diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c new file mode 100644 index 000000000..c6b1f3b96 --- /dev/null +++ b/arch/arm64/kernel/process.c @@ -0,0 +1,388 @@ +/* + * 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/compat.h> +#include <linux/efi.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/fpsimd.h> +#include <asm/mmu_context.h> +#include <asm/processor.h> +#include <asm/stacktrace.h> + +#ifdef CONFIG_CC_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + +void soft_restart(unsigned long addr) +{ + setup_mm_for_reboot(); + cpu_soft_restart(virt_to_phys(cpu_reset), addr); + /* Should never get here */ + BUG(); +} + +/* + * Function pointers to optional machine specific functions + */ +void (*pm_power_off)(void); +EXPORT_SYMBOL_GPL(pm_power_off); + +void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); + +/* + * This is our default idle handler. + */ +void arch_cpu_idle(void) +{ + /* + * This should do all the clock switching and wait for interrupt + * tricks + */ + cpu_do_idle(); + local_irq_enable(); +} + +#ifdef CONFIG_HOTPLUG_CPU +void arch_cpu_idle_dead(void) +{ + cpu_die(); +} +#endif + +/* + * Called by kexec, immediately prior to machine_kexec(). + * + * This must completely disable all secondary CPUs; simply causing those CPUs + * to execute e.g. a RAM-based pin loop is not sufficient. This allows the + * kexec'd kernel to use any and all RAM as it sees fit, without having to + * avoid any code or data used by any SW CPU pin loop. The CPU hotplug + * functionality embodied in disable_nonboot_cpus() to achieve this. + */ +void machine_shutdown(void) +{ + disable_nonboot_cpus(); +} + +/* + * Halting simply requires that the secondary CPUs stop performing any + * activity (executing tasks, handling interrupts). smp_send_stop() + * achieves this. + */ +void machine_halt(void) +{ + local_irq_disable(); + smp_send_stop(); + while (1); +} + +/* + * Power-off simply requires that the secondary CPUs stop performing any + * activity (executing tasks, handling interrupts). smp_send_stop() + * achieves this. When the system power is turned off, it will take all CPUs + * with it. + */ +void machine_power_off(void) +{ + local_irq_disable(); + smp_send_stop(); + if (pm_power_off) + pm_power_off(); +} + +/* + * Restart requires that the secondary CPUs stop performing any activity + * while the primary CPU resets the system. Systems with a single CPU can + * use soft_restart() as their machine descriptor's .restart hook, since that + * will cause the only available CPU to reset. Systems with multiple CPUs must + * provide a HW restart implementation, to ensure that all CPUs reset at once. + * This is required so that any code running after reset on the primary CPU + * doesn't have to co-ordinate with other CPUs to ensure they aren't still + * executing pre-reset code, and using RAM that the primary CPU's code wishes + * to use. Implementing such co-ordination would be essentially impossible. + */ +void machine_restart(char *cmd) +{ + /* Disable interrupts first */ + local_irq_disable(); + smp_send_stop(); + + /* + * UpdateCapsule() depends on the system being reset via + * ResetSystem(). + */ + if (efi_enabled(EFI_RUNTIME_SERVICES)) + efi_reboot(reboot_mode, NULL); + + /* Now call the architecture specific reboot code. */ + if (arm_pm_restart) + arm_pm_restart(reboot_mode, cmd); + else + do_kernel_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, top_reg; + u64 lr, sp; + + if (compat_user_mode(regs)) { + lr = regs->compat_lr; + sp = regs->compat_sp; + top_reg = 12; + } else { + lr = regs->regs[30]; + sp = regs->sp; + top_reg = 29; + } + + show_regs_print_info(KERN_DEFAULT); + print_symbol("PC is at %s\n", instruction_pointer(regs)); + print_symbol("LR is at %s\n", lr); + printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n", + regs->pc, lr, regs->pstate); + printk("sp : %016llx\n", sp); + for (i = top_reg; 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"); + __show_regs(regs); +} + +/* + * Free current thread data structures etc.. + */ +void exit_thread(void) +{ +} + +static void tls_thread_flush(void) +{ + asm ("msr tpidr_el0, xzr"); + + if (is_compat_task()) { + current->thread.tp_value = 0; + + /* + * We need to ensure ordering between the shadow state and the + * hardware state, so that we don't corrupt the hardware state + * with a stale shadow state during context switch. + */ + barrier(); + asm ("msr tpidrro_el0, xzr"); + } +} + +void flush_thread(void) +{ + fpsimd_flush_thread(); + tls_thread_flush(); + 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_preserve_current_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 *childregs = task_pt_regs(p); + unsigned long tls = p->thread.tp_value; + + memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context)); + + if (likely(!(p->flags & PF_KTHREAD))) { + *childregs = *current_pt_regs(); + childregs->regs[0] = 0; + if (is_compat_thread(task_thread_info(p))) { + if (stack_start) + 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)); + if (stack_start) { + /* 16-byte aligned stack mandatory on AArch64 */ + if (stack_start & 15) + return -EINVAL; + childregs->sp = stack_start; + } + } + /* + * If a TLS pointer was passed to clone (4th argument), use it + * for the new thread. + */ + if (clone_flags & CLONE_SETTLS) + tls = childregs->regs[3]; + } else { + memset(childregs, 0, sizeof(struct pt_regs)); + childregs->pstate = PSR_MODE_EL1h; + p->thread.cpu_context.x19 = stack_start; + p->thread.cpu_context.x20 = stk_sz; + } + p->thread.cpu_context.pc = (unsigned long)ret_from_fork; + p->thread.cpu_context.sp = (unsigned long)childregs; + 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); + contextidr_thread_switch(next); + + /* + * Complete any pending TLB or cache maintenance on this CPU in case + * the thread migrates to a different CPU. + */ + dsb(ish); + + /* the actual thread switch */ + last = cpu_switch_to(prev, next); + + return last; +} + +unsigned long get_wchan(struct task_struct *p) +{ + struct stackframe frame; + unsigned long stack_page; + 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); + stack_page = (unsigned long)task_stack_page(p); + do { + if (frame.sp < stack_page || + frame.sp >= stack_page + THREAD_SIZE || + unwind_frame(&frame)) + 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); +} |