LXR linux/include/linux/intel

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Intel(R) Trace Hub data structures for implementing buffer sinks.
   4 *
   5 * Copyright (C) 2019 Intel Corporation.
   6 */
   7
   8#ifndef _INTEL_TH_H_
   9#define _INTEL_TH_H_
  10
  11#include <linux/scatterlist.h>
  12
  13/* MSC operating modes (MSC_MODE) */
  14enum {
  15        MSC_MODE_SINGLE = 0,
  16        MSC_MODE_MULTI,
  17        MSC_MODE_EXI,
  18        MSC_MODE_DEBUG,
  19};
  20
  21struct msu_buffer {
  22        const char      *name;
  23        /*
  24         * ->assign() called when buffer 'mode' is set to this driver
  25         *   (aka mode_store())
  26         * @device:     struct device * of the msc
  27         * @mode:       allows the driver to set HW mode (see the enum above)
  28         * Returns:     a pointer to a private structure associated with this
  29         *              msc or NULL in case of error. This private structure
  30         *              will then be passed into all other callbacks.
  31         */
  32        void    *(*assign)(struct device *dev, int *mode);
  33        /* ->unassign():        some other mode is selected, clean up */
  34        void    (*unassign)(void *priv);
  35        /*
  36         * ->alloc_window(): allocate memory for the window of a given
  37         *              size
  38         * @sgt:        pointer to sg_table, can be overridden by the buffer
  39         *              driver, or kept intact
  40         * Returns:     number of sg table entries <= number of pages;
  41         *              0 is treated as an allocation failure.
  42         */
  43        int     (*alloc_window)(void *priv, struct sg_table **sgt,
  44                                size_t size);
  45        void    (*free_window)(void *priv, struct sg_table *sgt);
  46        /* ->activate():        trace has started */
  47        void    (*activate)(void *priv);
  48        /* ->deactivate():      trace is about to stop */
  49        void    (*deactivate)(void *priv);
  50        /*
  51         * ->ready():   window @sgt is filled up to the last block OR
  52         *              tracing is stopped by the user; this window contains
  53         *              @bytes data. The window in question transitions into
  54         *              the "LOCKED" state, indicating that it can't be used
  55         *              by hardware. To clear this state and make the window
  56         *              available to the hardware again, call
  57         *              intel_th_msc_window_unlock().
  58         */
  59        int     (*ready)(void *priv, struct sg_table *sgt, size_t bytes);
  60};
  61
  62int intel_th_msu_buffer_register(const struct msu_buffer *mbuf,
  63                                 struct module *owner);
  64void intel_th_msu_buffer_unregister(const struct msu_buffer *mbuf);
  65void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt);
  66
  67#define module_intel_th_msu_buffer(__buffer) \
  68static int __init __buffer##_init(void) \
  69{ \
  70        return intel_th_msu_buffer_register(&(__buffer), THIS_MODULE); \
  71} \
  72module_init(__buffer##_init); \
  73static void __exit __buffer##_exit(void) \
  74{ \
  75        intel_th_msu_buffer_unregister(&(__buffer)); \
  76} \
  77module_exit(__buffer##_exit);
  78
  79#endif /* _INTEL_TH_H_ */
  80