/* * IEEE 1394 for Linux * * kernel ISO transmission/reception * * Copyright (C) 2002 Maas Digital LLC * * This code is licensed under the GPL. See the file COPYING in the root * directory of the kernel sources for details. */ #include <linux/pci.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/slab.h> #include "hosts.h" #include "iso.h" /** * hpsb_iso_stop - stop DMA */ void hpsb_iso_stop(struct hpsb_iso *iso) { if (!(iso->flags & HPSB_ISO_DRIVER_STARTED)) return; iso->host->driver->isoctl(iso, iso->type == HPSB_ISO_XMIT ? XMIT_STOP : RECV_STOP, 0); iso->flags &= ~HPSB_ISO_DRIVER_STARTED; } /** * hpsb_iso_shutdown - deallocate buffer and DMA context */ void hpsb_iso_shutdown(struct hpsb_iso *iso) { if (iso->flags & HPSB_ISO_DRIVER_INIT) { hpsb_iso_stop(iso); iso->host->driver->isoctl(iso, iso->type == HPSB_ISO_XMIT ? XMIT_SHUTDOWN : RECV_SHUTDOWN, 0); iso->flags &= ~HPSB_ISO_DRIVER_INIT; } dma_region_free(&iso->data_buf); kfree(iso); } static struct hpsb_iso *hpsb_iso_common_init(struct hpsb_host *host, enum hpsb_iso_type type, unsigned int data_buf_size, unsigned int buf_packets, int channel, int dma_mode, int irq_interval, void (*callback) (struct hpsb_iso *)) { struct hpsb_iso *iso; int dma_direction; /* make sure driver supports the ISO API */ if (!host->driver->isoctl) { printk(KERN_INFO "ieee1394: host driver '%s' does not support the rawiso API\n", host->driver->name); return NULL; } /* sanitize parameters */ if (buf_packets < 2) buf_packets = 2; if ((dma_mode < HPSB_ISO_DMA_DEFAULT) || (dma_mode > HPSB_ISO_DMA_PACKET_PER_BUFFER)) dma_mode = HPSB_ISO_DMA_DEFAULT; if ((irq_interval < 0) || (irq_interval > buf_packets / 4)) irq_interval = buf_packets / 4; if (irq_interval == 0) /* really interrupt for each packet */ irq_interval = 1; if (channel < -1 || channel >= 64) return NULL; /* channel = -1 is OK for multi-channel recv but not for xmit */ if (type == HPSB_ISO_XMIT && channel < 0) return NULL; /* allocate and write the struct hpsb_iso */ iso = kmalloc(sizeof(*iso) + buf_packets * sizeof(struct hpsb_iso_packet_info), GFP_KERNEL); if (!iso) return NULL; iso->infos = (struct hpsb_iso_packet_info *)(iso + 1); iso->type = type; iso->host = host; iso->hostdata = NULL; iso->callback = callback; init_waitqueue_head(&iso->waitq); iso->channel = channel; iso->irq_interval = irq_interval; iso->dma_mode = dma_mode; dma_region_init(&iso->data_buf); iso->buf_size = PAGE_ALIGN(data_buf_size); iso->buf_packets = buf_packets; iso->pkt_dma = 0; iso->first_packet = 0; spin_lock_init(&iso->lock); if (iso->type == HPSB_ISO_XMIT) { iso->n_ready_packets = iso->buf_packets; dma_direction = PCI_DMA_TODEVICE; } else { iso->n_ready_packets = 0; dma_direction = PCI_DMA_FROMDEVICE; } atomic_set(&iso->overflows, 0); iso->bytes_discarded = 0; iso->flags = 0; iso->prebuffer = 0; /* allocate the packet buffer */ if (dma_region_alloc (&iso->data_buf, iso->buf_size, host->pdev, dma_direction)) goto err; return iso; err: hpsb_iso_shutdown(iso); return NULL; } /** * hpsb_iso_n_ready - returns number of packets ready to send or receive */ int hpsb_iso_n_ready(struct hpsb_iso *iso) { unsigned long flags; int val; spin_lock_irqsave(&iso->lock, flags); val = iso->n_ready_packets; spin_unlock_irqrestore(&iso->lock, flags); return val; } /** * hpsb_iso_xmit_init - allocate the buffer and DMA context */ struct hpsb_iso *hpsb_iso_xmit_init(struct hpsb_host *host, unsigned int data_buf_size, unsigned int buf_packets, int channel, int speed, int irq_interval, void (*callback) (struct hpsb_iso *)) { struct hpsb_iso *iso = hpsb_iso_common_init(host, HPSB_ISO_XMIT, data_buf_size, buf_packets, channel, HPSB_ISO_DMA_DEFAULT, irq_interval, callback); if (!iso) return NULL; iso->speed = speed; /* tell the driver to start working */ if (host->driver->isoctl(iso, XMIT_INIT, 0)) goto err; iso->flags |= HPSB_ISO_DRIVER_INIT; return iso; err: hpsb_iso_shutdown(iso); return NULL; } /** * hpsb_iso_recv_init - allocate the buffer and DMA context * * Note, if channel = -1, multi-channel receive is enabled. */ struct hpsb_iso *hpsb_iso_recv_init(struct hpsb_host *host, unsigned int data_buf_size, unsigned int buf_packets, int channel, int dma_mode, int irq_interval, void (*callback) (struct hpsb_iso *)) { struct hpsb_iso *iso = hpsb_iso_common_init(host, HPSB_ISO_RECV, data_buf_size, buf_packets, channel, dma_mode, irq_interval, callback); if (!iso) return NULL; /* tell the driver to start working */ if (host->driver->isoctl(iso, RECV_INIT, 0)) goto err; iso->flags |= HPSB_ISO_DRIVER_INIT; return iso; err: hpsb_iso_shutdown(iso); return NULL; } /** * hpsb_iso_recv_listen_channel * * multi-channel only */ int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel) { if (iso->type != HPSB_ISO_RECV || iso->channel != -1 || channel >= 64) return -EINVAL; return iso->host->driver->isoctl(iso, RECV_LISTEN_CHANNEL, channel); } /** * hpsb_iso_recv_unlisten_channel * * multi-channel only */ int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel) { if (iso->type != HPSB_ISO_RECV || iso->channel != -1 || channel >= 64) return -EINVAL; return iso->host->driver->isoctl(iso, RECV_UNLISTEN_CHANNEL, channel); } /** * hpsb_iso_recv_set_channel_mask * * multi-channel only */ int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask) { if (iso->type != HPSB_ISO_RECV || iso->channel != -1) return -EINVAL; return iso->host->driver->isoctl(iso, RECV_SET_CHANNEL_MASK, (unsigned long)&mask); } /** * hpsb_iso_recv_flush - check for arrival of new packets * * check for arrival of new packets immediately (even if irq_interval * has not yet been reached) */ int hpsb_iso_recv_flush(struct hpsb_iso *iso) { if (iso->type != HPSB_ISO_RECV) return -EINVAL; return iso->host->driver->isoctl(iso, RECV_FLUSH, 0); } static int do_iso_xmit_start(struct hpsb_iso *iso, int cycle) { int retval = iso->host->driver->isoctl(iso, XMIT_START, cycle); if (retval) return retval; iso->flags |= HPSB_ISO_DRIVER_STARTED; return retval; } /** * hpsb_iso_xmit_start - start DMA */ int hpsb_iso_xmit_start(struct hpsb_iso *iso, int cycle, int prebuffer) { if (iso->type != HPSB_ISO_XMIT) return -1; if (iso->flags & HPSB_ISO_DRIVER_STARTED) return 0; if (cycle < -1) cycle = -1; else if (cycle >= 8000) cycle %= 8000; iso->xmit_cycle = cycle; if (prebuffer < 0) prebuffer = iso->buf_packets - 1; else if (prebuffer == 0) prebuffer = 1; if (prebuffer >= iso->buf_packets) prebuffer = iso->buf_packets - 1; iso->prebuffer = prebuffer; /* remember the starting cycle; DMA will commence from xmit_queue_packets() once enough packets have been buffered */ iso->start_cycle = cycle; return 0; } /** * hpsb_iso_recv_start - start DMA */ int hpsb_iso_recv_start(struct hpsb_iso *iso, int cycle, int tag_mask, int sync) { int retval = 0; int isoctl_args[3]; if (iso->type != HPSB_ISO_RECV) return -1; if (iso->flags & HPSB_ISO_DRIVER_STARTED) return 0; if (cycle < -1) cycle = -1; else if (cycle >= 8000) cycle %= 8000; isoctl_args[0] = cycle; if (tag_mask < 0) /* match all tags */ tag_mask = 0xF; isoctl_args[1] = tag_mask; isoctl_args[2] = sync; retval = iso->host->driver->isoctl(iso, RECV_START, (unsigned long)&isoctl_args[0]); if (retval) return retval; iso->flags |= HPSB_ISO_DRIVER_STARTED; return retval; } /* check to make sure the user has not supplied bogus values of offset/len * that would cause the kernel to access memory outside the buffer */ static int hpsb_iso_check_offset_len(struct hpsb_iso *iso, unsigned int offset, unsigned short len, unsigned int *out_offset, unsigned short *out_len) { if (offset >= iso->buf_size) return -EFAULT; /* make sure the packet does not go beyond the end of the buffer */ if (offset + len > iso->buf_size) return -EFAULT; /* check for wrap-around */ if (offset + len < offset) return -EFAULT; /* now we can trust 'offset' and 'length' */ *out_offset = offset; *out_len = len; return 0; } /** * hpsb_iso_xmit_queue_packet - queue a packet for transmission. * * @offset is relative to the beginning of the DMA buffer, where the packet's * data payload should already have been placed. */ int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len, u8 tag, u8 sy) { struct hpsb_iso_packet_info *info; unsigned long flags; int rv; if (iso->type != HPSB_ISO_XMIT) return -EINVAL; /* is there space in the buffer? */ if (iso->n_ready_packets <= 0) { return -EBUSY; } info = &iso->infos[iso->first_packet]; /* check for bogus offset/length */ if (hpsb_iso_check_offset_len (iso, offset, len, &info->offset, &info->len)) return -EFAULT; info->tag = tag; info->sy = sy; spin_lock_irqsave(&iso->lock, flags); rv = iso->host->driver->isoctl(iso, XMIT_QUEUE, (unsigned long)info); if (rv) goto out; /* increment cursors */ iso->first_packet = (iso->first_packet + 1) % iso->buf_packets; iso->xmit_cycle = (iso->xmit_cycle + 1) % 8000; iso->n_ready_packets--; if (iso->prebuffer != 0) { iso->prebuffer--; if (iso->prebuffer <= 0) { iso->prebuffer = 0; rv = do_iso_xmit_start(iso, iso->start_cycle); } } out: spin_unlock_irqrestore(&iso->lock, flags); return rv; } /** * hpsb_iso_xmit_sync - wait until all queued packets have been transmitted */ int hpsb_iso_xmit_sync(struct hpsb_iso *iso) { if (iso->type != HPSB_ISO_XMIT) return -EINVAL; return wait_event_interruptible(iso->waitq, hpsb_iso_n_ready(iso) == iso->buf_packets); } /** * hpsb_iso_packet_sent * * Available to low-level drivers. * * Call after a packet has been transmitted to the bus (interrupt context is * OK). @cycle is the _exact_ cycle the packet was sent on. @error should be * non-zero if some sort of error occurred when sending the packet. */ void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error) { unsigned long flags; spin_lock_irqsave(&iso->lock, flags); /* predict the cycle of the next packet to be queued */ /* jump ahead by the number of packets that are already buffered */ cycle += iso->buf_packets - iso->n_ready_packets; cycle %= 8000; iso->xmit_cycle = cycle; iso->n_ready_packets++; iso->pkt_dma = (iso->pkt_dma + 1) % iso->buf_packets; if (iso->n_ready_packets == iso->buf_packets || error != 0) { /* the buffer has run empty! */ atomic_inc(&iso->overflows); } spin_unlock_irqrestore(&iso->lock, flags); } /** * hpsb_iso_packet_received * * Available to low-level drivers. * * Call after a packet has been received (interrupt context is OK). */ void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len, u16 total_len, u16 cycle, u8 channel, u8 tag, u8 sy) { unsigned long flags; spin_lock_irqsave(&iso->lock, flags); if (iso->n_ready_packets == iso->buf_packets) { /* overflow! */ atomic_inc(&iso->overflows); /* Record size of this discarded packet */ iso->bytes_discarded += total_len; } else { struct hpsb_iso_packet_info *info = &iso->infos[iso->pkt_dma]; info->offset = offset; info->len = len; info->total_len = total_len; info->cycle = cycle; info->channel = channel; info->tag = tag; info->sy = sy; iso->pkt_dma = (iso->pkt_dma + 1) % iso->buf_packets; iso->n_ready_packets++; } spin_unlock_irqrestore(&iso->lock, flags); } /** * hpsb_iso_recv_release_packets - release packets, reuse buffer * * @n_packets have been read out of the buffer, re-use the buffer space */ int hpsb_iso_recv_release_packets(struct hpsb_iso *iso, unsigned int n_packets) { unsigned long flags; unsigned int i; int rv = 0; if (iso->type != HPSB_ISO_RECV) return -1; spin_lock_irqsave(&iso->lock, flags); for (i = 0; i < n_packets; i++) { rv = iso->host->driver->isoctl(iso, RECV_RELEASE, (unsigned long)&iso->infos[iso-> first_packet]); if (rv) break; iso->first_packet = (iso->first_packet + 1) % iso->buf_packets; iso->n_ready_packets--; /* release memory from packets discarded when queue was full */ if (iso->n_ready_packets == 0) { /* Release only after all prior packets handled */ if (iso->bytes_discarded != 0) { struct hpsb_iso_packet_info inf; inf.total_len = iso->bytes_discarded; iso->host->driver->isoctl(iso, RECV_RELEASE, (unsigned long)&inf); iso->bytes_discarded = 0; } } } spin_unlock_irqrestore(&iso->lock, flags); return rv; } /** * hpsb_iso_wake * * Available to low-level drivers. * * Call to wake waiting processes after buffer space has opened up. */ void hpsb_iso_wake(struct hpsb_iso *iso) { wake_up_interruptible(&iso->waitq); if (iso->callback) iso->callback(iso); }