Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965128AbWIKXWf (ORCPT ); Mon, 11 Sep 2006 19:22:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965107AbWIKXSr (ORCPT ); Mon, 11 Sep 2006 19:18:47 -0400 Received: from mga03.intel.com ([143.182.124.21]:64441 "EHLO mga03.intel.com") by vger.kernel.org with ESMTP id S965095AbWIKXSU (ORCPT ); Mon, 11 Sep 2006 19:18:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: i="4.09,147,1157353200"; d="scan'208"; a="114947036:sNHT288867355" From: Dan Williams Subject: [PATCH 08/19] dmaengine: enable multiple clients and operations Date: Mon, 11 Sep 2006 16:18:17 -0700 To: neilb@suse.de, linux-raid@vger.kernel.org Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, christopher.leech@intel.com Message-Id: <20060911231817.4737.49381.stgit@dwillia2-linux.ch.intel.com> In-Reply-To: <1158015632.4241.31.camel@dwillia2-linux.ch.intel.com> References: <1158015632.4241.31.camel@dwillia2-linux.ch.intel.com> Content-Type: text/plain; charset=utf-8; format=fixed Content-Transfer-Encoding: 8bit User-Agent: StGIT/0.10 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 32052 Lines: 963 From: Dan Williams Enable the dmaengine interface to allow multiple clients to share a channel, and enable clients to request channels based on an operations capability mask. This prepares the interface for use with the RAID5 client and the future RAID6 client. Multi-client support is achieved by modifying channels to maintain a list of peer clients. Multi-operation support is achieved by modifying clients to maintain lists of channel references. Channel references in a given request list satisfy a client specified capability mask. Changelog: * make the dmaengine api EXPORT_SYMBOL_GPL * zero sum support should be standalone, not integrated into xor Signed-off-by: Dan Williams --- drivers/dma/dmaengine.c | 357 ++++++++++++++++++++++++++++++++++++--------- drivers/dma/ioatdma.c | 12 +- include/linux/dmaengine.h | 164 ++++++++++++++++++--- net/core/dev.c | 21 +-- net/ipv4/tcp.c | 4 - 5 files changed, 443 insertions(+), 115 deletions(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 1527804..e10f19d 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -37,8 +37,13 @@ * Each device has a channels list, which runs unlocked but is never modified * once the device is registered, it's just setup by the driver. * - * Each client has a channels list, it's only modified under the client->lock - * and in an RCU callback, so it's safe to read under rcu_read_lock(). + * Each client has 'n' lists of channel references where + * n == DMA_MAX_CHAN_TYPE_REQ. These lists are only modified under the + * client->lock and in an RCU callback, so they are safe to read under + * rcu_read_lock(). + * + * Each channel has a list of peer clients, it's only modified under the + * chan->lock. This allows a channel to be shared amongst several clients * * Each device has a kref, which is initialized to 1 when the device is * registered. A kref_put is done for each class_device registered. When the @@ -85,6 +90,18 @@ static ssize_t show_memcpy_count(struct return sprintf(buf, "%lu\n", count); } +static ssize_t show_xor_count(struct class_device *cd, char *buf) +{ + struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); + unsigned long count = 0; + int i; + + for_each_possible_cpu(i) + count += per_cpu_ptr(chan->local, i)->xor_count; + + return sprintf(buf, "%lu\n", count); +} + static ssize_t show_bytes_transferred(struct class_device *cd, char *buf) { struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); @@ -97,16 +114,37 @@ static ssize_t show_bytes_transferred(st return sprintf(buf, "%lu\n", count); } +static ssize_t show_bytes_xor(struct class_device *cd, char *buf) +{ + struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); + unsigned long count = 0; + int i; + + for_each_possible_cpu(i) + count += per_cpu_ptr(chan->local, i)->bytes_xor; + + return sprintf(buf, "%lu\n", count); +} + static ssize_t show_in_use(struct class_device *cd, char *buf) { + unsigned int clients = 0; + struct list_head *peer; struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); - return sprintf(buf, "%d\n", (chan->client ? 1 : 0)); + rcu_read_lock(); + list_for_each_rcu(peer, &chan->peers) + clients++; + rcu_read_unlock(); + + return sprintf(buf, "%d\n", clients); } static struct class_device_attribute dma_class_attrs[] = { __ATTR(memcpy_count, S_IRUGO, show_memcpy_count, NULL), + __ATTR(xor_count, S_IRUGO, show_xor_count, NULL), __ATTR(bytes_transferred, S_IRUGO, show_bytes_transferred, NULL), + __ATTR(bytes_xor, S_IRUGO, show_bytes_xor, NULL), __ATTR(in_use, S_IRUGO, show_in_use, NULL), __ATTR_NULL }; @@ -130,34 +168,79 @@ static struct class dma_devclass = { /** * dma_client_chan_alloc - try to allocate a channel to a client * @client: &dma_client + * @req: request descriptor * * Called with dma_list_mutex held. */ -static struct dma_chan *dma_client_chan_alloc(struct dma_client *client) +static struct dma_chan *dma_client_chan_alloc(struct dma_client *client, + struct dma_req *req) { struct dma_device *device; struct dma_chan *chan; + struct dma_client_chan_peer *peer; + struct dma_chan_client_ref *chan_ref; unsigned long flags; int desc; /* allocated descriptor count */ + int allocated; /* flag re-allocations */ - /* Find a channel, any DMA engine will do */ + /* Find a channel */ list_for_each_entry(device, &dma_device_list, global_node) { + if ((req->cap_mask & device->capabilities) + != req->cap_mask) + continue; list_for_each_entry(chan, &device->channels, device_node) { - if (chan->client) + allocated = 0; + rcu_read_lock(); + list_for_each_entry_rcu(chan_ref, &req->channels, req_node) { + if (chan_ref->chan == chan) { + allocated = 1; + break; + } + } + rcu_read_unlock(); + + if (allocated) continue; + /* can the channel be shared between multiple clients */ + if ((req->exclusive && !list_empty(&chan->peers)) || + chan->exclusive) + continue; + + chan_ref = kmalloc(sizeof(*chan_ref), GFP_KERNEL); + if (!chan_ref) + continue; + + peer = kmalloc(sizeof(*peer), GFP_KERNEL); + if (!peer) { + kfree(chan_ref); + continue; + } + desc = chan->device->device_alloc_chan_resources(chan); - if (desc >= 0) { + if (desc) { kref_get(&device->refcount); - kref_init(&chan->refcount); - chan->slow_ref = 0; - INIT_RCU_HEAD(&chan->rcu); - chan->client = client; + kref_get(&chan->refcount); + INIT_RCU_HEAD(&peer->rcu); + INIT_RCU_HEAD(&chan_ref->rcu); + INIT_LIST_HEAD(&peer->peer_node); + INIT_LIST_HEAD(&chan_ref->req_node); + peer->client = client; + chan_ref->chan = chan; + + spin_lock_irqsave(&chan->lock, flags); + list_add_tail_rcu(&peer->peer_node, &chan->peers); + spin_unlock_irqrestore(&chan->lock, flags); + spin_lock_irqsave(&client->lock, flags); - list_add_tail_rcu(&chan->client_node, - &client->channels); + chan->exclusive = req->exclusive ? client : NULL; + list_add_tail_rcu(&chan_ref->req_node, + &req->channels); spin_unlock_irqrestore(&client->lock, flags); return chan; + } else { + kfree(peer); + kfree(chan_ref); } } } @@ -173,7 +256,6 @@ void dma_chan_cleanup(struct kref *kref) { struct dma_chan *chan = container_of(kref, struct dma_chan, refcount); chan->device->device_free_chan_resources(chan); - chan->client = NULL; kref_put(&chan->device->refcount, dma_async_device_cleanup); } @@ -186,51 +268,93 @@ static void dma_chan_free_rcu(struct rcu bias -= local_read(&per_cpu_ptr(chan->local, i)->refcount); atomic_sub(bias, &chan->refcount.refcount); kref_put(&chan->refcount, dma_chan_cleanup); + kref_put(&chan->device->refcount, dma_async_device_cleanup); +} + +static void dma_peer_free_rcu(struct rcu_head *rcu) +{ + struct dma_client_chan_peer *peer = + container_of(rcu, struct dma_client_chan_peer, rcu); + + kfree(peer); +} + +static void dma_chan_ref_free_rcu(struct rcu_head *rcu) +{ + struct dma_chan_client_ref *chan_ref = + container_of(rcu, struct dma_chan_client_ref, rcu); + + kfree(chan_ref); } -static void dma_client_chan_free(struct dma_chan *chan) +static void dma_client_chan_free(struct dma_client *client, + struct dma_chan_client_ref *chan_ref) { + struct dma_client_chan_peer *peer; + struct dma_chan *chan = chan_ref->chan; atomic_add(0x7FFFFFFF, &chan->refcount.refcount); chan->slow_ref = 1; - call_rcu(&chan->rcu, dma_chan_free_rcu); + rcu_read_lock(); + list_for_each_entry_rcu(peer, &chan->peers, peer_node) + if (peer->client == client) { + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + list_del_rcu(&peer->peer_node); + if (list_empty(&chan->peers)) + chan->exclusive = NULL; + spin_unlock_irqrestore(&chan->lock, flags); + call_rcu(&peer->rcu, dma_peer_free_rcu); + call_rcu(&chan_ref->rcu, dma_chan_ref_free_rcu); + call_rcu(&chan->rcu, dma_chan_free_rcu); + break; + } + rcu_read_unlock(); } /** * dma_chans_rebalance - reallocate channels to clients * - * When the number of DMA channel in the system changes, - * channels need to be rebalanced among clients. + * When the number of DMA channels in the system changes, + * channels need to be rebalanced among clients */ static void dma_chans_rebalance(void) { struct dma_client *client; struct dma_chan *chan; + struct dma_chan_client_ref *chan_ref; + unsigned long flags; + int i; mutex_lock(&dma_list_mutex); list_for_each_entry(client, &dma_client_list, global_node) { - while (client->chans_desired > client->chan_count) { - chan = dma_client_chan_alloc(client); - if (!chan) - break; - client->chan_count++; - client->event_callback(client, - chan, - DMA_RESOURCE_ADDED); - } - while (client->chans_desired < client->chan_count) { - spin_lock_irqsave(&client->lock, flags); - chan = list_entry(client->channels.next, - struct dma_chan, - client_node); - list_del_rcu(&chan->client_node); - spin_unlock_irqrestore(&client->lock, flags); - client->chan_count--; - client->event_callback(client, - chan, - DMA_RESOURCE_REMOVED); - dma_client_chan_free(chan); + for (i = 0; i < DMA_MAX_CHAN_TYPE_REQ; i++) { + struct dma_req *req = &client->req[i]; + while (req->chans_desired > atomic_read(&req->chan_count)) { + chan = dma_client_chan_alloc(client, req); + if (!chan) + break; + atomic_inc(&req->chan_count); + client->event_callback(client, + chan, + DMA_RESOURCE_ADDED); + } + while (req->chans_desired < atomic_read(&req->chan_count)) { + spin_lock_irqsave(&client->lock, flags); + chan_ref = list_entry(req->channels.next, + struct dma_chan_client_ref, + req_node); + list_del_rcu(&chan_ref->req_node); + spin_unlock_irqrestore(&client->lock, flags); + atomic_dec(&req->chan_count); + + client->event_callback(client, + chan_ref->chan, + DMA_RESOURCE_REMOVED); + dma_client_chan_free(client, chan_ref); + } } } @@ -244,15 +368,18 @@ static void dma_chans_rebalance(void) struct dma_client *dma_async_client_register(dma_event_callback event_callback) { struct dma_client *client; + int i; client = kzalloc(sizeof(*client), GFP_KERNEL); if (!client) return NULL; - INIT_LIST_HEAD(&client->channels); + for (i = 0; i < DMA_MAX_CHAN_TYPE_REQ; i++) { + INIT_LIST_HEAD(&client->req[i].channels); + atomic_set(&client->req[i].chan_count, 0); + } + spin_lock_init(&client->lock); - client->chans_desired = 0; - client->chan_count = 0; client->event_callback = event_callback; mutex_lock(&dma_list_mutex); @@ -270,14 +397,16 @@ struct dma_client *dma_async_client_regi */ void dma_async_client_unregister(struct dma_client *client) { - struct dma_chan *chan; + struct dma_chan_client_ref *chan_ref; + int i; if (!client) return; rcu_read_lock(); - list_for_each_entry_rcu(chan, &client->channels, client_node) - dma_client_chan_free(chan); + for (i = 0; i < DMA_MAX_CHAN_TYPE_REQ; i++) + list_for_each_entry_rcu(chan_ref, &client->req[i].channels, req_node) + dma_client_chan_free(client, chan_ref); rcu_read_unlock(); mutex_lock(&dma_list_mutex); @@ -292,17 +421,46 @@ void dma_async_client_unregister(struct * dma_async_client_chan_request - request DMA channels * @client: &dma_client * @number: count of DMA channels requested + * @mask: limits the DMA channels returned to those that + * have the requisite capabilities * * Clients call dma_async_client_chan_request() to specify how many * DMA channels they need, 0 to free all currently allocated. * The resulting allocations/frees are indicated to the client via the - * event callback. + * event callback. If the client has exhausted the number of distinct + * requests allowed (DMA_MAX_CHAN_TYPE_REQ) this function will return 0. */ -void dma_async_client_chan_request(struct dma_client *client, - unsigned int number) +int dma_async_client_chan_request(struct dma_client *client, + unsigned int number, unsigned int mask) { - client->chans_desired = number; - dma_chans_rebalance(); + int request_slot_found = 0, i; + + /* adjust an outstanding request */ + for (i = 0; i < DMA_MAX_CHAN_TYPE_REQ; i++) { + struct dma_req *req = &client->req[i]; + if (req->cap_mask == mask) { + req->chans_desired = number; + request_slot_found = 1; + break; + } + } + + /* start a new request */ + if (!request_slot_found) + for (i = 0; i < DMA_MAX_CHAN_TYPE_REQ; i++) { + struct dma_req *req = &client->req[i]; + if (!req->chans_desired) { + req->chans_desired = number; + req->cap_mask = mask; + request_slot_found = 1; + break; + } + } + + if (request_slot_found) + dma_chans_rebalance(); + + return request_slot_found; } /** @@ -335,6 +493,7 @@ int dma_async_device_register(struct dma device->dev_id, chan->chan_id); kref_get(&device->refcount); + kref_init(&chan->refcount); class_device_register(&chan->class_dev); } @@ -348,6 +507,20 @@ int dma_async_device_register(struct dma } /** + * dma_async_chan_init - common channel initialization + * @chan: &dma_chan + * @device: &dma_device + */ +void dma_async_chan_init(struct dma_chan *chan, struct dma_device *device) +{ + INIT_LIST_HEAD(&chan->peers); + INIT_RCU_HEAD(&chan->rcu); + spin_lock_init(&chan->lock); + chan->device = device; + list_add_tail(&chan->device_node, &device->channels); +} + +/** * dma_async_device_cleanup - function called when all references are released * @kref: kernel reference object */ @@ -366,31 +539,70 @@ static void dma_async_device_cleanup(str void dma_async_device_unregister(struct dma_device *device) { struct dma_chan *chan; + struct dma_client_chan_peer *peer; + struct dma_req *req; + struct dma_chan_client_ref *chan_ref; + struct dma_client *client; + int i; unsigned long flags; mutex_lock(&dma_list_mutex); list_del(&device->global_node); mutex_unlock(&dma_list_mutex); + /* look up and free each reference to a channel + * note: a channel can be allocated to a client once per + * request type (DMA_MAX_CHAN_TYPE_REQ) + */ list_for_each_entry(chan, &device->channels, device_node) { - if (chan->client) { - spin_lock_irqsave(&chan->client->lock, flags); - list_del(&chan->client_node); - chan->client->chan_count--; - spin_unlock_irqrestore(&chan->client->lock, flags); - chan->client->event_callback(chan->client, - chan, - DMA_RESOURCE_REMOVED); - dma_client_chan_free(chan); + rcu_read_lock(); + list_for_each_entry_rcu(peer, &chan->peers, peer_node) { + client = peer->client; + for (i = 0; i < DMA_MAX_CHAN_TYPE_REQ; i++) { + req = &client->req[i]; + list_for_each_entry_rcu(chan_ref, + &req->channels, + req_node) { + if (chan_ref->chan == chan) { + spin_lock_irqsave(&client->lock, flags); + list_del_rcu(&chan_ref->req_node); + spin_unlock_irqrestore(&client->lock, flags); + atomic_dec(&req->chan_count); + client->event_callback( + client, + chan, + DMA_RESOURCE_REMOVED); + dma_client_chan_free(client, + chan_ref); + break; + } + } + } } - class_device_unregister(&chan->class_dev); + rcu_read_unlock(); + kref_put(&chan->refcount, dma_chan_cleanup); + kref_put(&device->refcount, dma_async_device_cleanup); } + + class_device_unregister(&chan->class_dev); + dma_chans_rebalance(); kref_put(&device->refcount, dma_async_device_cleanup); wait_for_completion(&device->done); } +/** + * dma_async_xor_pgs_to_pg_err - default function for dma devices that + * do not support xor + */ +dma_cookie_t dma_async_xor_pgs_to_pg_err(struct dma_chan *chan, + struct page *dest_pg, unsigned int dest_off, struct page *src_pgs, + unsigned int src_cnt, unsigned int src_off, size_t len) +{ + return -ENXIO; +} + static int __init dma_bus_init(void) { mutex_init(&dma_list_mutex); @@ -399,14 +611,17 @@ static int __init dma_bus_init(void) subsys_initcall(dma_bus_init); -EXPORT_SYMBOL(dma_async_client_register); -EXPORT_SYMBOL(dma_async_client_unregister); -EXPORT_SYMBOL(dma_async_client_chan_request); -EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf); -EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg); -EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg); -EXPORT_SYMBOL(dma_async_memcpy_complete); -EXPORT_SYMBOL(dma_async_memcpy_issue_pending); -EXPORT_SYMBOL(dma_async_device_register); -EXPORT_SYMBOL(dma_async_device_unregister); -EXPORT_SYMBOL(dma_chan_cleanup); +EXPORT_SYMBOL_GPL(dma_async_client_register); +EXPORT_SYMBOL_GPL(dma_async_client_unregister); +EXPORT_SYMBOL_GPL(dma_async_client_chan_request); +EXPORT_SYMBOL_GPL(dma_async_memcpy_buf_to_buf); +EXPORT_SYMBOL_GPL(dma_async_memcpy_buf_to_pg); +EXPORT_SYMBOL_GPL(dma_async_memcpy_pg_to_pg); +EXPORT_SYMBOL_GPL(dma_async_xor_pgs_to_pg); +EXPORT_SYMBOL_GPL(dma_async_operation_complete); +EXPORT_SYMBOL_GPL(dma_async_issue_pending); +EXPORT_SYMBOL_GPL(dma_async_device_register); +EXPORT_SYMBOL_GPL(dma_async_device_unregister); +EXPORT_SYMBOL_GPL(dma_chan_cleanup); +EXPORT_SYMBOL_GPL(dma_async_xor_pgs_to_pg_err); +EXPORT_SYMBOL_GPL(dma_async_chan_init); diff --git a/drivers/dma/ioatdma.c b/drivers/dma/ioatdma.c index dbd4d6c..415de03 100644 --- a/drivers/dma/ioatdma.c +++ b/drivers/dma/ioatdma.c @@ -69,11 +69,7 @@ static int enumerate_dma_channels(struct spin_lock_init(&ioat_chan->desc_lock); INIT_LIST_HEAD(&ioat_chan->free_desc); INIT_LIST_HEAD(&ioat_chan->used_desc); - /* This should be made common somewhere in dmaengine.c */ - ioat_chan->common.device = &device->common; - ioat_chan->common.client = NULL; - list_add_tail(&ioat_chan->common.device_node, - &device->common.channels); + dma_async_chan_init(&ioat_chan->common, &device->common); } return device->common.chancnt; } @@ -759,8 +755,10 @@ #endif device->common.device_memcpy_buf_to_buf = ioat_dma_memcpy_buf_to_buf; device->common.device_memcpy_buf_to_pg = ioat_dma_memcpy_buf_to_pg; device->common.device_memcpy_pg_to_pg = ioat_dma_memcpy_pg_to_pg; - device->common.device_memcpy_complete = ioat_dma_is_complete; - device->common.device_memcpy_issue_pending = ioat_dma_memcpy_issue_pending; + device->common.device_operation_complete = ioat_dma_is_complete; + device->common.device_xor_pgs_to_pg = dma_async_xor_pgs_to_pg_err; + device->common.device_issue_pending = ioat_dma_memcpy_issue_pending; + device->common.capabilities = DMA_MEMCPY; printk(KERN_INFO "Intel(R) I/OAT DMA Engine found, %d channels\n", device->common.chancnt); diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index c94d8f1..3599472 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -20,7 +20,7 @@ */ #ifndef DMAENGINE_H #define DMAENGINE_H - +#include #ifdef CONFIG_DMA_ENGINE #include @@ -65,6 +65,27 @@ enum dma_status { }; /** + * enum dma_capabilities - DMA operational capabilities + * @DMA_MEMCPY: src to dest copy + * @DMA_XOR: src*n to dest xor + * @DMA_DUAL_XOR: src*n to dest_diag and dest_horiz xor + * @DMA_PQ_XOR: src*n to dest_q and dest_p gf/xor + * @DMA_MEMCPY_CRC32C: src to dest copy and crc-32c sum + * @DMA_SHARE: multiple clients can use this channel + */ +enum dma_capabilities { + DMA_MEMCPY = 0x1, + DMA_XOR = 0x2, + DMA_PQ_XOR = 0x4, + DMA_DUAL_XOR = 0x8, + DMA_PQ_UPDATE = 0x10, + DMA_ZERO_SUM = 0x20, + DMA_PQ_ZERO_SUM = 0x40, + DMA_MEMSET = 0x80, + DMA_MEMCPY_CRC32C = 0x100, +}; + +/** * struct dma_chan_percpu - the per-CPU part of struct dma_chan * @refcount: local_t used for open-coded "bigref" counting * @memcpy_count: transaction counter @@ -75,27 +96,32 @@ struct dma_chan_percpu { local_t refcount; /* stats */ unsigned long memcpy_count; + unsigned long xor_count; unsigned long bytes_transferred; + unsigned long bytes_xor; }; /** * struct dma_chan - devices supply DMA channels, clients use them - * @client: ptr to the client user of this chan, will be %NULL when unused + * @peers: list of the clients of this chan, will be 'empty' when unused * @device: ptr to the dma device who supplies this channel, always !%NULL * @cookie: last cookie value returned to client + * @exclusive: ptr to the client that is exclusively using this channel + * @lock: protects access to the peer list * @chan_id: channel ID for sysfs * @class_dev: class device for sysfs * @refcount: kref, used in "bigref" slow-mode * @slow_ref: indicates that the DMA channel is free * @rcu: the DMA channel's RCU head - * @client_node: used to add this to the client chan list * @device_node: used to add this to the device chan list * @local: per-cpu pointer to a struct dma_chan_percpu */ struct dma_chan { - struct dma_client *client; + struct list_head peers; struct dma_device *device; dma_cookie_t cookie; + struct dma_client *exclusive; + spinlock_t lock; /* sysfs */ int chan_id; @@ -105,7 +131,6 @@ struct dma_chan { int slow_ref; struct rcu_head rcu; - struct list_head client_node; struct list_head device_node; struct dma_chan_percpu *local; }; @@ -139,29 +164,66 @@ typedef void (*dma_event_callback) (stru struct dma_chan *chan, enum dma_event event); /** - * struct dma_client - info on the entity making use of DMA services - * @event_callback: func ptr to call when something happens + * struct dma_req - info on the type and number of channels allocated to a client * @chan_count: number of chans allocated * @chans_desired: number of chans requested. Can be +/- chan_count + * @cap_mask: DMA capabilities required to satisfy this request + * @exclusive: Whether this client would like exclusive use of the channel(s) + */ +struct dma_req { + atomic_t chan_count; + unsigned int chans_desired; + unsigned int cap_mask; + int exclusive; + struct list_head channels; +}; + +/** + * struct dma_client - info on the entity making use of DMA services + * @event_callback: func ptr to call when something happens + * @dma_req: tracks client channel requests per capability mask * @lock: protects access to the channels list * @channels: the list of DMA channels allocated * @global_node: list_head for global dma_client_list */ +#define DMA_MAX_CHAN_TYPE_REQ 2 struct dma_client { dma_event_callback event_callback; - unsigned int chan_count; - unsigned int chans_desired; - + struct dma_req req[DMA_MAX_CHAN_TYPE_REQ]; spinlock_t lock; - struct list_head channels; struct list_head global_node; }; /** + * struct dma_client_chan_peer - info on the entities sharing a DMA channel + * @client: &dma_client + * @peer_node: node list of other clients on the channel + * @rcu: rcu head for the peer object + */ +struct dma_client_chan_peer { + struct dma_client *client; + struct list_head peer_node; + struct rcu_head rcu; +}; + +/** + * struct dma_chan_client_ref - reference object for clients to track channels + * @chan: channel reference + * @chan_node: node in the list of other channels on the client + * @rcu: rcu head for the chan_ref object + */ +struct dma_chan_client_ref { + struct dma_chan *chan; + struct list_head req_node; + struct rcu_head rcu; +}; + +/** * struct dma_device - info on the entity supplying DMA services * @chancnt: how many DMA channels are supported * @channels: the list of struct dma_chan * @global_node: list_head for global dma_device_list + * @capabilities: channel operations capabilities * @refcount: reference count * @done: IO completion struct * @dev_id: unique device ID @@ -179,6 +241,7 @@ struct dma_device { unsigned int chancnt; struct list_head channels; struct list_head global_node; + unsigned long capabilities; struct kref refcount; struct completion done; @@ -195,18 +258,26 @@ struct dma_device { dma_cookie_t (*device_memcpy_pg_to_pg)(struct dma_chan *chan, struct page *dest_pg, unsigned int dest_off, struct page *src_pg, unsigned int src_off, size_t len); - enum dma_status (*device_memcpy_complete)(struct dma_chan *chan, + dma_cookie_t (*device_xor_pgs_to_pg)(struct dma_chan *chan, + struct page *dest_pg, unsigned int dest_off, + struct page **src_pgs, unsigned int src_cnt, + unsigned int src_off, size_t len); + enum dma_status (*device_operation_complete)(struct dma_chan *chan, dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used); - void (*device_memcpy_issue_pending)(struct dma_chan *chan); + void (*device_issue_pending)(struct dma_chan *chan); }; /* --- public DMA engine API --- */ struct dma_client *dma_async_client_register(dma_event_callback event_callback); void dma_async_client_unregister(struct dma_client *client); -void dma_async_client_chan_request(struct dma_client *client, - unsigned int number); +int dma_async_client_chan_request(struct dma_client *client, + unsigned int number, unsigned int mask); +void dma_async_chan_init(struct dma_chan *chan, struct dma_device *device); +dma_cookie_t dma_async_xor_pgs_to_pg_err(struct dma_chan *chan, + struct page *dest_pg, unsigned int dest_off, struct page *src_pgs, + unsigned int src_cnt, unsigned int src_off, size_t len); /** * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses @@ -284,19 +355,65 @@ static inline dma_cookie_t dma_async_mem } /** - * dma_async_memcpy_issue_pending - flush pending copies to HW + * dma_async_xor_pgs_to_pg - offloaded xor from pages to page + * @chan: DMA channel to offload xor to + * @dest_page: destination page + * @dest_off: offset in page to xor to + * @src_pgs: array of source pages + * @src_cnt: number of source pages + * @src_off: offset in pages to xor from + * @len: length + * + * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus + * address according to the DMA mapping API rules for streaming mappings. + * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident + * (kernel memory or locked user space pages) + */ +static inline dma_cookie_t dma_async_xor_pgs_to_pg(struct dma_chan *chan, + struct page *dest_pg, unsigned int dest_off, struct page **src_pgs, + unsigned int src_cnt, unsigned int src_off, size_t len) +{ + int cpu = get_cpu(); + per_cpu_ptr(chan->local, cpu)->bytes_xor += len * src_cnt; + per_cpu_ptr(chan->local, cpu)->xor_count++; + put_cpu(); + + return chan->device->device_xor_pgs_to_pg(chan, dest_pg, dest_off, + src_pgs, src_cnt, src_off, len); +} + +/** + * dma_async_issue_pending - flush pending copies to HW * @chan: target DMA channel * - * This allows drivers to push copies to HW in batches, + * This allows drivers to push operations to HW in batches, * reducing MMIO writes where possible. */ -static inline void dma_async_memcpy_issue_pending(struct dma_chan *chan) +static inline void dma_async_issue_pending(struct dma_chan *chan) +{ + return chan->device->device_issue_pending(chan); +} + +/** + * dma_async_issue_all - call dma_async_issue_pending on all channels + * @client: &dma_client + */ +static inline void dma_async_issue_all(struct dma_client *client) { - return chan->device->device_memcpy_issue_pending(chan); + int i; + struct dma_chan_client_ref *chan_ref; + struct dma_req *req; + for (i = 0; i < DMA_MAX_CHAN_TYPE_REQ; i++) { + req = &client->req[i]; + rcu_read_lock(); + list_for_each_entry_rcu(chan_ref, &req->channels, req_node) + dma_async_issue_pending(chan_ref->chan); + rcu_read_unlock(); + } } /** - * dma_async_memcpy_complete - poll for transaction completion + * dma_async_operations_complete - poll for transaction completion * @chan: DMA channel * @cookie: transaction identifier to check status of * @last: returns last completed cookie, can be NULL @@ -306,10 +423,10 @@ static inline void dma_async_memcpy_issu * internal state and can be used with dma_async_is_complete() to check * the status of multiple cookies without re-checking hardware state. */ -static inline enum dma_status dma_async_memcpy_complete(struct dma_chan *chan, +static inline enum dma_status dma_async_operation_complete(struct dma_chan *chan, dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used) { - return chan->device->device_memcpy_complete(chan, cookie, last, used); + return chan->device->device_operation_complete(chan, cookie, last, used); } /** @@ -318,7 +435,7 @@ static inline enum dma_status dma_async_ * @last_complete: last know completed transaction * @last_used: last cookie value handed out * - * dma_async_is_complete() is used in dma_async_memcpy_complete() + * dma_async_is_complete() is used in dma_async_operation_complete() * the test logic is seperated for lightweight testing of multiple cookies */ static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie, @@ -334,7 +451,6 @@ static inline enum dma_status dma_async_ return DMA_IN_PROGRESS; } - /* --- DMA device --- */ int dma_async_device_register(struct dma_device *device); diff --git a/net/core/dev.c b/net/core/dev.c index d4a1ec3..9447f94 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1941,13 +1941,8 @@ #ifdef CONFIG_NET_DMA * There may not be any more sk_buffs coming right now, so push * any pending DMA copies to hardware */ - if (net_dma_client) { - struct dma_chan *chan; - rcu_read_lock(); - list_for_each_entry_rcu(chan, &net_dma_client->channels, client_node) - dma_async_memcpy_issue_pending(chan); - rcu_read_unlock(); - } + if (net_dma_client) + dma_async_issue_all(net_dma_client); #endif local_irq_enable(); return; @@ -3410,7 +3405,8 @@ #ifdef CONFIG_NET_DMA static void net_dma_rebalance(void) { unsigned int cpu, i, n; - struct dma_chan *chan; + struct dma_chan_client_ref *chan_ref; + struct dma_req *req; if (net_dma_count == 0) { for_each_online_cpu(cpu) @@ -3421,13 +3417,16 @@ static void net_dma_rebalance(void) i = 0; cpu = first_cpu(cpu_online_map); + /* NET_DMA only requests one type of dma channel (memcpy) */ + req = &net_dma_client->req[0]; + rcu_read_lock(); - list_for_each_entry(chan, &net_dma_client->channels, client_node) { + list_for_each_entry(chan_ref, &req->channels, req_node) { n = ((num_online_cpus() / net_dma_count) + (i < (num_online_cpus() % net_dma_count) ? 1 : 0)); while(n) { - per_cpu(softnet_data, cpu).net_dma = chan; + per_cpu(softnet_data, cpu).net_dma = chan_ref->chan; cpu = next_cpu(cpu, cpu_online_map); n--; } @@ -3471,7 +3470,7 @@ static int __init netdev_dma_register(vo if (net_dma_client == NULL) return -ENOMEM; - dma_async_client_chan_request(net_dma_client, num_online_cpus()); + dma_async_client_chan_request(net_dma_client, num_online_cpus(), DMA_MEMCPY); return 0; } diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 934396b..cd8ad41 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1431,9 +1431,9 @@ #ifdef CONFIG_NET_DMA struct sk_buff *skb; dma_cookie_t done, used; - dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); + dma_async_issue_pending(tp->ucopy.dma_chan); - while (dma_async_memcpy_complete(tp->ucopy.dma_chan, + while (dma_async_operation_complete(tp->ucopy.dma_chan, tp->ucopy.dma_cookie, &done, &used) == DMA_IN_PROGRESS) { /* do partial cleanup of sk_async_wait_queue */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/