// 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 <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/reboot.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 <linux/sched/hotplug.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/unwind.h> #include <asm/sections.h> #include <asm/cacheflush.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); /* prevent interrupts during reboot */ set_eiem(0); /* "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) ; } /* * This routine is called from sys_reboot to actually turn off the * machine */ void machine_power_off(void) { /* 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. */ do_kernel_power_off(); /* It seems we have no way to power the system off via * software. The user has to press the button himself. */ printk("Power off or press RETURN to reboot.\n"); /* prevent soft lockup/stalled CPU messages for endless loop. */ rcu_sysrq_start(); lockup_detector_soft_poweroff(); while (1) { /* reboot if user presses RETURN key */ if (pdc_iodc_getc() == 13) { printk("Rebooting...\n"); machine_restart(NULL); } } } 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". */ } /* * 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); /* * Called from the idle thread for the CPU which has been shutdown. */ void __noreturn arch_cpu_idle_dead(void) { #ifdef CONFIG_HOTPLUG_CPU idle_task_exit(); local_irq_disable(); /* Tell the core that this CPU is now safe to dispose of. */ cpuhp_ap_report_dead(); /* Ensure that the cache lines are written out. */ flush_cache_all_local(); flush_tlb_all_local(NULL); /* Let PDC firmware put CPU into firmware idle loop. */ __pdc_cpu_rendezvous(); pr_warn("PDC does not provide rendezvous function.\n"); #endif while (1); } void __cpuidle arch_cpu_idle(void) { /* 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(struct task_struct *p, const struct kernel_clone_args *args) { u64 clone_flags = args->flags; unsigned long usp = args->stack; unsigned long tls = args->tls; 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(args->fn)) { /* kernel thread */ memset(cregs, 0, sizeof(struct pt_regs)); if (args->idle) /* idle thread */ return 0; /* Must exit via ret_from_kernel_thread in order * to call schedule_tail() */ cregs->ksp = (unsigned long) stack + FRAME_SIZE + PT_SZ_ALGN; 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 *)args->fn)[3]; cregs->gr[26] = ((unsigned long *)args->fn)[2]; #else cregs->gr[26] = (unsigned long) args->fn; #endif cregs->gr[25] = (unsigned long) args->fn_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 + FRAME_SIZE; cregs->kpc = (unsigned long) &child_return; /* Setup thread TLS area */ if (clone_flags & CLONE_SETTLS) cregs->cr27 = tls; } return 0; } unsigned long __get_wchan(struct task_struct *p) { struct unwind_frame_info info; unsigned long ip; int count = 0; /* * These bracket the sleeping functions.. */ unwind_frame_init_from_blocked_task(&info, p); do { if (unwind_once(&info) < 0) return 0; if (task_is_running(p)) return 0; ip = info.ip; if (!in_sched_functions(ip)) return ip; } while (count++ < MAX_UNWIND_ENTRIES); return 0; }
