1 // SPDX-License-Identifier: GPL-2.0+ 2 // Copyright 2017 IBM Corp. 3 #include <linux/interrupt.h> 4 #include <linux/eventfd.h> 5 #include <asm/pnv-ocxl.h> 6 #include "ocxl_internal.h" 7 8 struct afu_irq { 9 int id; 10 int hw_irq; 11 unsigned int virq; 12 char *name; 13 u64 trigger_page; 14 struct eventfd_ctx *ev_ctx; 15 }; 16 17 static int irq_offset_to_id(struct ocxl_context *ctx, u64 offset) 18 { 19 return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT; 20 } 21 22 static u64 irq_id_to_offset(struct ocxl_context *ctx, int id) 23 { 24 return ctx->afu->irq_base_offset + (id << PAGE_SHIFT); 25 } 26 27 static irqreturn_t afu_irq_handler(int virq, void *data) 28 { 29 struct afu_irq *irq = (struct afu_irq *) data; 30 31 if (irq->ev_ctx) 32 eventfd_signal(irq->ev_ctx, 1); 33 return IRQ_HANDLED; 34 } 35 36 static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq) 37 { 38 int rc; 39 40 irq->virq = irq_create_mapping(NULL, irq->hw_irq); 41 if (!irq->virq) { 42 pr_err("irq_create_mapping failed\n"); 43 return -ENOMEM; 44 } 45 pr_debug("hw_irq %d mapped to virq %u\n", irq->hw_irq, irq->virq); 46 47 irq->name = kasprintf(GFP_KERNEL, "ocxl-afu-%u", irq->virq); 48 if (!irq->name) { 49 irq_dispose_mapping(irq->virq); 50 return -ENOMEM; 51 } 52 53 rc = request_irq(irq->virq, afu_irq_handler, 0, irq->name, irq); 54 if (rc) { 55 kfree(irq->name); 56 irq->name = NULL; 57 irq_dispose_mapping(irq->virq); 58 pr_err("request_irq failed: %d\n", rc); 59 return rc; 60 } 61 return 0; 62 } 63 64 static void release_afu_irq(struct afu_irq *irq) 65 { 66 free_irq(irq->virq, irq); 67 irq_dispose_mapping(irq->virq); 68 kfree(irq->name); 69 } 70 71 int ocxl_afu_irq_alloc(struct ocxl_context *ctx, u64 *irq_offset) 72 { 73 struct afu_irq *irq; 74 int rc; 75 76 irq = kzalloc(sizeof(struct afu_irq), GFP_KERNEL); 77 if (!irq) 78 return -ENOMEM; 79 80 /* 81 * We limit the number of afu irqs per context and per link to 82 * avoid a single process or user depleting the pool of IPIs 83 */ 84 85 mutex_lock(&ctx->irq_lock); 86 87 irq->id = idr_alloc(&ctx->irq_idr, irq, 0, MAX_IRQ_PER_CONTEXT, 88 GFP_KERNEL); 89 if (irq->id < 0) { 90 rc = -ENOSPC; 91 goto err_unlock; 92 } 93 94 rc = ocxl_link_irq_alloc(ctx->afu->fn->link, &irq->hw_irq, 95 &irq->trigger_page); 96 if (rc) 97 goto err_idr; 98 99 rc = setup_afu_irq(ctx, irq); 100 if (rc) 101 goto err_alloc; 102 103 *irq_offset = irq_id_to_offset(ctx, irq->id); 104 105 mutex_unlock(&ctx->irq_lock); 106 return 0; 107 108 err_alloc: 109 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq); 110 err_idr: 111 idr_remove(&ctx->irq_idr, irq->id); 112 err_unlock: 113 mutex_unlock(&ctx->irq_lock); 114 kfree(irq); 115 return rc; 116 } 117 118 static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx) 119 { 120 if (ctx->mapping) 121 unmap_mapping_range(ctx->mapping, 122 irq_id_to_offset(ctx, irq->id), 123 1 << PAGE_SHIFT, 1); 124 release_afu_irq(irq); 125 if (irq->ev_ctx) 126 eventfd_ctx_put(irq->ev_ctx); 127 ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq); 128 kfree(irq); 129 } 130 131 int ocxl_afu_irq_free(struct ocxl_context *ctx, u64 irq_offset) 132 { 133 struct afu_irq *irq; 134 int id = irq_offset_to_id(ctx, irq_offset); 135 136 mutex_lock(&ctx->irq_lock); 137 138 irq = idr_find(&ctx->irq_idr, id); 139 if (!irq) { 140 mutex_unlock(&ctx->irq_lock); 141 return -EINVAL; 142 } 143 idr_remove(&ctx->irq_idr, irq->id); 144 afu_irq_free(irq, ctx); 145 mutex_unlock(&ctx->irq_lock); 146 return 0; 147 } 148 149 void ocxl_afu_irq_free_all(struct ocxl_context *ctx) 150 { 151 struct afu_irq *irq; 152 int id; 153 154 mutex_lock(&ctx->irq_lock); 155 idr_for_each_entry(&ctx->irq_idr, irq, id) 156 afu_irq_free(irq, ctx); 157 mutex_unlock(&ctx->irq_lock); 158 } 159 160 int ocxl_afu_irq_set_fd(struct ocxl_context *ctx, u64 irq_offset, int eventfd) 161 { 162 struct afu_irq *irq; 163 struct eventfd_ctx *ev_ctx; 164 int rc = 0, id = irq_offset_to_id(ctx, irq_offset); 165 166 mutex_lock(&ctx->irq_lock); 167 irq = idr_find(&ctx->irq_idr, id); 168 if (!irq) { 169 rc = -EINVAL; 170 goto unlock; 171 } 172 173 ev_ctx = eventfd_ctx_fdget(eventfd); 174 if (IS_ERR(ev_ctx)) { 175 rc = -EINVAL; 176 goto unlock; 177 } 178 179 irq->ev_ctx = ev_ctx; 180 unlock: 181 mutex_unlock(&ctx->irq_lock); 182 return rc; 183 } 184 185 u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, u64 irq_offset) 186 { 187 struct afu_irq *irq; 188 int id = irq_offset_to_id(ctx, irq_offset); 189 u64 addr = 0; 190 191 mutex_lock(&ctx->irq_lock); 192 irq = idr_find(&ctx->irq_idr, id); 193 if (irq) 194 addr = irq->trigger_page; 195 mutex_unlock(&ctx->irq_lock); 196 return addr; 197 } 198