vnic_rq.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
  4 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
  5 */
  6
  7#ifndef _VNIC_RQ_H_
  8#define _VNIC_RQ_H_
  9
 10#include <linux/pci.h>
 11#include <linux/netdevice.h>
 12
 13#include "vnic_dev.h"
 14#include "vnic_cq.h"
 15
 16/* Receive queue control */
 17struct vnic_rq_ctrl {
 18	u64 ring_base;			/* 0x00 */
 19	u32 ring_size;			/* 0x08 */
 20	u32 pad0;
 21	u32 posted_index;		/* 0x10 */
 22	u32 pad1;
 23	u32 cq_index;			/* 0x18 */
 24	u32 pad2;
 25	u32 enable;			/* 0x20 */
 26	u32 pad3;
 27	u32 running;			/* 0x28 */
 28	u32 pad4;
 29	u32 fetch_index;		/* 0x30 */
 30	u32 pad5;
 31	u32 error_interrupt_enable;	/* 0x38 */
 32	u32 pad6;
 33	u32 error_interrupt_offset;	/* 0x40 */
 34	u32 pad7;
 35	u32 error_status;		/* 0x48 */
 36	u32 pad8;
 37	u32 dropped_packet_count;	/* 0x50 */
 38	u32 pad9;
 39	u32 dropped_packet_count_rc;	/* 0x58 */
 40	u32 pad10;
 41};
 42
 43/* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
 44#define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
 45#define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
 46#define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
 47	((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
 48	VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
 49#define VNIC_RQ_BUF_BLK_SZ(entries) \
 50	(VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
 51#define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
 52	DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
 53#define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(16384)
 54
 55struct vnic_rq_buf {
 56	struct vnic_rq_buf *next;
 57	dma_addr_t dma_addr;
 58	void *os_buf;
 59	unsigned int os_buf_index;
 60	unsigned int len;
 61	unsigned int index;
 62	void *desc;
 63	uint64_t wr_id;
 64	unsigned int offset;
 65	unsigned int truesize;
 66};
 67
 68enum enic_poll_state {
 69	ENIC_POLL_STATE_IDLE,
 70	ENIC_POLL_STATE_NAPI,
 71	ENIC_POLL_STATE_POLL
 72};
 73
 74struct vnic_rq {
 75	unsigned int index;
 76	struct vnic_dev *vdev;
 77	struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
 78	struct vnic_dev_ring ring;
 79	struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
 80	struct vnic_rq_buf *to_use;
 81	struct vnic_rq_buf *to_clean;
 82	void *os_buf_head;
 83	unsigned int pkts_outstanding;
 84};
 85
 86static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
 87{
 88	/* how many does SW own? */
 89	return rq->ring.desc_avail;
 90}
 91
 92static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
 93{
 94	/* how many does HW own? */
 95	return rq->ring.desc_count - rq->ring.desc_avail - 1;
 96}
 97
 98static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
 99{
100	return rq->to_use->desc;
101}
102
103static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
104{
105	return rq->to_use->index;
106}
107
108static inline void vnic_rq_post(struct vnic_rq *rq,
109	void *os_buf, unsigned int os_buf_index,
110	dma_addr_t dma_addr, unsigned int len,
111	uint64_t wrid)
112{
113	struct vnic_rq_buf *buf = rq->to_use;
114
115	buf->os_buf = os_buf;
116	buf->os_buf_index = os_buf_index;
117	buf->dma_addr = dma_addr;
118	buf->len = len;
119	buf->wr_id = wrid;
120
121	buf = buf->next;
122	rq->to_use = buf;
123	rq->ring.desc_avail--;
124
125	/* Move the posted_index every nth descriptor
126	 */
127
128#ifndef VNIC_RQ_RETURN_RATE
129#define VNIC_RQ_RETURN_RATE		0xf	/* keep 2^n - 1 */
130#endif
131
132	if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
133		/* Adding write memory barrier prevents compiler and/or CPU
134		 * reordering, thus avoiding descriptor posting before
135		 * descriptor is initialized. Otherwise, hardware can read
136		 * stale descriptor fields.
137		 */
138		wmb();
139		iowrite32(buf->index, &rq->ctrl->posted_index);
140	}
141}
142
143static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
144{
145	rq->ring.desc_avail += count;
146}
147
148enum desc_return_options {
149	VNIC_RQ_RETURN_DESC,
150	VNIC_RQ_DEFER_RETURN_DESC,
151};
152
153static inline void vnic_rq_service(struct vnic_rq *rq,
154	struct cq_desc *cq_desc, u16 completed_index,
155	int desc_return, void (*buf_service)(struct vnic_rq *rq,
156	struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
157	int skipped, void *opaque), void *opaque)
158{
159	struct vnic_rq_buf *buf;
160	int skipped;
161
162	buf = rq->to_clean;
163	while (1) {
164
165		skipped = (buf->index != completed_index);
166
167		(*buf_service)(rq, cq_desc, buf, skipped, opaque);
168
169		if (desc_return == VNIC_RQ_RETURN_DESC)
170			rq->ring.desc_avail++;
171
172		rq->to_clean = buf->next;
173
174		if (!skipped)
175			break;
176
177		buf = rq->to_clean;
178	}
179}
180
181static inline int vnic_rq_fill(struct vnic_rq *rq,
182	int (*buf_fill)(struct vnic_rq *rq))
183{
184	int err;
185
186	while (vnic_rq_desc_avail(rq) > 0) {
187
188		err = (*buf_fill)(rq);
189		if (err)
190			return err;
191	}
192
193	return 0;
194}
195
196void vnic_rq_free(struct vnic_rq *rq);
197int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
198	unsigned int desc_count, unsigned int desc_size);
199void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
200	unsigned int error_interrupt_enable,
201	unsigned int error_interrupt_offset);
202unsigned int vnic_rq_error_status(struct vnic_rq *rq);
203void vnic_rq_enable(struct vnic_rq *rq);
204int vnic_rq_disable(struct vnic_rq *rq);
205void vnic_rq_clean(struct vnic_rq *rq,
206	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
207
208#endif /* _VNIC_RQ_H_ */