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![Greg Ungerer](/assets/img/avatar_default.png)
Our local m68k architecture dump_fpu() is conditionally compiled in on CONFIG_FPU. That is OK for all existing MMU enabled CPU types, but won't handle the case for some ColdFire SoC CPU parts that we want to support that have no FPU hardware. dump_fpu() is expected to be present by the ELF loader, so we must always have it available and exported. Remove the conditional and reorganize the dump_fpu hard FPU code path to let the compiler remove code when not needed. This change based on changes and discussion from Yannick Gicquel <yannick.gicquel@open.eurogiciel.org>. Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
277 lines
6.9 KiB
C
277 lines
6.9 KiB
C
/*
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* linux/arch/m68k/kernel/process.c
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*
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* Copyright (C) 1995 Hamish Macdonald
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*
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* 68060 fixes by Jesper Skov
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*/
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/*
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* This file handles the architecture-dependent parts of process handling..
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*/
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/smp.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/ptrace.h>
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#include <linux/user.h>
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#include <linux/reboot.h>
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#include <linux/init_task.h>
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#include <linux/mqueue.h>
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#include <linux/rcupdate.h>
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#include <asm/uaccess.h>
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#include <asm/traps.h>
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#include <asm/machdep.h>
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#include <asm/setup.h>
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#include <asm/pgtable.h>
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asmlinkage void ret_from_fork(void);
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asmlinkage void ret_from_kernel_thread(void);
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/*
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* Return saved PC from a blocked thread
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*/
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unsigned long thread_saved_pc(struct task_struct *tsk)
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{
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struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
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/* Check whether the thread is blocked in resume() */
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if (in_sched_functions(sw->retpc))
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return ((unsigned long *)sw->a6)[1];
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else
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return sw->retpc;
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}
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void arch_cpu_idle(void)
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{
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#if defined(MACH_ATARI_ONLY)
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/* block out HSYNC on the atari (falcon) */
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__asm__("stop #0x2200" : : : "cc");
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#else
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__asm__("stop #0x2000" : : : "cc");
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#endif
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}
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void machine_restart(char * __unused)
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{
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if (mach_reset)
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mach_reset();
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for (;;);
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}
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void machine_halt(void)
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{
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if (mach_halt)
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mach_halt();
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for (;;);
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}
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void machine_power_off(void)
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{
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if (mach_power_off)
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mach_power_off();
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for (;;);
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}
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void (*pm_power_off)(void) = machine_power_off;
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EXPORT_SYMBOL(pm_power_off);
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void show_regs(struct pt_regs * regs)
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{
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printk("\n");
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printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
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regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
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printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
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regs->orig_d0, regs->d0, regs->a2, regs->a1);
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printk("A0: %08lx D5: %08lx D4: %08lx\n",
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regs->a0, regs->d5, regs->d4);
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printk("D3: %08lx D2: %08lx D1: %08lx\n",
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regs->d3, regs->d2, regs->d1);
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if (!(regs->sr & PS_S))
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printk("USP: %08lx\n", rdusp());
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}
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void flush_thread(void)
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{
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current->thread.fs = __USER_DS;
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#ifdef CONFIG_FPU
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if (!FPU_IS_EMU) {
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unsigned long zero = 0;
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asm volatile("frestore %0": :"m" (zero));
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}
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#endif
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}
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/*
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* Why not generic sys_clone, you ask? m68k passes all arguments on stack.
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* And we need all registers saved, which means a bunch of stuff pushed
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* on top of pt_regs, which means that sys_clone() arguments would be
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* buried. We could, of course, copy them, but it's too costly for no
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* good reason - generic clone() would have to copy them *again* for
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* do_fork() anyway. So in this case it's actually better to pass pt_regs *
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* and extract arguments for do_fork() from there. Eventually we might
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* go for calling do_fork() directly from the wrapper, but only after we
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* are finished with do_fork() prototype conversion.
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*/
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asmlinkage int m68k_clone(struct pt_regs *regs)
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{
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/* regs will be equal to current_pt_regs() */
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return do_fork(regs->d1, regs->d2, 0,
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(int __user *)regs->d3, (int __user *)regs->d4);
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}
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int copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long arg, struct task_struct *p)
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{
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struct fork_frame {
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struct switch_stack sw;
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struct pt_regs regs;
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} *frame;
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frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
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p->thread.ksp = (unsigned long)frame;
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p->thread.esp0 = (unsigned long)&frame->regs;
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/*
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* Must save the current SFC/DFC value, NOT the value when
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* the parent was last descheduled - RGH 10-08-96
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*/
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p->thread.fs = get_fs().seg;
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if (unlikely(p->flags & PF_KTHREAD)) {
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/* kernel thread */
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memset(frame, 0, sizeof(struct fork_frame));
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frame->regs.sr = PS_S;
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frame->sw.a3 = usp; /* function */
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frame->sw.d7 = arg;
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frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
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p->thread.usp = 0;
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return 0;
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}
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memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
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sizeof(struct fork_frame));
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frame->regs.d0 = 0;
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frame->sw.retpc = (unsigned long)ret_from_fork;
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p->thread.usp = usp ?: rdusp();
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if (clone_flags & CLONE_SETTLS)
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task_thread_info(p)->tp_value = frame->regs.d5;
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#ifdef CONFIG_FPU
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if (!FPU_IS_EMU) {
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/* Copy the current fpu state */
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asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
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if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
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if (CPU_IS_COLDFIRE) {
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asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
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"fmovel %/fpiar,%1\n\t"
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"fmovel %/fpcr,%2\n\t"
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"fmovel %/fpsr,%3"
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:
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: "m" (p->thread.fp[0]),
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"m" (p->thread.fpcntl[0]),
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"m" (p->thread.fpcntl[1]),
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"m" (p->thread.fpcntl[2])
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: "memory");
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} else {
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asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
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"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
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:
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: "m" (p->thread.fp[0]),
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"m" (p->thread.fpcntl[0])
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: "memory");
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}
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}
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/* Restore the state in case the fpu was busy */
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asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
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}
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#endif /* CONFIG_FPU */
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return 0;
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}
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/* Fill in the fpu structure for a core dump. */
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int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
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{
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if (FPU_IS_EMU) {
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int i;
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memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
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memcpy(fpu->fpregs, current->thread.fp, 96);
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/* Convert internal fpu reg representation
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* into long double format
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*/
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for (i = 0; i < 24; i += 3)
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fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
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((fpu->fpregs[i] & 0x0000ffff) << 16);
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return 1;
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}
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if (IS_ENABLED(CONFIG_FPU)) {
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char fpustate[216];
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/* First dump the fpu context to avoid protocol violation. */
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asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
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if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
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return 0;
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if (CPU_IS_COLDFIRE) {
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asm volatile ("fmovel %/fpiar,%0\n\t"
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"fmovel %/fpcr,%1\n\t"
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"fmovel %/fpsr,%2\n\t"
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"fmovemd %/fp0-%/fp7,%3"
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:
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: "m" (fpu->fpcntl[0]),
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"m" (fpu->fpcntl[1]),
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"m" (fpu->fpcntl[2]),
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"m" (fpu->fpregs[0])
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: "memory");
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} else {
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asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
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:
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: "m" (fpu->fpcntl[0])
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: "memory");
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asm volatile ("fmovemx %/fp0-%/fp7,%0"
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:
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: "m" (fpu->fpregs[0])
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: "memory");
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}
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}
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return 1;
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}
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EXPORT_SYMBOL(dump_fpu);
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unsigned long get_wchan(struct task_struct *p)
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{
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unsigned long fp, pc;
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unsigned long stack_page;
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int count = 0;
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if (!p || p == current || p->state == TASK_RUNNING)
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return 0;
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stack_page = (unsigned long)task_stack_page(p);
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fp = ((struct switch_stack *)p->thread.ksp)->a6;
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do {
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if (fp < stack_page+sizeof(struct thread_info) ||
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fp >= 8184+stack_page)
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return 0;
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pc = ((unsigned long *)fp)[1];
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if (!in_sched_functions(pc))
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return pc;
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fp = *(unsigned long *) fp;
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} while (count++ < 16);
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return 0;
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}
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