linux/arch/x86/include/asm/intel_pt.h
Alexander Shishkin 161a9a3370 perf/x86/intel/pt: Add a capability and config bit for disabling TNTs
As of Intel SDM (https://www.intel.com/sdm) version 076, there is a new
Intel PT feature called TNT-Disable which is enabled config bit 55.

TNT-Disable disables Taken-Not-Taken packets to reduce the tracing
overhead, but with the result that exact control flow information is
lost.

Add a capability and config bit for TNT-Disable.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20220126104815.2807416-3-adrian.hunter@intel.com
2022-02-15 17:47:11 +01:00

42 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_INTEL_PT_H
#define _ASM_X86_INTEL_PT_H
#define PT_CPUID_LEAVES 2
#define PT_CPUID_REGS_NUM 4 /* number of registers (eax, ebx, ecx, edx) */
enum pt_capabilities {
PT_CAP_max_subleaf = 0,
PT_CAP_cr3_filtering,
PT_CAP_psb_cyc,
PT_CAP_ip_filtering,
PT_CAP_mtc,
PT_CAP_ptwrite,
PT_CAP_power_event_trace,
PT_CAP_event_trace,
PT_CAP_tnt_disable,
PT_CAP_topa_output,
PT_CAP_topa_multiple_entries,
PT_CAP_single_range_output,
PT_CAP_output_subsys,
PT_CAP_payloads_lip,
PT_CAP_num_address_ranges,
PT_CAP_mtc_periods,
PT_CAP_cycle_thresholds,
PT_CAP_psb_periods,
};
#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
void cpu_emergency_stop_pt(void);
extern u32 intel_pt_validate_hw_cap(enum pt_capabilities cap);
extern u32 intel_pt_validate_cap(u32 *caps, enum pt_capabilities cap);
extern int is_intel_pt_event(struct perf_event *event);
#else
static inline void cpu_emergency_stop_pt(void) {}
static inline u32 intel_pt_validate_hw_cap(enum pt_capabilities cap) { return 0; }
static inline u32 intel_pt_validate_cap(u32 *caps, enum pt_capabilities capability) { return 0; }
static inline int is_intel_pt_event(struct perf_event *event) { return 0; }
#endif
#endif /* _ASM_X86_INTEL_PT_H */