1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017 IBM Corp.
3 #include <linux/interrupt.h>
4 #include <linux/irqdomain.h>
5 #include <asm/pnv-ocxl.h>
6 #include <asm/xive.h>
7 #include "ocxl_internal.h"
8 #include "trace.h"
9 
10 struct afu_irq {
11 	int id;
12 	int hw_irq;
13 	unsigned int virq;
14 	char *name;
15 	irqreturn_t (*handler)(void *private);
16 	void (*free_private)(void *private);
17 	void *private;
18 };
19 
ocxl_irq_offset_to_id(struct ocxl_context * ctx,u64 offset)20 int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
21 {
22 	return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT;
23 }
24 
ocxl_irq_id_to_offset(struct ocxl_context * ctx,int irq_id)25 u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id)
26 {
27 	return ctx->afu->irq_base_offset + (irq_id << PAGE_SHIFT);
28 }
29 
ocxl_irq_set_handler(struct ocxl_context * ctx,int irq_id,irqreturn_t (* handler)(void * private),void (* free_private)(void * private),void * private)30 int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
31 		irqreturn_t (*handler)(void *private),
32 		void (*free_private)(void *private),
33 		void *private)
34 {
35 	struct afu_irq *irq;
36 	int rc;
37 
38 	mutex_lock(&ctx->irq_lock);
39 	irq = idr_find(&ctx->irq_idr, irq_id);
40 	if (!irq) {
41 		rc = -EINVAL;
42 		goto unlock;
43 	}
44 
45 	irq->handler = handler;
46 	irq->private = private;
47 	irq->free_private = free_private;
48 
49 	rc = 0;
50 	// Fall through to unlock
51 
52 unlock:
53 	mutex_unlock(&ctx->irq_lock);
54 	return rc;
55 }
56 EXPORT_SYMBOL_GPL(ocxl_irq_set_handler);
57 
afu_irq_handler(int virq,void * data)58 static irqreturn_t afu_irq_handler(int virq, void *data)
59 {
60 	struct afu_irq *irq = (struct afu_irq *) data;
61 
62 	trace_ocxl_afu_irq_receive(virq);
63 
64 	if (irq->handler)
65 		return irq->handler(irq->private);
66 
67 	return IRQ_HANDLED; // Just drop it on the ground
68 }
69 
setup_afu_irq(struct ocxl_context * ctx,struct afu_irq * irq)70 static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq)
71 {
72 	int rc;
73 
74 	irq->virq = irq_create_mapping(NULL, irq->hw_irq);
75 	if (!irq->virq) {
76 		pr_err("irq_create_mapping failed\n");
77 		return -ENOMEM;
78 	}
79 	pr_debug("hw_irq %d mapped to virq %u\n", irq->hw_irq, irq->virq);
80 
81 	irq->name = kasprintf(GFP_KERNEL, "ocxl-afu-%u", irq->virq);
82 	if (!irq->name) {
83 		irq_dispose_mapping(irq->virq);
84 		return -ENOMEM;
85 	}
86 
87 	rc = request_irq(irq->virq, afu_irq_handler, 0, irq->name, irq);
88 	if (rc) {
89 		kfree(irq->name);
90 		irq->name = NULL;
91 		irq_dispose_mapping(irq->virq);
92 		pr_err("request_irq failed: %d\n", rc);
93 		return rc;
94 	}
95 	return 0;
96 }
97 
release_afu_irq(struct afu_irq * irq)98 static void release_afu_irq(struct afu_irq *irq)
99 {
100 	free_irq(irq->virq, irq);
101 	irq_dispose_mapping(irq->virq);
102 	kfree(irq->name);
103 }
104 
ocxl_afu_irq_alloc(struct ocxl_context * ctx,int * irq_id)105 int ocxl_afu_irq_alloc(struct ocxl_context *ctx, int *irq_id)
106 {
107 	struct afu_irq *irq;
108 	int rc;
109 
110 	irq = kzalloc(sizeof(struct afu_irq), GFP_KERNEL);
111 	if (!irq)
112 		return -ENOMEM;
113 
114 	/*
115 	 * We limit the number of afu irqs per context and per link to
116 	 * avoid a single process or user depleting the pool of IPIs
117 	 */
118 
119 	mutex_lock(&ctx->irq_lock);
120 
121 	irq->id = idr_alloc(&ctx->irq_idr, irq, 0, MAX_IRQ_PER_CONTEXT,
122 			GFP_KERNEL);
123 	if (irq->id < 0) {
124 		rc = -ENOSPC;
125 		goto err_unlock;
126 	}
127 
128 	rc = ocxl_link_irq_alloc(ctx->afu->fn->link, &irq->hw_irq);
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 xive_irq_data *xd;
200 	struct afu_irq *irq;
201 	u64 addr = 0;
202 
203 	mutex_lock(&ctx->irq_lock);
204 	irq = idr_find(&ctx->irq_idr, irq_id);
205 	if (irq) {
206 		xd = irq_get_handler_data(irq->virq);
207 		addr = xd ? xd->trig_page : 0;
208 	}
209 	mutex_unlock(&ctx->irq_lock);
210 	return addr;
211 }
212 EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);
213