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
  8struct 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
 19int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
 20{
 21	return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT;
 22}
 23
 24u64 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
 29int 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
 51unlock:
 52	mutex_unlock(&ctx->irq_lock);
 53	return rc;
 54}
 55EXPORT_SYMBOL_GPL(ocxl_irq_set_handler);
 56
 57static 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
 69static 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
 97static 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
104int 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
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 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}
209EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);