linux/drivers/net/enic/vnic_rq.h
Scott Feldman 845964515a enic: move wmb closer to where needed: before writing posted_index to hw
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-21 21:29:01 -08:00

211 lines
5.2 KiB
C

/*
* Copyright 2008 Cisco Systems, Inc. All rights reserved.
* Copyright 2007 Nuova Systems, Inc. All rights reserved.
*
* This program is free software; you may redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#ifndef _VNIC_RQ_H_
#define _VNIC_RQ_H_
#include <linux/pci.h>
#include "vnic_dev.h"
#include "vnic_cq.h"
/* Receive queue control */
struct vnic_rq_ctrl {
u64 ring_base; /* 0x00 */
u32 ring_size; /* 0x08 */
u32 pad0;
u32 posted_index; /* 0x10 */
u32 pad1;
u32 cq_index; /* 0x18 */
u32 pad2;
u32 enable; /* 0x20 */
u32 pad3;
u32 running; /* 0x28 */
u32 pad4;
u32 fetch_index; /* 0x30 */
u32 pad5;
u32 error_interrupt_enable; /* 0x38 */
u32 pad6;
u32 error_interrupt_offset; /* 0x40 */
u32 pad7;
u32 error_status; /* 0x48 */
u32 pad8;
u32 dropped_packet_count; /* 0x50 */
u32 pad9;
u32 dropped_packet_count_rc; /* 0x58 */
u32 pad10;
};
/* Break the vnic_rq_buf allocations into blocks of 64 entries */
#define VNIC_RQ_BUF_BLK_ENTRIES 64
#define VNIC_RQ_BUF_BLK_SZ \
(VNIC_RQ_BUF_BLK_ENTRIES * sizeof(struct vnic_rq_buf))
#define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES)
#define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
struct vnic_rq_buf {
struct vnic_rq_buf *next;
dma_addr_t dma_addr;
void *os_buf;
unsigned int os_buf_index;
unsigned int len;
unsigned int index;
void *desc;
};
struct vnic_rq {
unsigned int index;
struct vnic_dev *vdev;
struct vnic_rq_ctrl __iomem *ctrl; /* memory-mapped */
struct vnic_dev_ring ring;
struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
struct vnic_rq_buf *to_use;
struct vnic_rq_buf *to_clean;
void *os_buf_head;
unsigned int buf_index;
unsigned int pkts_outstanding;
};
static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
{
/* how many does SW own? */
return rq->ring.desc_avail;
}
static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
{
/* how many does HW own? */
return rq->ring.desc_count - rq->ring.desc_avail - 1;
}
static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
{
return rq->to_use->desc;
}
static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
{
return rq->to_use->index;
}
static inline unsigned int vnic_rq_next_buf_index(struct vnic_rq *rq)
{
return rq->buf_index++;
}
static inline void vnic_rq_post(struct vnic_rq *rq,
void *os_buf, unsigned int os_buf_index,
dma_addr_t dma_addr, unsigned int len)
{
struct vnic_rq_buf *buf = rq->to_use;
buf->os_buf = os_buf;
buf->os_buf_index = os_buf_index;
buf->dma_addr = dma_addr;
buf->len = len;
buf = buf->next;
rq->to_use = buf;
rq->ring.desc_avail--;
/* Move the posted_index every nth descriptor
*/
#ifndef VNIC_RQ_RETURN_RATE
#define VNIC_RQ_RETURN_RATE 0xf /* keep 2^n - 1 */
#endif
if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
/* Adding write memory barrier prevents compiler and/or CPU
* reordering, thus avoiding descriptor posting before
* descriptor is initialized. Otherwise, hardware can read
* stale descriptor fields.
*/
wmb();
iowrite32(buf->index, &rq->ctrl->posted_index);
}
}
static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
{
rq->ring.desc_avail += count;
}
enum desc_return_options {
VNIC_RQ_RETURN_DESC,
VNIC_RQ_DEFER_RETURN_DESC,
};
static inline void vnic_rq_service(struct vnic_rq *rq,
struct cq_desc *cq_desc, u16 completed_index,
int desc_return, void (*buf_service)(struct vnic_rq *rq,
struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
int skipped, void *opaque), void *opaque)
{
struct vnic_rq_buf *buf;
int skipped;
buf = rq->to_clean;
while (1) {
skipped = (buf->index != completed_index);
(*buf_service)(rq, cq_desc, buf, skipped, opaque);
if (desc_return == VNIC_RQ_RETURN_DESC)
rq->ring.desc_avail++;
rq->to_clean = buf->next;
if (!skipped)
break;
buf = rq->to_clean;
}
}
static inline int vnic_rq_fill(struct vnic_rq *rq,
int (*buf_fill)(struct vnic_rq *rq))
{
int err;
while (vnic_rq_desc_avail(rq) > 1) {
err = (*buf_fill)(rq);
if (err)
return err;
}
return 0;
}
void vnic_rq_free(struct vnic_rq *rq);
int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
unsigned int desc_count, unsigned int desc_size);
void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
unsigned int error_interrupt_enable,
unsigned int error_interrupt_offset);
unsigned int vnic_rq_error_status(struct vnic_rq *rq);
void vnic_rq_enable(struct vnic_rq *rq);
int vnic_rq_disable(struct vnic_rq *rq);
void vnic_rq_clean(struct vnic_rq *rq,
void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
#endif /* _VNIC_RQ_H_ */