2 * Performance counter support - PowerPC-specific definitions.
4 * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 #include <linux/types.h>
13 #define MAX_HWCOUNTERS 8
14 #define MAX_EVENT_ALTERNATIVES 8
17 * This struct provides the constants and functions needed to
18 * describe the PMU on a particular POWER-family CPU.
25 int (*compute_mmcr)(unsigned int events[], int n_ev,
26 unsigned int hwc[], u64 mmcr[]);
27 int (*get_constraint)(unsigned int event, u64 *mskp, u64 *valp);
28 int (*get_alternatives)(unsigned int event, unsigned int alt[]);
29 void (*disable_pmc)(unsigned int pmc, u64 mmcr[]);
34 extern struct power_pmu *ppmu;
37 * The power_pmu.get_constraint function returns a 64-bit value and
38 * a 64-bit mask that express the constraints between this event and
41 * The value and mask are divided up into (non-overlapping) bitfields
42 * of three different types:
44 * Select field: this expresses the constraint that some set of bits
45 * in MMCR* needs to be set to a specific value for this event. For a
46 * select field, the mask contains 1s in every bit of the field, and
47 * the value contains a unique value for each possible setting of the
48 * MMCR* bits. The constraint checking code will ensure that two events
49 * that set the same field in their masks have the same value in their
52 * Add field: this expresses the constraint that there can be at most
53 * N events in a particular class. A field of k bits can be used for
54 * N <= 2^(k-1) - 1. The mask has the most significant bit of the field
55 * set (and the other bits 0), and the value has only the least significant
56 * bit of the field set. In addition, the 'add_fields' and 'test_adder'
57 * in the struct power_pmu for this processor come into play. The
58 * add_fields value contains 1 in the LSB of the field, and the
59 * test_adder contains 2^(k-1) - 1 - N in the field.
61 * NAND field: this expresses the constraint that you may not have events
62 * in all of a set of classes. (For example, on PPC970, you can't select
63 * events from the FPU, ISU and IDU simultaneously, although any two are
64 * possible.) For N classes, the field is N+1 bits wide, and each class
65 * is assigned one bit from the least-significant N bits. The mask has
66 * only the most-significant bit set, and the value has only the bit
67 * for the event's class set. The test_adder has the least significant
68 * bit set in the field.
70 * If an event is not subject to the constraint expressed by a particular
71 * field, then it will have 0 in both the mask and value for that field.