+ }
+ }
+
+ return 1;
+}
+EXPORT_SYMBOL(dump_fpu);
+
+unsigned long __get_wchan(struct task_struct *p)
+{
+ unsigned long fp, pc;
+ unsigned long stack_page;
+ int count = 0;
+
+ stack_page = (unsigned long)task_stack_page(p);
+ fp = ((struct switch_stack *)p->thread.ksp)->a6;
+ do {
+ if (fp < stack_page+sizeof(struct thread_info) ||
+ fp >= 8184+stack_page)
+ return 0;
+ pc = ((unsigned long *)fp)[1];
+ if (!in_sched_functions(pc))
+ return pc;
+ fp = *(unsigned long *) fp;
+ } while (count++ < 16);
+ return 0;
+}
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