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Diffstat (limited to 'drivers/staging/memrar/memrar.h')
| -rw-r--r-- | drivers/staging/memrar/memrar.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/staging/memrar/memrar.h b/drivers/staging/memrar/memrar.h new file mode 100644 index 000000000000..0b735b827c09 --- /dev/null +++ b/drivers/staging/memrar/memrar.h @@ -0,0 +1,155 @@ +/* + * RAR Handler (/dev/memrar) internal driver API. + * Copyright (C) 2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General + * Public License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be + * useful, but WITHOUT ANY WARRANTY; without even the implied + * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR + * PURPOSE. See the GNU General Public License for more details. + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * The full GNU General Public License is included in this + * distribution in the file called COPYING. + */ + + +#ifndef _MEMRAR_H +#define _MEMRAR_H + +#include <linux/ioctl.h> +#include <linux/types.h> + + +/** + * struct RAR_stat - RAR statistics structure + * @type: Type of RAR memory (e.g., audio vs. video) + * @capacity: Total size of RAR memory region. + * @largest_block_size: Size of the largest reservable block. + * + * This structure is used for RAR_HANDLER_STAT ioctl and for the + * RAR_get_stat() user space wrapper function. + */ +struct RAR_stat { + __u32 type; + __u32 capacity; + __u32 largest_block_size; +}; + + +/** + * struct RAR_block_info - user space struct that describes RAR buffer + * @type: Type of RAR memory (e.g., audio vs. video) + * @size: Requested size of a block to be reserved in RAR. + * @handle: Handle that can be used to refer to reserved block. + * + * This is the basic structure exposed to the user space that + * describes a given RAR buffer. The buffer's underlying bus address + * is not exposed to the user. User space code refers to the buffer + * entirely by "handle". + */ +struct RAR_block_info { + __u32 type; + __u32 size; + __u32 handle; +}; + + +#define RAR_IOCTL_BASE 0xE0 + +/* Reserve RAR block. */ +#define RAR_HANDLER_RESERVE _IOWR(RAR_IOCTL_BASE, 0x00, struct RAR_block_info) + +/* Release previously reserved RAR block. */ +#define RAR_HANDLER_RELEASE _IOW(RAR_IOCTL_BASE, 0x01, __u32) + +/* Get RAR stats. */ +#define RAR_HANDLER_STAT _IOWR(RAR_IOCTL_BASE, 0x02, struct RAR_stat) + + +#ifdef __KERNEL__ + +/* -------------------------------------------------------------- */ +/* Kernel Side RAR Handler Interface */ +/* -------------------------------------------------------------- */ + +/** + * struct RAR_buffer - kernel space struct that describes RAR buffer + * @info: structure containing base RAR buffer information + * @bus_address: buffer bus address + * + * Structure that contains all information related to a given block of + * memory in RAR. It is generally only used when retrieving RAR + * related bus addresses. + * + * Note: This structure is used only by RAR-enabled drivers, and is + * not intended to be exposed to the user space. + */ +struct RAR_buffer { + struct RAR_block_info info; + dma_addr_t bus_address; +}; + +/** + * rar_reserve() - reserve RAR buffers + * @buffers: array of RAR_buffers where type and size of buffers to + * reserve are passed in, handle and bus address are + * passed out + * @count: number of RAR_buffers in the "buffers" array + * + * This function will reserve buffers in the restricted access regions + * of given types. + * + * It returns the number of successfully reserved buffers. Successful + * buffer reservations will have the corresponding bus_address field + * set to a non-zero value in the given buffers vector. + */ +extern size_t rar_reserve(struct RAR_buffer *buffers, + size_t count); + +/** + * rar_release() - release RAR buffers + * @buffers: array of RAR_buffers where handles to buffers to be + * released are passed in + * @count: number of RAR_buffers in the "buffers" array + * + * This function will release RAR buffers that were retrieved through + * a call to rar_reserve() or rar_handle_to_bus() by decrementing the + * reference count. The RAR buffer will be reclaimed when the + * reference count drops to zero. + * + * It returns the number of successfully released buffers. Successful + * releases will have their handle field set to zero in the given + * buffers vector. + */ +extern size_t rar_release(struct RAR_buffer *buffers, + size_t count); + +/** + * rar_handle_to_bus() - convert a vector of RAR handles to bus addresses + * @buffers: array of RAR_buffers containing handles to be + * converted to bus_addresses + * @count: number of RAR_buffers in the "buffers" array + + * This function will retrieve the RAR buffer bus addresses, type and + * size corresponding to the RAR handles provided in the buffers + * vector. + * + * It returns the number of successfully converted buffers. The bus + * address will be set to 0 for unrecognized handles. + * + * The reference count for each corresponding buffer in RAR will be + * incremented. Call rar_release() when done with the buffers. + */ +extern size_t rar_handle_to_bus(struct RAR_buffer *buffers, + size_t count); + + +#endif /* __KERNEL__ */ + +#endif /* _MEMRAR_H */ |