1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017 IBM Corp.
3 #include <linux/interrupt.h>
4 #include <asm/pnv-ocxl.h>
5 #include "ocxl_internal.h"
6 #include "trace.h"
7
8 struct afu_irq {
9 int id;
10 int hw_irq;
11 unsigned int virq;
12 char *name;
13 u64 trigger_page;
14 irqreturn_t (*handler)(void *private);
15 void (*free_private)(void *private);
16 void *private;
17 };
18
ocxl_irq_offset_to_id(struct ocxl_context * ctx,u64 offset)19 int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
20 {
21 return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT;
22 }
23
ocxl_irq_id_to_offset(struct ocxl_context * ctx,int irq_id)24 u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id)
25 {
26 return ctx->afu->irq_base_offset + (irq_id << PAGE_SHIFT);
27 }
28
ocxl_irq_set_handler(struct ocxl_context * ctx,int irq_id,irqreturn_t (* handler)(void * private),void (* free_private)(void * private),void * private)29 int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
30 irqreturn_t (*handler)(void *private),
31 void (*free_private)(void *private),
32 void *private)
33 {
34 struct afu_irq *irq;
35 int rc;
36
37 mutex_lock(&ctx->irq_lock);
38 irq = idr_find(&ctx->irq_idr, irq_id);
39 if (!irq) {
40 rc = -EINVAL;
41 goto unlock;
42 }
43
44 irq->handler = handler;
45 irq->private = private;
46 irq->free_private = free_private;
47
48 rc = 0;
49 // Fall through to unlock
50
51 unlock:
52 mutex_unlock(&ctx->irq_lock);
53 return rc;
54 }
55 EXPORT_SYMBOL_GPL(ocxl_irq_set_handler);
56
afu_irq_handler(int virq,void * data)57 static irqreturn_t afu_irq_handler(int virq, void *data)
58 {
59 struct afu_irq *irq = (struct afu_irq *) data;
60
61 trace_ocxl_afu_irq_receive(virq);
62
63 if (irq->handler)
64 return irq->handler(irq->private);
65
66 return IRQ_HANDLED; // Just drop it on the ground
67 }
68
setup_afu_irq(struct ocxl_context * ctx,struct afu_irq * irq)69 static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq)
70 {
71 int rc;
72
73 irq->virq = irq_create_mapping(NULL, irq->hw_irq);
74 if (!irq->virq) {
75 pr_err("irq_create_mapping failed\n");
76 return -ENOMEM;
77 }
78 pr_debug("hw_irq %d mapped to virq %u\n", irq->hw_irq, irq->virq);
79
80 irq->name = kasprintf(GFP_KERNEL, "ocxl-afu-%u", irq->virq);
81 if (!irq->name) {
82 irq_dispose_mapping(irq->virq);
83 return -ENOMEM;
84 }
85
86 rc = request_irq(irq->virq, afu_irq_handler, 0, irq->name, irq);
87 if (rc) {
88 kfree(irq->name);
89 irq->name = NULL;
90 irq_dispose_mapping(irq->virq);
91 pr_err("request_irq failed: %d\n", rc);
92 return rc;
93 }
94 return 0;
95 }
96
release_afu_irq(struct afu_irq * irq)97 static void release_afu_irq(struct afu_irq *irq)
98 {
99 free_irq(irq->virq, irq);
100 irq_dispose_mapping(irq->virq);
101 kfree(irq->name);
102 }
103
ocxl_afu_irq_alloc(struct ocxl_context * ctx,int * irq_id)104 int ocxl_afu_irq_alloc(struct ocxl_context *ctx, int *irq_id)
105 {
106 struct afu_irq *irq;
107 int rc;
108
109 irq = kzalloc(sizeof(struct afu_irq), GFP_KERNEL);
110 if (!irq)
111 return -ENOMEM;
112
113 /*
114 * We limit the number of afu irqs per context and per link to
115 * avoid a single process or user depleting the pool of IPIs
116 */
117
118 mutex_lock(&ctx->irq_lock);
119
120 irq->id = idr_alloc(&ctx->irq_idr, irq, 0, MAX_IRQ_PER_CONTEXT,
121 GFP_KERNEL);
122 if (irq->id < 0) {
123 rc = -ENOSPC;
124 goto err_unlock;
125 }
126
127 rc = ocxl_link_irq_alloc(ctx->afu->fn->link, &irq->hw_irq,
128 &irq->trigger_page);
129 if (rc)
130 goto err_idr;
131
132 rc = setup_afu_irq(ctx, irq);
133 if (rc)
134 goto err_alloc;
135
136 trace_ocxl_afu_irq_alloc(ctx->pasid, irq->id, irq->virq, irq->hw_irq);
137 mutex_unlock(&ctx->irq_lock);
138
139 *irq_id = irq->id;
140
141 return 0;
142
143 err_alloc:
144 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
145 err_idr:
146 idr_remove(&ctx->irq_idr, irq->id);
147 err_unlock:
148 mutex_unlock(&ctx->irq_lock);
149 kfree(irq);
150 return rc;
151 }
152 EXPORT_SYMBOL_GPL(ocxl_afu_irq_alloc);
153
afu_irq_free(struct afu_irq * irq,struct ocxl_context * ctx)154 static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx)
155 {
156 trace_ocxl_afu_irq_free(ctx->pasid, irq->id);
157 if (ctx->mapping)
158 unmap_mapping_range(ctx->mapping,
159 ocxl_irq_id_to_offset(ctx, irq->id),
160 1 << PAGE_SHIFT, 1);
161 release_afu_irq(irq);
162 if (irq->free_private)
163 irq->free_private(irq->private);
164 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
165 kfree(irq);
166 }
167
ocxl_afu_irq_free(struct ocxl_context * ctx,int irq_id)168 int ocxl_afu_irq_free(struct ocxl_context *ctx, int irq_id)
169 {
170 struct afu_irq *irq;
171
172 mutex_lock(&ctx->irq_lock);
173
174 irq = idr_find(&ctx->irq_idr, irq_id);
175 if (!irq) {
176 mutex_unlock(&ctx->irq_lock);
177 return -EINVAL;
178 }
179 idr_remove(&ctx->irq_idr, irq->id);
180 afu_irq_free(irq, ctx);
181 mutex_unlock(&ctx->irq_lock);
182 return 0;
183 }
184 EXPORT_SYMBOL_GPL(ocxl_afu_irq_free);
185
ocxl_afu_irq_free_all(struct ocxl_context * ctx)186 void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
187 {
188 struct afu_irq *irq;
189 int id;
190
191 mutex_lock(&ctx->irq_lock);
192 idr_for_each_entry(&ctx->irq_idr, irq, id)
193 afu_irq_free(irq, ctx);
194 mutex_unlock(&ctx->irq_lock);
195 }
196
ocxl_afu_irq_get_addr(struct ocxl_context * ctx,int irq_id)197 u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id)
198 {
199 struct afu_irq *irq;
200 u64 addr = 0;
201
202 mutex_lock(&ctx->irq_lock);
203 irq = idr_find(&ctx->irq_idr, irq_id);
204 if (irq)
205 addr = irq->trigger_page;
206 mutex_unlock(&ctx->irq_lock);
207 return addr;
208 }
209 EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);
210
