alistair23-linux/arch/arm/mm/vmregion.h
Russell King 5bc23d32d8 ARM: DMA coherent allocator: align remapped addresses
The DMA coherent remap area is used to provide an uncached mapping
of memory for coherency with DMA engines.  Currently, we look for
any free hole which our allocation will fit in with page alignment.

However, this can lead to fragmentation of the area, and allows small
allocations to cross L1 entry boundaries.  This is undesirable as we
want to move towards allocating sections of memory.

Align allocations according to the size, limiting the alignment between
the page and section sizes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27 10:43:48 +01:00

30 lines
730 B
C

#ifndef VMREGION_H
#define VMREGION_H
#include <linux/spinlock.h>
#include <linux/list.h>
struct page;
struct arm_vmregion_head {
spinlock_t vm_lock;
struct list_head vm_list;
unsigned long vm_start;
unsigned long vm_end;
};
struct arm_vmregion {
struct list_head vm_list;
unsigned long vm_start;
unsigned long vm_end;
struct page *vm_pages;
int vm_active;
};
struct arm_vmregion *arm_vmregion_alloc(struct arm_vmregion_head *, size_t, size_t, gfp_t);
struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *, unsigned long);
struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *, unsigned long);
void arm_vmregion_free(struct arm_vmregion_head *, struct arm_vmregion *);
#endif