forked from Minki/linux
52fcb3ecc6
Add a Memory Descriptor List (MDL) layer to buffer handling to implement scatter-gather I/O. Currently there is still only 1 buffer per MDL. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
112 lines
3.3 KiB
C
112 lines
3.3 KiB
C
/*
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* cx18 buffer queues
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*
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* Derived from ivtv-queue.h
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*
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* Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
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* Copyright (C) 2008 Andy Walls <awalls@radix.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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* 02111-1307 USA
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*/
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#define CX18_DMA_UNMAPPED ((u32) -1)
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/* cx18_buffer utility functions */
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static inline void cx18_buf_sync_for_cpu(struct cx18_stream *s,
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struct cx18_buffer *buf)
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{
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pci_dma_sync_single_for_cpu(s->cx->pci_dev, buf->dma_handle,
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s->buf_size, s->dma);
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}
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void _cx18_mdl_sync_for_cpu(struct cx18_stream *s, struct cx18_mdl *mdl);
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static inline void cx18_mdl_sync_for_cpu(struct cx18_stream *s,
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struct cx18_mdl *mdl)
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{
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if (list_is_singular(&mdl->buf_list))
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cx18_buf_sync_for_cpu(s, list_first_entry(&mdl->buf_list,
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struct cx18_buffer,
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list));
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else
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_cx18_mdl_sync_for_cpu(s, mdl);
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}
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static inline void cx18_buf_sync_for_device(struct cx18_stream *s,
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struct cx18_buffer *buf)
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{
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pci_dma_sync_single_for_device(s->cx->pci_dev, buf->dma_handle,
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s->buf_size, s->dma);
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}
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void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl);
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static inline void cx18_mdl_sync_for_device(struct cx18_stream *s,
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struct cx18_mdl *mdl)
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{
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if (list_is_singular(&mdl->buf_list))
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cx18_buf_sync_for_device(s, list_first_entry(&mdl->buf_list,
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struct cx18_buffer,
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list));
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else
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_cx18_mdl_sync_for_device(s, mdl);
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}
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void cx18_buf_swap(struct cx18_buffer *buf);
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void _cx18_mdl_swap(struct cx18_mdl *mdl);
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static inline void cx18_mdl_swap(struct cx18_mdl *mdl)
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{
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if (list_is_singular(&mdl->buf_list))
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cx18_buf_swap(list_first_entry(&mdl->buf_list,
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struct cx18_buffer, list));
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else
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_cx18_mdl_swap(mdl);
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}
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/* cx18_queue utility functions */
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struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
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struct cx18_queue *q, int to_front);
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static inline
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struct cx18_queue *cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
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struct cx18_queue *q)
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{
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return _cx18_enqueue(s, mdl, q, 0); /* FIFO */
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}
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static inline
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struct cx18_queue *cx18_push(struct cx18_stream *s, struct cx18_mdl *mdl,
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struct cx18_queue *q)
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{
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return _cx18_enqueue(s, mdl, q, 1); /* LIFO */
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}
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void cx18_queue_init(struct cx18_queue *q);
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struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q);
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struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
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u32 bytesused);
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void cx18_flush_queues(struct cx18_stream *s);
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/* queue MDL reconfiguration helpers */
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void cx18_unload_queues(struct cx18_stream *s);
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void cx18_load_queues(struct cx18_stream *s);
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/* cx18_stream utility functions */
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int cx18_stream_alloc(struct cx18_stream *s);
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void cx18_stream_free(struct cx18_stream *s);
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