1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017 IBM Corp.
3 #include <linux/interrupt.h>
4 #include <linux/eventfd.h>
5 #include <asm/pnv-ocxl.h>
6 #include "ocxl_internal.h"
7 #include "trace.h"
8
9 struct afu_irq {
10 int id;
11 int hw_irq;
12 unsigned int virq;
13 char *name;
14 u64 trigger_page;
15 struct eventfd_ctx *ev_ctx;
16 };
17
irq_offset_to_id(struct ocxl_context * ctx,u64 offset)18 static int irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
19 {
20 return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT;
21 }
22
irq_id_to_offset(struct ocxl_context * ctx,int id)23 static u64 irq_id_to_offset(struct ocxl_context *ctx, int id)
24 {
25 return ctx->afu->irq_base_offset + (id << PAGE_SHIFT);
26 }
27
afu_irq_handler(int virq,void * data)28 static irqreturn_t afu_irq_handler(int virq, void *data)
29 {
30 struct afu_irq *irq = (struct afu_irq *) data;
31
32 trace_ocxl_afu_irq_receive(virq);
33 if (irq->ev_ctx)
34 eventfd_signal(irq->ev_ctx, 1);
35 return IRQ_HANDLED;
36 }
37
setup_afu_irq(struct ocxl_context * ctx,struct afu_irq * irq)38 static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq)
39 {
40 int rc;
41
42 irq->virq = irq_create_mapping(NULL, irq->hw_irq);
43 if (!irq->virq) {
44 pr_err("irq_create_mapping failed\n");
45 return -ENOMEM;
46 }
47 pr_debug("hw_irq %d mapped to virq %u\n", irq->hw_irq, irq->virq);
48
49 irq->name = kasprintf(GFP_KERNEL, "ocxl-afu-%u", irq->virq);
50 if (!irq->name) {
51 irq_dispose_mapping(irq->virq);
52 return -ENOMEM;
53 }
54
55 rc = request_irq(irq->virq, afu_irq_handler, 0, irq->name, irq);
56 if (rc) {
57 kfree(irq->name);
58 irq->name = NULL;
59 irq_dispose_mapping(irq->virq);
60 pr_err("request_irq failed: %d\n", rc);
61 return rc;
62 }
63 return 0;
64 }
65
release_afu_irq(struct afu_irq * irq)66 static void release_afu_irq(struct afu_irq *irq)
67 {
68 free_irq(irq->virq, irq);
69 irq_dispose_mapping(irq->virq);
70 kfree(irq->name);
71 }
72
ocxl_afu_irq_alloc(struct ocxl_context * ctx,u64 * irq_offset)73 int ocxl_afu_irq_alloc(struct ocxl_context *ctx, u64 *irq_offset)
74 {
75 struct afu_irq *irq;
76 int rc;
77
78 irq = kzalloc(sizeof(struct afu_irq), GFP_KERNEL);
79 if (!irq)
80 return -ENOMEM;
81
82 /*
83 * We limit the number of afu irqs per context and per link to
84 * avoid a single process or user depleting the pool of IPIs
85 */
86
87 mutex_lock(&ctx->irq_lock);
88
89 irq->id = idr_alloc(&ctx->irq_idr, irq, 0, MAX_IRQ_PER_CONTEXT,
90 GFP_KERNEL);
91 if (irq->id < 0) {
92 rc = -ENOSPC;
93 goto err_unlock;
94 }
95
96 rc = ocxl_link_irq_alloc(ctx->afu->fn->link, &irq->hw_irq,
97 &irq->trigger_page);
98 if (rc)
99 goto err_idr;
100
101 rc = setup_afu_irq(ctx, irq);
102 if (rc)
103 goto err_alloc;
104
105 *irq_offset = irq_id_to_offset(ctx, irq->id);
106
107 trace_ocxl_afu_irq_alloc(ctx->pasid, irq->id, irq->virq, irq->hw_irq,
108 *irq_offset);
109 mutex_unlock(&ctx->irq_lock);
110 return 0;
111
112 err_alloc:
113 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
114 err_idr:
115 idr_remove(&ctx->irq_idr, irq->id);
116 err_unlock:
117 mutex_unlock(&ctx->irq_lock);
118 kfree(irq);
119 return rc;
120 }
121
afu_irq_free(struct afu_irq * irq,struct ocxl_context * ctx)122 static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx)
123 {
124 trace_ocxl_afu_irq_free(ctx->pasid, irq->id);
125 if (ctx->mapping)
126 unmap_mapping_range(ctx->mapping,
127 irq_id_to_offset(ctx, irq->id),
128 1 << PAGE_SHIFT, 1);
129 release_afu_irq(irq);
130 if (irq->ev_ctx)
131 eventfd_ctx_put(irq->ev_ctx);
132 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
133 kfree(irq);
134 }
135
ocxl_afu_irq_free(struct ocxl_context * ctx,u64 irq_offset)136 int ocxl_afu_irq_free(struct ocxl_context *ctx, u64 irq_offset)
137 {
138 struct afu_irq *irq;
139 int id = irq_offset_to_id(ctx, irq_offset);
140
141 mutex_lock(&ctx->irq_lock);
142
143 irq = idr_find(&ctx->irq_idr, id);
144 if (!irq) {
145 mutex_unlock(&ctx->irq_lock);
146 return -EINVAL;
147 }
148 idr_remove(&ctx->irq_idr, irq->id);
149 afu_irq_free(irq, ctx);
150 mutex_unlock(&ctx->irq_lock);
151 return 0;
152 }
153
ocxl_afu_irq_free_all(struct ocxl_context * ctx)154 void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
155 {
156 struct afu_irq *irq;
157 int id;
158
159 mutex_lock(&ctx->irq_lock);
160 idr_for_each_entry(&ctx->irq_idr, irq, id)
161 afu_irq_free(irq, ctx);
162 mutex_unlock(&ctx->irq_lock);
163 }
164
ocxl_afu_irq_set_fd(struct ocxl_context * ctx,u64 irq_offset,int eventfd)165 int ocxl_afu_irq_set_fd(struct ocxl_context *ctx, u64 irq_offset, int eventfd)
166 {
167 struct afu_irq *irq;
168 struct eventfd_ctx *ev_ctx;
169 int rc = 0, id = irq_offset_to_id(ctx, irq_offset);
170
171 mutex_lock(&ctx->irq_lock);
172 irq = idr_find(&ctx->irq_idr, id);
173 if (!irq) {
174 rc = -EINVAL;
175 goto unlock;
176 }
177
178 ev_ctx = eventfd_ctx_fdget(eventfd);
179 if (IS_ERR(ev_ctx)) {
180 rc = -EINVAL;
181 goto unlock;
182 }
183
184 irq->ev_ctx = ev_ctx;
185 unlock:
186 mutex_unlock(&ctx->irq_lock);
187 return rc;
188 }
189
ocxl_afu_irq_get_addr(struct ocxl_context * ctx,u64 irq_offset)190 u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, u64 irq_offset)
191 {
192 struct afu_irq *irq;
193 int id = irq_offset_to_id(ctx, irq_offset);
194 u64 addr = 0;
195
196 mutex_lock(&ctx->irq_lock);
197 irq = idr_find(&ctx->irq_idr, id);
198 if (irq)
199 addr = irq->trigger_page;
200 mutex_unlock(&ctx->irq_lock);
201 return addr;
202 }
203