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
10struct 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
20int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
21{
22	return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT;
23}
24
25u64 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
30int 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
52unlock:
53	mutex_unlock(&ctx->irq_lock);
54	return rc;
55}
56EXPORT_SYMBOL_GPL(ocxl_irq_set_handler);
57
58static irqreturn_t afu_irq_handler(int virq, void *data)
59{
60	struct afu_irq *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
70static 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
98static 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
105int 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
143err_alloc:
144	ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
145err_idr:
146	idr_remove(&ctx->irq_idr, irq->id);
147err_unlock:
148	mutex_unlock(&ctx->irq_lock);
149	kfree(irq);
150	return rc;
151}
152EXPORT_SYMBOL_GPL(ocxl_afu_irq_alloc);
153
154static 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
168int 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}
184EXPORT_SYMBOL_GPL(ocxl_afu_irq_free);
185
186void 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
197u64 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}
212EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);
213