diff options
Diffstat (limited to 'arch/powerpc/mm/imalloc.c')
-rw-r--r-- | arch/powerpc/mm/imalloc.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/arch/powerpc/mm/imalloc.c b/arch/powerpc/mm/imalloc.c new file mode 100644 index 00000000000..f9587bcc6a4 --- /dev/null +++ b/arch/powerpc/mm/imalloc.c @@ -0,0 +1,313 @@ +/* + * 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/cacheflush.h> + +#include "mmu_decl.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; + unmap_vm_area(tmp); + kfree(tmp); + up(&imlist_sem); + return; + } + } + up(&imlist_sem); + printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__, + addr); +} |