646 lines
		
	
	
	
		
			19 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			646 lines
		
	
	
	
		
			19 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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| 
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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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| 
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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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| 
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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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| 
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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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| /*
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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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| 
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| 
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| 	current_thread_info()->status |= TS_POLLING;
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| 
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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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| 
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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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| 
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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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| 
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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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| /*
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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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| 
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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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| 
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| 	if (step_state) {
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| 
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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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| 
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| static void save_arch_state(struct thread_struct *t);
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| 
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| int copy_thread(unsigned long clone_flags, unsigned long sp,
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| 		unsigned long arg, struct task_struct *p)
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| {
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| 	struct pt_regs *childregs = task_pt_regs(p);
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| 	unsigned long ksp;
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| 	unsigned long *callee_regs;
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| 
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| 	/*
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| 	 * Set up the stack and stack pointer appropriately for the
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| 	 * new child to find itself woken up in __switch_to().
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| 	 * The callee-saved registers must be on the stack to be read;
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| 	 * the new task will then jump to assembly support to handle
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| 	 * calling schedule_tail(), etc., and (for userspace tasks)
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| 	 * returning to the context set up in the pt_regs.
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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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| 	callee_regs = (unsigned long *)ksp;
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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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| 
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| 	/* Record the pid of the task that created this one. */
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| 	p->thread.creator_pid = current->pid;
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| 
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| 	if (unlikely(p->flags & PF_KTHREAD)) {
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| 		/* kernel thread */
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| 		memset(childregs, 0, sizeof(struct pt_regs));
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| 		memset(&callee_regs[2], 0,
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| 		       (CALLEE_SAVED_REGS_COUNT - 2) * sizeof(unsigned long));
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| 		callee_regs[0] = sp;   /* r30 = function */
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| 		callee_regs[1] = arg;  /* r31 = arg */
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| 		childregs->ex1 = PL_ICS_EX1(KERNEL_PL, 0);
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| 		p->thread.pc = (unsigned long) ret_from_kernel_thread;
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| 		return 0;
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| 	}
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| 
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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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| 
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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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| 	/*
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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 = *current_pt_regs();
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| 	childregs->regs[0] = 0;         /* return value is zero */
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| 	if (sp)
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| 		childregs->sp = sp;  /* override with new user stack pointer */
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| 	memcpy(callee_regs, &childregs->regs[CALLEE_SAVED_FIRST_REG],
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| 	       CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long));
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| 
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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 = childregs->sp;
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| 
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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 = childregs->regs[4];
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| 
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 	return 0;
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| }
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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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| 
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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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| 
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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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| 
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| #if CHIP_HAS_TILE_DMA()
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| 
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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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| 
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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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| 
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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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| 
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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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| 	/*
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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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| 
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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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| 
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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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| 	/*
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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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| 
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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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| 	/*
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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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| 
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| #endif
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| 
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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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| 
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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]);
 | |
| 	__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. */
 | |
| 	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);
 | |
| }
 | |
| 
 | |
| 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;
 | |
| }
 | |
| 
 | |
| /* 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);
 | |
| }
 |