/*
* c 2001 PPC 64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/semaphore.h>
#include <asm/imalloc.h>
#include <asm/cacheflush.h>
static DECLARE_MUTEX(imlist_sem);
struct vm_struct * imlist = NULL;
static int get_free_im_addr(unsigned long size, unsigned long *im_addr)
{
unsigned long addr;
struct vm_struct **p, *tmp;
addr = ioremap_bot;
for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
if (size + addr < (unsigned long) tmp->addr)
break;
if ((unsigned long)tmp->addr >= ioremap_bot)
addr = tmp->size + (unsigned long) tmp->addr;
if (addr >= IMALLOC_END-size)
return 1;
}
*im_addr = addr;
return 0;
}
/* Return whether the region described by v_addr and size is a subset
* of the region described by parent
*/
static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
struct vm_struct *parent)
{
return (int) (v_addr >= (unsigned long) parent->addr &&
v_addr < (unsigned long) parent->addr + parent->size &&
size < parent->size);
}
/* Return whether the region described by v_addr and size is a superset
* of the region described by child
*/
static int im_region_is_superset(unsigned long v_addr, unsigned long size,
struct vm_struct *child)
{
struct vm_struct parent;
parent.addr = (void *) v_addr;
parent.size = size;
return im_region_is_subset((unsigned long) child->addr, child->size,
&parent);
}
/* Return whether the region described by v_addr and size overlaps
* the region described by vm. Overlapping regions meet the
* following conditions:
* 1) The regions share some part of the address space
* 2) The regions aren't identical
* 3) Neither region is a subset of the other
*/
static int im_region_overlaps(unsigned long v_addr, unsigned long size,
struct vm_struct *vm)
{
if (im_region_is_superset(v_addr, size, vm))
return 0;
return (v_addr + size > (unsigned long) vm->addr + vm->size &&
v_addr < (unsigned long) vm->addr + vm->size) ||
(v_addr < (unsigned long) vm->addr &&
v_addr + size > (unsigned long) vm->addr);
}
/* Determine imalloc status of region described by v_addr and size.
* Can return one of the following:
* IM_REGION_UNUSED - Entire region is unallocated in imalloc space.
* IM_REGION_SUBSET - Region is a subset of a region that is already
* allocated in imalloc space.
* vm will be assigned to a ptr to the parent region.
* IM_REGION_EXISTS - Exact region already allocated in imalloc space.
* vm will be assigned to a ptr to the existing imlist
* member.
* IM_REGION_OVERLAPS - Region overlaps an allocated region in imalloc space.
* IM_REGION_SUPERSET - Region is a superset of a region that is already
* allocated in imalloc space.
*/
static int im_region_status(unsigned long v_addr, unsigned long size,
struct vm_struct **vm)
{
struct vm_struct *tmp;
for (tmp = imlist; tmp; tmp = tmp->next)
if (v_addr < (unsigned long) tmp->addr + tmp->size)
break;
if (tmp) {
if (im_region_overlaps(v_addr, size, tmp))
return IM_REGION_OVERLAP;
*vm = tmp;
if (im_region_is_subset(v_addr, size, tmp)) {
/* Return with tmp pointing to superset */
return IM_REGION_SUBSET;
}
if (im_region_is_superset(v_addr, size, tmp)) {
/* Return with tmp pointing to first subset */
return IM_REGION_SUPERSET;
}
else if (v_addr == (unsigned long) tmp->addr &&
size == tmp->size) {
/* Return with tmp pointing to exact region */
return IM_REGION_EXISTS;
}
}
*vm = NULL;
return IM_REGION_UNUSED;
}
static struct vm_struct * split_im_region(unsigned long v_addr,
unsigned long size, struct vm_struct *parent)
{
struct vm_struct *vm1 = NULL;
struct vm_struct *vm2 = NULL;
struct vm_struct *new_vm = NULL;
vm1 = (struct vm_struct *) kmalloc(sizeof(*vm1), GFP_KERNEL);
if (vm1 == NULL) {
printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
return NULL;
}
if (v_addr == (unsigned long) parent->addr) {
/* Use existing parent vm_struct to represent child, allocate
* new one for the remainder of parent range
*/
vm1->size = parent->size - size;
vm1->addr = (void *) (v_addr + size);
vm1->next = parent->next;
parent->size = size;
parent->next = vm1;
new_vm = parent;
} else if (v_addr + size == (unsigned long) parent->addr +
parent->size) {
/* Allocate new vm_struct to represent child, use existing
* parent one for remainder of parent range
*/
vm1->size = size;
vm1->addr = (void *) v_addr;
vm1->next = parent->next;
new_vm = vm1;
parent->size -= size;
parent->next = vm1;
} else {
/* Allocate two new vm_structs for the new child and
* uppermost remainder, and use existing parent one for the
* lower remainder of parent range
*/
vm2 = (struct vm_struct *) kmalloc(sizeof(*vm2), GFP_KERNEL);
if (vm2 == NULL) {
printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
kfree(vm1);
return NULL;
}
vm1->size = size;
vm1->addr = (void *) v_addr;
vm1->next = vm2;
new_vm = vm1;
vm2->size = ((unsigned long) parent->addr + parent->size) -
(v_addr + size);
vm2->addr = (void *) v_addr + size;
vm2->next = parent->next;
parent->size = v_addr - (unsigned long) parent->addr;
parent->next = vm1;
}
return new_vm;
}
static struct vm_struct * __add_new_im_area(unsigned long req_addr,
unsigned long size)
{
struct vm_struct **p, *tmp, *area;
for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
if (req_addr + size <= (unsigned long)tmp->addr)
break;
}
area = (struct vm_struct *) kmalloc(sizeof(*area), GFP_KERNEL);
if (!area)
return NULL;
area->flags = 0;
area->addr = (void *)req_addr;
area->size = size;
area->next = *p;
*p = area;
return area;
}
static struct vm_struct * __im_get_area(unsigned long req_addr,
unsigned long size,
int criteria)
{
struct vm_struct *tmp;
int status;
status = im_region_status(req_addr, size, &tmp);
if ((criteria & status) == 0) {
return NULL;
}
switch (status) {
case IM_REGION_UNUSED:
tmp = __add_new_im_area(req_addr, size);
break;
case IM_REGION_SUBSET:
tmp = split_im_region(req_addr, size, tmp);
break;
case IM_REGION_EXISTS:
/* Return requested region */
break;
case IM_REGION_SUPERSET:
/* Return first existing subset of requested region */
break;
default:
printk(KERN_ERR "%s() unexpected imalloc region status\n",
__FUNCTION__);
tmp = NULL;
}
return tmp;
}
struct vm_struct * im_get_free_area(unsigned long size)
{
struct vm_struct *area;
unsigned long addr;
down(&imlist_sem);
if (get_free_im_addr(size, &addr)) {
printk(KERN_ERR "%s() cannot obtain addr for size 0x%lx\n",
__FUNCTION__, size);
area = NULL;
goto next_im_done;
}
area = __im_get_area(addr, size, IM_REGION_UNUSED);
if (area == NULL) {
printk(KERN_ERR
"%s() cannot obtain area for addr 0x%lx size 0x%lx\n",
__FUNCTION__, addr, size);
}
next_im_done:
up(&imlist_sem);
return area;
}
struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size,
int criteria)
{
struct vm_struct *area;
down(&imlist_sem);
area = __im_get_area(v_addr, size, criteria);
up(&imlist_sem);
return area;
}
void im_free(void * addr)
{
struct vm_struct **p, *tmp;
if (!addr)
return;
if ((unsigned long) addr & ~PAGE_MASK) {
printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__, addr);
return;
}
down(&imlist_sem);
for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
if (tmp->addr == addr) {
*p = tmp->next;
/* XXX: do we need the lock? */
spin_lock(&init_mm.page_table_lock);
unmap_vm_area(tmp);
spin_unlock(&init_mm.page_table_lock);
kfree(tmp);
up(&imlist_sem);
return;
}
}
up(&imlist_sem);
printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,
addr);
}
