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Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c new file mode 100644 index 000000000000..f22965ea1cfc --- /dev/null +++ b/arch/arm64/kernel/process.c @@ -0,0 +1,408 @@ +/* + * Based on arch/arm/kernel/process.c + * + * Original Copyright (C) 1995 Linus Torvalds + * Copyright (C) 1996-2000 Russell King - Converted to ARM. + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <stdarg.h> + +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/stddef.h> +#include <linux/unistd.h> +#include <linux/user.h> +#include <linux/delay.h> +#include <linux/reboot.h> +#include <linux/interrupt.h> +#include <linux/kallsyms.h> +#include <linux/init.h> +#include <linux/cpu.h> +#include <linux/elfcore.h> +#include <linux/pm.h> +#include <linux/tick.h> +#include <linux/utsname.h> +#include <linux/uaccess.h> +#include <linux/random.h> +#include <linux/hw_breakpoint.h> +#include <linux/personality.h> +#include <linux/notifier.h> + +#include <asm/compat.h> +#include <asm/cacheflush.h> +#include <asm/processor.h> +#include <asm/stacktrace.h> +#include <asm/fpsimd.h> + +static void setup_restart(void) +{ + /* + * Tell the mm system that we are going to reboot - + * we may need it to insert some 1:1 mappings so that + * soft boot works. + */ + setup_mm_for_reboot(); + + /* Clean and invalidate caches */ + flush_cache_all(); + + /* Turn D-cache off */ + cpu_cache_off(); + + /* Push out any further dirty data, and ensure cache is empty */ + flush_cache_all(); +} + +void soft_restart(unsigned long addr) +{ + setup_restart(); + cpu_reset(addr); +} + +/* + * Function pointers to optional machine specific functions + */ +void (*pm_power_off)(void); +EXPORT_SYMBOL_GPL(pm_power_off); + +void (*pm_restart)(const char *cmd); +EXPORT_SYMBOL_GPL(pm_restart); + + +/* + * This is our default idle handler. + */ +static void default_idle(void) +{ + /* + * This should do all the clock switching and wait for interrupt + * tricks + */ + cpu_do_idle(); + local_irq_enable(); +} + +void (*pm_idle)(void) = default_idle; +EXPORT_SYMBOL_GPL(pm_idle); + +/* + * The idle thread, has rather strange semantics for calling pm_idle, + * but this is what x86 does and we need to do the same, so that + * things like cpuidle get called in the same way. The only difference + * is that we always respect 'hlt_counter' to prevent low power idle. + */ +void cpu_idle(void) +{ + local_fiq_enable(); + + /* endless idle loop with no priority at all */ + while (1) { + tick_nohz_idle_enter(); + rcu_idle_enter(); + while (!need_resched()) { + /* + * We need to disable interrupts here to ensure + * we don't miss a wakeup call. + */ + local_irq_disable(); + if (!need_resched()) { + stop_critical_timings(); + pm_idle(); + start_critical_timings(); + /* + * pm_idle functions should always return + * with IRQs enabled. + */ + WARN_ON(irqs_disabled()); + } else { + local_irq_enable(); + } + } + rcu_idle_exit(); + tick_nohz_idle_exit(); + schedule_preempt_disabled(); + } +} + +void machine_shutdown(void) +{ +#ifdef CONFIG_SMP + smp_send_stop(); +#endif +} + +void machine_halt(void) +{ + machine_shutdown(); + while (1); +} + +void machine_power_off(void) +{ + machine_shutdown(); + if (pm_power_off) + pm_power_off(); +} + +void machine_restart(char *cmd) +{ + machine_shutdown(); + + /* Disable interrupts first */ + local_irq_disable(); + local_fiq_disable(); + + /* Now call the architecture specific reboot code. */ + if (pm_restart) + pm_restart(cmd); + + /* + * Whoops - the architecture was unable to reboot. + */ + printk("Reboot failed -- System halted\n"); + while (1); +} + +void __show_regs(struct pt_regs *regs) +{ + int i; + + printk("CPU: %d %s (%s %.*s)\n", + raw_smp_processor_id(), print_tainted(), + init_utsname()->release, + (int)strcspn(init_utsname()->version, " "), + init_utsname()->version); + print_symbol("PC is at %s\n", instruction_pointer(regs)); + print_symbol("LR is at %s\n", regs->regs[30]); + printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n", + regs->pc, regs->regs[30], regs->pstate); + printk("sp : %016llx\n", regs->sp); + for (i = 29; i >= 0; i--) { + printk("x%-2d: %016llx ", i, regs->regs[i]); + if (i % 2 == 0) + printk("\n"); + } + printk("\n"); +} + +void show_regs(struct pt_regs * regs) +{ + printk("\n"); + printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); + __show_regs(regs); +} + +/* + * Free current thread data structures etc.. + */ +void exit_thread(void) +{ +} + +void flush_thread(void) +{ + fpsimd_flush_thread(); + flush_ptrace_hw_breakpoint(current); +} + +void release_thread(struct task_struct *dead_task) +{ +} + +int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) +{ + fpsimd_save_state(¤t->thread.fpsimd_state); + *dst = *src; + return 0; +} + +asmlinkage void ret_from_fork(void) asm("ret_from_fork"); + +int copy_thread(unsigned long clone_flags, unsigned long stack_start, + unsigned long stk_sz, struct task_struct *p, + struct pt_regs *regs) +{ + struct pt_regs *childregs = task_pt_regs(p); + unsigned long tls = p->thread.tp_value; + + *childregs = *regs; + childregs->regs[0] = 0; + + if (is_compat_thread(task_thread_info(p))) + childregs->compat_sp = stack_start; + else { + /* + * Read the current TLS pointer from tpidr_el0 as it may be + * out-of-sync with the saved value. + */ + asm("mrs %0, tpidr_el0" : "=r" (tls)); + childregs->sp = stack_start; + } + + memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context)); + p->thread.cpu_context.sp = (unsigned long)childregs; + p->thread.cpu_context.pc = (unsigned long)ret_from_fork; + + /* If a TLS pointer was passed to clone, use that for the new thread. */ + if (clone_flags & CLONE_SETTLS) + tls = regs->regs[3]; + p->thread.tp_value = tls; + + ptrace_hw_copy_thread(p); + + return 0; +} + +static void tls_thread_switch(struct task_struct *next) +{ + unsigned long tpidr, tpidrro; + + if (!is_compat_task()) { + asm("mrs %0, tpidr_el0" : "=r" (tpidr)); + current->thread.tp_value = tpidr; + } + + if (is_compat_thread(task_thread_info(next))) { + tpidr = 0; + tpidrro = next->thread.tp_value; + } else { + tpidr = next->thread.tp_value; + tpidrro = 0; + } + + asm( + " msr tpidr_el0, %0\n" + " msr tpidrro_el0, %1" + : : "r" (tpidr), "r" (tpidrro)); +} + +/* + * Thread switching. + */ +struct task_struct *__switch_to(struct task_struct *prev, + struct task_struct *next) +{ + struct task_struct *last; + + fpsimd_thread_switch(next); + tls_thread_switch(next); + hw_breakpoint_thread_switch(next); + + /* the actual thread switch */ + last = cpu_switch_to(prev, next); + + return last; +} + +/* + * Fill in the task's elfregs structure for a core dump. + */ +int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) +{ + elf_core_copy_regs(elfregs, task_pt_regs(t)); + return 1; +} + +/* + * fill in the fpe structure for a core dump... + */ +int dump_fpu (struct pt_regs *regs, struct user_fp *fp) +{ + return 0; +} +EXPORT_SYMBOL(dump_fpu); + +/* + * Shuffle the argument into the correct register before calling the + * thread function. x1 is the thread argument, x2 is the pointer to + * the thread function, and x3 points to the exit function. + */ +extern void kernel_thread_helper(void); +asm( ".section .text\n" +" .align\n" +" .type kernel_thread_helper, #function\n" +"kernel_thread_helper:\n" +" mov x0, x1\n" +" mov x30, x3\n" +" br x2\n" +" .size kernel_thread_helper, . - kernel_thread_helper\n" +" .previous"); + +#define kernel_thread_exit do_exit + +/* + * Create a kernel thread. + */ +pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) +{ + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + + regs.regs[1] = (unsigned long)arg; + regs.regs[2] = (unsigned long)fn; + regs.regs[3] = (unsigned long)kernel_thread_exit; + regs.pc = (unsigned long)kernel_thread_helper; + regs.pstate = PSR_MODE_EL1h; + + return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); +} +EXPORT_SYMBOL(kernel_thread); + +unsigned long get_wchan(struct task_struct *p) +{ + struct stackframe frame; + int count = 0; + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + frame.fp = thread_saved_fp(p); + frame.sp = thread_saved_sp(p); + frame.pc = thread_saved_pc(p); + do { + int ret = unwind_frame(&frame); + if (ret < 0) + return 0; + if (!in_sched_functions(frame.pc)) + return frame.pc; + } while (count ++ < 16); + return 0; +} + +unsigned long arch_align_stack(unsigned long sp) +{ + if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) + sp -= get_random_int() & ~PAGE_MASK; + return sp & ~0xf; +} + +static unsigned long randomize_base(unsigned long base) +{ + unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1; + return randomize_range(base, range_end, 0) ? : base; +} + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + return randomize_base(mm->brk); +} + +unsigned long randomize_et_dyn(unsigned long base) +{ + return randomize_base(base); +} |