From 2dbd7d7e2327b0c2cc4e2de903e1cfa19980a504 Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Sun, 14 Dec 2008 21:45:45 +0100 Subject: firewire: standardize a variable name "ret" is the new "retval". Signed-off-by: Stefan Richter --- drivers/firewire/fw-iso.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/firewire/fw-iso.c') diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c index e14c03dc0065..cb32b20da9a0 100644 --- a/drivers/firewire/fw-iso.c +++ b/drivers/firewire/fw-iso.c @@ -32,7 +32,7 @@ int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, int page_count, enum dma_data_direction direction) { - int i, j, retval = -ENOMEM; + int i, j; dma_addr_t address; buffer->page_count = page_count; @@ -69,19 +69,19 @@ fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, kfree(buffer->pages); out: buffer->pages = NULL; - return retval; + return -ENOMEM; } int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma) { unsigned long uaddr; - int i, retval; + int i, ret; uaddr = vma->vm_start; for (i = 0; i < buffer->page_count; i++) { - retval = vm_insert_page(vma, uaddr, buffer->pages[i]); - if (retval) - return retval; + ret = vm_insert_page(vma, uaddr, buffer->pages[i]); + if (ret) + return ret; uaddr += PAGE_SIZE; } -- cgit v1.2.2 From 53dca51175cc2f66d21aeb1e70146cca65c53dad Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Sun, 14 Dec 2008 21:47:04 +0100 Subject: firewire: remove line breaks before function names type function_name(parameters); is nice to look at but was not used consistently. Signed-off-by: Stefan Richter --- drivers/firewire/fw-iso.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) (limited to 'drivers/firewire/fw-iso.c') diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c index cb32b20da9a0..3ff2cfc1bba6 100644 --- a/drivers/firewire/fw-iso.c +++ b/drivers/firewire/fw-iso.c @@ -28,9 +28,8 @@ #include "fw-topology.h" #include "fw-device.h" -int -fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, - int page_count, enum dma_data_direction direction) +int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, + int page_count, enum dma_data_direction direction) { int i, j; dma_addr_t address; @@ -105,10 +104,9 @@ void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, buffer->pages = NULL; } -struct fw_iso_context * -fw_iso_context_create(struct fw_card *card, int type, - int channel, int speed, size_t header_size, - fw_iso_callback_t callback, void *callback_data) +struct fw_iso_context *fw_iso_context_create(struct fw_card *card, + int type, int channel, int speed, size_t header_size, + fw_iso_callback_t callback, void *callback_data) { struct fw_iso_context *ctx; @@ -134,25 +132,23 @@ void fw_iso_context_destroy(struct fw_iso_context *ctx) card->driver->free_iso_context(ctx); } -int -fw_iso_context_start(struct fw_iso_context *ctx, int cycle, int sync, int tags) +int fw_iso_context_start(struct fw_iso_context *ctx, + int cycle, int sync, int tags) { return ctx->card->driver->start_iso(ctx, cycle, sync, tags); } -int -fw_iso_context_queue(struct fw_iso_context *ctx, - struct fw_iso_packet *packet, - struct fw_iso_buffer *buffer, - unsigned long payload) +int fw_iso_context_queue(struct fw_iso_context *ctx, + struct fw_iso_packet *packet, + struct fw_iso_buffer *buffer, + unsigned long payload) { struct fw_card *card = ctx->card; return card->driver->queue_iso(ctx, packet, buffer, payload); } -int -fw_iso_context_stop(struct fw_iso_context *ctx) +int fw_iso_context_stop(struct fw_iso_context *ctx) { return ctx->card->driver->stop_iso(ctx); } -- cgit v1.2.2 From 4817ed240232e89583b0506c2d8e426739af5da3 Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Sun, 21 Dec 2008 16:39:46 +0100 Subject: firewire: prevent creation of multiple IR DMA contexts for the same channel OHCI-1394 1.1 clause 10.4.3 says: "If more than one IR DMA context specifies receives for packets from the same isochronous channel, the context destination for that channel's packets is undefined." Any userspace client and in the future also kernelspace clients can allocate IR DMA contexts for any channel. We don't want them to interfere with each other, hence it is preferable to return -EBUSY if allocation of a second context for a channel is attempted. Notes: - This limitation is OHCI-1394 specific, therefore its proper place of implementation is down in the low-level driver. - Since the ABI simply maps one userspace iso client context to one hardware iso context, this OHCI-1394 limitation alas requires userspace to implement its own multiplexing of iso reception from the same channel and card to multiple clients when needed. - The limitation is independent of channel allocation at the IRM; the latter is really only important for the initiation of iso transmission but not of iso reception. - We don't need to do the same for IT DMA because OHCI-1394 does not have any ties between IT contexts and channels. Only the voluntary channel allocation protocol via the IRM, globally to the FireWire bus, can ensure proper isochronous transmit behaviour anyway. Signed-off-by: Stefan Richter --- drivers/firewire/fw-iso.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/firewire/fw-iso.c') diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c index 3ff2cfc1bba6..39f3bacee404 100644 --- a/drivers/firewire/fw-iso.c +++ b/drivers/firewire/fw-iso.c @@ -110,7 +110,8 @@ struct fw_iso_context *fw_iso_context_create(struct fw_card *card, { struct fw_iso_context *ctx; - ctx = card->driver->allocate_iso_context(card, type, header_size); + ctx = card->driver->allocate_iso_context(card, + type, channel, header_size); if (IS_ERR(ctx)) return ctx; -- cgit v1.2.2 From b1bda4cdc2037447bd66753bf5ccab66d91b0b59 Mon Sep 17 00:00:00 2001 From: "Jay Fenlason, Stefan Richter" Date: Sun, 4 Jan 2009 16:23:29 +0100 Subject: firewire: cdev: add ioctls for isochronous resource management Based on Date: Tue, 18 Nov 2008 11:41:27 -0500 From: Jay Fenlason Subject: [Patch V4] Add ISO resource management support with several changes to the ABI and implementation. Only the part of the ABI which enables auto-reallocation and auto-deallocation is included here. This implements ioctls for kernel-assisted allocation of isochronous channels and isochronous bandwidth. The benefits are: - The client does not have to have write access to the /dev/fw* device corresponding to the IRM. - The client does not have to perform reallocation after bus resets. - Channel and bandwidth are deallocated by the kernel if the file is closed before the client deallocated the resources. Thus resources are released even if the client crashes. It is anticipated that future in-kernel code (firewire-core IRM code; the firewire port of firedtv), will use the fw-iso.c portions of this code too. Signed-off-by: Stefan Richter Tested-by: David Moore --- drivers/firewire/fw-iso.c | 176 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 170 insertions(+), 6 deletions(-) (limited to 'drivers/firewire/fw-iso.c') diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c index 39f3bacee404..a7b57b253b06 100644 --- a/drivers/firewire/fw-iso.c +++ b/drivers/firewire/fw-iso.c @@ -1,5 +1,7 @@ /* - * Isochronous IO functionality + * Isochronous I/O functionality: + * - Isochronous DMA context management + * - Isochronous bus resource management (channels, bandwidth), client side * * Copyright (C) 2006 Kristian Hoegsberg * @@ -18,15 +20,20 @@ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -#include -#include #include -#include +#include +#include +#include #include +#include +#include -#include "fw-transaction.h" #include "fw-topology.h" -#include "fw-device.h" +#include "fw-transaction.h" + +/* + * Isochronous DMA context management + */ int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, int page_count, enum dma_data_direction direction) @@ -153,3 +160,160 @@ int fw_iso_context_stop(struct fw_iso_context *ctx) { return ctx->card->driver->stop_iso(ctx); } + +/* + * Isochronous bus resource management (channels, bandwidth), client side + */ + +static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, + int bandwidth, bool allocate) +{ + __be32 data[2]; + int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0; + + /* + * On a 1394a IRM with low contention, try < 1 is enough. + * On a 1394-1995 IRM, we need at least try < 2. + * Let's just do try < 5. + */ + for (try = 0; try < 5; try++) { + new = allocate ? old - bandwidth : old + bandwidth; + if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL) + break; + + data[0] = cpu_to_be32(old); + data[1] = cpu_to_be32(new); + switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, + irm_id, generation, SCODE_100, + CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE, + data, sizeof(data))) { + case RCODE_GENERATION: + /* A generation change frees all bandwidth. */ + return allocate ? -EAGAIN : bandwidth; + + case RCODE_COMPLETE: + if (be32_to_cpup(data) == old) + return bandwidth; + + old = be32_to_cpup(data); + /* Fall through. */ + } + } + + return -EIO; +} + +static int manage_channel(struct fw_card *card, int irm_id, int generation, + __be32 channels_mask, u64 offset, bool allocate) +{ + __be32 data[2], c, old = allocate ? cpu_to_be32(~0) : 0; + int i, retry = 5; + + for (i = 0; i < 32; i++) { + c = cpu_to_be32(1 << (31 - i)); + if (!(channels_mask & c)) + continue; + + if (allocate == !(old & c)) + continue; + + data[0] = old; + data[1] = old ^ c; + switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, + irm_id, generation, SCODE_100, + offset, data, sizeof(data))) { + case RCODE_GENERATION: + /* A generation change frees all channels. */ + return allocate ? -EAGAIN : i; + + case RCODE_COMPLETE: + if (data[0] == old) + return i; + + old = data[0]; + + /* Is the IRM 1394a-2000 compliant? */ + if ((data[0] & c) != (data[1] & c)) + continue; + + /* 1394-1995 IRM, fall through to retry. */ + default: + if (retry--) + i--; + } + } + + return -EIO; +} + +static void deallocate_channel(struct fw_card *card, int irm_id, + int generation, int channel) +{ + __be32 mask; + u64 offset; + + mask = channel < 32 ? cpu_to_be32(1 << (31 - channel)) : + cpu_to_be32(1 << (63 - channel)); + offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : + CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO; + + manage_channel(card, irm_id, generation, mask, offset, false); +} + +/** + * fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth + * + * In parameters: card, generation, channels_mask, bandwidth, allocate + * Out parameters: channel, bandwidth + * This function blocks (sleeps) during communication with the IRM. + * Allocates or deallocates at most one channel out of channels_mask. + * + * Returns channel < 0 if no channel was allocated or deallocated. + * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. + * + * If generation is stale, deallocations succeed but allocations fail with + * channel = -EAGAIN. + * + * If channel (de)allocation fails, bandwidth (de)allocation fails too. + * If bandwidth allocation fails, no channel will be allocated either. + * If bandwidth deallocation fails, channel deallocation may still have been + * successful. + */ +void fw_iso_resource_manage(struct fw_card *card, int generation, + u64 channels_mask, int *channel, int *bandwidth, + bool allocate) +{ + __be32 channels_hi = cpu_to_be32(channels_mask >> 32); + __be32 channels_lo = cpu_to_be32(channels_mask); + int irm_id, ret, c = -EINVAL; + + spin_lock_irq(&card->lock); + irm_id = card->irm_node->node_id; + spin_unlock_irq(&card->lock); + + if (channels_hi) + c = manage_channel(card, irm_id, generation, channels_hi, + CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, allocate); + if (channels_lo && c < 0) { + c = manage_channel(card, irm_id, generation, channels_lo, + CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, allocate); + if (c >= 0) + c += 32; + } + *channel = c; + + if (channels_mask != 0 && c < 0) + *bandwidth = 0; + + if (*bandwidth == 0) + return; + + ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate); + if (ret < 0) + *bandwidth = 0; + + if (ret < 0 && c >= 0 && allocate) { + deallocate_channel(card, irm_id, generation, c); + *channel = ret; + } +} -- cgit v1.2.2 From 5d9cb7d276a9c465fef5a771792eac2cf1929f2b Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Thu, 8 Jan 2009 23:07:40 +0100 Subject: firewire: cdev: add ioctls for iso resource management, amendment Some fixes: - Remove stale documentation. - Fix a != vs. == thinko that got in the way of channel management. - Try bandwidth deallocation even if channel deallocation failed. A simplification: - fw_cdev_allocate_iso_resource.channels is now ordered like libdc1394's dc1394_iso_allocate_channel() channels_allowed argument. By the way, I looked closer at cards from NEC, TI, and VIA, and noticed that they all don't implement IEEE 1394a behaviour which is meant to deviate from IEEE 1212's notion of lock compare-swap. This means that we have to do two lock transactions instead of one in many cases where one transaction would already succeed on a fully 1394a compliant IRM. Signed-off-by: Stefan Richter --- drivers/firewire/fw-iso.c | 38 ++++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-) (limited to 'drivers/firewire/fw-iso.c') diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c index a7b57b253b06..f511d16efaee 100644 --- a/drivers/firewire/fw-iso.c +++ b/drivers/firewire/fw-iso.c @@ -204,17 +204,19 @@ static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, } static int manage_channel(struct fw_card *card, int irm_id, int generation, - __be32 channels_mask, u64 offset, bool allocate) + u32 channels_mask, u64 offset, bool allocate) { - __be32 data[2], c, old = allocate ? cpu_to_be32(~0) : 0; + __be32 data[2], c, all, old; int i, retry = 5; + old = all = allocate ? cpu_to_be32(~0) : 0; + for (i = 0; i < 32; i++) { - c = cpu_to_be32(1 << (31 - i)); - if (!(channels_mask & c)) + if (!(channels_mask & 1 << i)) continue; - if (allocate == !(old & c)) + c = cpu_to_be32(1 << (31 - i)); + if ((old & c) != (all & c)) continue; data[0] = old; @@ -233,7 +235,7 @@ static int manage_channel(struct fw_card *card, int irm_id, int generation, old = data[0]; /* Is the IRM 1394a-2000 compliant? */ - if ((data[0] & c) != (data[1] & c)) + if ((data[0] & c) == (data[1] & c)) continue; /* 1394-1995 IRM, fall through to retry. */ @@ -249,11 +251,10 @@ static int manage_channel(struct fw_card *card, int irm_id, int generation, static void deallocate_channel(struct fw_card *card, int irm_id, int generation, int channel) { - __be32 mask; + u32 mask; u64 offset; - mask = channel < 32 ? cpu_to_be32(1 << (31 - channel)) : - cpu_to_be32(1 << (63 - channel)); + mask = channel < 32 ? 1 << channel : 1 << (channel - 32); offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO; @@ -266,7 +267,12 @@ static void deallocate_channel(struct fw_card *card, int irm_id, * In parameters: card, generation, channels_mask, bandwidth, allocate * Out parameters: channel, bandwidth * This function blocks (sleeps) during communication with the IRM. + * * Allocates or deallocates at most one channel out of channels_mask. + * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. + * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for + * channel 0 and LSB for channel 63.) + * Allocates or deallocates as many bandwidth allocation units as specified. * * Returns channel < 0 if no channel was allocated or deallocated. * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. @@ -274,17 +280,17 @@ static void deallocate_channel(struct fw_card *card, int irm_id, * If generation is stale, deallocations succeed but allocations fail with * channel = -EAGAIN. * - * If channel (de)allocation fails, bandwidth (de)allocation fails too. + * If channel allocation fails, no bandwidth will be allocated either. * If bandwidth allocation fails, no channel will be allocated either. - * If bandwidth deallocation fails, channel deallocation may still have been - * successful. + * But deallocations of channel and bandwidth are tried independently + * of each other's success. */ void fw_iso_resource_manage(struct fw_card *card, int generation, u64 channels_mask, int *channel, int *bandwidth, bool allocate) { - __be32 channels_hi = cpu_to_be32(channels_mask >> 32); - __be32 channels_lo = cpu_to_be32(channels_mask); + u32 channels_hi = channels_mask; /* channels 31...0 */ + u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ int irm_id, ret, c = -EINVAL; spin_lock_irq(&card->lock); @@ -302,7 +308,7 @@ void fw_iso_resource_manage(struct fw_card *card, int generation, } *channel = c; - if (channels_mask != 0 && c < 0) + if (allocate && channels_mask != 0 && c < 0) *bandwidth = 0; if (*bandwidth == 0) @@ -312,7 +318,7 @@ void fw_iso_resource_manage(struct fw_card *card, int generation, if (ret < 0) *bandwidth = 0; - if (ret < 0 && c >= 0 && allocate) { + if (allocate && ret < 0 && c >= 0) { deallocate_channel(card, irm_id, generation, c); *channel = ret; } -- cgit v1.2.2 From e1eff7a393d4a4e3ad1cf65fcba899146840bfd2 Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Tue, 3 Feb 2009 17:55:19 +0100 Subject: firewire: normalize a variable name Standardize on if (err) handle_error; and if (ret < 0) handle_error; Don't call a variable err if we store values in it which mean success. Also, offset some return statements by a blank line since this how we do it in drivers/firewire. Signed-off-by: Stefan Richter --- drivers/firewire/fw-iso.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/firewire/fw-iso.c') diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c index f511d16efaee..2baf1007253e 100644 --- a/drivers/firewire/fw-iso.c +++ b/drivers/firewire/fw-iso.c @@ -75,19 +75,21 @@ int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, kfree(buffer->pages); out: buffer->pages = NULL; + return -ENOMEM; } int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma) { unsigned long uaddr; - int i, ret; + int i, err; uaddr = vma->vm_start; for (i = 0; i < buffer->page_count; i++) { - ret = vm_insert_page(vma, uaddr, buffer->pages[i]); - if (ret) - return ret; + err = vm_insert_page(vma, uaddr, buffer->pages[i]); + if (err) + return err; + uaddr += PAGE_SIZE; } -- cgit v1.2.2