cisco/enic/vnic_rq.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
0004  * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
0005  */
0006
0007 #ifndef _VNIC_RQ_H_
0008 #define _VNIC_RQ_H_
0009
0010 #include <linux/pci.h>
0011 #include <linux/netdevice.h>
0012
0013 #include "vnic_dev.h"
0014 #include "vnic_cq.h"
0015
0016 /* Receive queue control */
0017 struct vnic_rq_ctrl {
0018     u64 ring_base;          /* 0x00 */
0019     u32 ring_size;          /* 0x08 */
0020     u32 pad0;
0021     u32 posted_index;       /* 0x10 */
0022     u32 pad1;
0023     u32 cq_index;           /* 0x18 */
0024     u32 pad2;
0025     u32 enable;         /* 0x20 */
0026     u32 pad3;
0027     u32 running;            /* 0x28 */
0028     u32 pad4;
0029     u32 fetch_index;        /* 0x30 */
0030     u32 pad5;
0031     u32 error_interrupt_enable; /* 0x38 */
0032     u32 pad6;
0033     u32 error_interrupt_offset; /* 0x40 */
0034     u32 pad7;
0035     u32 error_status;       /* 0x48 */
0036     u32 pad8;
0037     u32 dropped_packet_count;   /* 0x50 */
0038     u32 pad9;
0039     u32 dropped_packet_count_rc;    /* 0x58 */
0040     u32 pad10;
0041 };
0042
0043 /* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
0044 #define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
0045 #define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
0046 #define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
0047     ((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
0048     VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
0049 #define VNIC_RQ_BUF_BLK_SZ(entries) \
0050     (VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
0051 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
0052     DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
0053 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
0054
0055 struct vnic_rq_buf {
0056     struct vnic_rq_buf *next;
0057     dma_addr_t dma_addr;
0058     void *os_buf;
0059     unsigned int os_buf_index;
0060     unsigned int len;
0061     unsigned int index;
0062     void *desc;
0063     uint64_t wr_id;
0064 };
0065
0066 enum enic_poll_state {
0067     ENIC_POLL_STATE_IDLE,
0068     ENIC_POLL_STATE_NAPI,
0069     ENIC_POLL_STATE_POLL
0070 };
0071
0072 struct vnic_rq {
0073     unsigned int index;
0074     struct vnic_dev *vdev;
0075     struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
0076     struct vnic_dev_ring ring;
0077     struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
0078     struct vnic_rq_buf *to_use;
0079     struct vnic_rq_buf *to_clean;
0080     void *os_buf_head;
0081     unsigned int pkts_outstanding;
0082 };
0083
0084 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
0085 {
0086     /* how many does SW own? */
0087     return rq->ring.desc_avail;
0088 }
0089
0090 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
0091 {
0092     /* how many does HW own? */
0093     return rq->ring.desc_count - rq->ring.desc_avail - 1;
0094 }
0095
0096 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
0097 {
0098     return rq->to_use->desc;
0099 }
0100
0101 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
0102 {
0103     return rq->to_use->index;
0104 }
0105
0106 static inline void vnic_rq_post(struct vnic_rq *rq,
0107     void *os_buf, unsigned int os_buf_index,
0108     dma_addr_t dma_addr, unsigned int len,
0109     uint64_t wrid)
0110 {
0111     struct vnic_rq_buf *buf = rq->to_use;
0112
0113     buf->os_buf = os_buf;
0114     buf->os_buf_index = os_buf_index;
0115     buf->dma_addr = dma_addr;
0116     buf->len = len;
0117     buf->wr_id = wrid;
0118
0119     buf = buf->next;
0120     rq->to_use = buf;
0121     rq->ring.desc_avail--;
0122
0123     /* Move the posted_index every nth descriptor
0124      */
0125
0126 #ifndef VNIC_RQ_RETURN_RATE
0127 #define VNIC_RQ_RETURN_RATE     0xf /* keep 2^n - 1 */
0128 #endif
0129
0130     if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
0131         /* Adding write memory barrier prevents compiler and/or CPU
0132          * reordering, thus avoiding descriptor posting before
0133          * descriptor is initialized. Otherwise, hardware can read
0134          * stale descriptor fields.
0135          */
0136         wmb();
0137         iowrite32(buf->index, &rq->ctrl->posted_index);
0138     }
0139 }
0140
0141 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
0142 {
0143     rq->ring.desc_avail += count;
0144 }
0145
0146 enum desc_return_options {
0147     VNIC_RQ_RETURN_DESC,
0148     VNIC_RQ_DEFER_RETURN_DESC,
0149 };
0150
0151 static inline void vnic_rq_service(struct vnic_rq *rq,
0152     struct cq_desc *cq_desc, u16 completed_index,
0153     int desc_return, void (*buf_service)(struct vnic_rq *rq,
0154     struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
0155     int skipped, void *opaque), void *opaque)
0156 {
0157     struct vnic_rq_buf *buf;
0158     int skipped;
0159
0160     buf = rq->to_clean;
0161     while (1) {
0162
0163         skipped = (buf->index != completed_index);
0164
0165         (*buf_service)(rq, cq_desc, buf, skipped, opaque);
0166
0167         if (desc_return == VNIC_RQ_RETURN_DESC)
0168             rq->ring.desc_avail++;
0169
0170         rq->to_clean = buf->next;
0171
0172         if (!skipped)
0173             break;
0174
0175         buf = rq->to_clean;
0176     }
0177 }
0178
0179 static inline int vnic_rq_fill(struct vnic_rq *rq,
0180     int (*buf_fill)(struct vnic_rq *rq))
0181 {
0182     int err;
0183
0184     while (vnic_rq_desc_avail(rq) > 0) {
0185
0186         err = (*buf_fill)(rq);
0187         if (err)
0188             return err;
0189     }
0190
0191     return 0;
0192 }
0193
0194 void vnic_rq_free(struct vnic_rq *rq);
0195 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
0196     unsigned int desc_count, unsigned int desc_size);
0197 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
0198     unsigned int error_interrupt_enable,
0199     unsigned int error_interrupt_offset);
0200 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
0201 void vnic_rq_enable(struct vnic_rq *rq);
0202 int vnic_rq_disable(struct vnic_rq *rq);
0203 void vnic_rq_clean(struct vnic_rq *rq,
0204     void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
0205
0206 #endif /* _VNIC_RQ_H_ */