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 <asm/xive.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 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 if (rc)
129 goto err_idr;
130
131 rc = setup_afu_irq(ctx, irq);
132 if (rc)
133 goto err_alloc;
134
135 trace_ocxl_afu_irq_alloc(ctx->pasid, irq->id, irq->virq, irq->hw_irq);
136 mutex_unlock(&ctx->irq_lock);
137
138 *irq_id = irq->id;
139
140 return 0;
141
142 err_alloc:
143 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
144 err_idr:
145 idr_remove(&ctx->irq_idr, irq->id);
146 err_unlock:
147 mutex_unlock(&ctx->irq_lock);
148 kfree(irq);
149 return rc;
150 }
151 EXPORT_SYMBOL_GPL(ocxl_afu_irq_alloc);
152
afu_irq_free(struct afu_irq * irq,struct ocxl_context * ctx)153 static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx)
154 {
155 trace_ocxl_afu_irq_free(ctx->pasid, irq->id);
156 if (ctx->mapping)
157 unmap_mapping_range(ctx->mapping,
158 ocxl_irq_id_to_offset(ctx, irq->id),
159 1 << PAGE_SHIFT, 1);
160 release_afu_irq(irq);
161 if (irq->free_private)
162 irq->free_private(irq->private);
163 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
164 kfree(irq);
165 }
166
ocxl_afu_irq_free(struct ocxl_context * ctx,int irq_id)167 int ocxl_afu_irq_free(struct ocxl_context *ctx, int irq_id)
168 {
169 struct afu_irq *irq;
170
171 mutex_lock(&ctx->irq_lock);
172
173 irq = idr_find(&ctx->irq_idr, irq_id);
174 if (!irq) {
175 mutex_unlock(&ctx->irq_lock);
176 return -EINVAL;
177 }
178 idr_remove(&ctx->irq_idr, irq->id);
179 afu_irq_free(irq, ctx);
180 mutex_unlock(&ctx->irq_lock);
181 return 0;
182 }
183 EXPORT_SYMBOL_GPL(ocxl_afu_irq_free);
184
ocxl_afu_irq_free_all(struct ocxl_context * ctx)185 void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
186 {
187 struct afu_irq *irq;
188 int id;
189
190 mutex_lock(&ctx->irq_lock);
191 idr_for_each_entry(&ctx->irq_idr, irq, id)
192 afu_irq_free(irq, ctx);
193 mutex_unlock(&ctx->irq_lock);
194 }
195
ocxl_afu_irq_get_addr(struct ocxl_context * ctx,int irq_id)196 u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id)
197 {
198 struct xive_irq_data *xd;
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 xd = irq_get_handler_data(irq->virq);
206 addr = xd ? xd->trig_page : 0;
207 }
208 mutex_unlock(&ctx->irq_lock);
209 return addr;
210 }
211 EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);
212
