freebsd-dev/sys/powerpc/aim/vm_machdep.c
Konstantin Belousov 55aabb7fd1 For architectures not using direct map , and requiring real KVA page for
sf buf allocation, use wakeup() instead of wakeup_one() to notify sf
buffer waiters about free buffer.

sf_buf_alloc() calls msleep(PCATCH) when SFB_CATCH flag was given,
and for simultaneous wakeup and signal delivery, msleep() returns
EINTR/ERESTART despite the thread was selected for wakeup_one(). As
result, we loose a wakeup, and some other waiter will not be woken up.

Reported and tested by:	az
Reviewed by:	alc, jhb
MFC after:	1 week
2011-01-18 21:57:02 +00:00

402 lines
11 KiB
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 $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
* $FreeBSD$
*/
/*-
* Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Chris G. Demetriou
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/vnode.h>
#include <sys/vmmeter.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/sf_buf.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/unistd.h>
#include <machine/cpu.h>
#include <machine/fpu.h>
#include <machine/frame.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <dev/ofw/openfirm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_extern.h>
/*
* On systems without a direct mapped region (e.g. PPC64),
* we use the same code as the Book E implementation. Since
* we need to have runtime detection of this, define some machinery
* for sf_bufs in this case, and ignore it on systems with direct maps.
*/
#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;
#ifdef __powerpc64__
extern uintptr_t tocbase;
#endif
/*
* 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(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
{
struct trapframe *tf;
struct callframe *cf;
struct pcb *pcb;
KASSERT(td1 == curthread || td1 == &thread0,
("cpu_fork: p1 not curproc and not proc0"));
CTR3(KTR_PROC, "cpu_fork: called td1=%p p2=%p flags=%x",
td1, p2, flags);
if ((flags & RFPROC) == 0)
return;
pcb = (struct pcb *)((td2->td_kstack +
td2->td_kstack_pages * PAGE_SIZE - sizeof(struct pcb)) & ~0x2fUL);
td2->td_pcb = pcb;
/* Copy the pcb */
bcopy(td1->td_pcb, pcb, sizeof(struct pcb));
/*
* Create a fresh stack for the new process.
* Copy the trap frame for the return to user mode as if from a
* syscall. This copies most of the user mode register values.
*/
tf = (struct trapframe *)pcb - 1;
bcopy(td1->td_frame, tf, sizeof(*tf));
/* Set up trap frame. */
tf->fixreg[FIRSTARG] = 0;
tf->fixreg[FIRSTARG + 1] = 0;
tf->cr &= ~0x10000000;
td2->td_frame = tf;
cf = (struct callframe *)tf - 1;
memset(cf, 0, sizeof(struct callframe));
#ifdef __powerpc64__
cf->cf_toc = tocbase;
#endif
cf->cf_func = (register_t)fork_return;
cf->cf_arg0 = (register_t)td2;
cf->cf_arg1 = (register_t)tf;
pcb->pcb_sp = (register_t)cf;
#ifdef __powerpc64__
pcb->pcb_lr = ((register_t *)fork_trampoline)[0];
pcb->pcb_toc = ((register_t *)fork_trampoline)[1];
#else
pcb->pcb_lr = (register_t)fork_trampoline;
#endif
pcb->pcb_cpu.aim.usr_vsid = 0;
/* Setup to release spin count in fork_exit(). */
td2->td_md.md_spinlock_count = 1;
td2->td_md.md_saved_msr = PSL_KERNSET;
/*
* Now cpu_switch() can schedule the new process.
*/
}
/*
* 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(td, func, arg)
struct thread *td;
void (*func)(void *);
void *arg;
{
struct callframe *cf;
CTR4(KTR_PROC, "%s called with td=%p func=%p arg=%p",
__func__, td, func, arg);
cf = (struct callframe *)td->td_pcb->pcb_sp;
cf->cf_func = (register_t)func;
cf->cf_arg0 = (register_t)arg;
}
void
cpu_exit(td)
register struct thread *td;
{
}
/*
* 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;
/* Don't bother on systems with a direct map */
if (hw_direct_map)
return;
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;
if (hw_direct_map) {
/* Shortcut the direct mapped case */
return ((struct sf_buf *)m);
}
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);
}
/*
* Detatch mapped page and release resources back to the system.
*
* Remove a reference from the given sf_buf, adding it to the free
* list when its reference count reaches zero. A freed sf_buf still,
* however, retains its virtual-to-physical mapping until it is
* recycled or reactivated by sf_buf_alloc(9).
*/
void
sf_buf_free(struct sf_buf *sf)
{
if (hw_direct_map)
return;
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(&sf_buf_freelist);
}
mtx_unlock(&sf_buf_lock);
}
/*
* Software interrupt handler for queued VM system processing.
*/
void
swi_vm(void *dummy)
{
if (busdma_swi_pending != 0)
busdma_swi();
}
/*
* Tell whether this address is in some physical memory region.
* Currently used by the kernel coredump code in order to avoid
* dumping the ``ISA memory hole'' which could cause indefinite hangs,
* or other unpredictable behaviour.
*/
int
is_physical_memory(addr)
vm_offset_t addr;
{
/*
* stuff other tests for known memory-mapped devices (PCI?)
* here
*/
return 1;
}
/*
* CPU threading functions related to the VM layer. These could be used
* to map the SLB bits required for the kernel stack instead of forcing a
* fixed-size KVA.
*/
void
cpu_thread_swapin(struct thread *td)
{
}
void
cpu_thread_swapout(struct thread *td)
{
}