1// SPDX-License-Identifier: GPL-2.0+
2// Copyright 2017 IBM Corp.
3#include "ocxl_internal.h"
4
5
6struct id_range {
7 struct list_head list;
8 u32 start;
9 u32 end;
10};
11
12#ifdef DEBUG
13static void dump_list(struct list_head *head, char *type_str)
14{
15 struct id_range *cur;
16
17 pr_debug("%s ranges allocated:\n", type_str);
18 list_for_each_entry(cur, head, list) {
19 pr_debug("Range %d->%d\n", cur->start, cur->end);
20 }
21}
22#endif
23
24static int range_alloc(struct list_head *head, u32 size, int max_id,
25 char *type_str)
26{
27 struct list_head *pos;
28 struct id_range *cur, *new;
29 int rc, last_end;
30
31 new = kmalloc(size: sizeof(struct id_range), GFP_KERNEL);
32 if (!new)
33 return -ENOMEM;
34
35 pos = head;
36 last_end = -1;
37 list_for_each_entry(cur, head, list) {
38 if ((cur->start - last_end) > size)
39 break;
40 last_end = cur->end;
41 pos = &cur->list;
42 }
43
44 new->start = last_end + 1;
45 new->end = new->start + size - 1;
46
47 if (new->end > max_id) {
48 kfree(objp: new);
49 rc = -ENOSPC;
50 } else {
51 list_add(new: &new->list, head: pos);
52 rc = new->start;
53 }
54
55#ifdef DEBUG
56 dump_list(head, type_str);
57#endif
58 return rc;
59}
60
61static void range_free(struct list_head *head, u32 start, u32 size,
62 char *type_str)
63{
64 bool found = false;
65 struct id_range *cur, *tmp;
66
67 list_for_each_entry_safe(cur, tmp, head, list) {
68 if (cur->start == start && cur->end == (start + size - 1)) {
69 found = true;
70 list_del(entry: &cur->list);
71 kfree(objp: cur);
72 break;
73 }
74 }
75 WARN_ON(!found);
76#ifdef DEBUG
77 dump_list(head, type_str);
78#endif
79}
80
81int ocxl_pasid_afu_alloc(struct ocxl_fn *fn, u32 size)
82{
83 int max_pasid;
84
85 if (fn->config.max_pasid_log < 0)
86 return -ENOSPC;
87 max_pasid = 1 << fn->config.max_pasid_log;
88 return range_alloc(head: &fn->pasid_list, size, max_id: max_pasid, type_str: "afu pasid");
89}
90
91void ocxl_pasid_afu_free(struct ocxl_fn *fn, u32 start, u32 size)
92{
93 return range_free(head: &fn->pasid_list, start, size, type_str: "afu pasid");
94}
95
96int ocxl_actag_afu_alloc(struct ocxl_fn *fn, u32 size)
97{
98 int max_actag;
99
100 max_actag = fn->actag_enabled;
101 return range_alloc(head: &fn->actag_list, size, max_id: max_actag, type_str: "afu actag");
102}
103
104void ocxl_actag_afu_free(struct ocxl_fn *fn, u32 start, u32 size)
105{
106 return range_free(head: &fn->actag_list, start, size, type_str: "afu actag");
107}
108

source code of linux/drivers/misc/ocxl/pasid.c