1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/staging/gasket/gasket_interrupt.h b/drivers/staging/gasket/gasket_interrupt.h
new file mode 100644
index 000000000000..835af439e96a
--- /dev/null
+++ b/drivers/staging/gasket/gasket_interrupt.h
@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Gasket common interrupt module. Defines functions for enabling
+ * eventfd-triggered interrupts between a Gasket device and a host process.
+ *
+ * Copyright (C) 2018 Google, Inc.
+ */
+#ifndef __GASKET_INTERRUPT_H__
+#define __GASKET_INTERRUPT_H__
+
+#include <linux/eventfd.h>
+#include <linux/pci.h>
+
+#include "gasket_core.h"
+
+/* Note that this currently assumes that device interrupts are a dense set,
+ * numbered from 0 - (num_interrupts - 1). Should this have to change, these
+ * APIs will have to be updated.
+ */
+
+/* Opaque type used to hold interrupt subsystem data. */
+struct gasket_interrupt_data;
+
+/*
+ * Initialize the interrupt module.
+ * @gasket_dev: The Gasket device structure for the device to be initted.
+ * @type: Type of the interrupt. (See gasket_interrupt_type).
+ * @name: The name to associate with these interrupts.
+ * @interrupts: An array of all interrupt descriptions for this device.
+ * @num_interrupts: The length of the @interrupts array.
+ * @pack_width: The width, in bits, of a single field in a packed interrupt reg.
+ * @bar_index: The bar containing all interrupt registers.
+ *
+ * Allocates and initializes data to track interrupt state for a device.
+ * After this call, no interrupts will be configured/delivered; call
+ * gasket_interrupt_set_vector[_packed] to associate each interrupt with an
+ * __iomem location, then gasket_interrupt_set_eventfd to associate an eventfd
+ * with an interrupt.
+ *
+ * If num_interrupts interrupts are not available, this call will return a
+ * negative error code. In that case, gasket_interrupt_cleanup should still be
+ * called. Returns 0 on success (which can include a device where interrupts
+ * are not possible to set up, but is otherwise OK; that device will report
+ * status LAMED.)
+ */
+int gasket_interrupt_init(struct gasket_dev *gasket_dev, const char *name,
+			  int type,
+			  const struct gasket_interrupt_desc *interrupts,
+			  int num_interrupts, int pack_width, int bar_index,
+			  const struct gasket_wire_interrupt_offsets *wire_int_offsets);
+
+/*
+ * Clean up a device's interrupt structure.
+ * @gasket_dev: The Gasket information structure for this device.
+ *
+ * Cleans up the device's interrupts and deallocates data.
+ */
+void gasket_interrupt_cleanup(struct gasket_dev *gasket_dev);
+
+/*
+ * Clean up and re-initialize the MSI-x subsystem.
+ * @gasket_dev: The Gasket information structure for this device.
+ *
+ * Performs a teardown of the MSI-x subsystem and re-initializes it. Does not
+ * free the underlying data structures. Returns 0 on success and an error code
+ * on error.
+ */
+int gasket_interrupt_reinit(struct gasket_dev *gasket_dev);
+
+/*
+ * Reset the counts stored in the interrupt subsystem.
+ * @gasket_dev: The Gasket information structure for this device.
+ *
+ * Sets the counts of all interrupts in the subsystem to 0.
+ */
+int gasket_interrupt_reset_counts(struct gasket_dev *gasket_dev);
+
+/*
+ * Associates an eventfd with a device interrupt.
+ * @data: Pointer to device interrupt data.
+ * @interrupt: The device interrupt to configure.
+ * @event_fd: The eventfd to associate with the interrupt.
+ *
+ * Prepares the host to receive notification of device interrupts by associating
+ * event_fd with interrupt. Upon receipt of a device interrupt, event_fd will be
+ * signaled, after successful configuration.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int gasket_interrupt_set_eventfd(struct gasket_interrupt_data *interrupt_data,
+				 int interrupt, int event_fd);
+
+/*
+ * Removes an interrupt-eventfd association.
+ * @data: Pointer to device interrupt data.
+ * @interrupt: The device interrupt to de-associate.
+ *
+ * Removes any eventfd associated with the specified interrupt, if any.
+ */
+int gasket_interrupt_clear_eventfd(struct gasket_interrupt_data *interrupt_data,
+				   int interrupt);
+
+/*
+ * The below functions exist for backwards compatibility.
+ * No new uses should be written.
+ */
+/*
+ * Get the health of the interrupt subsystem.
+ * @gasket_dev: The Gasket device struct.
+ *
+ * Returns DEAD if not set up, LAMED if initialization failed, and ALIVE
+ * otherwise.
+ */
+
+int gasket_interrupt_system_status(struct gasket_dev *gasket_dev);
+
+#endif