| // SPDX-License-Identifier: GPL-2.0 |
| /* linux/arch/sparc/kernel/process.c |
| * |
| * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net) |
| * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) |
| */ |
| |
| /* |
| * 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)(); |
| raw_local_irq_enable(); |
| } |
| |
| /* 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(unsigned long clone_flags, unsigned long sp, unsigned long arg, |
| struct task_struct *p, unsigned long 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(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { |
| extern int nwindows; |
| unsigned long psr; |
| memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); |
| p->thread.current_ds = KERNEL_DS; |
| ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); |
| childregs->u_regs[UREG_G1] = sp; /* function */ |
| childregs->u_regs[UREG_G2] = 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; |
| p->thread.current_ds = USER_DS; |
| 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; |
| |
| if (!task || task == current || task_is_running(task)) |
| goto out; |
| |
| 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; |
| } |
| |