1254794Sdumbbell/************************************************************************** 2254794Sdumbbell * 3254794Sdumbbell * Copyright 2010 Pauli Nieminen. 4254794Sdumbbell * All Rights Reserved. 5254794Sdumbbell * 6254794Sdumbbell * Permission is hereby granted, free of charge, to any person obtaining a 7254794Sdumbbell * copy of this software and associated documentation files (the 8254794Sdumbbell * "Software"), to deal in the Software without restriction, including 9254794Sdumbbell * without limitation the rights to use, copy, modify, merge, publish, 10254794Sdumbbell * distribute, sub license, and/or sell copies of the Software, and to 11254794Sdumbbell * permit persons to whom the Software is furnished to do so, subject to 12254794Sdumbbell * the following conditions: 13254794Sdumbbell * 14254794Sdumbbell * The above copyright notice and this permission notice (including the 15254794Sdumbbell * next paragraph) shall be included in all copies or substantial portions 16254794Sdumbbell * of the Software. 17254794Sdumbbell * 18254794Sdumbbell * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19254794Sdumbbell * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20254794Sdumbbell * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 21254794Sdumbbell * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 22254794Sdumbbell * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 23254794Sdumbbell * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 24254794Sdumbbell * USE OR OTHER DEALINGS IN THE SOFTWARE. 25254794Sdumbbell * 26254794Sdumbbell * 27254794Sdumbbell **************************************************************************/ 28254794Sdumbbell/* 29254794Sdumbbell * Multipart buffer for coping data which is larger than the page size. 30254794Sdumbbell * 31254794Sdumbbell * Authors: 32254794Sdumbbell * Pauli Nieminen <suokkos-at-gmail-dot-com> 33254794Sdumbbell */ 34254794Sdumbbell 35254794Sdumbbell#include <sys/cdefs.h> 36254794Sdumbbell__FBSDID("$FreeBSD$"); 37254794Sdumbbell 38254794Sdumbbell#ifndef _DRM_BUFFER_H_ 39254794Sdumbbell#define _DRM_BUFFER_H_ 40254794Sdumbbell 41254794Sdumbbell#include <dev/drm2/drmP.h> 42254794Sdumbbell 43254794Sdumbbellstruct drm_buffer { 44254794Sdumbbell int iterator; 45254794Sdumbbell int size; 46254794Sdumbbell char *data[]; 47254794Sdumbbell}; 48254794Sdumbbell 49254794Sdumbbell 50254794Sdumbbell/** 51254794Sdumbbell * Return the index of page that buffer is currently pointing at. 52254794Sdumbbell */ 53254794Sdumbbellstatic inline int drm_buffer_page(struct drm_buffer *buf) 54254794Sdumbbell{ 55254794Sdumbbell return buf->iterator / PAGE_SIZE; 56254794Sdumbbell} 57254794Sdumbbell/** 58254794Sdumbbell * Return the index of the current byte in the page 59254794Sdumbbell */ 60254794Sdumbbellstatic inline int drm_buffer_index(struct drm_buffer *buf) 61254794Sdumbbell{ 62254794Sdumbbell return buf->iterator & (PAGE_SIZE - 1); 63254794Sdumbbell} 64254794Sdumbbell/** 65254794Sdumbbell * Return number of bytes that is left to process 66254794Sdumbbell */ 67254794Sdumbbellstatic inline int drm_buffer_unprocessed(struct drm_buffer *buf) 68254794Sdumbbell{ 69254794Sdumbbell return buf->size - buf->iterator; 70254794Sdumbbell} 71254794Sdumbbell 72254794Sdumbbell/** 73254794Sdumbbell * Advance the buffer iterator number of bytes that is given. 74254794Sdumbbell */ 75254794Sdumbbellstatic inline void drm_buffer_advance(struct drm_buffer *buf, int bytes) 76254794Sdumbbell{ 77254794Sdumbbell buf->iterator += bytes; 78254794Sdumbbell} 79254794Sdumbbell 80254794Sdumbbell/** 81254794Sdumbbell * Allocate the drm buffer object. 82254794Sdumbbell * 83254794Sdumbbell * buf: A pointer to a pointer where the object is stored. 84254794Sdumbbell * size: The number of bytes to allocate. 85254794Sdumbbell */ 86254794Sdumbbellextern int drm_buffer_alloc(struct drm_buffer **buf, int size); 87254794Sdumbbell 88254794Sdumbbell/** 89254794Sdumbbell * Copy the user data to the begin of the buffer and reset the processing 90254794Sdumbbell * iterator. 91254794Sdumbbell * 92254794Sdumbbell * user_data: A pointer the data that is copied to the buffer. 93254794Sdumbbell * size: The Number of bytes to copy. 94254794Sdumbbell */ 95254794Sdumbbellextern int drm_buffer_copy_from_user(struct drm_buffer *buf, 96254794Sdumbbell void __user *user_data, int size); 97254794Sdumbbell 98254794Sdumbbell/** 99254794Sdumbbell * Free the drm buffer object 100254794Sdumbbell */ 101254794Sdumbbellextern void drm_buffer_free(struct drm_buffer *buf); 102254794Sdumbbell 103254794Sdumbbell/** 104254794Sdumbbell * Read an object from buffer that may be split to multiple parts. If object 105254794Sdumbbell * is not split function just returns the pointer to object in buffer. But in 106254794Sdumbbell * case of split object data is copied to given stack object that is suplied 107254794Sdumbbell * by caller. 108254794Sdumbbell * 109254794Sdumbbell * The processing location of the buffer is also advanced to the next byte 110254794Sdumbbell * after the object. 111254794Sdumbbell * 112254794Sdumbbell * objsize: The size of the objet in bytes. 113254794Sdumbbell * stack_obj: A pointer to a memory location where object can be copied. 114254794Sdumbbell */ 115254794Sdumbbellextern void *drm_buffer_read_object(struct drm_buffer *buf, 116254794Sdumbbell int objsize, void *stack_obj); 117254794Sdumbbell 118254794Sdumbbell/** 119254794Sdumbbell * Returns the pointer to the dword which is offset number of elements from the 120254794Sdumbbell * current processing location. 121254794Sdumbbell * 122254794Sdumbbell * Caller must make sure that dword is not split in the buffer. This 123254794Sdumbbell * requirement is easily met if all the sizes of objects in buffer are 124254794Sdumbbell * multiples of dword and PAGE_SIZE is multiple dword. 125254794Sdumbbell * 126254794Sdumbbell * Call to this function doesn't change the processing location. 127254794Sdumbbell * 128254794Sdumbbell * offset: The index of the dword relative to the internat iterator. 129254794Sdumbbell */ 130254794Sdumbbellstatic inline void *drm_buffer_pointer_to_dword(struct drm_buffer *buffer, 131254794Sdumbbell int offset) 132254794Sdumbbell{ 133254794Sdumbbell int iter = buffer->iterator + offset * 4; 134254794Sdumbbell return &buffer->data[iter / PAGE_SIZE][iter & (PAGE_SIZE - 1)]; 135254794Sdumbbell} 136254794Sdumbbell/** 137254794Sdumbbell * Returns the pointer to the dword which is offset number of elements from 138254794Sdumbbell * the current processing location. 139254794Sdumbbell * 140254794Sdumbbell * Call to this function doesn't change the processing location. 141254794Sdumbbell * 142254794Sdumbbell * offset: The index of the byte relative to the internat iterator. 143254794Sdumbbell */ 144254794Sdumbbellstatic inline void *drm_buffer_pointer_to_byte(struct drm_buffer *buffer, 145254794Sdumbbell int offset) 146254794Sdumbbell{ 147254794Sdumbbell int iter = buffer->iterator + offset; 148254794Sdumbbell return &buffer->data[iter / PAGE_SIZE][iter & (PAGE_SIZE - 1)]; 149254794Sdumbbell} 150254794Sdumbbell 151254794Sdumbbell#endif 152