linux/drivers/dma/ioatdma.h
Dan Williams 7405f74bad dmaengine: refactor dmaengine around dma_async_tx_descriptor
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>
2007-07-13 08:06:11 -07:00

125 lines
3.2 KiB
C

/*
* 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 IOATDMA_H
#define IOATDMA_H
#include <linux/dmaengine.h>
#include "ioatdma_hw.h"
#include <linux/init.h>
#include <linux/dmapool.h>
#include <linux/cache.h>
#include <linux/pci_ids.h>
#define IOAT_LOW_COMPLETION_MASK 0xffffffc0
extern struct list_head dma_device_list;
extern struct list_head dma_client_list;
/**
* struct ioat_device - internal representation of a IOAT device
* @pdev: PCI-Express device
* @reg_base: MMIO register space base address
* @dma_pool: for allocating DMA descriptors
* @common: embedded struct dma_device
* @msi: Message Signaled Interrupt number
*/
struct ioat_device {
struct pci_dev *pdev;
void __iomem *reg_base;
struct pci_pool *dma_pool;
struct pci_pool *completion_pool;
struct dma_device common;
u8 msi;
};
/**
* struct ioat_dma_chan - internal representation of a DMA channel
* @device:
* @reg_base:
* @sw_in_use:
* @completion:
* @completion_low:
* @completion_high:
* @completed_cookie: last cookie seen completed on cleanup
* @cookie: value of last cookie given to client
* @last_completion:
* @xfercap:
* @desc_lock:
* @free_desc:
* @used_desc:
* @resource:
* @device_node:
*/
struct ioat_dma_chan {
void __iomem *reg_base;
dma_cookie_t completed_cookie;
unsigned long last_completion;
u32 xfercap; /* XFERCAP register value expanded out */
spinlock_t cleanup_lock;
spinlock_t desc_lock;
struct list_head free_desc;
struct list_head used_desc;
int pending;
struct ioat_device *device;
struct dma_chan common;
dma_addr_t completion_addr;
union {
u64 full; /* HW completion writeback */
struct {
u32 low;
u32 high;
};
} *completion_virt;
};
/* wrapper around hardware descriptor format + additional software fields */
/**
* struct ioat_desc_sw - wrapper around hardware descriptor
* @hw: hardware DMA descriptor
* @node: this descriptor will either be on the free list,
* or attached to a transaction list (async_tx.tx_list)
* @tx_cnt: number of descriptors required to complete the transaction
* @async_tx: the generic software descriptor for all engines
*/
struct ioat_desc_sw {
struct ioat_dma_descriptor *hw;
struct list_head node;
int tx_cnt;
DECLARE_PCI_UNMAP_ADDR(src)
DECLARE_PCI_UNMAP_LEN(src_len)
DECLARE_PCI_UNMAP_ADDR(dst)
DECLARE_PCI_UNMAP_LEN(dst_len)
struct dma_async_tx_descriptor async_tx;
};
#endif /* IOATDMA_H */