| /* drm_lists.h -- Buffer list handling routines -*- linux-c -*- |
| * Created: Mon Apr 19 20:54:22 1999 by faith@valinux.com |
| * |
| * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. |
| * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. |
| * 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, sublicense, |
| * 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 NONINFRINGEMENT. IN NO EVENT SHALL |
| * VA LINUX SYSTEMS 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. |
| * |
| * Authors: |
| * Rickard E. (Rik) Faith <faith@valinux.com> |
| * Gareth Hughes <gareth@valinux.com> |
| */ |
| |
| #include "drmP.h" |
| |
| |
| int DRM(waitlist_create)(drm_waitlist_t *bl, int count) |
| { |
| if (bl->count) return -EINVAL; |
| |
| bl->bufs = DRM(alloc)((bl->count + 2) * sizeof(*bl->bufs), |
| DRM_MEM_BUFLISTS); |
| |
| if(!bl->bufs) return -ENOMEM; |
| memset(bl->bufs, 0, sizeof(*bl->bufs)); |
| bl->count = count; |
| bl->rp = bl->bufs; |
| bl->wp = bl->bufs; |
| bl->end = &bl->bufs[bl->count+1]; |
| spin_lock_init(&bl->write_lock); |
| spin_lock_init(&bl->read_lock); |
| return 0; |
| } |
| |
| int DRM(waitlist_destroy)(drm_waitlist_t *bl) |
| { |
| if (bl->rp != bl->wp) return -EINVAL; |
| if (bl->bufs) DRM(free)(bl->bufs, |
| (bl->count + 2) * sizeof(*bl->bufs), |
| DRM_MEM_BUFLISTS); |
| bl->count = 0; |
| bl->bufs = NULL; |
| bl->rp = NULL; |
| bl->wp = NULL; |
| bl->end = NULL; |
| return 0; |
| } |
| |
| int DRM(waitlist_put)(drm_waitlist_t *bl, drm_buf_t *buf) |
| { |
| int left; |
| unsigned long flags; |
| |
| left = DRM_LEFTCOUNT(bl); |
| if (!left) { |
| DRM_ERROR("Overflow while adding buffer %d from filp %p\n", |
| buf->idx, buf->filp); |
| return -EINVAL; |
| } |
| buf->list = DRM_LIST_WAIT; |
| |
| spin_lock_irqsave(&bl->write_lock, flags); |
| *bl->wp = buf; |
| if (++bl->wp >= bl->end) bl->wp = bl->bufs; |
| spin_unlock_irqrestore(&bl->write_lock, flags); |
| |
| return 0; |
| } |
| |
| drm_buf_t *DRM(waitlist_get)(drm_waitlist_t *bl) |
| { |
| drm_buf_t *buf; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&bl->read_lock, flags); |
| buf = *bl->rp; |
| if (bl->rp == bl->wp) { |
| spin_unlock_irqrestore(&bl->read_lock, flags); |
| return NULL; |
| } |
| if (++bl->rp >= bl->end) bl->rp = bl->bufs; |
| spin_unlock_irqrestore(&bl->read_lock, flags); |
| |
| return buf; |
| } |
| |
| int DRM(freelist_create)(drm_freelist_t *bl, int count) |
| { |
| atomic_set(&bl->count, 0); |
| bl->next = NULL; |
| init_waitqueue_head(&bl->waiting); |
| bl->low_mark = 0; |
| bl->high_mark = 0; |
| atomic_set(&bl->wfh, 0); |
| spin_lock_init(&bl->lock); |
| ++bl->initialized; |
| return 0; |
| } |
| |
| int DRM(freelist_destroy)(drm_freelist_t *bl) |
| { |
| atomic_set(&bl->count, 0); |
| bl->next = NULL; |
| return 0; |
| } |
| |
| int DRM(freelist_put)(drm_device_t *dev, drm_freelist_t *bl, drm_buf_t *buf) |
| { |
| drm_device_dma_t *dma = dev->dma; |
| |
| if (!dma) { |
| DRM_ERROR("No DMA support\n"); |
| return 1; |
| } |
| |
| if (buf->waiting || buf->pending || buf->list == DRM_LIST_FREE) { |
| DRM_ERROR("Freed buffer %d: w%d, p%d, l%d\n", |
| buf->idx, buf->waiting, buf->pending, buf->list); |
| } |
| if (!bl) return 1; |
| buf->list = DRM_LIST_FREE; |
| |
| spin_lock(&bl->lock); |
| buf->next = bl->next; |
| bl->next = buf; |
| spin_unlock(&bl->lock); |
| |
| atomic_inc(&bl->count); |
| if (atomic_read(&bl->count) > dma->buf_count) { |
| DRM_ERROR("%d of %d buffers free after addition of %d\n", |
| atomic_read(&bl->count), dma->buf_count, buf->idx); |
| return 1; |
| } |
| /* Check for high water mark */ |
| if (atomic_read(&bl->wfh) && atomic_read(&bl->count)>=bl->high_mark) { |
| atomic_set(&bl->wfh, 0); |
| wake_up_interruptible(&bl->waiting); |
| } |
| return 0; |
| } |
| |
| static drm_buf_t *DRM(freelist_try)(drm_freelist_t *bl) |
| { |
| drm_buf_t *buf; |
| |
| if (!bl) return NULL; |
| |
| /* Get buffer */ |
| spin_lock(&bl->lock); |
| if (!bl->next) { |
| spin_unlock(&bl->lock); |
| return NULL; |
| } |
| buf = bl->next; |
| bl->next = bl->next->next; |
| spin_unlock(&bl->lock); |
| |
| atomic_dec(&bl->count); |
| buf->next = NULL; |
| buf->list = DRM_LIST_NONE; |
| if (buf->waiting || buf->pending) { |
| DRM_ERROR("Free buffer %d: w%d, p%d, l%d\n", |
| buf->idx, buf->waiting, buf->pending, buf->list); |
| } |
| |
| return buf; |
| } |
| |
| drm_buf_t *DRM(freelist_get)(drm_freelist_t *bl, int block) |
| { |
| drm_buf_t *buf = NULL; |
| DECLARE_WAITQUEUE(entry, current); |
| |
| if (!bl || !bl->initialized) return NULL; |
| |
| /* Check for low water mark */ |
| if (atomic_read(&bl->count) <= bl->low_mark) /* Became low */ |
| atomic_set(&bl->wfh, 1); |
| if (atomic_read(&bl->wfh)) { |
| if (block) { |
| add_wait_queue(&bl->waiting, &entry); |
| for (;;) { |
| current->state = TASK_INTERRUPTIBLE; |
| if (!atomic_read(&bl->wfh) |
| && (buf = DRM(freelist_try)(bl))) break; |
| schedule(); |
| if (signal_pending(current)) break; |
| } |
| current->state = TASK_RUNNING; |
| remove_wait_queue(&bl->waiting, &entry); |
| } |
| return buf; |
| } |
| |
| return DRM(freelist_try)(bl); |
| } |
| |