kernel-ark/include/linux/async_tx.h
Dan Williams eb0645a8b1 async_tx: fix kmap_atomic usage in async_memcpy
Andrew Morton:
	[async_memcpy] is very wrong if both ASYNC_TX_KMAP_DST and
	ASYNC_TX_KMAP_SRC can ever be set.  We'll end up using the same kmap
	slot for both src add dest and we get either corrupted data or a BUG.

Evgeniy Polyakov:
	Btw, shouldn't it always be kmap_atomic() even if flag is not set.
	That pages are usual one returned by alloc_page().

So fix the usage of kmap_atomic and kill the ASYNC_TX_KMAP_DST and
ASYNC_TX_KMAP_SRC flags.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20 08:44:19 -07:00

151 lines
5.0 KiB
C

/*
* Copyright © 2006, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#ifndef _ASYNC_TX_H_
#define _ASYNC_TX_H_
#include <linux/dmaengine.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
/**
* dma_chan_ref - object used to manage dma channels received from the
* dmaengine core.
* @chan - the channel being tracked
* @node - node for the channel to be placed on async_tx_master_list
* @rcu - for list_del_rcu
* @count - number of times this channel is listed in the pool
* (for channels with multiple capabiities)
*/
struct dma_chan_ref {
struct dma_chan *chan;
struct list_head node;
struct rcu_head rcu;
atomic_t count;
};
/**
* async_tx_flags - modifiers for the async_* calls
* @ASYNC_TX_XOR_ZERO_DST: this flag must be used for xor operations where the
* the destination address is not a source. The asynchronous case handles this
* implicitly, the synchronous case needs to zero the destination block.
* @ASYNC_TX_XOR_DROP_DST: this flag must be used if the destination address is
* also one of the source addresses. In the synchronous case the destination
* address is an implied source, whereas the asynchronous case it must be listed
* as a source. The destination address must be the first address in the source
* array.
* @ASYNC_TX_ASSUME_COHERENT: skip cache maintenance operations
* @ASYNC_TX_ACK: immediately ack the descriptor, precludes setting up a
* dependency chain
* @ASYNC_TX_DEP_ACK: ack the dependency descriptor. Useful for chaining.
*/
enum async_tx_flags {
ASYNC_TX_XOR_ZERO_DST = (1 << 0),
ASYNC_TX_XOR_DROP_DST = (1 << 1),
ASYNC_TX_ASSUME_COHERENT = (1 << 2),
ASYNC_TX_ACK = (1 << 3),
ASYNC_TX_DEP_ACK = (1 << 4),
};
#ifdef CONFIG_DMA_ENGINE
void async_tx_issue_pending_all(void);
enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
void async_tx_run_dependencies(struct dma_async_tx_descriptor *tx);
struct dma_chan *
async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx,
enum dma_transaction_type tx_type);
#else
static inline void async_tx_issue_pending_all(void)
{
do { } while (0);
}
static inline enum dma_status
dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
{
return DMA_SUCCESS;
}
static inline void
async_tx_run_dependencies(struct dma_async_tx_descriptor *tx,
struct dma_chan *host_chan)
{
do { } while (0);
}
static inline struct dma_chan *
async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx,
enum dma_transaction_type tx_type)
{
return NULL;
}
#endif
/**
* async_tx_sync_epilog - actions to take if an operation is run synchronously
* @flags: async_tx flags
* @depend_tx: transaction depends on depend_tx
* @cb_fn: function to call when the transaction completes
* @cb_fn_param: parameter to pass to the callback routine
*/
static inline void
async_tx_sync_epilog(unsigned long flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param)
{
if (cb_fn)
cb_fn(cb_fn_param);
if (depend_tx && (flags & ASYNC_TX_DEP_ACK))
async_tx_ack(depend_tx);
}
void
async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param);
struct dma_async_tx_descriptor *
async_xor(struct page *dest, struct page **src_list, unsigned int offset,
int src_cnt, size_t len, enum async_tx_flags flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param);
struct dma_async_tx_descriptor *
async_xor_zero_sum(struct page *dest, struct page **src_list,
unsigned int offset, int src_cnt, size_t len,
u32 *result, enum async_tx_flags flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param);
struct dma_async_tx_descriptor *
async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
unsigned int src_offset, size_t len, enum async_tx_flags flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param);
struct dma_async_tx_descriptor *
async_memset(struct page *dest, int val, unsigned int offset,
size_t len, enum async_tx_flags flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param);
struct dma_async_tx_descriptor *
async_trigger_callback(enum async_tx_flags flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param);
#endif /* _ASYNC_TX_H_ */