// SPDX-License-Identifier: GPL-2.0
/* linux/arch/sparc/kernel/process.c
*
* Copyright (C) 1995, 2008 David S. Miller ([email protected])
* Copyright (C) 1996 Eddie C. Dost ([email protected])
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/elfcore.h>
#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/stddef.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <asm/auxio.h>
#include <asm/oplib.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/delay.h>
#include <asm/processor.h>
#include <asm/psr.h>
#include <asm/elf.h>
#include <asm/prom.h>
#include <asm/unistd.h>
#include <asm/setup.h>
#include "kernel.h"
/*
* Power management idle function
* Set in pm platform drivers (apc.c and pmc.c)
*/
void (*sparc_idle)(void);
/*
* Power-off handler instantiation for pm.h compliance
* This is done via auxio, but could be used as a fallback
* handler when auxio is not present-- unused for now...
*/
void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);
/*
* sysctl - toggle power-off restriction for serial console
* systems in machine_power_off()
*/
int scons_pwroff = 1;
extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
struct task_struct *last_task_used_math = NULL;
struct thread_info *current_set[NR_CPUS];
/* Idle loop support. */
void arch_cpu_idle(void)
{
if (sparc_idle)
(*sparc_idle)();
}
/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
void machine_halt(void)
{
local_irq_enable();
mdelay(8);
local_irq_disable();
prom_halt();
panic("Halt failed!");
}
void machine_restart(char * cmd)
{
char *p;
local_irq_enable();
mdelay(8);
local_irq_disable();
p = strchr (reboot_command, '\n');
if (p) *p = 0;
if (cmd)
prom_reboot(cmd);
if (*reboot_command)
prom_reboot(reboot_command);
prom_feval ("reset");
panic("Reboot failed!");
}
void machine_power_off(void)
{
if (auxio_power_register &&
(!of_node_is_type(of_console_device, "serial") || scons_pwroff)) {
u8 power_register = sbus_readb(auxio_power_register);
power_register |= AUXIO_POWER_OFF;
sbus_writeb(power_register, auxio_power_register);
}
machine_halt();
}
void show_regs(struct pt_regs *r)
{
struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
show_regs_print_info(KERN_DEFAULT);
printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
r->psr, r->pc, r->npc, r->y, print_tainted());
printk("PC: <%pS>\n", (void *) r->pc);
printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
}
/*
* The show_stack() is external API which we do not use ourselves.
* The oops is printed in die_if_kernel.
*/
void show_stack(struct task_struct *tsk, unsigned long *_ksp, const char *loglvl)
{
unsigned long pc, fp;
unsigned long task_base;
struct reg_window32 *rw;
int count = 0;
if (!tsk)
tsk = current;
if (tsk == current && !_ksp)
__asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp));
task_base = (unsigned long) task_stack_page(tsk);
fp = (unsigned long) _ksp;
do {
/* Bogus frame pointer? */
if (fp < (task_base + sizeof(struct thread_info)) ||
fp >= (task_base + (PAGE_SIZE << 1)))
break;
rw = (struct reg_window32 *) fp;
pc = rw->ins[7];
printk("%s[%08lx : ", loglvl, pc);
printk("%s%pS ] ", loglvl, (void *) pc);
fp = rw->ins[6];
} while (++count < 16);
printk("%s\n", loglvl);
}
/*
* Free current thread data structures etc..
*/
void exit_thread(struct task_struct *tsk)
{
#ifndef CONFIG_SMP
if (last_task_used_math == tsk) {
#else
if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) {
#endif
/* Keep process from leaving FPU in a bogon state. */
put_psr(get_psr() | PSR_EF);
fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr,
&tsk->thread.fpqueue[0], &tsk->thread.fpqdepth);
#ifndef CONFIG_SMP
last_task_used_math = NULL;
#else
clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU);
#endif
}
}
void flush_thread(void)
{
current_thread_info()->w_saved = 0;
#ifndef CONFIG_SMP
if(last_task_used_math == current) {
#else
if (test_thread_flag(TIF_USEDFPU)) {
#endif
/* Clean the fpu. */
put_psr(get_psr() | PSR_EF);
fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
#ifndef CONFIG_SMP
last_task_used_math = NULL;
#else
clear_thread_flag(TIF_USEDFPU);
#endif
}
}
static inline struct sparc_stackf __user *
clone_stackframe(struct sparc_stackf __user *dst,
struct sparc_stackf __user *src)
{
unsigned long size, fp;
struct sparc_stackf *tmp;
struct sparc_stackf __user *sp;
if (get_user(tmp, &src->fp))
return NULL;
fp = (unsigned long) tmp;
size = (fp - ((unsigned long) src));
fp = (unsigned long) dst;
sp = (struct sparc_stackf __user *)(fp - size);
/* do_fork() grabs the parent semaphore, we must release it
* temporarily so we can build the child clone stack frame
* without deadlocking.
*/
if (__copy_user(sp, src, size))
sp = NULL;
else if (put_user(fp, &sp->fp))
sp = NULL;
return sp;
}
/* Copy a Sparc thread. The fork() return value conventions
* under SunOS are nothing short of bletcherous:
* Parent --> %o0 == childs pid, %o1 == 0
* Child --> %o0 == parents pid, %o1 == 1
*
* NOTE: We have a separate fork kpsr/kwim because
* the parent could change these values between
* sys_fork invocation and when we reach here
* if the parent should sleep while trying to
* allocate the task_struct and kernel stack in
* do_fork().
* XXX See comment above sys_vfork in sparc64. todo.
*/
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
{
unsigned long clone_flags = args->flags;
unsigned long sp = args->stack;
unsigned long tls = args->tls;
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs, *regs = current_pt_regs();
char *new_stack;
#ifndef CONFIG_SMP
if(last_task_used_math == current) {
#else
if (test_thread_flag(TIF_USEDFPU)) {
#endif
put_psr(get_psr() | PSR_EF);
fpsave(&p->thread.float_regs[0], &p->thread.fsr,
&p->thread.fpqueue[0], &p->thread.fpqdepth);
}
/*
* p->thread_info new_stack childregs stack bottom
* ! ! ! !
* V V (stk.fr.) V (pt_regs) V
* +----- - - - - - ------+===========+=============+
*/
new_stack = task_stack_page(p) + THREAD_SIZE;
new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
/*
* A new process must start with interrupts disabled, see schedule_tail()
* and finish_task_switch(). (If we do not do it and if a timer interrupt
* hits before we unlock and attempts to take the rq->lock, we deadlock.)
*
* Thus, kpsr |= PSR_PIL.
*/
ti->ksp = (unsigned long) new_stack;
p->thread.kregs = childregs;
if (unlikely(args->fn)) {
extern int nwindows;
unsigned long psr;
memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
childregs->u_regs[UREG_G1] = (unsigned long) args->fn;
childregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg;
psr = childregs->psr = get_psr();
ti->kpsr = psr | PSR_PIL;
ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows);
return 0;
}
memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
childregs->u_regs[UREG_FP] = sp;
ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
ti->kwim = current->thread.fork_kwim;
if (sp != regs->u_regs[UREG_FP]) {
struct sparc_stackf __user *childstack;
struct sparc_stackf __user *parentstack;
/*
* This is a clone() call with supplied user stack.
* Set some valid stack frames to give to the child.
*/
childstack = (struct sparc_stackf __user *)
(sp & ~0xfUL);
parentstack = (struct sparc_stackf __user *)
regs->u_regs[UREG_FP];
#if 0
printk("clone: parent stack:\n");
show_stackframe(parentstack);
#endif
childstack = clone_stackframe(childstack, parentstack);
if (!childstack)
return -EFAULT;
#if 0
printk("clone: child stack:\n");
show_stackframe(childstack);
#endif
childregs->u_regs[UREG_FP] = (unsigned long)childstack;
}
#ifdef CONFIG_SMP
/* FPU must be disabled on SMP. */
childregs->psr &= ~PSR_EF;
clear_tsk_thread_flag(p, TIF_USEDFPU);
#endif
/* Set the return value for the child. */
childregs->u_regs[UREG_I0] = current->pid;
childregs->u_regs[UREG_I1] = 1;
/* Set the return value for the parent. */
regs->u_regs[UREG_I1] = 0;
if (clone_flags & CLONE_SETTLS)
childregs->u_regs[UREG_G7] = tls;
return 0;
}
unsigned long __get_wchan(struct task_struct *task)
{
unsigned long pc, fp, bias = 0;
unsigned long task_base = (unsigned long) task;
unsigned long ret = 0;
struct reg_window32 *rw;
int count = 0;
fp = task_thread_info(task)->ksp + bias;
do {
/* Bogus frame pointer? */
if (fp < (task_base + sizeof(struct thread_info)) ||
fp >= (task_base + (2 * PAGE_SIZE)))
break;
rw = (struct reg_window32 *) fp;
pc = rw->ins[7];
if (!in_sched_functions(pc)) {
ret = pc;
goto out;
}
fp = rw->ins[6] + bias;
} while (++count < 16);
out:
return ret;
}
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