root/drivers/staging/gasket/gasket_interrupt.h

INCLUDED FROM

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Gasket common interrupt module. Defines functions for enabling
   4  * eventfd-triggered interrupts between a Gasket device and a host process.
   5  *
   6  * Copyright (C) 2018 Google, Inc.
   7  */
   8 #ifndef __GASKET_INTERRUPT_H__
   9 #define __GASKET_INTERRUPT_H__
  10 
  11 #include <linux/eventfd.h>
  12 #include <linux/pci.h>
  13 
  14 #include "gasket_core.h"
  15 
  16 /* Note that this currently assumes that device interrupts are a dense set,
  17  * numbered from 0 - (num_interrupts - 1). Should this have to change, these
  18  * APIs will have to be updated.
  19  */
  20 
  21 /* Opaque type used to hold interrupt subsystem data. */
  22 struct gasket_interrupt_data;
  23 
  24 /*
  25  * Initialize the interrupt module.
  26  * @gasket_dev: The Gasket device structure for the device to be initted.
  27  */
  28 int gasket_interrupt_init(struct gasket_dev *gasket_dev);
  29 
  30 /*
  31  * Clean up a device's interrupt structure.
  32  * @gasket_dev: The Gasket information structure for this device.
  33  *
  34  * Cleans up the device's interrupts and deallocates data.
  35  */
  36 void gasket_interrupt_cleanup(struct gasket_dev *gasket_dev);
  37 
  38 /*
  39  * Clean up and re-initialize the MSI-x subsystem.
  40  * @gasket_dev: The Gasket information structure for this device.
  41  *
  42  * Performs a teardown of the MSI-x subsystem and re-initializes it. Does not
  43  * free the underlying data structures. Returns 0 on success and an error code
  44  * on error.
  45  */
  46 int gasket_interrupt_reinit(struct gasket_dev *gasket_dev);
  47 
  48 /*
  49  * Reset the counts stored in the interrupt subsystem.
  50  * @gasket_dev: The Gasket information structure for this device.
  51  *
  52  * Sets the counts of all interrupts in the subsystem to 0.
  53  */
  54 int gasket_interrupt_reset_counts(struct gasket_dev *gasket_dev);
  55 
  56 /*
  57  * Associates an eventfd with a device interrupt.
  58  * @data: Pointer to device interrupt data.
  59  * @interrupt: The device interrupt to configure.
  60  * @event_fd: The eventfd to associate with the interrupt.
  61  *
  62  * Prepares the host to receive notification of device interrupts by associating
  63  * event_fd with interrupt. Upon receipt of a device interrupt, event_fd will be
  64  * signaled, after successful configuration.
  65  *
  66  * Returns 0 on success, a negative error code otherwise.
  67  */
  68 int gasket_interrupt_set_eventfd(struct gasket_interrupt_data *interrupt_data,
  69                                  int interrupt, int event_fd);
  70 
  71 /*
  72  * Removes an interrupt-eventfd association.
  73  * @data: Pointer to device interrupt data.
  74  * @interrupt: The device interrupt to de-associate.
  75  *
  76  * Removes any eventfd associated with the specified interrupt, if any.
  77  */
  78 int gasket_interrupt_clear_eventfd(struct gasket_interrupt_data *interrupt_data,
  79                                    int interrupt);
  80 
  81 /*
  82  * The below functions exist for backwards compatibility.
  83  * No new uses should be written.
  84  */
  85 /*
  86  * Get the health of the interrupt subsystem.
  87  * @gasket_dev: The Gasket device struct.
  88  *
  89  * Returns DEAD if not set up, LAMED if initialization failed, and ALIVE
  90  * otherwise.
  91  */
  92 
  93 int gasket_interrupt_system_status(struct gasket_dev *gasket_dev);
  94 
  95 #endif