| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * PARISC Architecture-dependent parts of process handling |
| * based on the work for i386 |
| * |
| * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org> |
| * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net> |
| * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org> |
| * Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org> |
| * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org> |
| * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org> |
| * Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com> |
| * Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org> |
| * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org> |
| * Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org> |
| * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org> |
| * Copyright (C) 2001-2014 Helge Deller <deller@gmx.de> |
| * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org> |
| */ |
| |
| #include <stdarg.h> |
| |
| #include <linux/elf.h> |
| #include <linux/errno.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/fs.h> |
| #include <linux/cpu.h> |
| #include <linux/module.h> |
| #include <linux/personality.h> |
| #include <linux/ptrace.h> |
| #include <linux/sched.h> |
| #include <linux/sched/debug.h> |
| #include <linux/sched/task.h> |
| #include <linux/sched/task_stack.h> |
| #include <linux/slab.h> |
| #include <linux/stddef.h> |
| #include <linux/unistd.h> |
| #include <linux/kallsyms.h> |
| #include <linux/uaccess.h> |
| #include <linux/rcupdate.h> |
| #include <linux/random.h> |
| #include <linux/nmi.h> |
| |
| #include <asm/io.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/assembly.h> |
| #include <asm/pdc.h> |
| #include <asm/pdc_chassis.h> |
| #include <asm/pgalloc.h> |
| #include <asm/unwind.h> |
| #include <asm/sections.h> |
| |
| #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) |
| #define CMD_RESET 5 /* reset any module */ |
| |
| /* |
| ** The Wright Brothers and Gecko systems have a H/W problem |
| ** (Lasi...'nuf said) may cause a broadcast reset to lockup |
| ** the system. An HVERSION dependent PDC call was developed |
| ** to perform a "safe", platform specific broadcast reset instead |
| ** of kludging up all the code. |
| ** |
| ** Older machines which do not implement PDC_BROADCAST_RESET will |
| ** return (with an error) and the regular broadcast reset can be |
| ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET |
| ** the PDC call will not return (the system will be reset). |
| */ |
| void machine_restart(char *cmd) |
| { |
| #ifdef FASTBOOT_SELFTEST_SUPPORT |
| /* |
| ** If user has modified the Firmware Selftest Bitmap, |
| ** run the tests specified in the bitmap after the |
| ** system is rebooted w/PDC_DO_RESET. |
| ** |
| ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" |
| ** |
| ** Using "directed resets" at each processor with the MEM_TOC |
| ** vector cleared will also avoid running destructive |
| ** memory self tests. (Not implemented yet) |
| */ |
| if (ftc_bitmap) { |
| pdc_do_firm_test_reset(ftc_bitmap); |
| } |
| #endif |
| /* set up a new led state on systems shipped with a LED State panel */ |
| pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); |
| |
| /* "Normal" system reset */ |
| pdc_do_reset(); |
| |
| /* Nope...box should reset with just CMD_RESET now */ |
| gsc_writel(CMD_RESET, COMMAND_GLOBAL); |
| |
| /* Wait for RESET to lay us to rest. */ |
| while (1) ; |
| |
| } |
| |
| void (*chassis_power_off)(void); |
| |
| /* |
| * This routine is called from sys_reboot to actually turn off the |
| * machine |
| */ |
| void machine_power_off(void) |
| { |
| /* If there is a registered power off handler, call it. */ |
| if (chassis_power_off) |
| chassis_power_off(); |
| |
| /* Put the soft power button back under hardware control. |
| * If the user had already pressed the power button, the |
| * following call will immediately power off. */ |
| pdc_soft_power_button(0); |
| |
| pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); |
| |
| /* ipmi_poweroff may have been installed. */ |
| if (pm_power_off) |
| pm_power_off(); |
| |
| /* It seems we have no way to power the system off via |
| * software. The user has to press the button himself. */ |
| |
| printk(KERN_EMERG "System shut down completed.\n" |
| "Please power this system off now."); |
| |
| /* prevent soft lockup/stalled CPU messages for endless loop. */ |
| rcu_sysrq_start(); |
| lockup_detector_soft_poweroff(); |
| for (;;); |
| } |
| |
| void (*pm_power_off)(void); |
| EXPORT_SYMBOL(pm_power_off); |
| |
| void machine_halt(void) |
| { |
| machine_power_off(); |
| } |
| |
| void flush_thread(void) |
| { |
| /* Only needs to handle fpu stuff or perf monitors. |
| ** REVISIT: several arches implement a "lazy fpu state". |
| */ |
| } |
| |
| void release_thread(struct task_struct *dead_task) |
| { |
| } |
| |
| /* |
| * Fill in the FPU structure for a core dump. |
| */ |
| |
| int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) |
| { |
| if (regs == NULL) |
| return 0; |
| |
| memcpy(r, regs->fr, sizeof *r); |
| return 1; |
| } |
| |
| int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) |
| { |
| memcpy(r, tsk->thread.regs.fr, sizeof(*r)); |
| return 1; |
| } |
| |
| /* |
| * Idle thread support |
| * |
| * Detect when running on QEMU with SeaBIOS PDC Firmware and let |
| * QEMU idle the host too. |
| */ |
| |
| int running_on_qemu __ro_after_init; |
| EXPORT_SYMBOL(running_on_qemu); |
| |
| void __cpuidle arch_cpu_idle_dead(void) |
| { |
| /* nop on real hardware, qemu will offline CPU. */ |
| asm volatile("or %%r31,%%r31,%%r31\n":::); |
| } |
| |
| void __cpuidle arch_cpu_idle(void) |
| { |
| local_irq_enable(); |
| |
| /* nop on real hardware, qemu will idle sleep. */ |
| asm volatile("or %%r10,%%r10,%%r10\n":::); |
| } |
| |
| static int __init parisc_idle_init(void) |
| { |
| if (!running_on_qemu) |
| cpu_idle_poll_ctrl(1); |
| |
| return 0; |
| } |
| arch_initcall(parisc_idle_init); |
| |
| /* |
| * Copy architecture-specific thread state |
| */ |
| int |
| copy_thread(unsigned long clone_flags, unsigned long usp, |
| unsigned long kthread_arg, struct task_struct *p) |
| { |
| struct pt_regs *cregs = &(p->thread.regs); |
| void *stack = task_stack_page(p); |
| |
| /* We have to use void * instead of a function pointer, because |
| * function pointers aren't a pointer to the function on 64-bit. |
| * Make them const so the compiler knows they live in .text */ |
| extern void * const ret_from_kernel_thread; |
| extern void * const child_return; |
| |
| if (unlikely(p->flags & PF_KTHREAD)) { |
| /* kernel thread */ |
| memset(cregs, 0, sizeof(struct pt_regs)); |
| if (!usp) /* idle thread */ |
| return 0; |
| /* Must exit via ret_from_kernel_thread in order |
| * to call schedule_tail() |
| */ |
| cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; |
| cregs->kpc = (unsigned long) &ret_from_kernel_thread; |
| /* |
| * Copy function and argument to be called from |
| * ret_from_kernel_thread. |
| */ |
| #ifdef CONFIG_64BIT |
| cregs->gr[27] = ((unsigned long *)usp)[3]; |
| cregs->gr[26] = ((unsigned long *)usp)[2]; |
| #else |
| cregs->gr[26] = usp; |
| #endif |
| cregs->gr[25] = kthread_arg; |
| } else { |
| /* user thread */ |
| /* usp must be word aligned. This also prevents users from |
| * passing in the value 1 (which is the signal for a special |
| * return for a kernel thread) */ |
| if (usp) { |
| usp = ALIGN(usp, 4); |
| if (likely(usp)) |
| cregs->gr[30] = usp; |
| } |
| cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; |
| cregs->kpc = (unsigned long) &child_return; |
| |
| /* Setup thread TLS area from the 4th parameter in clone */ |
| if (clone_flags & CLONE_SETTLS) |
| cregs->cr27 = cregs->gr[23]; |
| } |
| |
| return 0; |
| } |
| |
| unsigned long |
| get_wchan(struct task_struct *p) |
| { |
| struct unwind_frame_info info; |
| unsigned long ip; |
| int count = 0; |
| |
| if (!p || p == current || p->state == TASK_RUNNING) |
| return 0; |
| |
| /* |
| * These bracket the sleeping functions.. |
| */ |
| |
| unwind_frame_init_from_blocked_task(&info, p); |
| do { |
| if (unwind_once(&info) < 0) |
| return 0; |
| ip = info.ip; |
| if (!in_sched_functions(ip)) |
| return ip; |
| } while (count++ < MAX_UNWIND_ENTRIES); |
| return 0; |
| } |
| |
| #ifdef CONFIG_64BIT |
| void *dereference_function_descriptor(void *ptr) |
| { |
| Elf64_Fdesc *desc = ptr; |
| void *p; |
| |
| if (!probe_kernel_address(&desc->addr, p)) |
| ptr = p; |
| return ptr; |
| } |
| |
| void *dereference_kernel_function_descriptor(void *ptr) |
| { |
| if (ptr < (void *)__start_opd || |
| ptr >= (void *)__end_opd) |
| return ptr; |
| |
| return dereference_function_descriptor(ptr); |
| } |
| #endif |
| |
| static inline unsigned long brk_rnd(void) |
| { |
| return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; |
| } |
| |
| unsigned long arch_randomize_brk(struct mm_struct *mm) |
| { |
| unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); |
| |
| if (ret < mm->brk) |
| return mm->brk; |
| return ret; |
| } |