/* * 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 #include <linux/device.h> #include <linux/uio.h> #include <linux/kref.h> #include <linux/completion.h> #include <linux/rcupdate.h> #include <linux/dma-mapping.h> /** * enum dma_state - resource PNP/power management state * @DMA_RESOURCE_SUSPEND: DMA device going into low power state * @DMA_RESOURCE_RESUME: DMA device returning to full power * @DMA_RESOURCE_AVAILABLE: DMA device available to the system * @DMA_RESOURCE_REMOVED: DMA device removed from the system */ enum dma_state { DMA_RESOURCE_SUSPEND, DMA_RESOURCE_RESUME, DMA_RESOURCE_AVAILABLE, DMA_RESOURCE_REMOVED, }; /** * enum dma_state_client - state of the channel in the client * @DMA_ACK: client would like to use, or was using this channel * @DMA_DUP: client has already seen this channel, or is not using this channel * @DMA_NAK: client does not want to see any more channels */ enum dma_state_client { DMA_ACK, DMA_DUP, DMA_NAK, }; /** * typedef dma_cookie_t - an opaque DMA cookie * * 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, }; /** * enum dma_transaction_type - DMA transaction types/indexes */ enum dma_transaction_type { DMA_MEMCPY, DMA_XOR, DMA_PQ_XOR, DMA_DUAL_XOR, DMA_PQ_UPDATE, DMA_ZERO_SUM, DMA_PQ_ZERO_SUM, DMA_MEMSET, DMA_MEMCPY_CRC32C, DMA_INTERRUPT, }; /* last transaction type for creation of the capabilities mask */ #define DMA_TX_TYPE_END (DMA_INTERRUPT + 1) /** * enum dma_ctrl_flags - DMA flags to augment operation preparation, * control completion, and communicate status. * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of * this transaction * @DMA_CTRL_ACK - the descriptor cannot be reused until the client * acknowledges receipt, i.e. has has a chance to establish any * dependency chains */ enum dma_ctrl_flags { DMA_PREP_INTERRUPT = (1 << 0), DMA_CTRL_ACK = (1 << 1), }; /** * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t. * See linux/cpumask.h */ typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t; /** * 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 * @device: ptr to the dma device who supplies this channel, always !%NULL * @cookie: last cookie value returned to client * @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 * @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_device *device; dma_cookie_t cookie; /* sysfs */ int chan_id; struct device dev; struct kref refcount; int slow_ref; struct rcu_head rcu; struct list_head device_node; struct dma_chan_percpu *local; }; #define to_dma_chan(p) container_of(p, struct dma_chan, dev) 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 * For each channel added to the system this routine is called for each client. * If the client would like to use the channel it returns '1' to signal (ack) * the dmaengine core to take out a reference on the channel and its * corresponding device. A client must not 'ack' an available channel more * than once. When a channel is removed all clients are notified. If a client * is using the channel it must 'ack' the removal. A client must not 'ack' a * removed channel more than once. * @client - 'this' pointer for the client context * @chan - channel to be acted upon * @state - available or removed */ struct dma_client; typedef enum dma_state_client (*dma_event_callback) (struct dma_client *client, struct dma_chan *chan, enum dma_state state); /** * struct dma_client - info on the entity making use of DMA services * @event_callback: func ptr to call when something happens * @cap_mask: only return channels that satisfy the requested capabilities * a value of zero corresponds to any capability * @global_node: list_head for global dma_client_list */ struct dma_client { dma_event_callback event_callback; dma_cap_mask_t cap_mask; struct list_head global_node; }; typedef void (*dma_async_tx_callback)(void *dma_async_param); /** * struct dma_async_tx_descriptor - async transaction descriptor * ---dma generic offload fields--- * @cookie: tracking cookie for this transaction, set to -EBUSY if * this tx is sitting on a dependency list * @flags: flags to augment operation preparation, control completion, and * communicate status * @phys: physical address of the descriptor * @tx_list: driver common field for operations that require multiple * descriptors * @chan: target channel for this operation * @tx_submit: set the prepared descriptor(s) to be executed by the engine * @callback: routine to call after this operation is complete * @callback_param: general parameter to pass to the callback routine * ---async_tx api specific fields--- * @next: at completion submit this descriptor * @parent: pointer to the next level up in the dependency chain * @lock: protect the parent and next pointers */ struct dma_async_tx_descriptor { dma_cookie_t cookie; enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */ dma_addr_t phys; struct list_head tx_list; struct dma_chan *chan; dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx); dma_async_tx_callback callback; void *callback_param; struct dma_async_tx_descriptor *next; struct dma_async_tx_descriptor *parent; spinlock_t lock; }; /** * 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 * @cap_mask: one or more dma_capability flags * @max_xor: maximum number of xor sources, 0 if no capability * @refcount: reference count * @done: IO completion struct * @dev_id: unique device ID * @dev: struct device reference for dma mapping api * @device_alloc_chan_resources: allocate resources and return the * number of allocated descriptors * @device_free_chan_resources: release DMA channel's resources * @device_prep_dma_memcpy: prepares a memcpy operation * @device_prep_dma_xor: prepares a xor operation * @device_prep_dma_zero_sum: prepares a zero_sum operation * @device_prep_dma_memset: prepares a memset operation * @device_prep_dma_interrupt: prepares an end of chain interrupt operation * @device_issue_pending: push pending transactions to hardware */ struct dma_device { unsigned int chancnt; struct list_head channels; struct list_head global_node; dma_cap_mask_t cap_mask; int max_xor; struct kref refcount; struct completion done; int dev_id; struct device *dev; int (*device_alloc_chan_resources)(struct dma_chan *chan); void (*device_free_chan_resources)(struct dma_chan *chan); struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)( struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len, unsigned long flags); struct dma_async_tx_descriptor *(*device_prep_dma_xor)( struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src, unsigned int src_cnt, size_t len, unsigned long flags); struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)( struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt, size_t len, u32 *result, unsigned long flags); struct dma_async_tx_descriptor *(*device_prep_dma_memset)( struct dma_chan *chan, dma_addr_t dest, int value, size_t len, unsigned long flags); struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)( struct dma_chan *chan, unsigned long flags); enum dma_status (*device_is_tx_complete)(struct dma_chan *chan, dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used); void (*device_issue_pending)(struct dma_chan *chan); }; /* --- public DMA engine API --- */ void dma_async_client_register(struct dma_client *client); void dma_async_client_unregister(struct dma_client *client); void dma_async_client_chan_request(struct dma_client *client); dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, void *src, size_t len); dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page, unsigned int offset, void *kdata, size_t len); 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); void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, struct dma_chan *chan); static inline void async_tx_ack(struct dma_async_tx_descriptor *tx) { tx->flags |= DMA_CTRL_ACK; } static inline int async_tx_test_ack(struct dma_async_tx_descriptor *tx) { return tx->flags & DMA_CTRL_ACK; } #define first_dma_cap(mask) __first_dma_cap(&(mask)) static inline int __first_dma_cap(const dma_cap_mask_t *srcp) { return min_t(int, DMA_TX_TYPE_END, find_first_bit(srcp->bits, DMA_TX_TYPE_END)); } #define next_dma_cap(n, mask) __next_dma_cap((n), &(mask)) static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp) { return min_t(int, DMA_TX_TYPE_END, find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1)); } #define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask)) static inline void __dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp) { set_bit(tx_type, dstp->bits); } #define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask)) static inline int __dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp) { return test_bit(tx_type, srcp->bits); } #define for_each_dma_cap_mask(cap, mask) \ for ((cap) = first_dma_cap(mask); \ (cap) < DMA_TX_TYPE_END; \ (cap) = next_dma_cap((cap), (mask))) /** * dma_async_issue_pending - flush pending transactions to HW * @chan: target DMA channel * * This allows drivers to push copies to HW in batches, * reducing MMIO writes where possible. */ static inline void dma_async_issue_pending(struct dma_chan *chan) { chan->device->device_issue_pending(chan); } #define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan) /** * dma_async_is_tx_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_is_tx_complete(struct dma_chan *chan, dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used) { return chan->device->device_is_tx_complete(chan, cookie, last, used); } #define dma_async_memcpy_complete(chan, cookie, last, used)\ dma_async_is_tx_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 separated 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; } enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie); /* --- 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 __user *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 /* DMAENGINE_H */