linux-sg2042/include/linux/intel_th.h

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Intel(R) Trace Hub data structures for implementing buffer sinks.
*
* Copyright (C) 2019 Intel Corporation.
*/
#ifndef _INTEL_TH_H_
#define _INTEL_TH_H_
#include <linux/scatterlist.h>
/* MSC operating modes (MSC_MODE) */
enum {
MSC_MODE_SINGLE = 0,
MSC_MODE_MULTI,
MSC_MODE_EXI,
MSC_MODE_DEBUG,
};
struct msu_buffer {
const char *name;
/*
* ->assign() called when buffer 'mode' is set to this driver
* (aka mode_store())
* @device: struct device * of the msc
* @mode: allows the driver to set HW mode (see the enum above)
* Returns: a pointer to a private structure associated with this
* msc or NULL in case of error. This private structure
* will then be passed into all other callbacks.
*/
void *(*assign)(struct device *dev, int *mode);
/* ->unassign(): some other mode is selected, clean up */
void (*unassign)(void *priv);
/*
* ->alloc_window(): allocate memory for the window of a given
* size
* @sgt: pointer to sg_table, can be overridden by the buffer
* driver, or kept intact
* Returns: number of sg table entries <= number of pages;
* 0 is treated as an allocation failure.
*/
int (*alloc_window)(void *priv, struct sg_table **sgt,
size_t size);
void (*free_window)(void *priv, struct sg_table *sgt);
/* ->activate(): trace has started */
void (*activate)(void *priv);
/* ->deactivate(): trace is about to stop */
void (*deactivate)(void *priv);
/*
* ->ready(): window @sgt is filled up to the last block OR
* tracing is stopped by the user; this window contains
* @bytes data. The window in question transitions into
* the "LOCKED" state, indicating that it can't be used
* by hardware. To clear this state and make the window
* available to the hardware again, call
* intel_th_msc_window_unlock().
*/
int (*ready)(void *priv, struct sg_table *sgt, size_t bytes);
};
int intel_th_msu_buffer_register(const struct msu_buffer *mbuf,
struct module *owner);
void intel_th_msu_buffer_unregister(const struct msu_buffer *mbuf);
void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt);
#define module_intel_th_msu_buffer(__buffer) \
static int __init __buffer##_init(void) \
{ \
return intel_th_msu_buffer_register(&(__buffer), THIS_MODULE); \
} \
module_init(__buffer##_init); \
static void __exit __buffer##_exit(void) \
{ \
intel_th_msu_buffer_unregister(&(__buffer)); \
} \
module_exit(__buffer##_exit);
#endif /* _INTEL_TH_H_ */