120 lines
4.6 KiB
C
120 lines
4.6 KiB
C
/*-
|
|
* Copyright (c) 2012 Ian Lepore
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* A buffer pool manager, for use by a platform's busdma implementation.
|
|
*/
|
|
|
|
#ifndef _MACHINE_BUSDMA_BUFALLOC_H_
|
|
#define _MACHINE_BUSDMA_BUFALLOC_H_
|
|
|
|
#include <machine/bus.h>
|
|
#include <vm/uma.h>
|
|
|
|
/*
|
|
* Information about a buffer zone, returned by busdma_bufalloc_findzone().
|
|
*/
|
|
struct busdma_bufzone {
|
|
bus_size_t size;
|
|
uma_zone_t umazone;
|
|
char name[24];
|
|
};
|
|
|
|
/*
|
|
* Opaque handle type returned by busdma_bufalloc_create().
|
|
*/
|
|
struct busdma_bufalloc;
|
|
typedef struct busdma_bufalloc *busdma_bufalloc_t;
|
|
|
|
/*
|
|
* Create an allocator that manages a pool of DMA buffers.
|
|
*
|
|
* The allocator manages a collection of uma(9) zones of buffers in power-of-two
|
|
* sized increments ranging from minimum_alignment to the platform's PAGE_SIZE.
|
|
* The buffers within each zone are aligned on boundaries corresponding to the
|
|
* buffer size, and thus by implication each buffer is contiguous within a page
|
|
* and does not cross a power of two boundary larger than the buffer size.
|
|
* These rules are intended to make it easy for a busdma implementation to
|
|
* check whether a tag's constraints allow use of a buffer from the allocator.
|
|
*
|
|
* minimum_alignment is also the minimum buffer allocation size. For platforms
|
|
* with software-assisted cache coherency, this is typically the data cache line
|
|
* size (and MUST not be smaller than the cache line size).
|
|
*
|
|
* name appears in zone stats as 'dma name nnnnn' where 'dma' is fixed and
|
|
* 'nnnnn' is the size of buffers in that zone.
|
|
*
|
|
* If if the alloc/free function pointers are NULL, the regular uma internal
|
|
* allocators are used (I.E., you get "plain old kernel memory"). On a platform
|
|
* with an exclusion zone that applies to all DMA operations, a custom allocator
|
|
* could be used to ensure no buffer memory is ever allocated from that zone,
|
|
* allowing the bus_dmamem_alloc() implementation to make the assumption that
|
|
* buffers provided by the allocation could never lead to the need for a bounce.
|
|
*/
|
|
busdma_bufalloc_t busdma_bufalloc_create(const char *name,
|
|
bus_size_t minimum_alignment,
|
|
uma_alloc uma_alloc_func, uma_free uma_free_func,
|
|
u_int32_t uma_zcreate_flags);
|
|
|
|
/*
|
|
* Destroy an allocator created by busdma_bufalloc_create().
|
|
* Safe to call with a NULL pointer.
|
|
*/
|
|
void busdma_bufalloc_destroy(busdma_bufalloc_t ba);
|
|
|
|
/*
|
|
* Return a pointer to the busdma_bufzone that should be used to allocate or
|
|
* free a buffer of the given size. Returns NULL if the size is larger than the
|
|
* largest zone handled by the allocator.
|
|
*/
|
|
struct busdma_bufzone * busdma_bufalloc_findzone(busdma_bufalloc_t ba,
|
|
bus_size_t size);
|
|
|
|
/*
|
|
* These built-in allocation routines are available for managing a pools of
|
|
* uncacheable memory on platforms that support VM_MEMATTR_UNCACHEABLE.
|
|
*
|
|
* Allocation is done using kmem_alloc_attr() with these parameters:
|
|
* lowaddr = 0
|
|
* highaddr = BUS_SPACE_MAXADDR
|
|
* memattr = VM_MEMATTR_UNCACHEABLE.
|
|
*
|
|
* If your platform has no exclusion region (lowaddr/highaddr), and its pmap
|
|
* routines support pmap_page_set_memattr() and the VM_MEMATTR_UNCACHEABLE flag
|
|
* you can probably use these when you need uncacheable buffers.
|
|
*/
|
|
void * busdma_bufalloc_alloc_uncacheable(uma_zone_t zone, vm_size_t size,
|
|
uint8_t *pflag, int wait);
|
|
void busdma_bufalloc_free_uncacheable(void *item, vm_size_t size,
|
|
uint8_t pflag);
|
|
|
|
#endif /* _MACHINE_BUSDMA_BUFALLOC_H_ */
|
|
|