/* * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 * Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * The full GNU General Public License is included in this distribution in the * file called COPYING. */ #ifndef DMAENGINE_H #define DMAENGINE_H #ifdef CONFIG_DMA_ENGINE #include <linux/device.h> #include <linux/uio.h> #include <linux/kref.h> #include <linux/completion.h> #include <linux/rcupdate.h> /** * enum dma_event - resource PNP/power managment events * @DMA_RESOURCE_SUSPEND: DMA device going into low power state * @DMA_RESOURCE_RESUME: DMA device returning to full power * @DMA_RESOURCE_ADDED: DMA device added to the system * @DMA_RESOURCE_REMOVED: DMA device removed from the system */ enum dma_event { DMA_RESOURCE_SUSPEND, DMA_RESOURCE_RESUME, DMA_RESOURCE_ADDED, DMA_RESOURCE_REMOVED, }; /** * typedef dma_cookie_t * * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code */ typedef s32 dma_cookie_t; #define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0) /** * enum dma_status - DMA transaction status * @DMA_SUCCESS: transaction completed successfully * @DMA_IN_PROGRESS: transaction not yet processed * @DMA_ERROR: transaction failed */ enum dma_status { DMA_SUCCESS, DMA_IN_PROGRESS, DMA_ERROR, }; /** * 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 * @bytes_transferred: byte counter */ struct dma_chan_percpu { local_t refcount; /* stats */ unsigned long memcpy_count; unsigned long bytes_transferred; }; /** * struct dma_chan - devices supply DMA channels, clients use them * @client: ptr to the client user of this chan, will be NULL when unused * @device: ptr to the dma device who supplies this channel, always !NULL * @cookie: last cookie value returned to client * @chan_id: * @class_dev: * @refcount: kref, used in "bigref" slow-mode * @slow_ref: * @rcu: * @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 dma_device *device; dma_cookie_t cookie; /* sysfs */ int chan_id; struct class_device class_dev; struct kref refcount; int slow_ref; struct rcu_head rcu; struct list_head client_node; struct list_head device_node; struct dma_chan_percpu *local; }; void dma_chan_cleanup(struct kref *kref); static inline void dma_chan_get(struct dma_chan *chan) { if (unlikely(chan->slow_ref)) kref_get(&chan->refcount); else { local_inc(&(per_cpu_ptr(chan->local, get_cpu())->refcount)); put_cpu(); } } static inline void dma_chan_put(struct dma_chan *chan) { if (unlikely(chan->slow_ref)) kref_put(&chan->refcount, dma_chan_cleanup); else { local_dec(&(per_cpu_ptr(chan->local, get_cpu())->refcount)); put_cpu(); } } /* * typedef dma_event_callback - function pointer to a DMA event callback */ typedef void (*dma_event_callback) (struct dma_client *client, 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 * @chan_count: number of chans allocated * @chans_desired: number of chans requested. Can be +/- chan_count * @lock: protects access to the channels list * @channels: the list of DMA channels allocated * @global_node: list_head for global dma_client_list */ struct dma_client { dma_event_callback event_callback; unsigned int chan_count; unsigned int chans_desired; spinlock_t lock; struct list_head channels; struct list_head global_node; }; /** * 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 * @refcount: * @done: * @dev_id: * Other func ptrs: used to make use of this device's capabilities */ struct dma_device { unsigned int chancnt; struct list_head channels; struct list_head global_node; struct kref refcount; struct completion done; int dev_id; int (*device_alloc_chan_resources)(struct dma_chan *chan); void (*device_free_chan_resources)(struct dma_chan *chan); dma_cookie_t (*device_memcpy_buf_to_buf)(struct dma_chan *chan, void *dest, void *src, size_t len); dma_cookie_t (*device_memcpy_buf_to_pg)(struct dma_chan *chan, struct page *page, unsigned int offset, void *kdata, size_t len); 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 cookie, dma_cookie_t *last, dma_cookie_t *used); void (*device_memcpy_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); /** * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses * @chan: DMA channel to offload copy to * @dest: destination address (virtual) * @src: source address (virtual) * @len: length * * Both @dest and @src must be mappable to a bus address according to the * DMA mapping API rules for streaming mappings. * Both @dest and @src must stay memory resident (kernel memory or locked * user space pages) */ static inline dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, void *src, size_t len) { int cpu = get_cpu(); per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; per_cpu_ptr(chan->local, cpu)->memcpy_count++; put_cpu(); return chan->device->device_memcpy_buf_to_buf(chan, dest, src, len); } /** * dma_async_memcpy_buf_to_pg - offloaded copy * @chan: DMA channel to offload copy to * @page: destination page * @offset: offset in page to copy to * @kdata: source address (virtual) * @len: length * * Both @page/@offset and @kdata must be mappable to a bus address according * to the DMA mapping API rules for streaming mappings. * Both @page/@offset and @kdata must stay memory resident (kernel memory or * locked user space pages) */ static inline dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page, unsigned int offset, void *kdata, size_t len) { int cpu = get_cpu(); per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; per_cpu_ptr(chan->local, cpu)->memcpy_count++; put_cpu(); return chan->device->device_memcpy_buf_to_pg(chan, page, offset, kdata, len); } /** * dma_async_memcpy_buf_to_pg - offloaded copy * @chan: DMA channel to offload copy to * @dest_page: destination page * @dest_off: offset in page to copy to * @src_page: source page * @src_off: offset in page to copy 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_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) { int cpu = get_cpu(); per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; per_cpu_ptr(chan->local, cpu)->memcpy_count++; put_cpu(); return chan->device->device_memcpy_pg_to_pg(chan, dest_pg, dest_off, src_pg, src_off, len); } /** * dma_async_memcpy_issue_pending - flush pending copies to HW * @chan: * * This allows drivers to push copies to HW in batches, * reducing MMIO writes where possible. */ static inline void dma_async_memcpy_issue_pending(struct dma_chan *chan) { return chan->device->device_memcpy_issue_pending(chan); } /** * dma_async_memcpy_complete - poll for transaction completion * @chan: DMA channel * @cookie: transaction identifier to check status of * @last: returns last completed cookie, can be NULL * @used: returns last issued cookie, can be NULL * * If @last and @used are passed in, upon return they reflect the driver * 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, dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used) { return chan->device->device_memcpy_complete(chan, cookie, last, used); } /** * dma_async_is_complete - test a cookie against chan state * @cookie: transaction identifier to test status of * @last_complete: last know completed transaction * @last_used: last cookie value handed out * * dma_async_is_complete() is used in dma_async_memcpy_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, dma_cookie_t last_complete, dma_cookie_t last_used) { if (last_complete <= last_used) { if ((cookie <= last_complete) || (cookie > last_used)) return DMA_SUCCESS; } else { if ((cookie <= last_complete) && (cookie > last_used)) return DMA_SUCCESS; } return DMA_IN_PROGRESS; } /* --- DMA device --- */ int dma_async_device_register(struct dma_device *device); void dma_async_device_unregister(struct dma_device *device); /* --- Helper iov-locking functions --- */ struct dma_page_list { char *base_address; int nr_pages; struct page **pages; }; struct dma_pinned_list { int nr_iovecs; struct dma_page_list page_list[0]; }; struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len); void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list); dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov, struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len); dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov, struct dma_pinned_list *pinned_list, struct page *page, unsigned int offset, size_t len); #endif /* CONFIG_DMA_ENGINE */ #endif /* DMAENGINE_H */