diff options
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/Makefile | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_buffer.c | 184 |
2 files changed, 185 insertions, 1 deletions
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 39c5aa75b8f1..abe3f446ca48 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -4,7 +4,7 @@ ccflags-y := -Iinclude/drm -drm-y := drm_auth.o drm_bufs.o drm_cache.o \ +drm-y := drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \ drm_context.o drm_dma.o drm_drawable.o \ drm_drv.o drm_fops.o drm_gem.o drm_ioctl.o drm_irq.o \ drm_lock.o drm_memory.o drm_proc.o drm_stub.o drm_vm.o \ diff --git a/drivers/gpu/drm/drm_buffer.c b/drivers/gpu/drm/drm_buffer.c new file mode 100644 index 000000000000..55d03ed05000 --- /dev/null +++ b/drivers/gpu/drm/drm_buffer.c @@ -0,0 +1,184 @@ +/************************************************************************** + * + * 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 "drm_buffer.h" + +/** + * Allocate the drm buffer object. + * + * buf: Pointer to a pointer where the object is stored. + * size: The number of bytes to allocate. + */ +int drm_buffer_alloc(struct drm_buffer **buf, int size) +{ + int nr_pages = size / PAGE_SIZE + 1; + int idx; + + /* Allocating pointer table to end of structure makes drm_buffer + * variable sized */ + *buf = kzalloc(sizeof(struct drm_buffer) + nr_pages*sizeof(char *), + GFP_KERNEL); + + if (*buf == NULL) { + DRM_ERROR("Failed to allocate drm buffer object to hold" + " %d bytes in %d pages.\n", + size, nr_pages); + return -ENOMEM; + } + + (*buf)->size = size; + + for (idx = 0; idx < nr_pages; ++idx) { + + (*buf)->data[idx] = + kmalloc(min(PAGE_SIZE, size - idx * PAGE_SIZE), + GFP_KERNEL); + + + if ((*buf)->data[idx] == NULL) { + DRM_ERROR("Failed to allocate %dth page for drm" + " buffer with %d bytes and %d pages.\n", + idx + 1, size, nr_pages); + goto error_out; + } + + } + + return 0; + +error_out: + + /* Only last element can be null pointer so check for it first. */ + if ((*buf)->data[idx]) + kfree((*buf)->data[idx]); + + for (--idx; idx >= 0; --idx) + kfree((*buf)->data[idx]); + + kfree(*buf); + return -ENOMEM; +} +EXPORT_SYMBOL(drm_buffer_alloc); + +/** + * 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) +{ + int nr_pages = size / PAGE_SIZE + 1; + int idx; + + if (size > buf->size) { + DRM_ERROR("Requesting to copy %d bytes to a drm buffer with" + " %d bytes space\n", + size, buf->size); + return -EFAULT; + } + + for (idx = 0; idx < nr_pages; ++idx) { + + if (DRM_COPY_FROM_USER(buf->data[idx], + user_data + idx * PAGE_SIZE, + min(PAGE_SIZE, size - idx * PAGE_SIZE))) { + DRM_ERROR("Failed to copy user data (%p) to drm buffer" + " (%p) %dth page.\n", + user_data, buf, idx); + return -EFAULT; + + } + } + buf->iterator = 0; + return 0; +} +EXPORT_SYMBOL(drm_buffer_copy_from_user); + +/** + * Free the drm buffer object + */ +void drm_buffer_free(struct drm_buffer *buf) +{ + + if (buf != NULL) { + + int nr_pages = buf->size / PAGE_SIZE + 1; + int idx; + for (idx = 0; idx < nr_pages; ++idx) + kfree(buf->data[idx]); + + kfree(buf); + } +} +EXPORT_SYMBOL(drm_buffer_free); + +/** + * 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. + */ +void *drm_buffer_read_object(struct drm_buffer *buf, + int objsize, void *stack_obj) +{ + int idx = drm_buffer_index(buf); + int page = drm_buffer_page(buf); + void *obj = 0; + + if (idx + objsize <= PAGE_SIZE) { + obj = &buf->data[page][idx]; + } else { + /* The object is split which forces copy to temporary object.*/ + int beginsz = PAGE_SIZE - idx; + memcpy(stack_obj, &buf->data[page][idx], beginsz); + + memcpy(stack_obj + beginsz, &buf->data[page + 1][0], + objsize - beginsz); + + obj = stack_obj; + } + + drm_buffer_advance(buf, objsize); + return obj; +} +EXPORT_SYMBOL(drm_buffer_read_object); |