Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 202 insertions, 0 deletions

diff --git a/drivers/misc/ocxl/afu_irq.c b/drivers/misc/ocxl/afu_irq.c
new file mode 100644
index 000000000..e70cfa245
--- /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;
+}