Staging
v0.5.2
v0.5.2
https://github.com/torvalds/linux
Tip revision: 60b341b778cc2929df16c0a504c91621b3c6a4ad authored by Linus Torvalds on 24 February 2010, 18:52:17 UTC
Linux 2.6.33
Linux 2.6.33
Tip revision: 60b341b
dmaengine.h
/*
* 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/dma-mapping.h>
/**
* 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
*
* Note: The DMA_ASYNC_TX capability is not to be set by drivers. It is
* automatically set as dma devices are registered.
*/
enum dma_transaction_type {
DMA_MEMCPY,
DMA_XOR,
DMA_PQ,
DMA_XOR_VAL,
DMA_PQ_VAL,
DMA_MEMSET,
DMA_INTERRUPT,
DMA_PRIVATE,
DMA_ASYNC_TX,
DMA_SLAVE,
};
/* last transaction type for creation of the capabilities mask */
#define DMA_TX_TYPE_END (DMA_SLAVE + 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 - if clear, the descriptor cannot be reused until the client
* acknowledges receipt, i.e. has has a chance to establish any dependency
* chains
* @DMA_COMPL_SKIP_SRC_UNMAP - set to disable dma-unmapping the source buffer(s)
* @DMA_COMPL_SKIP_DEST_UNMAP - set to disable dma-unmapping the destination(s)
* @DMA_COMPL_SRC_UNMAP_SINGLE - set to do the source dma-unmapping as single
* (if not set, do the source dma-unmapping as page)
* @DMA_COMPL_DEST_UNMAP_SINGLE - set to do the destination dma-unmapping as single
* (if not set, do the destination dma-unmapping as page)
* @DMA_PREP_PQ_DISABLE_P - prevent generation of P while generating Q
* @DMA_PREP_PQ_DISABLE_Q - prevent generation of Q while generating P
* @DMA_PREP_CONTINUE - indicate to a driver that it is reusing buffers as
* sources that were the result of a previous operation, in the case of a PQ
* operation it continues the calculation with new sources
* @DMA_PREP_FENCE - tell the driver that subsequent operations depend
* on the result of this operation
*/
enum dma_ctrl_flags {
DMA_PREP_INTERRUPT = (1 << 0),
DMA_CTRL_ACK = (1 << 1),
DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
DMA_COMPL_SRC_UNMAP_SINGLE = (1 << 4),
DMA_COMPL_DEST_UNMAP_SINGLE = (1 << 5),
DMA_PREP_PQ_DISABLE_P = (1 << 6),
DMA_PREP_PQ_DISABLE_Q = (1 << 7),
DMA_PREP_CONTINUE = (1 << 8),
DMA_PREP_FENCE = (1 << 9),
};
/**
* enum sum_check_bits - bit position of pq_check_flags
*/
enum sum_check_bits {
SUM_CHECK_P = 0,
SUM_CHECK_Q = 1,
};
/**
* enum pq_check_flags - result of async_{xor,pq}_zero_sum operations
* @SUM_CHECK_P_RESULT - 1 if xor zero sum error, 0 otherwise
* @SUM_CHECK_Q_RESULT - 1 if reed-solomon zero sum error, 0 otherwise
*/
enum sum_check_flags {
SUM_CHECK_P_RESULT = (1 << SUM_CHECK_P),
SUM_CHECK_Q_RESULT = (1 << SUM_CHECK_Q),
};
/**
* 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
* @memcpy_count: transaction counter
* @bytes_transferred: byte counter
*/
struct dma_chan_percpu {
/* 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
* @dev: class device for sysfs
* @device_node: used to add this to the device chan list
* @local: per-cpu pointer to a struct dma_chan_percpu
* @client-count: how many clients are using this channel
* @table_count: number of appearances in the mem-to-mem allocation table
* @private: private data for certain client-channel associations
*/
struct dma_chan {
struct dma_device *device;
dma_cookie_t cookie;
/* sysfs */
int chan_id;
struct dma_chan_dev *dev;
struct list_head device_node;
struct dma_chan_percpu *local;
int client_count;
int table_count;
void *private;
};
/**
* struct dma_chan_dev - relate sysfs device node to backing channel device
* @chan - driver channel device
* @device - sysfs device
* @dev_id - parent dma_device dev_id
* @idr_ref - reference count to gate release of dma_device dev_id
*/
struct dma_chan_dev {
struct dma_chan *chan;
struct device device;
int dev_id;
atomic_t *idr_ref;
};
static inline const char *dma_chan_name(struct dma_chan *chan)
{
return dev_name(&chan->dev->device);
}
void dma_chan_cleanup(struct kref *kref);
/**
* typedef dma_filter_fn - callback filter for dma_request_channel
* @chan: channel to be reviewed
* @filter_param: opaque parameter passed through dma_request_channel
*
* When this optional parameter is specified in a call to dma_request_channel a
* suitable channel is passed to this routine for further dispositioning before
* being returned. Where 'suitable' indicates a non-busy channel that
* satisfies the given capability mask. It returns 'true' to indicate that the
* channel is suitable.
*/
typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
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
* @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 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
* @privatecnt: how many DMA channels are requested by dma_request_channel
* @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
* @max_pq: maximum number of PQ sources and PQ-continue capability
* @copy_align: alignment shift for memcpy operations
* @xor_align: alignment shift for xor operations
* @pq_align: alignment shift for pq operations
* @fill_align: alignment shift for memset operations
* @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_xor_val: prepares a xor validation operation
* @device_prep_dma_pq: prepares a pq operation
* @device_prep_dma_pq_val: prepares a pqzero_sum operation
* @device_prep_dma_memset: prepares a memset operation
* @device_prep_dma_interrupt: prepares an end of chain interrupt operation
* @device_prep_slave_sg: prepares a slave dma operation
* @device_terminate_all: terminate all pending operations
* @device_is_tx_complete: poll for transaction completion
* @device_issue_pending: push pending transactions to hardware
*/
struct dma_device {
unsigned int chancnt;
unsigned int privatecnt;
struct list_head channels;
struct list_head global_node;
dma_cap_mask_t cap_mask;
unsigned short max_xor;
unsigned short max_pq;
u8 copy_align;
u8 xor_align;
u8 pq_align;
u8 fill_align;
#define DMA_HAS_PQ_CONTINUE (1 << 15)
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_xor_val)(
struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt,
size_t len, enum sum_check_flags *result, unsigned long flags);
struct dma_async_tx_descriptor *(*device_prep_dma_pq)(
struct dma_chan *chan, dma_addr_t *dst, dma_addr_t *src,
unsigned int src_cnt, const unsigned char *scf,
size_t len, unsigned long flags);
struct dma_async_tx_descriptor *(*device_prep_dma_pq_val)(
struct dma_chan *chan, dma_addr_t *pq, dma_addr_t *src,
unsigned int src_cnt, const unsigned char *scf, size_t len,
enum sum_check_flags *pqres, 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);
struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_data_direction direction,
unsigned long flags);
void (*device_terminate_all)(struct dma_chan *chan);
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);
};
static inline bool dmaengine_check_align(u8 align, size_t off1, size_t off2, size_t len)
{
size_t mask;
if (!align)
return true;
mask = (1 << align) - 1;
if (mask & (off1 | off2 | len))
return false;
return true;
}
static inline bool is_dma_copy_aligned(struct dma_device *dev, size_t off1,
size_t off2, size_t len)
{
return dmaengine_check_align(dev->copy_align, off1, off2, len);
}
static inline bool is_dma_xor_aligned(struct dma_device *dev, size_t off1,
size_t off2, size_t len)
{
return dmaengine_check_align(dev->xor_align, off1, off2, len);
}
static inline bool is_dma_pq_aligned(struct dma_device *dev, size_t off1,
size_t off2, size_t len)
{
return dmaengine_check_align(dev->pq_align, off1, off2, len);
}
static inline bool is_dma_fill_aligned(struct dma_device *dev, size_t off1,
size_t off2, size_t len)
{
return dmaengine_check_align(dev->fill_align, off1, off2, len);
}
static inline void
dma_set_maxpq(struct dma_device *dma, int maxpq, int has_pq_continue)
{
dma->max_pq = maxpq;
if (has_pq_continue)
dma->max_pq |= DMA_HAS_PQ_CONTINUE;
}
static inline bool dmaf_continue(enum dma_ctrl_flags flags)
{
return (flags & DMA_PREP_CONTINUE) == DMA_PREP_CONTINUE;
}
static inline bool dmaf_p_disabled_continue(enum dma_ctrl_flags flags)
{
enum dma_ctrl_flags mask = DMA_PREP_CONTINUE | DMA_PREP_PQ_DISABLE_P;
return (flags & mask) == mask;
}
static inline bool dma_dev_has_pq_continue(struct dma_device *dma)
{
return (dma->max_pq & DMA_HAS_PQ_CONTINUE) == DMA_HAS_PQ_CONTINUE;
}
static unsigned short dma_dev_to_maxpq(struct dma_device *dma)
{
return dma->max_pq & ~DMA_HAS_PQ_CONTINUE;
}
/* dma_maxpq - reduce maxpq in the face of continued operations
* @dma - dma device with PQ capability
* @flags - to check if DMA_PREP_CONTINUE and DMA_PREP_PQ_DISABLE_P are set
*
* When an engine does not support native continuation we need 3 extra
* source slots to reuse P and Q with the following coefficients:
* 1/ {00} * P : remove P from Q', but use it as a source for P'
* 2/ {01} * Q : use Q to continue Q' calculation
* 3/ {00} * Q : subtract Q from P' to cancel (2)
*
* In the case where P is disabled we only need 1 extra source:
* 1/ {01} * Q : use Q to continue Q' calculation
*/
static inline int dma_maxpq(struct dma_device *dma, enum dma_ctrl_flags flags)
{
if (dma_dev_has_pq_continue(dma) || !dmaf_continue(flags))
return dma_dev_to_maxpq(dma);
else if (dmaf_p_disabled_continue(flags))
return dma_dev_to_maxpq(dma) - 1;
else if (dmaf_continue(flags))
return dma_dev_to_maxpq(dma) - 3;
BUG();
}
/* --- public DMA engine API --- */
#ifdef CONFIG_DMA_ENGINE
void dmaengine_get(void);
void dmaengine_put(void);
#else
static inline void dmaengine_get(void)
{
}
static inline void dmaengine_put(void)
{
}
#endif
#ifdef CONFIG_NET_DMA
#define net_dmaengine_get() dmaengine_get()
#define net_dmaengine_put() dmaengine_put()
#else
static inline void net_dmaengine_get(void)
{
}
static inline void net_dmaengine_put(void)
{
}
#endif
#ifdef CONFIG_ASYNC_TX_DMA
#define async_dmaengine_get() dmaengine_get()
#define async_dmaengine_put() dmaengine_put()
#ifdef CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH
#define async_dma_find_channel(type) dma_find_channel(DMA_ASYNC_TX)
#else
#define async_dma_find_channel(type) dma_find_channel(type)
#endif /* CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH */
#else
static inline void async_dmaengine_get(void)
{
}
static inline void async_dmaengine_put(void)
{
}
static inline struct dma_chan *
async_dma_find_channel(enum dma_transaction_type type)
{
return NULL;
}
#endif /* CONFIG_ASYNC_TX_DMA */
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 void async_tx_clear_ack(struct dma_async_tx_descriptor *tx)
{
tx->flags &= ~DMA_CTRL_ACK;
}
static inline bool async_tx_test_ack(struct dma_async_tx_descriptor *tx)
{
return (tx->flags & DMA_CTRL_ACK) == 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_cap_clear(tx, mask) __dma_cap_clear((tx), &(mask))
static inline void
__dma_cap_clear(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
{
clear_bit(tx_type, dstp->bits);
}
#define dma_cap_zero(mask) __dma_cap_zero(&(mask))
static inline void __dma_cap_zero(dma_cap_mask_t *dstp)
{
bitmap_zero(dstp->bits, DMA_TX_TYPE_END);
}
#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);
#ifdef CONFIG_DMA_ENGINE
enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
void dma_issue_pending_all(void);
#else
static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
{
return DMA_SUCCESS;
}
static inline void dma_issue_pending_all(void)
{
do { } while (0);
}
#endif
/* --- DMA device --- */
int dma_async_device_register(struct dma_device *device);
void dma_async_device_unregister(struct dma_device *device);
void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
void dma_release_channel(struct dma_chan *chan);
/* --- 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 */