MdePkg/Library/BaseLib/Ia32/ReadPmc.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

/** @file
  AsmReadPmc function

  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

/**
  Reads the current value of a Performance Counter (PMC).

  Reads and returns the current value of performance counter specified by
  Index. This function is only available on IA-32 and x64.

  @param  Index The 32-bit Performance Counter index to read.

  @return The value of the PMC specified by Index.

**/
UINT64
EFIAPI
AsmReadPmc (
  IN UINT32  Index
  )
{
  _asm {
    mov     ecx, Index
    rdpmc
  }
}