1/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
  2/*
  3 * Copyright(c) 2016 Intel Corporation.
  4 */
  5
  6#ifndef DEF_RDMAVT_INCMR_H
  7#define DEF_RDMAVT_INCMR_H
  8
  9/*
 10 * For Memory Regions. This stuff should probably be moved into rdmavt/mr.h once
 11 * drivers no longer need access to the MR directly.
 12 */
 13#include <linux/percpu-refcount.h>
 14
 15/*
 16 * A segment is a linear region of low physical memory.
 17 * Used by the verbs layer.
 18 */
 19struct rvt_seg {
 20	void *vaddr;
 21	size_t length;
 22};
 23
 24/* The number of rvt_segs that fit in a page. */
 25#define RVT_SEGSZ     (PAGE_SIZE / sizeof(struct rvt_seg))
 26
 27struct rvt_segarray {
 28	struct rvt_seg segs[RVT_SEGSZ];
 29};
 30
 31struct rvt_mregion {
 32	struct ib_pd *pd;       /* shares refcnt of ibmr.pd */
 33	u64 user_base;          /* User's address for this region */
 34	u64 iova;               /* IB start address of this region */
 35	size_t length;
 36	u32 lkey;
 37	u32 offset;             /* offset (bytes) to start of region */
 38	int access_flags;
 39	u32 max_segs;           /* number of rvt_segs in all the arrays */
 40	u32 mapsz;              /* size of the map array */
 41	atomic_t lkey_invalid;	/* true if current lkey is invalid */
 42	u8  page_shift;         /* 0 - non unform/non powerof2 sizes */
 43	u8  lkey_published;     /* in global table */
 44	struct percpu_ref refcount;
 45	struct completion comp; /* complete when refcount goes to zero */
 46	struct rvt_segarray *map[];    /* the segments */
 47};
 48
 49#define RVT_MAX_LKEY_TABLE_BITS 23
 50
 51struct rvt_lkey_table {
 52	/* read mostly fields */
 53	u32 max;                /* size of the table */
 54	u32 shift;              /* lkey/rkey shift */
 55	struct rvt_mregion __rcu **table;
 56	/* writeable fields */
 57	/* protect changes in this struct */
 58	spinlock_t lock ____cacheline_aligned_in_smp;
 59	u32 next;               /* next unused index (speeds search) */
 60	u32 gen;                /* generation count */
 61};
 62
 63/*
 64 * These keep track of the copy progress within a memory region.
 65 * Used by the verbs layer.
 66 */
 67struct rvt_sge {
 68	struct rvt_mregion *mr;
 69	void *vaddr;            /* kernel virtual address of segment */
 70	u32 sge_length;         /* length of the SGE */
 71	u32 length;             /* remaining length of the segment */
 72	u16 m;                  /* current index: mr->map[m] */
 73	u16 n;                  /* current index: mr->map[m]->segs[n] */
 74};
 75
 76struct rvt_sge_state {
 77	struct rvt_sge *sg_list;      /* next SGE to be used if any */
 78	struct rvt_sge sge;   /* progress state for the current SGE */
 79	u32 total_len;
 80	u8 num_sge;
 81};
 82
 83static inline void rvt_put_mr(struct rvt_mregion *mr)
 84{
 85	percpu_ref_put(&mr->refcount);
 86}
 87
 88static inline void rvt_get_mr(struct rvt_mregion *mr)
 89{
 90	percpu_ref_get(&mr->refcount);
 91}
 92
 93static inline void rvt_put_ss(struct rvt_sge_state *ss)
 94{
 95	while (ss->num_sge) {
 96		rvt_put_mr(ss->sge.mr);
 97		if (--ss->num_sge)
 98			ss->sge = *ss->sg_list++;
 99	}
100}
101
102static inline u32 rvt_get_sge_length(struct rvt_sge *sge, u32 length)
103{
104	u32 len = sge->length;
105
106	if (len > length)
107		len = length;
108	if (len > sge->sge_length)
109		len = sge->sge_length;
110
111	return len;
112}
113
114static inline void rvt_update_sge(struct rvt_sge_state *ss, u32 length,
115				  bool release)
116{
117	struct rvt_sge *sge = &ss->sge;
118
119	sge->vaddr += length;
120	sge->length -= length;
121	sge->sge_length -= length;
122	if (sge->sge_length == 0) {
123		if (release)
124			rvt_put_mr(sge->mr);
125		if (--ss->num_sge)
126			*sge = *ss->sg_list++;
127	} else if (sge->length == 0 && sge->mr->lkey) {
128		if (++sge->n >= RVT_SEGSZ) {
129			if (++sge->m >= sge->mr->mapsz)
130				return;
131			sge->n = 0;
132		}
133		sge->vaddr = sge->mr->map[sge->m]->segs[sge->n].vaddr;
134		sge->length = sge->mr->map[sge->m]->segs[sge->n].length;
135	}
136}
137
138static inline void rvt_skip_sge(struct rvt_sge_state *ss, u32 length,
139				bool release)
140{
141	struct rvt_sge *sge = &ss->sge;
142
143	while (length) {
144		u32 len = rvt_get_sge_length(sge, length);
145
146		WARN_ON_ONCE(len == 0);
147		rvt_update_sge(ss, len, release);
148		length -= len;
149	}
150}
151
152bool rvt_ss_has_lkey(struct rvt_sge_state *ss, u32 lkey);
153bool rvt_mr_has_lkey(struct rvt_mregion *mr, u32 lkey);
154
155#endif          /* DEF_RDMAVT_INCMRH */