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amd.c
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1 #if defined(__i386__) || defined(__x86_64__)
2 #include <unistd.h>
3 #include <errno.h>
4 #include <stdio.h>
5 #include <stdint.h>
6 
7 #include <pci/pci.h>
8 
9 #include "helpers/helpers.h"
10 
11 #define MSR_AMD_PSTATE_STATUS 0xc0010063
12 #define MSR_AMD_PSTATE 0xc0010064
13 #define MSR_AMD_PSTATE_LIMIT 0xc0010061
14 
15 union msr_pstate {
16  struct {
17  unsigned fid:6;
18  unsigned did:3;
19  unsigned vid:7;
20  unsigned res1:6;
21  unsigned nbdid:1;
22  unsigned res2:2;
23  unsigned nbvid:7;
24  unsigned iddval:8;
25  unsigned idddiv:2;
26  unsigned res3:21;
27  unsigned en:1;
28  } bits;
29  unsigned long long val;
30 };
31 
32 static int get_did(int family, union msr_pstate pstate)
33 {
34  int t;
35 
36  if (family == 0x12)
37  t = pstate.val & 0xf;
38  else
39  t = pstate.bits.did;
40 
41  return t;
42 }
43 
44 static int get_cof(int family, union msr_pstate pstate)
45 {
46  int t;
47  int fid, did;
48 
49  did = get_did(family, pstate);
50 
51  t = 0x10;
52  fid = pstate.bits.fid;
53  if (family == 0x11)
54  t = 0x8;
55 
56  return (100 * (fid + t)) >> did;
57 }
58 
59 /* Needs:
60  * cpu -> the cpu that gets evaluated
61  * cpu_family -> The cpu's family (0x10, 0x12,...)
62  * boots_states -> how much boost states the machines support
63  *
64  * Fills up:
65  * pstates -> a pointer to an array of size MAX_HW_PSTATES
66  * must be initialized with zeros.
67  * All available HW pstates (including boost states)
68  * no -> amount of pstates above array got filled up with
69  *
70  * returns zero on success, -1 on failure
71  */
72 int decode_pstates(unsigned int cpu, unsigned int cpu_family,
73  int boost_states, unsigned long *pstates, int *no)
74 {
75  int i, psmax, pscur;
76  union msr_pstate pstate;
77  unsigned long long val;
78 
79  /* Only read out frequencies from HW when CPU might be boostable
80  to keep the code as short and clean as possible.
81  Otherwise frequencies are exported via ACPI tables.
82  */
83  if (cpu_family < 0x10 || cpu_family == 0x14)
84  return -1;
85 
86  if (read_msr(cpu, MSR_AMD_PSTATE_LIMIT, &val))
87  return -1;
88 
89  psmax = (val >> 4) & 0x7;
90 
91  if (read_msr(cpu, MSR_AMD_PSTATE_STATUS, &val))
92  return -1;
93 
94  pscur = val & 0x7;
95 
96  pscur += boost_states;
97  psmax += boost_states;
98  for (i = 0; i <= psmax; i++) {
99  if (i >= MAX_HW_PSTATES) {
100  fprintf(stderr, "HW pstates [%d] exceeding max [%d]\n",
101  psmax, MAX_HW_PSTATES);
102  return -1;
103  }
104  if (read_msr(cpu, MSR_AMD_PSTATE + i, &pstate.val))
105  return -1;
106  pstates[i] = get_cof(cpu_family, pstate);
107  }
108  *no = i;
109  return 0;
110 }
111 
112 int amd_pci_get_num_boost_states(int *active, int *states)
113 {
114  struct pci_access *pci_acc;
115  struct pci_dev *device;
116  uint8_t val = 0;
117 
118  *active = *states = 0;
119 
120  device = pci_slot_func_init(&pci_acc, 0x18, 4);
121 
122  if (device == NULL)
123  return -ENODEV;
124 
125  val = pci_read_byte(device, 0x15c);
126  if (val & 3)
127  *active = 1;
128  else
129  *active = 0;
130  *states = (val >> 2) & 7;
131 
132  pci_cleanup(pci_acc);
133  return 0;
134 }
135 #endif /* defined(__i386__) || defined(__x86_64__) */