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Diffstat (limited to 'arch/parisc/kernel/process.c')
| -rw-r--r-- | arch/parisc/kernel/process.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c new file mode 100644 index 000000000..b62d60009 --- /dev/null +++ b/arch/parisc/kernel/process.c @@ -0,0 +1,302 @@ +// 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); + + /* "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. */ + 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 arch_cpu_idle_dead(void) +{ +#ifdef CONFIG_HOTPLUG_CPU + idle_task_exit(); + + local_irq_disable(); + + /* Tell __cpu_die() that this CPU is now safe to dispose of. */ + (void)cpu_report_death(); + + /* 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) +{ + raw_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(struct task_struct *p, const struct kernel_clone_args *args) +{ + unsigned long 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; +} + +static inline unsigned long brk_rnd(void) +{ + return (get_random_u32() & 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; +} |