728 строки
21 KiB
C
728 строки
21 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/sched.h>
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#include <linux/preempt.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/kprobes.h>
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#include <linux/elfcore.h>
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#include <linux/tick.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/compat.h>
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#include <linux/hardirq.h>
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#include <linux/syscalls.h>
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#include <linux/kernel.h>
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#include <linux/tracehook.h>
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#include <linux/signal.h>
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#include <asm/stack.h>
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#include <asm/switch_to.h>
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#include <asm/homecache.h>
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#include <asm/syscalls.h>
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#include <asm/traps.h>
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#include <asm/setup.h>
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#ifdef CONFIG_HARDWALL
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#include <asm/hardwall.h>
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#endif
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#include <arch/chip.h>
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#include <arch/abi.h>
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#include <arch/sim_def.h>
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/*
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* Use the (x86) "idle=poll" option to prefer low latency when leaving the
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* idle loop over low power while in the idle loop, e.g. if we have
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* one thread per core and we want to get threads out of futex waits fast.
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*/
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static int no_idle_nap;
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static int __init idle_setup(char *str)
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{
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if (!str)
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return -EINVAL;
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if (!strcmp(str, "poll")) {
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pr_info("using polling idle threads.\n");
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no_idle_nap = 1;
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} else if (!strcmp(str, "halt"))
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no_idle_nap = 0;
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else
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return -1;
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return 0;
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}
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early_param("idle", idle_setup);
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/*
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* The idle thread. There's no useful work to be
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* done, so just try to conserve power and have a
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* low exit latency (ie sit in a loop waiting for
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* somebody to say that they'd like to reschedule)
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*/
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void cpu_idle(void)
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{
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int cpu = smp_processor_id();
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current_thread_info()->status |= TS_POLLING;
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if (no_idle_nap) {
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while (1) {
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while (!need_resched())
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cpu_relax();
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schedule();
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}
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}
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/* endless idle loop with no priority at all */
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while (1) {
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tick_nohz_idle_enter();
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rcu_idle_enter();
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while (!need_resched()) {
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if (cpu_is_offline(cpu))
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BUG(); /* no HOTPLUG_CPU */
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local_irq_disable();
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__get_cpu_var(irq_stat).idle_timestamp = jiffies;
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current_thread_info()->status &= ~TS_POLLING;
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/*
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* TS_POLLING-cleared state must be visible before we
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* test NEED_RESCHED:
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*/
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smp_mb();
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if (!need_resched())
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_cpu_idle();
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else
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local_irq_enable();
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current_thread_info()->status |= TS_POLLING;
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}
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rcu_idle_exit();
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tick_nohz_idle_exit();
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schedule_preempt_disabled();
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}
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}
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/*
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* Release a thread_info structure
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*/
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void arch_release_thread_info(struct thread_info *info)
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{
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struct single_step_state *step_state = info->step_state;
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#ifdef CONFIG_HARDWALL
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/*
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* We free a thread_info from the context of the task that has
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* been scheduled next, so the original task is already dead.
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* Calling deactivate here just frees up the data structures.
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* If the task we're freeing held the last reference to a
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* hardwall fd, it would have been released prior to this point
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* anyway via exit_files(), and the hardwall_task.info pointers
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* would be NULL by now.
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*/
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hardwall_deactivate_all(info->task);
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#endif
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if (step_state) {
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/*
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* FIXME: we don't munmap step_state->buffer
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* because the mm_struct for this process (info->task->mm)
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* has already been zeroed in exit_mm(). Keeping a
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* reference to it here seems like a bad move, so this
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* means we can't munmap() the buffer, and therefore if we
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* ptrace multiple threads in a process, we will slowly
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* leak user memory. (Note that as soon as the last
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* thread in a process dies, we will reclaim all user
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* memory including single-step buffers in the usual way.)
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* We should either assign a kernel VA to this buffer
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* somehow, or we should associate the buffer(s) with the
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* mm itself so we can clean them up that way.
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*/
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kfree(step_state);
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}
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}
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static void save_arch_state(struct thread_struct *t);
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int copy_thread(unsigned long clone_flags, unsigned long sp,
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unsigned long stack_size,
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struct task_struct *p, struct pt_regs *regs)
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{
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struct pt_regs *childregs;
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unsigned long ksp;
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/*
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* When creating a new kernel thread we pass sp as zero.
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* Assign it to a reasonable value now that we have the stack.
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*/
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if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0))
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sp = KSTK_TOP(p);
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/*
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* Do not clone step state from the parent; each thread
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* must make its own lazily.
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*/
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task_thread_info(p)->step_state = NULL;
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/*
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* Start new thread in ret_from_fork so it schedules properly
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* and then return from interrupt like the parent.
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*/
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p->thread.pc = (unsigned long) ret_from_fork;
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/* Save user stack top pointer so we can ID the stack vm area later. */
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p->thread.usp0 = sp;
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/* Record the pid of the process that created this one. */
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p->thread.creator_pid = current->pid;
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/*
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* Copy the registers onto the kernel stack so the
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* return-from-interrupt code will reload it into registers.
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*/
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childregs = task_pt_regs(p);
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*childregs = *regs;
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childregs->regs[0] = 0; /* return value is zero */
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childregs->sp = sp; /* override with new user stack pointer */
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/*
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* If CLONE_SETTLS is set, set "tp" in the new task to "r4",
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* which is passed in as arg #5 to sys_clone().
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*/
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if (clone_flags & CLONE_SETTLS)
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childregs->tp = regs->regs[4];
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/*
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* Copy the callee-saved registers from the passed pt_regs struct
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* into the context-switch callee-saved registers area.
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* This way when we start the interrupt-return sequence, the
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* callee-save registers will be correctly in registers, which
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* is how we assume the compiler leaves them as we start doing
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* the normal return-from-interrupt path after calling C code.
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* Zero out the C ABI save area to mark the top of the stack.
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*/
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ksp = (unsigned long) childregs;
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ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */
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((long *)ksp)[0] = ((long *)ksp)[1] = 0;
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ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long);
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memcpy((void *)ksp, ®s->regs[CALLEE_SAVED_FIRST_REG],
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CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long));
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ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */
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((long *)ksp)[0] = ((long *)ksp)[1] = 0;
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p->thread.ksp = ksp;
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#if CHIP_HAS_TILE_DMA()
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/*
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* No DMA in the new thread. We model this on the fact that
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* fork() clears the pending signals, alarms, and aio for the child.
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*/
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memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state));
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memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb));
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#endif
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#if CHIP_HAS_SN_PROC()
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/* Likewise, the new thread is not running static processor code. */
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p->thread.sn_proc_running = 0;
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memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb));
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#endif
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#if CHIP_HAS_PROC_STATUS_SPR()
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/* New thread has its miscellaneous processor state bits clear. */
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p->thread.proc_status = 0;
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#endif
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#ifdef CONFIG_HARDWALL
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/* New thread does not own any networks. */
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memset(&p->thread.hardwall[0], 0,
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sizeof(struct hardwall_task) * HARDWALL_TYPES);
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#endif
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/*
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* Start the new thread with the current architecture state
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* (user interrupt masks, etc.).
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*/
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save_arch_state(&p->thread);
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return 0;
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}
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/*
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* Return "current" if it looks plausible, or else a pointer to a dummy.
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* This can be helpful if we are just trying to emit a clean panic.
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*/
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struct task_struct *validate_current(void)
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{
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static struct task_struct corrupt = { .comm = "<corrupt>" };
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struct task_struct *tsk = current;
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if (unlikely((unsigned long)tsk < PAGE_OFFSET ||
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(high_memory && (void *)tsk > high_memory) ||
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((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) {
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pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer);
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tsk = &corrupt;
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}
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return tsk;
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}
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/* Take and return the pointer to the previous task, for schedule_tail(). */
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struct task_struct *sim_notify_fork(struct task_struct *prev)
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{
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struct task_struct *tsk = current;
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__insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT |
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(tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS));
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__insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK |
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(tsk->pid << _SIM_CONTROL_OPERATOR_BITS));
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return prev;
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}
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int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
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{
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struct pt_regs *ptregs = task_pt_regs(tsk);
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elf_core_copy_regs(regs, ptregs);
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return 1;
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}
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#if CHIP_HAS_TILE_DMA()
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/* Allow user processes to access the DMA SPRs */
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void grant_dma_mpls(void)
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{
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#if CONFIG_KERNEL_PL == 2
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__insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1);
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__insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1);
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#else
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__insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1);
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__insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1);
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#endif
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}
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/* Forbid user processes from accessing the DMA SPRs */
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void restrict_dma_mpls(void)
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{
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#if CONFIG_KERNEL_PL == 2
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__insn_mtspr(SPR_MPL_DMA_CPL_SET_2, 1);
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__insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_2, 1);
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#else
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__insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1);
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__insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1);
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#endif
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}
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/* Pause the DMA engine, then save off its state registers. */
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static void save_tile_dma_state(struct tile_dma_state *dma)
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{
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unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS);
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unsigned long post_suspend_state;
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/* If we're running, suspend the engine. */
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if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK)
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__insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK);
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/*
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* Wait for the engine to idle, then save regs. Note that we
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* want to record the "running" bit from before suspension,
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* and the "done" bit from after, so that we can properly
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* distinguish a case where the user suspended the engine from
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* the case where the kernel suspended as part of the context
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* swap.
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*/
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do {
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post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS);
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} while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK);
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dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR);
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dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR);
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dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR);
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dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR);
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dma->strides = __insn_mfspr(SPR_DMA_STRIDE);
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dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE);
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dma->byte = __insn_mfspr(SPR_DMA_BYTE);
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dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) |
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(post_suspend_state & SPR_DMA_STATUS__DONE_MASK);
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}
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/* Restart a DMA that was running before we were context-switched out. */
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static void restore_tile_dma_state(struct thread_struct *t)
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{
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const struct tile_dma_state *dma = &t->tile_dma_state;
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/*
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* The only way to restore the done bit is to run a zero
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* length transaction.
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*/
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if ((dma->status & SPR_DMA_STATUS__DONE_MASK) &&
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!(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) {
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__insn_mtspr(SPR_DMA_BYTE, 0);
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__insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK);
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while (__insn_mfspr(SPR_DMA_USER_STATUS) &
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SPR_DMA_STATUS__BUSY_MASK)
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;
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}
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__insn_mtspr(SPR_DMA_SRC_ADDR, dma->src);
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__insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk);
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__insn_mtspr(SPR_DMA_DST_ADDR, dma->dest);
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__insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk);
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__insn_mtspr(SPR_DMA_STRIDE, dma->strides);
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__insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size);
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__insn_mtspr(SPR_DMA_BYTE, dma->byte);
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/*
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* Restart the engine if we were running and not done.
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* Clear a pending async DMA fault that we were waiting on return
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* to user space to execute, since we expect the DMA engine
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* to regenerate those faults for us now. Note that we don't
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* try to clear the TIF_ASYNC_TLB flag, since it's relatively
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* harmless if set, and it covers both DMA and the SN processor.
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*/
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if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) {
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t->dma_async_tlb.fault_num = 0;
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__insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK);
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}
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}
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#endif
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static void save_arch_state(struct thread_struct *t)
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{
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#if CHIP_HAS_SPLIT_INTR_MASK()
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t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) |
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((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32);
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#else
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t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0);
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#endif
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t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0);
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t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1);
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t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0);
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t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1);
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t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2);
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t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3);
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t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS);
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#if CHIP_HAS_PROC_STATUS_SPR()
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t->proc_status = __insn_mfspr(SPR_PROC_STATUS);
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#endif
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#if !CHIP_HAS_FIXED_INTVEC_BASE()
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t->interrupt_vector_base = __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0);
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#endif
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#if CHIP_HAS_TILE_RTF_HWM()
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t->tile_rtf_hwm = __insn_mfspr(SPR_TILE_RTF_HWM);
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#endif
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#if CHIP_HAS_DSTREAM_PF()
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t->dstream_pf = __insn_mfspr(SPR_DSTREAM_PF);
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#endif
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}
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static void restore_arch_state(const struct thread_struct *t)
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{
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#if CHIP_HAS_SPLIT_INTR_MASK()
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__insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask);
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__insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32);
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#else
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__insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask);
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#endif
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__insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]);
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__insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]);
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__insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]);
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__insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]);
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__insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]);
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__insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]);
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__insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0);
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#if CHIP_HAS_PROC_STATUS_SPR()
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__insn_mtspr(SPR_PROC_STATUS, t->proc_status);
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#endif
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#if !CHIP_HAS_FIXED_INTVEC_BASE()
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__insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base);
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#endif
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#if CHIP_HAS_TILE_RTF_HWM()
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__insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm);
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#endif
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#if CHIP_HAS_DSTREAM_PF()
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|
__insn_mtspr(SPR_DSTREAM_PF, t->dstream_pf);
|
|
#endif
|
|
}
|
|
|
|
|
|
void _prepare_arch_switch(struct task_struct *next)
|
|
{
|
|
#if CHIP_HAS_SN_PROC()
|
|
int snctl;
|
|
#endif
|
|
#if CHIP_HAS_TILE_DMA()
|
|
struct tile_dma_state *dma = ¤t->thread.tile_dma_state;
|
|
if (dma->enabled)
|
|
save_tile_dma_state(dma);
|
|
#endif
|
|
#if CHIP_HAS_SN_PROC()
|
|
/*
|
|
* Suspend the static network processor if it was running.
|
|
* We do not suspend the fabric itself, just like we don't
|
|
* try to suspend the UDN.
|
|
*/
|
|
snctl = __insn_mfspr(SPR_SNCTL);
|
|
current->thread.sn_proc_running =
|
|
(snctl & SPR_SNCTL__FRZPROC_MASK) == 0;
|
|
if (current->thread.sn_proc_running)
|
|
__insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK);
|
|
#endif
|
|
}
|
|
|
|
|
|
struct task_struct *__sched _switch_to(struct task_struct *prev,
|
|
struct task_struct *next)
|
|
{
|
|
/* DMA state is already saved; save off other arch state. */
|
|
save_arch_state(&prev->thread);
|
|
|
|
#if CHIP_HAS_TILE_DMA()
|
|
/*
|
|
* Restore DMA in new task if desired.
|
|
* Note that it is only safe to restart here since interrupts
|
|
* are disabled, so we can't take any DMATLB miss or access
|
|
* interrupts before we have finished switching stacks.
|
|
*/
|
|
if (next->thread.tile_dma_state.enabled) {
|
|
restore_tile_dma_state(&next->thread);
|
|
grant_dma_mpls();
|
|
} else {
|
|
restrict_dma_mpls();
|
|
}
|
|
#endif
|
|
|
|
/* Restore other arch state. */
|
|
restore_arch_state(&next->thread);
|
|
|
|
#if CHIP_HAS_SN_PROC()
|
|
/*
|
|
* Restart static network processor in the new process
|
|
* if it was running before.
|
|
*/
|
|
if (next->thread.sn_proc_running) {
|
|
int snctl = __insn_mfspr(SPR_SNCTL);
|
|
__insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_HARDWALL
|
|
/* Enable or disable access to the network registers appropriately. */
|
|
hardwall_switch_tasks(prev, next);
|
|
#endif
|
|
|
|
/*
|
|
* Switch kernel SP, PC, and callee-saved registers.
|
|
* In the context of the new task, return the old task pointer
|
|
* (i.e. the task that actually called __switch_to).
|
|
* Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp.
|
|
*/
|
|
return __switch_to(prev, next, next_current_ksp0(next));
|
|
}
|
|
|
|
/*
|
|
* This routine is called on return from interrupt if any of the
|
|
* TIF_WORK_MASK flags are set in thread_info->flags. It is
|
|
* entered with interrupts disabled so we don't miss an event
|
|
* that modified the thread_info flags. If any flag is set, we
|
|
* handle it and return, and the calling assembly code will
|
|
* re-disable interrupts, reload the thread flags, and call back
|
|
* if more flags need to be handled.
|
|
*
|
|
* We return whether we need to check the thread_info flags again
|
|
* or not. Note that we don't clear TIF_SINGLESTEP here, so it's
|
|
* important that it be tested last, and then claim that we don't
|
|
* need to recheck the flags.
|
|
*/
|
|
int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
|
|
{
|
|
/* If we enter in kernel mode, do nothing and exit the caller loop. */
|
|
if (!user_mode(regs))
|
|
return 0;
|
|
|
|
/* Enable interrupts; they are disabled again on return to caller. */
|
|
local_irq_enable();
|
|
|
|
if (thread_info_flags & _TIF_NEED_RESCHED) {
|
|
schedule();
|
|
return 1;
|
|
}
|
|
#if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC()
|
|
if (thread_info_flags & _TIF_ASYNC_TLB) {
|
|
do_async_page_fault(regs);
|
|
return 1;
|
|
}
|
|
#endif
|
|
if (thread_info_flags & _TIF_SIGPENDING) {
|
|
do_signal(regs);
|
|
return 1;
|
|
}
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
return 1;
|
|
}
|
|
if (thread_info_flags & _TIF_SINGLESTEP) {
|
|
single_step_once(regs);
|
|
return 0;
|
|
}
|
|
panic("work_pending: bad flags %#x\n", thread_info_flags);
|
|
}
|
|
|
|
/* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */
|
|
SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
|
|
void __user *, parent_tidptr, void __user *, child_tidptr,
|
|
struct pt_regs *, regs)
|
|
{
|
|
if (!newsp)
|
|
newsp = regs->sp;
|
|
return do_fork(clone_flags, newsp, regs, 0,
|
|
parent_tidptr, child_tidptr);
|
|
}
|
|
|
|
/*
|
|
* sys_execve() executes a new program.
|
|
*/
|
|
SYSCALL_DEFINE4(execve, const char __user *, path,
|
|
const char __user *const __user *, argv,
|
|
const char __user *const __user *, envp,
|
|
struct pt_regs *, regs)
|
|
{
|
|
long error;
|
|
struct filename *filename;
|
|
|
|
filename = getname(path);
|
|
error = PTR_ERR(filename);
|
|
if (IS_ERR(filename))
|
|
goto out;
|
|
error = do_execve(filename->name, argv, envp, regs);
|
|
putname(filename);
|
|
if (error == 0)
|
|
single_step_execve();
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
long compat_sys_execve(const char __user *path,
|
|
compat_uptr_t __user *argv,
|
|
compat_uptr_t __user *envp,
|
|
struct pt_regs *regs)
|
|
{
|
|
long error;
|
|
struct filename *filename;
|
|
|
|
filename = getname(path);
|
|
error = PTR_ERR(filename);
|
|
if (IS_ERR(filename))
|
|
goto out;
|
|
error = compat_do_execve(filename->name, argv, envp, regs);
|
|
putname(filename);
|
|
if (error == 0)
|
|
single_step_execve();
|
|
out:
|
|
return error;
|
|
}
|
|
#endif
|
|
|
|
unsigned long get_wchan(struct task_struct *p)
|
|
{
|
|
struct KBacktraceIterator kbt;
|
|
|
|
if (!p || p == current || p->state == TASK_RUNNING)
|
|
return 0;
|
|
|
|
for (KBacktraceIterator_init(&kbt, p, NULL);
|
|
!KBacktraceIterator_end(&kbt);
|
|
KBacktraceIterator_next(&kbt)) {
|
|
if (!in_sched_functions(kbt.it.pc))
|
|
return kbt.it.pc;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We pass in lr as zero (cleared in kernel_thread) and the caller
|
|
* part of the backtrace ABI on the stack also zeroed (in copy_thread)
|
|
* so that backtraces will stop with this function.
|
|
* Note that we don't use r0, since copy_thread() clears it.
|
|
*/
|
|
static void start_kernel_thread(int dummy, int (*fn)(int), int arg)
|
|
{
|
|
do_exit(fn(arg));
|
|
}
|
|
|
|
/*
|
|
* Create a kernel thread
|
|
*/
|
|
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
|
|
{
|
|
struct pt_regs regs;
|
|
|
|
memset(®s, 0, sizeof(regs));
|
|
regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */
|
|
regs.pc = (long) start_kernel_thread;
|
|
regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */
|
|
regs.regs[1] = (long) fn; /* function pointer */
|
|
regs.regs[2] = (long) arg; /* parameter register */
|
|
|
|
/* Ok, create the new process.. */
|
|
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s,
|
|
0, NULL, NULL);
|
|
}
|
|
EXPORT_SYMBOL(kernel_thread);
|
|
|
|
/* Flush thread state. */
|
|
void flush_thread(void)
|
|
{
|
|
/* Nothing */
|
|
}
|
|
|
|
/*
|
|
* Free current thread data structures etc..
|
|
*/
|
|
void exit_thread(void)
|
|
{
|
|
/* Nothing */
|
|
}
|
|
|
|
void show_regs(struct pt_regs *regs)
|
|
{
|
|
struct task_struct *tsk = validate_current();
|
|
int i;
|
|
|
|
pr_err("\n");
|
|
pr_err(" Pid: %d, comm: %20s, CPU: %d\n",
|
|
tsk->pid, tsk->comm, smp_processor_id());
|
|
#ifdef __tilegx__
|
|
for (i = 0; i < 51; i += 3)
|
|
pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
|
|
i, regs->regs[i], i+1, regs->regs[i+1],
|
|
i+2, regs->regs[i+2]);
|
|
pr_err(" r51: "REGFMT" r52: "REGFMT" tp : "REGFMT"\n",
|
|
regs->regs[51], regs->regs[52], regs->tp);
|
|
pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr);
|
|
#else
|
|
for (i = 0; i < 52; i += 4)
|
|
pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT
|
|
" r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
|
|
i, regs->regs[i], i+1, regs->regs[i+1],
|
|
i+2, regs->regs[i+2], i+3, regs->regs[i+3]);
|
|
pr_err(" r52: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n",
|
|
regs->regs[52], regs->tp, regs->sp, regs->lr);
|
|
#endif
|
|
pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld\n",
|
|
regs->pc, regs->ex1, regs->faultnum);
|
|
|
|
dump_stack_regs(regs);
|
|
}
|