NetBSD-5.0.2/sys/kern/subr_kmem.c
/* $NetBSD: subr_kmem.c,v 1.19 2008/02/09 12:56:20 yamt Exp $ */
/*-
* Copyright (c)2006 YAMAMOTO Takashi,
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/*
* allocator of kernel wired memory.
*
* TODO:
* - worth to have "intrsafe" version? maybe..
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.19 2008/02/09 12:56:20 yamt Exp $");
#include <sys/param.h>
#include <sys/callback.h>
#include <sys/kmem.h>
#include <sys/vmem.h>
#include <sys/debug.h>
#include <sys/lockdebug.h>
#include <uvm/uvm_extern.h>
#include <uvm/uvm_map.h>
#include <lib/libkern/libkern.h>
#define KMEM_QUANTUM_SIZE (ALIGNBYTES + 1)
static vmem_t *kmem_arena;
static struct callback_entry kmem_kva_reclaim_entry;
#if defined(DEBUG)
static void *kmem_freecheck;
#define KMEM_POISON
#define KMEM_REDZONE
#endif /* defined(DEBUG) */
#if defined(KMEM_POISON)
static void kmem_poison_fill(void *, size_t);
static void kmem_poison_check(void *, size_t);
#else /* defined(KMEM_POISON) */
#define kmem_poison_fill(p, sz) /* nothing */
#define kmem_poison_check(p, sz) /* nothing */
#endif /* defined(KMEM_POISON) */
#if defined(KMEM_REDZONE)
#define REDZONE_SIZE 1
#else /* defined(KMEM_REDZONE) */
#define REDZONE_SIZE 0
#endif /* defined(KMEM_REDZONE) */
static vmem_addr_t kmem_backend_alloc(vmem_t *, vmem_size_t, vmem_size_t *,
vm_flag_t);
static void kmem_backend_free(vmem_t *, vmem_addr_t, vmem_size_t);
static int kmem_kva_reclaim_callback(struct callback_entry *, void *, void *);
static inline vm_flag_t
kmf_to_vmf(km_flag_t kmflags)
{
vm_flag_t vmflags;
KASSERT((kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0);
KASSERT((~kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0);
vmflags = 0;
if ((kmflags & KM_SLEEP) != 0) {
vmflags |= VM_SLEEP;
}
if ((kmflags & KM_NOSLEEP) != 0) {
vmflags |= VM_NOSLEEP;
}
return vmflags;
}
/* ---- kmem API */
/*
* kmem_alloc: allocate wired memory.
*
* => must not be called from interrupt context.
*/
void *
kmem_alloc(size_t size, km_flag_t kmflags)
{
void *p;
size += REDZONE_SIZE;
p = (void *)vmem_alloc(kmem_arena, size,
kmf_to_vmf(kmflags) | VM_INSTANTFIT);
if (p != NULL) {
kmem_poison_check(p, kmem_roundup_size(size));
FREECHECK_OUT(&kmem_freecheck, p);
}
return p;
}
/*
* kmem_zalloc: allocate wired memory.
*
* => must not be called from interrupt context.
*/
void *
kmem_zalloc(size_t size, km_flag_t kmflags)
{
void *p;
p = kmem_alloc(size, kmflags);
if (p != NULL) {
memset(p, 0, size);
}
return p;
}
/*
* kmem_free: free wired memory allocated by kmem_alloc.
*
* => must not be called from interrupt context.
*/
void
kmem_free(void *p, size_t size)
{
FREECHECK_IN(&kmem_freecheck, p);
LOCKDEBUG_MEM_CHECK(p, size);
kmem_poison_check((char *)p + size,
kmem_roundup_size(size + REDZONE_SIZE) - size);
kmem_poison_fill(p, size);
vmem_free(kmem_arena, (vmem_addr_t)p, size + REDZONE_SIZE);
}
void
kmem_init(void)
{
kmem_arena = vmem_create("kmem", 0, 0, KMEM_QUANTUM_SIZE,
kmem_backend_alloc, kmem_backend_free, NULL,
KMEM_QUANTUM_SIZE * 32, VM_SLEEP, IPL_NONE);
callback_register(&vm_map_to_kernel(kernel_map)->vmk_reclaim_callback,
&kmem_kva_reclaim_entry, kmem_arena, kmem_kva_reclaim_callback);
}
size_t
kmem_roundup_size(size_t size)
{
return vmem_roundup_size(kmem_arena, size);
}
/* ---- uvm glue */
static vmem_addr_t
kmem_backend_alloc(vmem_t *dummy, vmem_size_t size, vmem_size_t *resultsize,
vm_flag_t vmflags)
{
uvm_flag_t uflags;
vaddr_t va;
KASSERT(dummy == NULL);
KASSERT(size != 0);
KASSERT((vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0);
KASSERT((~vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0);
if ((vmflags & VM_NOSLEEP) != 0) {
uflags = UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT;
} else {
uflags = UVM_KMF_WAITVA;
}
*resultsize = size = round_page(size);
va = uvm_km_alloc(kernel_map, size, 0,
uflags | UVM_KMF_WIRED | UVM_KMF_CANFAIL);
if (va != 0) {
kmem_poison_fill((void *)va, size);
}
return (vmem_addr_t)va;
}
static void
kmem_backend_free(vmem_t *dummy, vmem_addr_t addr, vmem_size_t size)
{
KASSERT(dummy == NULL);
KASSERT(addr != 0);
KASSERT(size != 0);
KASSERT(size == round_page(size));
kmem_poison_check((void *)addr, size);
uvm_km_free(kernel_map, (vaddr_t)addr, size, UVM_KMF_WIRED);
}
static int
kmem_kva_reclaim_callback(struct callback_entry *ce, void *obj, void *arg)
{
vmem_t *vm = obj;
vmem_reap(vm);
return CALLBACK_CHAIN_CONTINUE;
}
/* ---- debug */
#if defined(KMEM_POISON)
#if defined(_LP64)
#define PRIME 0x9e37fffffffc0001UL
#else /* defined(_LP64) */
#define PRIME 0x9e3779b1
#endif /* defined(_LP64) */
static inline uint8_t
kmem_poison_pattern(const void *p)
{
return (uint8_t)((((uintptr_t)p) * PRIME)
>> ((sizeof(uintptr_t) - sizeof(uint8_t))) * CHAR_BIT);
}
static void
kmem_poison_fill(void *p, size_t sz)
{
uint8_t *cp;
const uint8_t *ep;
cp = p;
ep = cp + sz;
while (cp < ep) {
*cp = kmem_poison_pattern(cp);
cp++;
}
}
static void
kmem_poison_check(void *p, size_t sz)
{
uint8_t *cp;
const uint8_t *ep;
cp = p;
ep = cp + sz;
while (cp < ep) {
const uint8_t expected = kmem_poison_pattern(cp);
if (*cp != expected) {
panic("%s: %p: 0x%02x != 0x%02x\n",
__func__, cp, *cp, expected);
}
cp++;
}
}
#endif /* defined(KMEM_POISON) */