152 lines
4.5 KiB
C
152 lines
4.5 KiB
C
/**************************************************************************
|
|
*
|
|
* Copyright 2010 Pauli Nieminen.
|
|
* All Rights Reserved.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
|
* copy of this software and associated documentation files (the
|
|
* "Software"), to deal in the Software without restriction, including
|
|
* without limitation the rights to use, copy, modify, merge, publish,
|
|
* distribute, sub license, and/or sell copies of the Software, and to
|
|
* permit persons to whom the Software is furnished to do so, subject to
|
|
* the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice (including the
|
|
* next paragraph) shall be included in all copies or substantial portions
|
|
* of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
|
|
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
|
|
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
|
|
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
|
|
* USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*
|
|
*
|
|
**************************************************************************/
|
|
/*
|
|
* Multipart buffer for coping data which is larger than the page size.
|
|
*
|
|
* Authors:
|
|
* Pauli Nieminen <suokkos-at-gmail-dot-com>
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#ifndef _DRM_BUFFER_H_
|
|
#define _DRM_BUFFER_H_
|
|
|
|
#include <dev/drm2/drmP.h>
|
|
|
|
struct drm_buffer {
|
|
int iterator;
|
|
int size;
|
|
char *data[];
|
|
};
|
|
|
|
|
|
/**
|
|
* Return the index of page that buffer is currently pointing at.
|
|
*/
|
|
static inline int drm_buffer_page(struct drm_buffer *buf)
|
|
{
|
|
return buf->iterator / PAGE_SIZE;
|
|
}
|
|
/**
|
|
* Return the index of the current byte in the page
|
|
*/
|
|
static inline int drm_buffer_index(struct drm_buffer *buf)
|
|
{
|
|
return buf->iterator & (PAGE_SIZE - 1);
|
|
}
|
|
/**
|
|
* Return number of bytes that is left to process
|
|
*/
|
|
static inline int drm_buffer_unprocessed(struct drm_buffer *buf)
|
|
{
|
|
return buf->size - buf->iterator;
|
|
}
|
|
|
|
/**
|
|
* Advance the buffer iterator number of bytes that is given.
|
|
*/
|
|
static inline void drm_buffer_advance(struct drm_buffer *buf, int bytes)
|
|
{
|
|
buf->iterator += bytes;
|
|
}
|
|
|
|
/**
|
|
* Allocate the drm buffer object.
|
|
*
|
|
* buf: A pointer to a pointer where the object is stored.
|
|
* size: The number of bytes to allocate.
|
|
*/
|
|
extern int drm_buffer_alloc(struct drm_buffer **buf, int size);
|
|
|
|
/**
|
|
* Copy the user data to the begin of the buffer and reset the processing
|
|
* iterator.
|
|
*
|
|
* user_data: A pointer the data that is copied to the buffer.
|
|
* size: The Number of bytes to copy.
|
|
*/
|
|
extern int drm_buffer_copy_from_user(struct drm_buffer *buf,
|
|
void __user *user_data, int size);
|
|
|
|
/**
|
|
* Free the drm buffer object
|
|
*/
|
|
extern void drm_buffer_free(struct drm_buffer *buf);
|
|
|
|
/**
|
|
* Read an object from buffer that may be split to multiple parts. If object
|
|
* is not split function just returns the pointer to object in buffer. But in
|
|
* case of split object data is copied to given stack object that is suplied
|
|
* by caller.
|
|
*
|
|
* The processing location of the buffer is also advanced to the next byte
|
|
* after the object.
|
|
*
|
|
* objsize: The size of the objet in bytes.
|
|
* stack_obj: A pointer to a memory location where object can be copied.
|
|
*/
|
|
extern void *drm_buffer_read_object(struct drm_buffer *buf,
|
|
int objsize, void *stack_obj);
|
|
|
|
/**
|
|
* Returns the pointer to the dword which is offset number of elements from the
|
|
* current processing location.
|
|
*
|
|
* Caller must make sure that dword is not split in the buffer. This
|
|
* requirement is easily met if all the sizes of objects in buffer are
|
|
* multiples of dword and PAGE_SIZE is multiple dword.
|
|
*
|
|
* Call to this function doesn't change the processing location.
|
|
*
|
|
* offset: The index of the dword relative to the internat iterator.
|
|
*/
|
|
static inline void *drm_buffer_pointer_to_dword(struct drm_buffer *buffer,
|
|
int offset)
|
|
{
|
|
int iter = buffer->iterator + offset * 4;
|
|
return &buffer->data[iter / PAGE_SIZE][iter & (PAGE_SIZE - 1)];
|
|
}
|
|
/**
|
|
* Returns the pointer to the dword which is offset number of elements from
|
|
* the current processing location.
|
|
*
|
|
* Call to this function doesn't change the processing location.
|
|
*
|
|
* offset: The index of the byte relative to the internat iterator.
|
|
*/
|
|
static inline void *drm_buffer_pointer_to_byte(struct drm_buffer *buffer,
|
|
int offset)
|
|
{
|
|
int iter = buffer->iterator + offset;
|
|
return &buffer->data[iter / PAGE_SIZE][iter & (PAGE_SIZE - 1)];
|
|
}
|
|
|
|
#endif
|