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dmaengine: refactor dmaengine around dma_async_tx_descriptor

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The current dmaengine interface defines mutliple routines per operation,
i.e. dma_async_memcpy_buf_to_buf, dma_async_memcpy_buf_to_page etc.  Adding
more operation types (xor, crc, etc) to this model would result in an
unmanageable number of method permutations.

	Are we really going to add a set of hooks for each DMA engine
	whizbang feature?
		- Jeff Garzik

The descriptor creation process is refactored using the new common
dma_async_tx_descriptor structure.  Instead of per driver
do_<operation>_<dest>_to_<src> methods, drivers integrate
dma_async_tx_descriptor into their private software descriptor and then
define a 'prep' routine per operation.  The prep routine allocates a
descriptor and ensures that the tx_set_src, tx_set_dest, tx_submit routines
are valid.  Descriptor creation and submission becomes:

struct dma_device *dev;
struct dma_chan *chan;
struct dma_async_tx_descriptor *tx;

tx = dev->device_prep_dma_<operation>(chan, len, int_flag)
tx->tx_set_src(dma_addr_t, tx, index /* for multi-source ops */)
tx->tx_set_dest(dma_addr_t, tx, index)
tx->tx_submit(tx)

In addition to the refactoring, dma_async_tx_descriptor also lays the
groundwork for definining cross-channel-operation dependencies, and a
callback facility for asynchronous notification of operation completion.

Changelog:
* drop dma mapping methods, suggested by Chris Leech
* fix ioat_dma_dependency_added, also caught by Andrew Morton
* fix dma_sync_wait, change from Andrew Morton
* uninline large functions, change from Andrew Morton
* add tx->callback = NULL to dmaengine calls to interoperate with async_tx
  calls
* hookup ioat_tx_submit
* convert channel capabilities to a 'cpumask_t like' bitmap
* removed DMA_TX_ARRAY_INIT, no longer needed
* checkpatch.pl fixes
* make set_src, set_dest, and tx_submit descriptor specific methods
* fixup git-ioat merge
* move group_list and phys to dma_async_tx_descriptor

Cc: Jeff Garzik <jeff@garzik.org>
Cc: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Williams 2007-01-02 11:10:43 -07:00
parent 428ed6024f
commit 7405f74bad
4 changed files with 482 additions and 261 deletions
Download patch file Download diff file Expand all files Collapse all files

253
include/linux/dmaengine.h
View file

@ -21,13 +21,12 @@
#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>
#include <linux/dma-mapping.h>
/**
* enum dma_event - resource PNP/power managment events
@ -64,6 +63,31 @@ enum dma_status {
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)
/**
* 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
@ -157,48 +181,106 @@ struct dma_client {
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
* @ack: the descriptor can not be reused until the client acknowledges
* receipt, i.e. has has a chance to establish any dependency chains
* @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
* @tx_set_dest: set a destination address in a hardware descriptor
* @tx_set_src: set a source address in a hardware descriptor
* @callback: routine to call after this operation is complete
* @callback_param: general parameter to pass to the callback routine
* ---async_tx api specific fields---
* @depend_list: at completion this list of transactions are submitted
* @depend_node: allow this transaction to be executed after another
* transaction has completed, possibly on another channel
* @parent: pointer to the next level up in the dependency chain
* @lock: protect the dependency list
*/
struct dma_async_tx_descriptor {
dma_cookie_t cookie;
int ack;
dma_addr_t phys;
struct list_head tx_list;
struct dma_chan *chan;
dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
void (*tx_set_dest)(dma_addr_t addr,
struct dma_async_tx_descriptor *tx, int index);
void (*tx_set_src)(dma_addr_t addr,
struct dma_async_tx_descriptor *tx, int index);
dma_async_tx_callback callback;
void *callback_param;
struct list_head depend_list;
struct list_head depend_node;
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_memcpy_buf_to_buf: memcpy buf pointer to buf pointer
* @device_memcpy_buf_to_pg: memcpy buf pointer to struct page
* @device_memcpy_pg_to_pg: memcpy struct page/offset to struct page/offset
* @device_memcpy_complete: poll the status of an IOAT DMA transaction
* @device_memcpy_issue_pending: push appended descriptors to hardware
* @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_dependency_added: async_tx notifies the channel about new deps
* @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);
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,
struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
struct dma_chan *chan, size_t len, int int_en);
struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
struct dma_chan *chan, unsigned int src_cnt, size_t len,
int int_en);
struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
struct dma_chan *chan, unsigned int src_cnt, size_t len,
u32 *result, int int_en);
struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
struct dma_chan *chan, int value, size_t len, int int_en);
struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
struct dma_chan *chan);
void (*device_dependency_added)(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_memcpy_issue_pending)(struct dma_chan *chan);
void (*device_issue_pending)(struct dma_chan *chan);
};
/* --- public DMA engine API --- */
@ -207,96 +289,72 @@ 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 from address to page
* @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_pg_to_pg - offloaded copy from page to page
* @chan: DMA channel to offload copy to
* @dest_pg: destination page
* @dest_off: offset in page to copy to
* @src_pg: 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,
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)
{
int cpu = get_cpu();
per_cpu_ptr(chan->local, cpu)->bytes_transferred += len;
per_cpu_ptr(chan->local, cpu)->memcpy_count++;
put_cpu();
unsigned int src_off, size_t len);
void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
struct dma_chan *chan);
return chan->device->device_memcpy_pg_to_pg(chan, dest_pg, dest_off,
src_pg, src_off, len);
static inline void
async_tx_ack(struct dma_async_tx_descriptor *tx)
{
tx->ack = 1;
}
#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_memcpy_issue_pending - flush pending copies to HW
* 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_memcpy_issue_pending(struct dma_chan *chan)
static inline void dma_async_issue_pending(struct dma_chan *chan)
{
return chan->device->device_memcpy_issue_pending(chan);
return chan->device->device_issue_pending(chan);
}
#define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
/**
* dma_async_memcpy_complete - poll for transaction completion
* 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
@ -306,12 +364,15 @@ static inline void dma_async_memcpy_issue_pending(struct dma_chan *chan)
* 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_is_tx_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_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
@ -334,6 +395,7 @@ static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
return DMA_IN_PROGRESS;
}
enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
/* --- DMA device --- */
@ -362,5 +424,4 @@ 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 */