v4.19.13 snapshot.
diff --git a/drivers/misc/ocxl/afu_irq.c b/drivers/misc/ocxl/afu_irq.c
new file mode 100644
index 0000000..e70cfa2
--- /dev/null
+++ b/drivers/misc/ocxl/afu_irq.c
@@ -0,0 +1,202 @@
+// 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"
+#include "trace.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;
+
+ trace_ocxl_afu_irq_receive(virq);
+ 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);
+
+ trace_ocxl_afu_irq_alloc(ctx->pasid, irq->id, irq->virq, irq->hw_irq,
+ *irq_offset);
+ 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)
+{
+ trace_ocxl_afu_irq_free(ctx->pasid, irq->id);
+ 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;
+}