arm/arm/vm_machdep.c

/*-
 * Copyright (c) 1982, 1986 The Regents of the University of California.
 * Copyright (c) 1989, 1990 William Jolitz
 * Copyright (c) 1994 John Dyson
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department, and William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)vm_machdep.c	7.3 (Berkeley) 5/13/91
 *	Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: head/sys/arm/arm/vm_machdep.c 144637 2005-04-04 21:53:56Z jhb $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/socketvar.h>
#include <sys/sf_buf.h>
#include <machine/cpu.h>
#include <machine/pcb.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <sys/lock.h>
#include <sys/mutex.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_param.h>

#ifndef NSFBUFS
#define NSFBUFS		(512 + maxusers * 16)
#endif

static void     sf_buf_init(void *arg);
SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL)

LIST_HEAD(sf_head, sf_buf);


/*
 * A hash table of active sendfile(2) buffers
 */
static struct sf_head *sf_buf_active;
static u_long sf_buf_hashmask;

#define SF_BUF_HASH(m)  (((m) - vm_page_array) & sf_buf_hashmask)

static TAILQ_HEAD(, sf_buf) sf_buf_freelist;
static u_int    sf_buf_alloc_want;

/*
 * A lock used to synchronize access to the hash table and free list
 */
static struct mtx sf_buf_lock;

/*
 * Finish a fork operation, with process p2 nearly set up.
 * Copy and update the pcb, set up the stack so that the child
 * ready to run and return to user mode.
 */
void
cpu_fork(register struct thread *td1, register struct proc *p2,
    struct thread *td2, int flags)
{
	struct pcb *pcb1, *pcb2;
	struct trapframe *tf;
	struct switchframe *sf;
	struct mdproc *mdp2;

	pcb1 = td1->td_pcb;
	pcb2 = (struct pcb *)(td2->td_kstack + td2->td_kstack_pages * PAGE_SIZE) - 1;
#ifdef __XSCALE__
	pmap_use_minicache(td2->td_kstack, td2->td_kstack_pages * PAGE_SIZE);
#endif
	td2->td_pcb = pcb2;
	bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
	mdp2 = &p2->p_md;
	bcopy(&td1->td_proc->p_md, mdp2, sizeof(*mdp2));
	pcb2->un_32.pcb32_und_sp = td2->td_kstack + USPACE_UNDEF_STACK_TOP;
	pcb2->un_32.pcb32_sp = td2->td_kstack +
	    USPACE_SVC_STACK_TOP - sizeof(*pcb2);
	pmap_activate(td2);
	td2->td_frame = tf =
	    (struct trapframe *)pcb2->un_32.pcb32_sp - 1;
	*tf = *td1->td_frame;
	sf = (struct switchframe *)tf - 1;
	sf->sf_r4 = (u_int)fork_return;
	sf->sf_r5 = (u_int)td2;
	sf->sf_pc = (u_int)fork_trampoline;
	tf->tf_spsr &= ~PSR_C_bit;
	tf->tf_r0 = 0;
	tf->tf_r1 = 0;
	pcb2->un_32.pcb32_sp = (u_int)sf;

	/* Setup to release sched_lock in fork_exit(). */
	td2->td_md.md_spinlock_count = 1;
	td2->td_md.md_saved_cspr = 0;
}

void
cpu_thread_swapin(struct thread *td)
{
}

void
cpu_thread_swapout(struct thread *td)
{
}

/*
 * Detatch mapped page and release resources back to the system.
 */
void
sf_buf_free(struct sf_buf *sf)
{
	 mtx_lock(&sf_buf_lock);
	 sf->ref_count--;
	 if (sf->ref_count == 0) {
		 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry);
		 nsfbufsused--;
		 if (sf_buf_alloc_want > 0)
			 wakeup_one(&sf_buf_freelist);
	 }
	 mtx_unlock(&sf_buf_lock);
}

/*
 *  * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
 *   */
static void
sf_buf_init(void *arg)
{
	struct sf_buf *sf_bufs;
	vm_offset_t sf_base;
	int i;

	nsfbufs = NSFBUFS;
	TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs);

	sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask);
	TAILQ_INIT(&sf_buf_freelist);
	sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE);
	sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
	    M_NOWAIT | M_ZERO);
	for (i = 0; i < nsfbufs; i++) {
		sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
		TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry);
	}
	sf_buf_alloc_want = 0;
	mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF);
}

/*
 * Get an sf_buf from the freelist. Will block if none are available.
 */
struct sf_buf *
sf_buf_alloc(struct vm_page *m, int flags)
{
	struct sf_head *hash_list;
	struct sf_buf *sf;
	int error;

	hash_list = &sf_buf_active[SF_BUF_HASH(m)];
	mtx_lock(&sf_buf_lock);
	LIST_FOREACH(sf, hash_list, list_entry) {
		if (sf->m == m) {
			sf->ref_count++;
			if (sf->ref_count == 1) {
				TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
				nsfbufsused++;
				nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
			}
			goto done;
		}
	}
	while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) {
		if (flags & SFB_NOWAIT)
			goto done;
		sf_buf_alloc_want++;
		mbstat.sf_allocwait++;
		error = msleep(&sf_buf_freelist, &sf_buf_lock,
		    (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0);
		sf_buf_alloc_want--;


		/*
		 * If we got a signal, don't risk going back to sleep.
		 */
		if (error)
			goto done;
	}
	TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
	if (sf->m != NULL)
		LIST_REMOVE(sf, list_entry);
	LIST_INSERT_HEAD(hash_list, sf, list_entry);
	sf->ref_count = 1;
	sf->m = m;
	nsfbufsused++;
	nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
	pmap_qenter(sf->kva, &sf->m, 1);
done:
	mtx_unlock(&sf_buf_lock);
	return (sf);

}

/*
 * Initialize machine state (pcb and trap frame) for a new thread about to
 * upcall. Put enough state in the new thread's PCB to get it to go back
 * userret(), where we can intercept it again to set the return (upcall)
 * Address and stack, along with those from upcals that are from other sources
 * such as those generated in thread_userret() itself.
 */
void
cpu_set_upcall(struct thread *td, struct thread *td0)
{
	struct trapframe *tf;
	struct switchframe *sf;

	bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
	bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb));
	tf = td->td_frame;
	sf = (struct switchframe *)tf - 1;
	sf->sf_r4 = (u_int)fork_return;
	sf->sf_r5 = (u_int)td;
	sf->sf_pc = (u_int)fork_trampoline;
	tf->tf_spsr &= ~PSR_C_bit;
	tf->tf_r0 = 0;
	td->td_pcb->un_32.pcb32_sp = (u_int)sf;
	td->td_pcb->un_32.pcb32_und_sp = td->td_kstack + td->td_kstack_pages
	    * PAGE_SIZE + USPACE_UNDEF_STACK_TOP;

	/* Setup to release sched_lock in fork_exit(). */
	td->td_md.md_spinlock_count = 1;
	td->td_md.md_saved_cspr = 0;
}

/*
 * Set that machine state for performing an upcall that has to
 * be done in thread_userret() so that those upcalls generated
 * in thread_userret() itself can be done as well.
 */
void
cpu_set_upcall_kse(struct thread *td, struct kse_upcall *ku)
{
	struct trapframe *tf = td->td_frame;

	tf->tf_usr_sp = ((int)ku->ku_stack.ss_sp + ku->ku_stack.ss_size
	    - sizeof(struct trapframe)) & ~7;
	tf->tf_pc = (int)ku->ku_func;
	tf->tf_r0 = (int)ku->ku_mailbox;
	tf->tf_spsr = PSR_USR32_MODE;
}

void
cpu_thread_exit(struct thread *td)
{
}

void
cpu_thread_setup(struct thread *td)
{
	td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages *
	    PAGE_SIZE) - 1;
	td->td_frame = (struct trapframe *)
	    ((u_int)td->td_kstack + td->td_kstack_pages * PAGE_SIZE +
	     USPACE_SVC_STACK_TOP - sizeof(struct pcb)) - 1;
#ifdef __XSCALE__
	pmap_use_minicache(td->td_kstack, td->td_kstack_pages * PAGE_SIZE);
#endif

}
void
cpu_thread_clean(struct thread *td)
{
}

/*
 * Intercept the return address from a freshly forked process that has NOT
 * been scheduled yet.
 *
 * This is needed to make kernel threads stay in kernel mode.
 */
void
cpu_set_fork_handler(struct thread *td, void (*func)(void *), void *arg)
{
	struct switchframe *sf;
	struct trapframe *tf;

	tf = td->td_frame;
	sf = (struct switchframe *)tf - 1;
	sf->sf_r4 = (u_int)func;
	sf->sf_r5 = (u_int)arg;
	td->td_pcb->un_32.pcb32_sp = (u_int)sf;
}

/*
 * Software interrupt handler for queued VM system processing.
 */
void
swi_vm(void *dummy)
{
}

void
cpu_exit(struct thread *td)
{
}