pvrusb2-io.c

linux内核源码

/*
 *
 *  $Id$
 *
 *  Copyright (C) 2005 Mike Isely <[e-mail]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "pvrusb2-io.h"
#include "pvrusb2-debug.h"
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/mutex.h>

static const char *pvr2_buffer_state_decode(enum pvr2_buffer_state);

#define BUFFER_SIG 0x47653271

// #define SANITY_CHECK_BUFFERS


#ifdef SANITY_CHECK_BUFFERS
#define BUFFER_CHECK(bp) do { \
	if ((bp)->signature != BUFFER_SIG) { \
		pvr2_trace(PVR2_TRACE_ERROR_LEGS, \
		"Buffer %p is bad at %s:%d", \
		(bp),__FILE__,__LINE__); \
		pvr2_buffer_describe(bp,"BadSig"); \
		BUG(); \
	} \
} while (0)
#else
#define BUFFER_CHECK(bp) do {} while(0)
#endif

struct pvr2_stream {
	/* Buffers queued for reading */
	struct list_head queued_list;
	unsigned int q_count;
	unsigned int q_bcount;
	/* Buffers with retrieved data */
	struct list_head ready_list;
	unsigned int r_count;
	unsigned int r_bcount;
	/* Buffers available for use */
	struct list_head idle_list;
	unsigned int i_count;
	unsigned int i_bcount;
	/* Pointers to all buffers */
	struct pvr2_buffer **buffers;
	/* Array size of buffers */
	unsigned int buffer_slot_count;
	/* Total buffers actually in circulation */
	unsigned int buffer_total_count;
	/* Designed number of buffers to be in circulation */
	unsigned int buffer_target_count;
	/* Executed when ready list become non-empty */
	pvr2_stream_callback callback_func;
	void *callback_data;
	/* Context for transfer endpoint */
	struct usb_device *dev;
	int endpoint;
	/* Overhead for mutex enforcement */
	spinlock_t list_lock;
	struct mutex mutex;
	/* Tracking state for tolerating errors */
	unsigned int fail_count;
	unsigned int fail_tolerance;
};

struct pvr2_buffer {
	int id;
	int signature;
	enum pvr2_buffer_state state;
	void *ptr;               /* Pointer to storage area */
	unsigned int max_count;  /* Size of storage area */
	unsigned int used_count; /* Amount of valid data in storage area */
	int status;              /* Transfer result status */
	struct pvr2_stream *stream;
	struct list_head list_overhead;
	struct urb *purb;
};

static const char *pvr2_buffer_state_decode(enum pvr2_buffer_state st)
{
	switch (st) {
	case pvr2_buffer_state_none: return "none";
	case pvr2_buffer_state_idle: return "idle";
	case pvr2_buffer_state_queued: return "queued";
	case pvr2_buffer_state_ready: return "ready";
	}
	return "unknown";
}

#ifdef SANITY_CHECK_BUFFERS
static void pvr2_buffer_describe(struct pvr2_buffer *bp,const char *msg)
{
	pvr2_trace(PVR2_TRACE_INFO,
		   "buffer%s%s %p state=%s id=%d status=%d"
		   " stream=%p purb=%p sig=0x%x",
		   (msg ? " " : ""),
		   (msg ? msg : ""),
		   bp,
		   (bp ? pvr2_buffer_state_decode(bp->state) : "(invalid)"),
		   (bp ? bp->id : 0),
		   (bp ? bp->status : 0),
		   (bp ? bp->stream : NULL),
		   (bp ? bp->purb : NULL),
		   (bp ? bp->signature : 0));
}
#endif  /*  SANITY_CHECK_BUFFERS  */

static void pvr2_buffer_remove(struct pvr2_buffer *bp)
{
	unsigned int *cnt;
	unsigned int *bcnt;
	unsigned int ccnt;
	struct pvr2_stream *sp = bp->stream;
	switch (bp->state) {
	case pvr2_buffer_state_idle:
		cnt = &sp->i_count;
		bcnt = &sp->i_bcount;
		ccnt = bp->max_count;
		break;
	case pvr2_buffer_state_queued:
		cnt = &sp->q_count;
		bcnt = &sp->q_bcount;
		ccnt = bp->max_count;
		break;
	case pvr2_buffer_state_ready:
		cnt = &sp->r_count;
		bcnt = &sp->r_bcount;
		ccnt = bp->used_count;
		break;
	default:
		return;
	}
	list_del_init(&bp->list_overhead);
	(*cnt)--;
	(*bcnt) -= ccnt;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/"
		   " bufferPool     %8s dec cap=%07d cnt=%02d",
		   pvr2_buffer_state_decode(bp->state),*bcnt,*cnt);
	bp->state = pvr2_buffer_state_none;
}

static void pvr2_buffer_set_none(struct pvr2_buffer *bp)
{
	unsigned long irq_flags;
	struct pvr2_stream *sp;
	BUFFER_CHECK(bp);
	sp = bp->stream;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
		   bp,
		   pvr2_buffer_state_decode(bp->state),
		   pvr2_buffer_state_decode(pvr2_buffer_state_none));
	spin_lock_irqsave(&sp->list_lock,irq_flags);
	pvr2_buffer_remove(bp);
	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
}

static int pvr2_buffer_set_ready(struct pvr2_buffer *bp)
{
	int fl;
	unsigned long irq_flags;
	struct pvr2_stream *sp;
	BUFFER_CHECK(bp);
	sp = bp->stream;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
		   bp,
		   pvr2_buffer_state_decode(bp->state),
		   pvr2_buffer_state_decode(pvr2_buffer_state_ready));
	spin_lock_irqsave(&sp->list_lock,irq_flags);
	fl = (sp->r_count == 0);
	pvr2_buffer_remove(bp);
	list_add_tail(&bp->list_overhead,&sp->ready_list);
	bp->state = pvr2_buffer_state_ready;
	(sp->r_count)++;
	sp->r_bcount += bp->used_count;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/"
		   " bufferPool     %8s inc cap=%07d cnt=%02d",
		   pvr2_buffer_state_decode(bp->state),
		   sp->r_bcount,sp->r_count);
	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
	return fl;
}

static void pvr2_buffer_set_idle(struct pvr2_buffer *bp)
{
	unsigned long irq_flags;
	struct pvr2_stream *sp;
	BUFFER_CHECK(bp);
	sp = bp->stream;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
		   bp,
		   pvr2_buffer_state_decode(bp->state),
		   pvr2_buffer_state_decode(pvr2_buffer_state_idle));
	spin_lock_irqsave(&sp->list_lock,irq_flags);
	pvr2_buffer_remove(bp);
	list_add_tail(&bp->list_overhead,&sp->idle_list);
	bp->state = pvr2_buffer_state_idle;
	(sp->i_count)++;
	sp->i_bcount += bp->max_count;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/"
		   " bufferPool     %8s inc cap=%07d cnt=%02d",
		   pvr2_buffer_state_decode(bp->state),
		   sp->i_bcount,sp->i_count);
	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
}

static void pvr2_buffer_set_queued(struct pvr2_buffer *bp)
{
	unsigned long irq_flags;
	struct pvr2_stream *sp;
	BUFFER_CHECK(bp);
	sp = bp->stream;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
		   bp,
		   pvr2_buffer_state_decode(bp->state),
		   pvr2_buffer_state_decode(pvr2_buffer_state_queued));
	spin_lock_irqsave(&sp->list_lock,irq_flags);
	pvr2_buffer_remove(bp);
	list_add_tail(&bp->list_overhead,&sp->queued_list);
	bp->state = pvr2_buffer_state_queued;
	(sp->q_count)++;
	sp->q_bcount += bp->max_count;
	pvr2_trace(PVR2_TRACE_BUF_FLOW,
		   "/*---TRACE_FLOW---*/"
		   " bufferPool     %8s inc cap=%07d cnt=%02d",
		   pvr2_buffer_state_decode(bp->state),
		   sp->q_bcount,sp->q_count);
	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
}

static void pvr2_buffer_wipe(struct pvr2_buffer *bp)
{
	if (bp->state == pvr2_buffer_state_queued) {
		usb_kill_urb(bp->purb);
	}
}

static int pvr2_buffer_init(struct pvr2_buffer *bp,
			    struct pvr2_stream *sp,
			    unsigned int id)
{
	memset(bp,0,sizeof(*bp));
	bp->signature = BUFFER_SIG;
	bp->id = id;
	pvr2_trace(PVR2_TRACE_BUF_POOL,
		   "/*---TRACE_FLOW---*/ bufferInit     %p stream=%p",bp,sp);
	bp->stream = sp;
	bp->state = pvr2_buffer_state_none;
	INIT_LIST_HEAD(&bp->list_overhead);
	bp->purb = usb_alloc_urb(0,GFP_KERNEL);
	if (! bp->purb) return -ENOMEM;
#ifdef SANITY_CHECK_BUFFERS
	pvr2_buffer_describe(bp,"create");
#endif
	return 0;
}

static void pvr2_buffer_done(struct pvr2_buffer *bp)
{
#ifdef SANITY_CHECK_BUFFERS
	pvr2_buffer_describe(bp,"delete");
#endif
	pvr2_buffer_wipe(bp);
	pvr2_buffer_set_none(bp);
	bp->signature = 0;
	bp->stream = NULL;
	usb_free_urb(bp->purb);
	pvr2_trace(PVR2_TRACE_BUF_POOL,"/*---TRACE_FLOW---*/"
		   " bufferDone     %p",bp);
}

static int pvr2_stream_buffer_count(struct pvr2_stream *sp,unsigned int cnt)
{
	int ret;
	unsigned int scnt;

	/* Allocate buffers pointer array in multiples of 32 entries */
	if (cnt == sp->buffer_total_count) return 0;

	pvr2_trace(PVR2_TRACE_BUF_POOL,
		   "/*---TRACE_FLOW---*/ poolResize    "
		   " stream=%p cur=%d adj=%+d",
		   sp,
		   sp->buffer_total_count,
		   cnt-sp->buffer_total_count);

	scnt = cnt & ~0x1f;
	if (cnt > scnt) scnt += 0x20;

	if (cnt > sp->buffer_total_count) {
		if (scnt > sp->buffer_slot_count) {
			struct pvr2_buffer **nb;
			nb = kmalloc(scnt * sizeof(*nb),GFP_KERNEL);
			if (!nb) return -ENOMEM;
			if (sp->buffer_slot_count) {
				memcpy(nb,sp->buffers,
				       sp->buffer_slot_count * sizeof(*nb));
				kfree(sp->buffers);
			}
			sp->buffers = nb;
			sp->buffer_slot_count = scnt;
		}
		while (sp->buffer_total_count < cnt) {
			struct pvr2_buffer *bp;
			bp = kmalloc(sizeof(*bp),GFP_KERNEL);
			if (!bp) return -ENOMEM;
			ret = pvr2_buffer_init(bp,sp,sp->buffer_total_count);
			if (ret) {
				kfree(bp);