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linux/drivers/dma/ioat/dma_v2.h

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ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
/*
* Copyright(c) 2004 - 2009 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_V2_H
#define IOATDMA_V2_H
#include <linux/dmaengine.h>
ioat: convert to circ_buf Use the common power-of-2 circular buffer macros. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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#include <linux/circ_buf.h>
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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#include "dma.h"
#include "hw.h"
extern int ioat_pending_level;
ioat3: split ioat3 support to its own file, add memset Up until this point the driver for Intel(R) QuickData Technology engines, specification versions 2 and 3, were mostly identical save for a few quirks. Version 3.2 hardware adds many new capabilities (like raid offload support) requiring some infrastructure that is not relevant for v2. For better code organization of the new funcionality move v3 and v3.2 support to its own file dma_v3.c, and export some routines from the base files (dma.c and dma_v2.c) that can be reused directly. The first new capability included in this code reorganization is support for v3.2 memset operations. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:55 +08:00
extern int ioat_ring_alloc_order;
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
/*
* workaround for IOAT ver.3.0 null descriptor issue
* (channel returns error when size is 0)
*/
#define NULL_DESC_BUFFER_SIZE 1
#define IOAT_MAX_ORDER 16
#define ioat_get_alloc_order() \
(min(ioat_ring_alloc_order, IOAT_MAX_ORDER))
ioat2,3: dynamically resize descriptor ring Increment the allocation order of the descriptor ring every time we run out of descriptors up to a maximum of allocation order specified by the module parameter 'ioat_max_alloc_order'. After each idle period decrement the allocation order to a minimum order of 'ioat_ring_alloc_order' (i.e. the default ring size, tunable as a module parameter). Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 03:02:01 +08:00
#define ioat_get_max_alloc_order() \
(min(ioat_ring_max_alloc_order, IOAT_MAX_ORDER))
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
/* struct ioat2_dma_chan - ioat v2 / v3 channel attributes
* @base: common ioat channel parameters
* @xfercap_log; log2 of channel max transfer length (for fast division)
* @head: allocated index
* @issued: hardware notification point
* @tail: cleanup index
* @dmacount: identical to 'head' except for occasionally resetting to zero
* @alloc_order: log2 of the number of allocated descriptors
* @ring: software ring buffer implementation of hardware ring
* @ring_lock: protects ring attributes
*/
struct ioat2_dma_chan {
struct ioat_chan_common base;
size_t xfercap_log;
u16 head;
u16 issued;
u16 tail;
u16 dmacount;
u16 alloc_order;
struct ioat_ring_ent **ring;
spinlock_t ring_lock;
};
static inline struct ioat2_dma_chan *to_ioat2_chan(struct dma_chan *c)
{
struct ioat_chan_common *chan = to_chan_common(c);
return container_of(chan, struct ioat2_dma_chan, base);
}
ioat: convert to circ_buf Use the common power-of-2 circular buffer macros. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-02 06:22:54 +08:00
static inline u16 ioat2_ring_size(struct ioat2_dma_chan *ioat)
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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{
ioat: convert to circ_buf Use the common power-of-2 circular buffer macros. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-02 06:22:54 +08:00
return 1 << ioat->alloc_order;
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
}
/* count of descriptors in flight with the engine */
static inline u16 ioat2_ring_active(struct ioat2_dma_chan *ioat)
{
ioat: convert to circ_buf Use the common power-of-2 circular buffer macros. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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return CIRC_CNT(ioat->head, ioat->tail, ioat2_ring_size(ioat));
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
}
/* count of descriptors pending submission to hardware */
static inline u16 ioat2_ring_pending(struct ioat2_dma_chan *ioat)
{
ioat: convert to circ_buf Use the common power-of-2 circular buffer macros. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-02 06:22:54 +08:00
return CIRC_CNT(ioat->head, ioat->issued, ioat2_ring_size(ioat));
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
}
static inline u16 ioat2_ring_space(struct ioat2_dma_chan *ioat)
{
ioat: convert to circ_buf Use the common power-of-2 circular buffer macros. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-02 06:22:54 +08:00
return ioat2_ring_size(ioat) - ioat2_ring_active(ioat);
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
}
/* assumes caller already checked space */
static inline u16 ioat2_desc_alloc(struct ioat2_dma_chan *ioat, u16 len)
{
ioat->head += len;
return ioat->head - len;
}
static inline u16 ioat2_xferlen_to_descs(struct ioat2_dma_chan *ioat, size_t len)
{
u16 num_descs = len >> ioat->xfercap_log;
num_descs += !!(len & ((1 << ioat->xfercap_log) - 1));
return num_descs;
}
ioat3: hardware version 3.2 register / descriptor definitions ioat3.2 adds raid5 and raid6 offload capabilities. Signed-off-by: Tom Picard <tom.s.picard@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:54 +08:00
/**
* struct ioat_ring_ent - wrapper around hardware descriptor
* @hw: hardware DMA descriptor (for memcpy)
* @fill: hardware fill descriptor
* @xor: hardware xor descriptor
* @xor_ex: hardware xor extension descriptor
* @pq: hardware pq descriptor
* @pq_ex: hardware pq extension descriptor
* @pqu: hardware pq update descriptor
* @raw: hardware raw (un-typed) descriptor
* @txd: the generic software descriptor for all engines
* @len: total transaction length for unmap
ioat3: xor support ioat3.2 adds xor offload support for up to 8 sources. It can also perform an xor-zero-sum operation to validate whether all given sources sum to zero, without writing to a destination. Xor descriptors differ from memcpy in that one operation may require multiple descriptors depending on the number of sources. When the number of sources exceeds 5 an extended descriptor is needed. These descriptors need to be accounted for when updating the DMA_COUNT register. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:57 +08:00
* @result: asynchronous result of validate operations
ioat3: hardware version 3.2 register / descriptor definitions ioat3.2 adds raid5 and raid6 offload capabilities. Signed-off-by: Tom Picard <tom.s.picard@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:54 +08:00
* @id: identifier for debug
*/
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
struct ioat_ring_ent {
ioat3: hardware version 3.2 register / descriptor definitions ioat3.2 adds raid5 and raid6 offload capabilities. Signed-off-by: Tom Picard <tom.s.picard@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:54 +08:00
union {
struct ioat_dma_descriptor *hw;
struct ioat_fill_descriptor *fill;
struct ioat_xor_descriptor *xor;
struct ioat_xor_ext_descriptor *xor_ex;
struct ioat_pq_descriptor *pq;
struct ioat_pq_ext_descriptor *pq_ex;
struct ioat_pq_update_descriptor *pqu;
struct ioat_raw_descriptor *raw;
};
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
size_t len;
ioat2,3: cacheline align software descriptor allocations All the necessary fields for handling an ioat2,3 ring entry can fit into one cacheline. Move ->len prior to ->txd in struct ioat_ring_ent, and move allocation of these entries to a hw-cache-aligned kmem cache to reduce the number of cachelines dirtied for descriptor management. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:53:04 +08:00
struct dma_async_tx_descriptor txd;
ioat3: xor support ioat3.2 adds xor offload support for up to 8 sources. It can also perform an xor-zero-sum operation to validate whether all given sources sum to zero, without writing to a destination. Xor descriptors differ from memcpy in that one operation may require multiple descriptors depending on the number of sources. When the number of sources exceeds 5 an extended descriptor is needed. These descriptors need to be accounted for when updating the DMA_COUNT register. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:57 +08:00
enum sum_check_flags *result;
ioat: add some dev_dbg() calls Provide some output for debugging the driver. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 03:00:55 +08:00
#ifdef DEBUG
int id;
#endif
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
};
static inline struct ioat_ring_ent *
ioat2_get_ring_ent(struct ioat2_dma_chan *ioat, u16 idx)
{
ioat: convert to circ_buf Use the common power-of-2 circular buffer macros. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-02 06:22:54 +08:00
return ioat->ring[idx & (ioat2_ring_size(ioat) - 1)];
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
}
ioat: switch watchdog and reset handler from workqueue to timer In order to support dynamic resizing of the descriptor ring or polling for a descriptor in the presence of a hung channel the reset handler needs to make progress while in a non-preemptible context. The current workqueue implementation precludes polling channel reset completion under spin_lock(). This conversion also allows us to return to opportunistic cleanup in the ioat2 case as the timer implementation guarantees at least one cleanup after every descriptor is submitted. This means the worst case completion latency becomes the timer frequency (for exceptional circumstances), but with the benefit of avoiding busy waiting when the lock is contended. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 03:01:49 +08:00
static inline void ioat2_set_chainaddr(struct ioat2_dma_chan *ioat, u64 addr)
{
struct ioat_chan_common *chan = &ioat->base;
writel(addr & 0x00000000FFFFFFFF,
chan->reg_base + IOAT2_CHAINADDR_OFFSET_LOW);
writel(addr >> 32,
chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH);
}
ioat: ___devinit annotate the initialization paths Mark all single use initialization routines with __devinit. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 03:01:30 +08:00
int __devinit ioat2_dma_probe(struct ioatdma_device *dev, int dca);
int __devinit ioat3_dma_probe(struct ioatdma_device *dev, int dca);
struct dca_provider * __devinit ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase);
struct dca_provider * __devinit ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase);
ioat3: split ioat3 support to its own file, add memset Up until this point the driver for Intel(R) QuickData Technology engines, specification versions 2 and 3, were mostly identical save for a few quirks. Version 3.2 hardware adds many new capabilities (like raid offload support) requiring some infrastructure that is not relevant for v2. For better code organization of the new funcionality move v3 and v3.2 support to its own file dma_v3.c, and export some routines from the base files (dma.c and dma_v2.c) that can be reused directly. The first new capability included in this code reorganization is support for v3.2 memset operations. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:55 +08:00
int ioat2_alloc_and_lock(u16 *idx, struct ioat2_dma_chan *ioat, int num_descs);
int ioat2_enumerate_channels(struct ioatdma_device *device);
struct dma_async_tx_descriptor *
ioat2_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest,
dma_addr_t dma_src, size_t len, unsigned long flags);
void ioat2_issue_pending(struct dma_chan *chan);
int ioat2_alloc_chan_resources(struct dma_chan *c);
void ioat2_free_chan_resources(struct dma_chan *c);
void __ioat2_restart_chan(struct ioat2_dma_chan *ioat);
bool reshape_ring(struct ioat2_dma_chan *ioat, int order);
ioat3: xor support ioat3.2 adds xor offload support for up to 8 sources. It can also perform an xor-zero-sum operation to validate whether all given sources sum to zero, without writing to a destination. Xor descriptors differ from memcpy in that one operation may require multiple descriptors depending on the number of sources. When the number of sources exceeds 5 an extended descriptor is needed. These descriptors need to be accounted for when updating the DMA_COUNT register. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:57 +08:00
void __ioat2_issue_pending(struct ioat2_dma_chan *ioat);
ioat: cleanup ->timer_fn() and ->cleanup_fn() prototypes If the calling convention of ->timer_fn() and ->cleanup_fn() are unified across hardware versions we can drop parameters to ioat_init_channel() and unify ioat_is_dma_complete() implementations. Both ->timer_fn() and ->cleanup_fn() are modified to expect a struct dma_chan pointer. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-04 12:21:13 +08:00
void ioat2_cleanup_event(unsigned long data);
ioat3: segregate raid engines The cleanup routine for the raid cases imposes extra checks for handling raid descriptors and extended descriptors. If the channel does not support raid it can avoid this extra overhead by using the ioat2 cleanup path. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:43:02 +08:00
void ioat2_timer_event(unsigned long data);
ioat2,3: put channel hardware in known state at init Put the ioat2 and ioat3 state machines in the halted state with all errors cleared. The ioat1 init path is not disturbed for stability, there are no reported ioat1 initiaization issues. Cc: <stable@kernel.org> Reported-by: Roland Dreier <rdreier@cisco.com> Tested-by: Roland Dreier <rdreier@cisco.com> Acked-by: Simon Horman <horms@verge.net.au> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-12-20 06:36:02 +08:00
int ioat2_quiesce(struct ioat_chan_common *chan, unsigned long tmo);
int ioat2_reset_sync(struct ioat_chan_common *chan, unsigned long tmo);
ioat: add 'ioat' sysfs attributes Export driver attributes for diagnostic purposes: 'ring_size': total number of descriptors available to the engine 'ring_active': number of descriptors in-flight 'capabilities': supported operation types for this channel 'version': Intel(R) QuickData specfication revision This also allows some chattiness to be removed from the driver startup as this information is now available via sysfs. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:42:56 +08:00
extern struct kobj_type ioat2_ktype;
ioat2,3: cacheline align software descriptor allocations All the necessary fields for handling an ioat2,3 ring entry can fit into one cacheline. Move ->len prior to ->txd in struct ioat_ring_ent, and move allocation of these entries to a hw-cache-aligned kmem cache to reduce the number of cachelines dirtied for descriptor management. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-09 08:53:04 +08:00
extern struct kmem_cache *ioat2_cache;
ioat2,3: convert to a true ring buffer Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-27 04:01:44 +08:00
#endif /* IOATDMA_V2_H */