patch-2.3.42 linux/arch/sparc64/mm/asyncd.c

• Lines: 284
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.3.41/linux/arch/sparc64/mm/asyncd.c
• Orig date: Fri Jan 28 15:09:07 2000

diff -u --recursive --new-file v2.3.41/linux/arch/sparc64/mm/asyncd.c linux/arch/sparc64/mm/asyncd.c
@@ -1,283 +0,0 @@
-/*  $Id: asyncd.c,v 1.12 2000/01/21 11:39:13 jj Exp $
- *  The asyncd kernel daemon. This handles paging on behalf of 
- *  processes that receive page faults due to remote (async) memory
- *  accesses. 
- *
- *  Idea and skeleton code courtesy of David Miller (bless his cotton socks)
- *
- *  Implemented by tridge
- */
-
-#include <linux/mm.h>
-#include <linux/malloc.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/kernel_stat.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/stat.h>
-#include <linux/swap.h>
-#include <linux/fs.h>
-#include <linux/config.h>
-#include <linux/interrupt.h>
-#include <linux/signal.h>
-
-#include <asm/dma.h>
-#include <asm/system.h> /* for cli()/sti() */
-#include <asm/segment.h> /* for memcpy_to/fromfs */
-#include <asm/bitops.h>
-#include <asm/pgalloc.h>
-#include <asm/pgtable.h>
-
-#define DEBUG 0
-
-#define WRITE_LIMIT 100
-#define LOOP_LIMIT 200
-
-static struct {
-	int faults, read, write, success, failure, errors;
-} stats;
-
-/* 
- * The wait queue for waking up the async daemon:
- */
-static DECLARE_WAIT_QUEUE_HEAD(asyncd_wait);
-
-struct async_job {
-	volatile struct async_job *next;
-	int taskid;
-	struct mm_struct *mm;
-	unsigned long address;
-	int write;
-	void (*callback)(int,unsigned long,int,int);
-};
-
-static volatile struct async_job *async_queue = NULL;
-static volatile struct async_job *async_queue_end = NULL;
-
-static void add_to_async_queue(int taskid,
-			       struct mm_struct *mm,
-			       unsigned long address,
-			       int write,
-			       void (*callback)(int,unsigned long,int,int))
-{
-	struct async_job *a = kmalloc(sizeof(*a),GFP_ATOMIC);
-
-	if (!a) {
-		printk("ERROR: out of memory in asyncd\n");
-		a->callback(taskid,address,write,1);
-		return;
-	}
-
-	if (write)
-		stats.write++;
-	else
-		stats.read++;
-
-	a->next = NULL;
-	a->taskid = taskid;
-	a->mm = mm;
-	a->address = address;
-	a->write = write;
-	a->callback = callback;
-
-	if (!async_queue) {
-		async_queue = a;
-	} else {
-		async_queue_end->next = a;
-	}
-	async_queue_end = a;
-}
-
-
-void async_fault(unsigned long address, int write, int taskid,
-		 void (*callback)(int,unsigned long,int,int))
-{
-#warning Need some fixing here... -DaveM
-	struct task_struct *tsk = current /* XXX task[taskid] */;
-	struct mm_struct *mm = tsk->mm;
-
-	stats.faults++;
-
-#if 0
-	printk("paging in %x for task=%d\n",address,taskid);
-#endif
-
-	add_to_async_queue(taskid, mm, address, write, callback);
-	wake_up(&asyncd_wait);  
-	mark_bh(TQUEUE_BH);
-}
-
-static int fault_in_page(int taskid,
-			 struct vm_area_struct *vma,
-			 unsigned long address, int write)
-{
-	static unsigned last_address;
-	static int last_task, loop_counter;
-	siginfo_t info;
-#warning Need some fixing here... -DaveM
-	struct task_struct *tsk = current /* XXX task[taskid] */;
-	pgd_t *pgd;
-	pmd_t *pmd;
-	pte_t *pte;
-
-	if (!tsk || !tsk->mm)
-		return 1;
-
-	if (!vma || (write && !(vma->vm_flags & VM_WRITE)))
-	  goto bad_area;
-	if (vma->vm_start > address)
-	  goto bad_area;
-
-	if (address == last_address && taskid == last_task) {
-		loop_counter++;
-	} else {
-		loop_counter = 0;
-		last_address = address; 
-		last_task = taskid;
-	}
-
-	if (loop_counter == WRITE_LIMIT && !write) {
-		printk("MSC bug? setting write request\n");
-		stats.errors++;
-		write = 1;
-	}
-
-	if (loop_counter == LOOP_LIMIT) {
-		printk("MSC bug? failing request\n");
-		stats.errors++;
-		return 1;
-	}
-
-	pgd = pgd_offset(vma->vm_mm, address);
-	pmd = pmd_alloc(pgd,address);
-	if(!pmd)
-		goto no_memory;
-	pte = pte_alloc(pmd, address);
-	if(!pte)
-		goto no_memory;
-	if(!pte_present(*pte)) {
-		handle_mm_fault(tsk, vma, address, write);
-		goto finish_up;
-	}
-	set_pte(pte, pte_mkyoung(*pte));
-	flush_tlb_page(vma, address);
-	if(!write)
-		goto finish_up;
-	if(pte_write(*pte)) {
-		set_pte(pte, pte_mkdirty(*pte));
-		flush_tlb_page(vma, address);
-		goto finish_up;
-	}
-	handle_mm_fault(tsk, vma, address, write);
-
-	/* Fall through for do_wp_page */
-finish_up:
-	stats.success++;
-	return 0;
-
-no_memory:
-	stats.failure++;
-	oom(tsk);
-	return 1;
-	
-bad_area:	  
-	stats.failure++;
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_code = SEGV_MAPERR;
-	info.si_addr = (void *)address;
-	info.si_trapno = 0;
-	send_sig_info(SIGSEGV, &info, tsk);
-	return 1;
-}
-
-
-/* Note the semaphore operations must be done here, and _not_
- * in async_fault().
- */
-static void run_async_queue(void)
-{
-	int ret;
-	unsigned flags;
-
-	while (async_queue) {
-		volatile struct async_job *a;
-		struct mm_struct *mm;
-		struct vm_area_struct *vma;
-
-		save_flags(flags); cli();
-		a = async_queue;
-		async_queue = async_queue->next;
-		restore_flags(flags);
-
-		mm = a->mm;
-
-		down(&mm->mmap_sem);
-		vma = find_vma(mm, a->address);
-		ret = fault_in_page(a->taskid,vma,a->address,a->write);
-#if DEBUG
-		printk("fault_in_page(task=%d addr=%x write=%d) = %d\n",
-		       a->taskid,a->address,a->write,ret);
-#endif
-		a->callback(a->taskid,a->address,a->write,ret);
-		up(&mm->mmap_sem);
-		kfree_s((void *)a,sizeof(*a));
-	}
-}
-
-
-#if CONFIG_AP1000
-static void asyncd_info(void)
-{
-	printk("CID(%d) faults: total=%d  read=%d  write=%d  success=%d fail=%d err=%d\n",
-	       mpp_cid(),stats.faults, stats.read, stats.write, stats.success,
-	       stats.failure, stats.errors);
-}
-#endif
-
-
-/*
- * The background async daemon.
- * Started as a kernel thread from the init process.
- */
-int asyncd(void *unused)
-{
-	current->session = 1;
-	current->pgrp = 1;
-	sprintf(current->comm, "asyncd");
-	
-	sigfillset(&current->blocked); /* block all signals */
-	recalc_sigpending(current);
-  
-	/* Give asyncd a realtime priority. */
-	current->policy = SCHED_FIFO;
-	current->priority = 32;  /* Fixme --- we need to standardise our
-				    namings for POSIX.4 realtime scheduling
-				    priorities.  */
-  
-	printk("Started asyncd\n");
-
-#if CONFIG_AP1000
-	bif_add_debug_key('a',asyncd_info,"stats on asyncd");
-#endif
-
-	while (1) {
-		unsigned flags;
-
-		save_flags(flags); cli();
-
-		while (!async_queue) {
-			spin_lock(&current->sigmask_lock);
-			flush_signals(current);
-			spin_unlock(&current->sigmask_lock);
-			interruptible_sleep_on(&asyncd_wait);
-			__sti(); cli(); /* acquire gloabl_irq_lock */
-		}
-
-		restore_flags(flags);
-
-		run_async_queue();
-	}
-}
-