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