132 lines
3.1 KiB
C
132 lines
3.1 KiB
C
#include <linux/spinlock.h>
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "vmregion.h"
|
|
|
|
/*
|
|
* VM region handling support.
|
|
*
|
|
* This should become something generic, handling VM region allocations for
|
|
* vmalloc and similar (ioremap, module space, etc).
|
|
*
|
|
* I envisage vmalloc()'s supporting vm_struct becoming:
|
|
*
|
|
* struct vm_struct {
|
|
* struct vmregion region;
|
|
* unsigned long flags;
|
|
* struct page **pages;
|
|
* unsigned int nr_pages;
|
|
* unsigned long phys_addr;
|
|
* };
|
|
*
|
|
* get_vm_area() would then call vmregion_alloc with an appropriate
|
|
* struct vmregion head (eg):
|
|
*
|
|
* struct vmregion vmalloc_head = {
|
|
* .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list),
|
|
* .vm_start = VMALLOC_START,
|
|
* .vm_end = VMALLOC_END,
|
|
* };
|
|
*
|
|
* However, vmalloc_head.vm_start is variable (typically, it is dependent on
|
|
* the amount of RAM found at boot time.) I would imagine that get_vm_area()
|
|
* would have to initialise this each time prior to calling vmregion_alloc().
|
|
*/
|
|
|
|
struct arm_vmregion *
|
|
arm_vmregion_alloc(struct arm_vmregion_head *head, size_t align,
|
|
size_t size, gfp_t gfp)
|
|
{
|
|
unsigned long start = head->vm_start, addr = head->vm_end;
|
|
unsigned long flags;
|
|
struct arm_vmregion *c, *new;
|
|
|
|
if (head->vm_end - head->vm_start < size) {
|
|
printk(KERN_WARNING "%s: allocation too big (requested %#x)\n",
|
|
__func__, size);
|
|
goto out;
|
|
}
|
|
|
|
new = kmalloc(sizeof(struct arm_vmregion), gfp);
|
|
if (!new)
|
|
goto out;
|
|
|
|
spin_lock_irqsave(&head->vm_lock, flags);
|
|
|
|
addr = rounddown(addr - size, align);
|
|
list_for_each_entry_reverse(c, &head->vm_list, vm_list) {
|
|
if (addr >= c->vm_end)
|
|
goto found;
|
|
addr = rounddown(c->vm_start - size, align);
|
|
if (addr < start)
|
|
goto nospc;
|
|
}
|
|
|
|
found:
|
|
/*
|
|
* Insert this entry after the one we found.
|
|
*/
|
|
list_add(&new->vm_list, &c->vm_list);
|
|
new->vm_start = addr;
|
|
new->vm_end = addr + size;
|
|
new->vm_active = 1;
|
|
|
|
spin_unlock_irqrestore(&head->vm_lock, flags);
|
|
return new;
|
|
|
|
nospc:
|
|
spin_unlock_irqrestore(&head->vm_lock, flags);
|
|
kfree(new);
|
|
out:
|
|
return NULL;
|
|
}
|
|
|
|
static struct arm_vmregion *__arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr)
|
|
{
|
|
struct arm_vmregion *c;
|
|
|
|
list_for_each_entry(c, &head->vm_list, vm_list) {
|
|
if (c->vm_active && c->vm_start == addr)
|
|
goto out;
|
|
}
|
|
c = NULL;
|
|
out:
|
|
return c;
|
|
}
|
|
|
|
struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr)
|
|
{
|
|
struct arm_vmregion *c;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&head->vm_lock, flags);
|
|
c = __arm_vmregion_find(head, addr);
|
|
spin_unlock_irqrestore(&head->vm_lock, flags);
|
|
return c;
|
|
}
|
|
|
|
struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *head, unsigned long addr)
|
|
{
|
|
struct arm_vmregion *c;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&head->vm_lock, flags);
|
|
c = __arm_vmregion_find(head, addr);
|
|
if (c)
|
|
c->vm_active = 0;
|
|
spin_unlock_irqrestore(&head->vm_lock, flags);
|
|
return c;
|
|
}
|
|
|
|
void arm_vmregion_free(struct arm_vmregion_head *head, struct arm_vmregion *c)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&head->vm_lock, flags);
|
|
list_del(&c->vm_list);
|
|
spin_unlock_irqrestore(&head->vm_lock, flags);
|
|
|
|
kfree(c);
|
|
}
|