forked from Minki/linux
1268fbc746
Those two APIs were provided to optimize the calls of tick_nohz_idle_enter() and rcu_idle_enter() into a single irq disabled section. This way no interrupt happening in-between would needlessly process any RCU job. Now we are talking about an optimization for which benefits have yet to be measured. Let's start simple and completely decouple idle rcu and dyntick idle logics to simplify. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
747 lines
21 KiB
C
747 lines
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/system.h>
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#include <asm/stack.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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#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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/*
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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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preempt_enable_no_resched();
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schedule();
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preempt_disable();
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}
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}
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struct thread_info *alloc_thread_info_node(struct task_struct *task, int node)
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{
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struct page *page;
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gfp_t flags = GFP_KERNEL;
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#ifdef CONFIG_DEBUG_STACK_USAGE
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flags |= __GFP_ZERO;
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#endif
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page = alloc_pages_node(node, flags, THREAD_SIZE_ORDER);
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if (!page)
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return NULL;
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return (struct thread_info *)page_address(page);
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}
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/*
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* Free a thread_info node, and all of its derivative
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* data structures.
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*/
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void free_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 "hardwall" would be NULL by now.
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*/
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if (info->task->thread.hardwall)
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hardwall_deactivate(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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free_pages((unsigned long)info, THREAD_SIZE_ORDER);
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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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p->thread.hardwall = NULL;
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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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(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]);
|
|
__insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]);
|
|
__insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]);
|
|
__insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]);
|
|
__insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]);
|
|
__insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]);
|
|
__insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0);
|
|
#if CHIP_HAS_PROC_STATUS_SPR()
|
|
__insn_mtspr(SPR_PROC_STATUS, t->proc_status);
|
|
#endif
|
|
#if !CHIP_HAS_FIXED_INTVEC_BASE()
|
|
__insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base);
|
|
#endif
|
|
#if CHIP_HAS_TILE_RTF_HWM()
|
|
__insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm);
|
|
#endif
|
|
#if CHIP_HAS_DSTREAM_PF()
|
|
__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. */
|
|
if (prev->thread.hardwall != NULL) {
|
|
if (next->thread.hardwall == NULL)
|
|
restrict_network_mpls();
|
|
} else if (next->thread.hardwall != NULL) {
|
|
grant_network_mpls();
|
|
}
|
|
#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 (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);
|
|
if (current->replacement_session_keyring)
|
|
key_replace_session_keyring();
|
|
return 1;
|
|
}
|
|
if (thread_info_flags & _TIF_SINGLESTEP) {
|
|
if ((regs->ex1 & SPR_EX_CONTEXT_1_1__PL_MASK) == 0)
|
|
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;
|
|
char *filename;
|
|
|
|
filename = getname(path);
|
|
error = PTR_ERR(filename);
|
|
if (IS_ERR(filename))
|
|
goto out;
|
|
error = do_execve(filename, 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;
|
|
char *filename;
|
|
|
|
filename = getname(path);
|
|
error = PTR_ERR(filename);
|
|
if (IS_ERR(filename))
|
|
goto out;
|
|
error = compat_do_execve(filename, 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);
|
|
}
|