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/*
* Debug Store (DS) support
*
* This provides a low-level interface to the hardware's Debug Store
* feature that is used for last branch recording (LBR) and
* precise-event based sampling (PEBS).
*
* Different architectures use a different DS layout/pointer size.
* The below functions therefore work on a void*.
*
*
* Since there is no user for PEBS, yet, only LBR (or branch
* trace store, BTS) is supported.
*
*
* Copyright (C) 2007 Intel Corporation.
* Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
*/
#ifndef _ASM_X86_DS_H
#define _ASM_X86_DS_H
#include <linux/types.h>
#include <linux/init.h>
struct cpuinfo_x86;
/* a branch trace record entry
*
* In order to unify the interface between various processor versions,
* we use the below data structure for all processors.
*/
enum bts_qualifier {
BTS_INVALID = 0,
BTS_BRANCH,
BTS_TASK_ARRIVES,
BTS_TASK_DEPARTS
};
struct bts_struct {
enum bts_qualifier qualifier;
union {
/* BTS_BRANCH */
struct {
long from_ip;
long to_ip;
} lbr;
/* BTS_TASK_ARRIVES or
BTS_TASK_DEPARTS */
unsigned long jiffies;
} variant;
};
/* Overflow handling mechanisms */
#define DS_O_SIGNAL 1 /* send overflow signal */
#define DS_O_WRAP 2 /* wrap around */
extern int ds_allocate(void **, size_t);
extern int ds_free(void **);
extern int ds_get_bts_size(void *);
extern int ds_get_bts_end(void *);
extern int ds_get_bts_index(void *);
extern int ds_set_overflow(void *, int);
extern int ds_get_overflow(void *);
extern int ds_clear(void *);
extern int ds_read_bts(void *, size_t, struct bts_struct *);
extern int ds_write_bts(void *, const struct bts_struct *);
extern unsigned long ds_debugctl_mask(void);
extern void __cpuinit ds_init_intel(struct cpuinfo_x86 *c);
#endif /* _ASM_X86_DS_H */