diff options
Diffstat (limited to 'drivers/misc/ocxl/afu_irq.c')
| -rw-r--r-- | drivers/misc/ocxl/afu_irq.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/drivers/misc/ocxl/afu_irq.c b/drivers/misc/ocxl/afu_irq.c new file mode 100644 index 000000000000..f40d853de401 --- /dev/null +++ b/drivers/misc/ocxl/afu_irq.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2017 IBM Corp. +#include <linux/interrupt.h> +#include <linux/eventfd.h> +#include <asm/pnv-ocxl.h> +#include "ocxl_internal.h" + +struct afu_irq { + int id; + int hw_irq; + unsigned int virq; + char *name; + u64 trigger_page; + struct eventfd_ctx *ev_ctx; +}; + +static int irq_offset_to_id(struct ocxl_context *ctx, u64 offset) +{ + return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT; +} + +static u64 irq_id_to_offset(struct ocxl_context *ctx, int id) +{ + return ctx->afu->irq_base_offset + (id << PAGE_SHIFT); +} + +static irqreturn_t afu_irq_handler(int virq, void *data) +{ + struct afu_irq *irq = (struct afu_irq *) data; + + if (irq->ev_ctx) + eventfd_signal(irq->ev_ctx, 1); + return IRQ_HANDLED; +} + +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, u64 *irq_offset) +{ + 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; + + *irq_offset = irq_id_to_offset(ctx, irq->id); + + mutex_unlock(&ctx->irq_lock); + 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; +} + +static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx) +{ + if (ctx->mapping) + unmap_mapping_range(ctx->mapping, + irq_id_to_offset(ctx, irq->id), + 1 << PAGE_SHIFT, 1); + release_afu_irq(irq); + if (irq->ev_ctx) + eventfd_ctx_put(irq->ev_ctx); + ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq); + kfree(irq); +} + +int ocxl_afu_irq_free(struct ocxl_context *ctx, u64 irq_offset) +{ + struct afu_irq *irq; + int id = irq_offset_to_id(ctx, irq_offset); + + mutex_lock(&ctx->irq_lock); + + irq = idr_find(&ctx->irq_idr, 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; +} + +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); +} + +int ocxl_afu_irq_set_fd(struct ocxl_context *ctx, u64 irq_offset, int eventfd) +{ + struct afu_irq *irq; + struct eventfd_ctx *ev_ctx; + int rc = 0, id = irq_offset_to_id(ctx, irq_offset); + + mutex_lock(&ctx->irq_lock); + irq = idr_find(&ctx->irq_idr, id); + if (!irq) { + rc = -EINVAL; + goto unlock; + } + + ev_ctx = eventfd_ctx_fdget(eventfd); + if (IS_ERR(ev_ctx)) { + rc = -EINVAL; + goto unlock; + } + + irq->ev_ctx = ev_ctx; +unlock: + mutex_unlock(&ctx->irq_lock); + return rc; +} + +u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, u64 irq_offset) +{ + struct afu_irq *irq; + int id = irq_offset_to_id(ctx, irq_offset); + u64 addr = 0; + + mutex_lock(&ctx->irq_lock); + irq = idr_find(&ctx->irq_idr, id); + if (irq) + addr = irq->trigger_page; + mutex_unlock(&ctx->irq_lock); + return addr; +} |