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 */
156