diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/firewire/fw-cdev.c | 215 | ||||
| -rw-r--r-- | drivers/firewire/fw-iso.c | 176 | ||||
| -rw-r--r-- | drivers/firewire/fw-transaction.h | 4 |
3 files changed, 388 insertions, 7 deletions
diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c index 4c33b51b735a..a227853aa1e2 100644 --- a/drivers/firewire/fw-cdev.c +++ b/drivers/firewire/fw-cdev.c @@ -24,6 +24,7 @@ #include <linux/errno.h> #include <linux/firewire-cdev.h> #include <linux/idr.h> +#include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/kref.h> #include <linux/mm.h> @@ -35,6 +36,7 @@ #include <linux/time.h> #include <linux/vmalloc.h> #include <linux/wait.h> +#include <linux/workqueue.h> #include <asm/system.h> #include <asm/uaccess.h> @@ -114,6 +116,21 @@ struct descriptor_resource { u32 data[0]; }; +struct iso_resource { + struct client_resource resource; + struct client *client; + /* Schedule work and access todo only with client->lock held. */ + struct delayed_work work; + enum {ISO_RES_ALLOC, ISO_RES_REALLOC, ISO_RES_DEALLOC,} todo; + int generation; + u64 channels; + s32 bandwidth; + struct iso_resource_event *e_alloc, *e_dealloc; +}; + +static void schedule_iso_resource(struct iso_resource *); +static void release_iso_resource(struct client *, struct client_resource *); + /* * dequeue_event() just kfree()'s the event, so the event has to be * the first field in a struct XYZ_event. @@ -145,6 +162,11 @@ struct iso_interrupt_event { struct fw_cdev_event_iso_interrupt interrupt; }; +struct iso_resource_event { + struct event event; + struct fw_cdev_event_iso_resource resource; +}; + static inline void __user *u64_to_uptr(__u64 value) { return (void __user *)(unsigned long)value; @@ -290,6 +312,16 @@ static void for_each_client(struct fw_device *device, mutex_unlock(&device->client_list_mutex); } +static int schedule_reallocations(int id, void *p, void *data) +{ + struct client_resource *r = p; + + if (r->release == release_iso_resource) + schedule_iso_resource(container_of(r, + struct iso_resource, resource)); + return 0; +} + static void queue_bus_reset_event(struct client *client) { struct bus_reset_event *e; @@ -304,6 +336,10 @@ static void queue_bus_reset_event(struct client *client) queue_event(client, &e->event, &e->reset, sizeof(e->reset), NULL, 0); + + spin_lock_irq(&client->lock); + idr_for_each(&client->resource_idr, schedule_reallocations, client); + spin_unlock_irq(&client->lock); } void fw_device_cdev_update(struct fw_device *device) @@ -376,8 +412,12 @@ static int add_client_resource(struct client *client, else ret = idr_get_new(&client->resource_idr, resource, &resource->handle); - if (ret >= 0) + if (ret >= 0) { client_get(client); + if (resource->release == release_iso_resource) + schedule_iso_resource(container_of(resource, + struct iso_resource, resource)); + } spin_unlock_irqrestore(&client->lock, flags); if (ret == -EAGAIN) @@ -970,6 +1010,177 @@ static int ioctl_get_cycle_timer(struct client *client, void *buffer) return 0; } +static void iso_resource_work(struct work_struct *work) +{ + struct iso_resource_event *e; + struct iso_resource *r = + container_of(work, struct iso_resource, work.work); + struct client *client = r->client; + int generation, channel, bandwidth, todo; + bool skip, free, success; + + spin_lock_irq(&client->lock); + generation = client->device->generation; + todo = r->todo; + /* Allow 1000ms grace period for other reallocations. */ + if (todo == ISO_RES_ALLOC && + time_is_after_jiffies(client->device->card->reset_jiffies + HZ)) { + if (schedule_delayed_work(&r->work, DIV_ROUND_UP(HZ, 3))) + client_get(client); + skip = true; + } else { + /* We could be called twice within the same generation. */ + skip = todo == ISO_RES_REALLOC && + r->generation == generation; + } + free = todo == ISO_RES_DEALLOC; + r->generation = generation; + spin_unlock_irq(&client->lock); + + if (skip) + goto out; + + bandwidth = r->bandwidth; + + fw_iso_resource_manage(client->device->card, generation, + r->channels, &channel, &bandwidth, + todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC); + /* + * Is this generation outdated already? As long as this resource sticks + * in the idr, it will be scheduled again for a newer generation or at + * shutdown. + */ + if (channel == -EAGAIN && + (todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC)) + goto out; + + success = channel >= 0 || bandwidth > 0; + + spin_lock_irq(&client->lock); + /* + * Transit from allocation to reallocation, except if the client + * requested deallocation in the meantime. + */ + if (r->todo == ISO_RES_ALLOC) + r->todo = ISO_RES_REALLOC; + /* + * Allocation or reallocation failure? Pull this resource out of the + * idr and prepare for deletion, unless the client is shutting down. + */ + if (r->todo == ISO_RES_REALLOC && !success && + !client->in_shutdown && + idr_find(&client->resource_idr, r->resource.handle)) { + idr_remove(&client->resource_idr, r->resource.handle); + client_put(client); + free = true; + } + spin_unlock_irq(&client->lock); + + if (todo == ISO_RES_ALLOC && channel >= 0) + r->channels = 1ULL << (63 - channel); + + if (todo == ISO_RES_REALLOC && success) + goto out; + + if (todo == ISO_RES_ALLOC) { + e = r->e_alloc; + r->e_alloc = NULL; + } else { + e = r->e_dealloc; + r->e_dealloc = NULL; + } + e->resource.handle = r->resource.handle; + e->resource.channel = channel; + e->resource.bandwidth = bandwidth; + + queue_event(client, &e->event, + &e->resource, sizeof(e->resource), NULL, 0); + + if (free) { + cancel_delayed_work(&r->work); + kfree(r->e_alloc); + kfree(r->e_dealloc); + kfree(r); + } + out: + client_put(client); +} + +static void schedule_iso_resource(struct iso_resource *r) +{ + if (schedule_delayed_work(&r->work, 0)) + client_get(r->client); +} + +static void release_iso_resource(struct client *client, + struct client_resource *resource) +{ + struct iso_resource *r = + container_of(resource, struct iso_resource, resource); + + spin_lock_irq(&client->lock); + r->todo = ISO_RES_DEALLOC; + schedule_iso_resource(r); + spin_unlock_irq(&client->lock); +} + +static int ioctl_allocate_iso_resource(struct client *client, void *buffer) +{ + struct fw_cdev_allocate_iso_resource *request = buffer; + struct iso_resource_event *e1, *e2; + struct iso_resource *r; + int ret; + + if ((request->channels == 0 && request->bandwidth == 0) || + request->bandwidth > BANDWIDTH_AVAILABLE_INITIAL || + request->bandwidth < 0) + return -EINVAL; + + r = kmalloc(sizeof(*r), GFP_KERNEL); + e1 = kmalloc(sizeof(*e1), GFP_KERNEL); + e2 = kmalloc(sizeof(*e2), GFP_KERNEL); + if (r == NULL || e1 == NULL || e2 == NULL) { + ret = -ENOMEM; + goto fail; + } + + INIT_DELAYED_WORK(&r->work, iso_resource_work); + r->client = client; + r->todo = ISO_RES_ALLOC; + r->generation = -1; + r->channels = request->channels; + r->bandwidth = request->bandwidth; + r->e_alloc = e1; + r->e_dealloc = e2; + + e1->resource.closure = request->closure; + e1->resource.type = FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED; + e2->resource.closure = request->closure; + e2->resource.type = FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED; + + r->resource.release = release_iso_resource; + ret = add_client_resource(client, &r->resource, GFP_KERNEL); + if (ret < 0) + goto fail; + request->handle = r->resource.handle; + + return 0; + fail: + kfree(r); + kfree(e1); + kfree(e2); + + return ret; +} + +static int ioctl_deallocate_iso_resource(struct client *client, void *buffer) +{ + struct fw_cdev_deallocate *request = buffer; + + return release_client_resource(client, request->handle, + release_iso_resource, NULL); +} + static int (* const ioctl_handlers[])(struct client *client, void *buffer) = { ioctl_get_info, ioctl_send_request, @@ -984,6 +1195,8 @@ static int (* const ioctl_handlers[])(struct client *client, void *buffer) = { ioctl_start_iso, ioctl_stop_iso, ioctl_get_cycle_timer, + ioctl_allocate_iso_resource, + ioctl_deallocate_iso_resource, }; static int dispatch_ioctl(struct client *client, 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 <krh@bitplanet.net> * @@ -18,15 +20,20 @@ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -#include <linux/kernel.h> -#include <linux/module.h> #include <linux/dma-mapping.h> -#include <linux/vmalloc.h> +#include <linux/errno.h> +#include <linux/firewire-constants.h> +#include <linux/kernel.h> #include <linux/mm.h> +#include <linux/spinlock.h> +#include <linux/vmalloc.h> -#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; + } +} diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h index 48e88d53998b..212a10293828 100644 --- a/drivers/firewire/fw-transaction.h +++ b/drivers/firewire/fw-transaction.h @@ -82,6 +82,7 @@ #define CSR_SPEED_MAP 0x2000 #define CSR_SPEED_MAP_END 0x3000 +#define BANDWIDTH_AVAILABLE_INITIAL 4915 #define BROADCAST_CHANNEL_INITIAL (1 << 31 | 31) #define BROADCAST_CHANNEL_VALID (1 << 30) @@ -343,6 +344,9 @@ int fw_iso_context_start(struct fw_iso_context *ctx, int fw_iso_context_stop(struct fw_iso_context *ctx); void fw_iso_context_destroy(struct fw_iso_context *ctx); +void fw_iso_resource_manage(struct fw_card *card, int generation, + u64 channels_mask, int *channel, int *bandwidth, bool allocate); + struct fw_card_driver { /* * Enable the given card with the given initial config rom. |