summaryrefslogtreecommitdiffstats
path: root/drivers/misc/ocxl/afu_irq.c
blob: 70f8f1c3929dcadb2a9803e6ab2214479075a0be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
// SPDX-License-Identifier: GPL-2.0+
// Copyright 2017 IBM Corp.
#include <linux/interrupt.h>
#include <asm/pnv-ocxl.h>
#include "ocxl_internal.h"
#include "trace.h"

struct afu_irq {
	int id;
	int hw_irq;
	unsigned int virq;
	char *name;
	u64 trigger_page;
	irqreturn_t (*handler)(void *private);
	void (*free_private)(void *private);
	void *private;
};

int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
{
	return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT;
}

u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id)
{
	return ctx->afu->irq_base_offset + (irq_id << PAGE_SHIFT);
}

int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
		irqreturn_t (*handler)(void *private),
		void (*free_private)(void *private),
		void *private)
{
	struct afu_irq *irq;
	int rc;

	mutex_lock(&ctx->irq_lock);
	irq = idr_find(&ctx->irq_idr, irq_id);
	if (!irq) {
		rc = -EINVAL;
		goto unlock;
	}

	irq->handler = handler;
	irq->private = private;
	irq->free_private = free_private;

	rc = 0;
	// Fall through to unlock

unlock:
	mutex_unlock(&ctx->irq_lock);
	return rc;
}
EXPORT_SYMBOL_GPL(ocxl_irq_set_handler);

static irqreturn_t afu_irq_handler(int virq, void *data)
{
	struct afu_irq *irq = (struct afu_irq *) data;

	trace_ocxl_afu_irq_receive(virq);

	if (irq->handler)
		return irq->handler(irq->private);

	return IRQ_HANDLED; // Just drop it on the ground
}

static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq)
{
	int rc;

	irq->virq = irq_create_mapping(NULL, irq->hw_irq);
	if (!irq->virq) {
		pr_err("irq_create_mapping failed\n");
		return -ENOMEM;
	}
	pr_debug("hw_irq %d mapped to virq %u\n", irq->hw_irq, irq->virq);

	irq->name = kasprintf(GFP_KERNEL, "ocxl-afu-%u", irq->virq);
	if (!irq->name) {
		irq_dispose_mapping(irq->virq);
		return -ENOMEM;
	}

	rc = request_irq(irq->virq, afu_irq_handler, 0, irq->name, irq);
	if (rc) {
		kfree(irq->name);
		irq->name = NULL;
		irq_dispose_mapping(irq->virq);
		pr_err("request_irq failed: %d\n", rc);
		return rc;
	}
	return 0;
}

static void release_afu_irq(struct afu_irq *irq)
{
	free_irq(irq->virq, irq);
	irq_dispose_mapping(irq->virq);
	kfree(irq->name);
}

int ocxl_afu_irq_alloc(struct ocxl_context *ctx, int *irq_id)
{
	struct afu_irq *irq;
	int rc;

	irq = kzalloc(sizeof(struct afu_irq), GFP_KERNEL);
	if (!irq)
		return -ENOMEM;

	/*
	 * We limit the number of afu irqs per context and per link to
	 * avoid a single process or user depleting the pool of IPIs
	 */

	mutex_lock(&ctx->irq_lock);

	irq->id = idr_alloc(&ctx->irq_idr, irq, 0, MAX_IRQ_PER_CONTEXT,
			GFP_KERNEL);
	if (irq->id < 0) {
		rc = -ENOSPC;
		goto err_unlock;
	}

	rc = ocxl_link_irq_alloc(ctx->afu->fn->link, &irq->hw_irq,
				&irq->trigger_page);
	if (rc)
		goto err_idr;

	rc = setup_afu_irq(ctx, irq);
	if (rc)
		goto err_alloc;

	trace_ocxl_afu_irq_alloc(ctx->pasid, irq->id, irq->virq, irq->hw_irq);
	mutex_unlock(&ctx->irq_lock);

	*irq_id = irq->id;

	return 0;

err_alloc:
	ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
err_idr:
	idr_remove(&ctx->irq_idr, irq->id);
err_unlock:
	mutex_unlock(&ctx->irq_lock);
	kfree(irq);
	return rc;
}
EXPORT_SYMBOL_GPL(ocxl_afu_irq_alloc);

static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx)
{
	trace_ocxl_afu_irq_free(ctx->pasid, irq->id);
	if (ctx->mapping)
		unmap_mapping_range(ctx->mapping,
				ocxl_irq_id_to_offset(ctx, irq->id),
				1 << PAGE_SHIFT, 1);
	release_afu_irq(irq);
	if (irq->free_private)
		irq->free_private(irq->private);
	ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
	kfree(irq);
}

int ocxl_afu_irq_free(struct ocxl_context *ctx, int irq_id)
{
	struct afu_irq *irq;

	mutex_lock(&ctx->irq_lock);

	irq = idr_find(&ctx->irq_idr, irq_id);
	if (!irq) {
		mutex_unlock(&ctx->irq_lock);
		return -EINVAL;
	}
	idr_remove(&ctx->irq_idr, irq->id);
	afu_irq_free(irq, ctx);
	mutex_unlock(&ctx->irq_lock);
	return 0;
}
EXPORT_SYMBOL_GPL(ocxl_afu_irq_free);

void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
{
	struct afu_irq *irq;
	int id;

	mutex_lock(&ctx->irq_lock);
	idr_for_each_entry(&ctx->irq_idr, irq, id)
		afu_irq_free(irq, ctx);
	mutex_unlock(&ctx->irq_lock);
}

u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id)
{
	struct afu_irq *irq;
	u64 addr = 0;

	mutex_lock(&ctx->irq_lock);
	irq = idr_find(&ctx->irq_idr, irq_id);
	if (irq)
		addr = irq->trigger_page;
	mutex_unlock(&ctx->irq_lock);
	return addr;
}
EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);