From 872e330e38806d835bd6c311c93ab998e2fb9058 Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Thu, 29 Jul 2010 18:19:22 +0200 Subject: firewire: add isochronous multichannel reception This adds the DMA context programming and userspace ABI for multichannel reception, i.e. for listening on multiple channel numbers by means of a single DMA context. The use case is reception of more streams than there are IR DMA units offered by the link layer. This is already implemented by the older ohci1394 + ieee1394 + raw1394 stack. And as discussed recently on linux1394-devel, this feature is occasionally used in practice. The big drawbacks of this mode are that buffer layout and interrupt generation necessarily differ from single-channel reception: Headers and trailers are not stripped from packets, packets are not aligned with buffer chunks, interrupts are per buffer chunk, not per packet. These drawbacks also cause a rather hefty code footprint to support this rarely used OHCI-1394 feature. (367 lines added, among them 94 lines of added userspace ABI documentation.) This implementation enforces that a multichannel reception context may only listen to channels to which no single-channel context on the same link layer is presently listening to. OHCI-1394 would allow to overlay single-channel contexts by the multi-channel context, but this would be a departure from the present first-come-first-served policy of IR context creation. The implementation is heavily based on an earlier one by Jay Fenlason. Thanks Jay. Signed-off-by: Stefan Richter --- drivers/firewire/core-cdev.c | 93 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 72 insertions(+), 21 deletions(-) (limited to 'drivers/firewire/core-cdev.c') diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index cf989e1635e..ba23646bb10 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -193,6 +193,11 @@ struct iso_interrupt_event { struct fw_cdev_event_iso_interrupt interrupt; }; +struct iso_interrupt_mc_event { + struct event event; + struct fw_cdev_event_iso_interrupt_mc interrupt; +}; + struct iso_resource_event { struct event event; struct fw_cdev_event_iso_resource iso_resource; @@ -415,6 +420,7 @@ union ioctl_arg { struct fw_cdev_get_cycle_timer2 get_cycle_timer2; struct fw_cdev_send_phy_packet send_phy_packet; struct fw_cdev_receive_phy_packets receive_phy_packets; + struct fw_cdev_set_iso_channels set_iso_channels; }; static int ioctl_get_info(struct client *client, union ioctl_arg *arg) @@ -932,26 +938,54 @@ static void iso_callback(struct fw_iso_context *context, u32 cycle, sizeof(e->interrupt) + header_length, NULL, 0); } +static void iso_mc_callback(struct fw_iso_context *context, + dma_addr_t completed, void *data) +{ + struct client *client = data; + struct iso_interrupt_mc_event *e; + + e = kmalloc(sizeof(*e), GFP_ATOMIC); + if (e == NULL) { + fw_notify("Out of memory when allocating event\n"); + return; + } + e->interrupt.type = FW_CDEV_EVENT_ISO_INTERRUPT_MULTICHANNEL; + e->interrupt.closure = client->iso_closure; + e->interrupt.completed = fw_iso_buffer_lookup(&client->buffer, + completed); + queue_event(client, &e->event, &e->interrupt, + sizeof(e->interrupt), NULL, 0); +} + static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg) { struct fw_cdev_create_iso_context *a = &arg->create_iso_context; struct fw_iso_context *context; + fw_iso_callback_t cb; BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT || - FW_CDEV_ISO_CONTEXT_RECEIVE != FW_ISO_CONTEXT_RECEIVE); - - if (a->channel > 63) - return -EINVAL; + FW_CDEV_ISO_CONTEXT_RECEIVE != FW_ISO_CONTEXT_RECEIVE || + FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL != + FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL); switch (a->type) { - case FW_ISO_CONTEXT_RECEIVE: - if (a->header_size < 4 || (a->header_size & 3)) + case FW_ISO_CONTEXT_TRANSMIT: + if (a->speed > SCODE_3200 || a->channel > 63) return -EINVAL; + + cb = iso_callback; break; - case FW_ISO_CONTEXT_TRANSMIT: - if (a->speed > SCODE_3200) + case FW_ISO_CONTEXT_RECEIVE: + if (a->header_size < 4 || (a->header_size & 3) || + a->channel > 63) return -EINVAL; + + cb = iso_callback; + break; + + case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL: + cb = (fw_iso_callback_t)iso_mc_callback; break; default: @@ -959,8 +993,7 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg) } context = fw_iso_context_create(client->device->card, a->type, - a->channel, a->speed, a->header_size, - iso_callback, client); + a->channel, a->speed, a->header_size, cb, client); if (IS_ERR(context)) return PTR_ERR(context); @@ -980,6 +1013,17 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg) return 0; } +static int ioctl_set_iso_channels(struct client *client, union ioctl_arg *arg) +{ + struct fw_cdev_set_iso_channels *a = &arg->set_iso_channels; + struct fw_iso_context *ctx = client->iso_context; + + if (ctx == NULL || a->handle != 0) + return -EINVAL; + + return fw_iso_context_set_channels(ctx, &a->channels); +} + /* Macros for decoding the iso packet control header. */ #define GET_PAYLOAD_LENGTH(v) ((v) & 0xffff) #define GET_INTERRUPT(v) (((v) >> 16) & 0x01) @@ -993,7 +1037,7 @@ static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg) struct fw_cdev_queue_iso *a = &arg->queue_iso; struct fw_cdev_iso_packet __user *p, *end, *next; struct fw_iso_context *ctx = client->iso_context; - unsigned long payload, buffer_end, transmit_header_bytes; + unsigned long payload, buffer_end, transmit_header_bytes = 0; u32 control; int count; struct { @@ -1013,7 +1057,6 @@ static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg) * use the indirect payload, the iso buffer need not be mapped * and the a->data pointer is ignored. */ - payload = (unsigned long)a->data - client->vm_start; buffer_end = client->buffer.page_count << PAGE_SHIFT; if (a->data == 0 || client->buffer.pages == NULL || @@ -1022,8 +1065,10 @@ static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg) buffer_end = 0; } - p = (struct fw_cdev_iso_packet __user *)u64_to_uptr(a->packets); + if (ctx->type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL && payload & 3) + return -EINVAL; + p = (struct fw_cdev_iso_packet __user *)u64_to_uptr(a->packets); if (!access_ok(VERIFY_READ, p, a->size)) return -EFAULT; @@ -1039,19 +1084,24 @@ static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg) u.packet.sy = GET_SY(control); u.packet.header_length = GET_HEADER_LENGTH(control); - if (ctx->type == FW_ISO_CONTEXT_TRANSMIT) { - if (u.packet.header_length % 4 != 0) + switch (ctx->type) { + case FW_ISO_CONTEXT_TRANSMIT: + if (u.packet.header_length & 3) return -EINVAL; transmit_header_bytes = u.packet.header_length; - } else { - /* - * We require that header_length is a multiple of - * the fixed header size, ctx->header_size. - */ + break; + + case FW_ISO_CONTEXT_RECEIVE: if (u.packet.header_length == 0 || u.packet.header_length % ctx->header_size != 0) return -EINVAL; - transmit_header_bytes = 0; + break; + + case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL: + if (u.packet.payload_length == 0 || + u.packet.payload_length & 3) + return -EINVAL; + break; } next = (struct fw_cdev_iso_packet __user *) @@ -1534,6 +1584,7 @@ static int (* const ioctl_handlers[])(struct client *, union ioctl_arg *) = { [0x14] = ioctl_get_cycle_timer2, [0x15] = ioctl_send_phy_packet, [0x16] = ioctl_receive_phy_packets, + [0x17] = ioctl_set_iso_channels, }; static int dispatch_ioctl(struct client *client, -- cgit v1.2.3