root/tools/power/cpupower/utils/helpers/amd.c

DEFINITIONS

1. get_did
2. get_cof
3. decode_pstates
4. amd_pci_get_num_boost_states

   1 // SPDX-License-Identifier: GPL-2.0
   2 #if defined(__i386__) || defined(__x86_64__)
   3 #include <unistd.h>
   4 #include <errno.h>
   5 #include <stdio.h>
   6 #include <stdint.h>
   7 
   8 #include <pci/pci.h>
   9 
  10 #include "helpers/helpers.h"
  11 
  12 #define MSR_AMD_PSTATE_STATUS   0xc0010063
  13 #define MSR_AMD_PSTATE          0xc0010064
  14 #define MSR_AMD_PSTATE_LIMIT    0xc0010061
  15 
  16 union msr_pstate {
  17         struct {
  18                 unsigned fid:6;
  19                 unsigned did:3;
  20                 unsigned vid:7;
  21                 unsigned res1:6;
  22                 unsigned nbdid:1;
  23                 unsigned res2:2;
  24                 unsigned nbvid:7;
  25                 unsigned iddval:8;
  26                 unsigned idddiv:2;
  27                 unsigned res3:21;
  28                 unsigned en:1;
  29         } bits;
  30         struct {
  31                 unsigned fid:8;
  32                 unsigned did:6;
  33                 unsigned vid:8;
  34                 unsigned iddval:8;
  35                 unsigned idddiv:2;
  36                 unsigned res1:31;
  37                 unsigned en:1;
  38         } fam17h_bits;
  39         unsigned long long val;
  40 };
  41 
  42 static int get_did(int family, union msr_pstate pstate)
  43 {
  44         int t;
  45 
  46         if (family == 0x12)
  47                 t = pstate.val & 0xf;
  48         else if (family == 0x17 || family == 0x18)
  49                 t = pstate.fam17h_bits.did;
  50         else
  51                 t = pstate.bits.did;
  52 
  53         return t;
  54 }
  55 
  56 static int get_cof(int family, union msr_pstate pstate)
  57 {
  58         int t;
  59         int fid, did, cof;
  60 
  61         did = get_did(family, pstate);
  62         if (family == 0x17 || family == 0x18) {
  63                 fid = pstate.fam17h_bits.fid;
  64                 cof = 200 * fid / did;
  65         } else {
  66                 t = 0x10;
  67                 fid = pstate.bits.fid;
  68                 if (family == 0x11)
  69                         t = 0x8;
  70                 cof = (100 * (fid + t)) >> did;
  71         }
  72         return cof;
  73 }
  74 
  75 /* Needs:
  76  * cpu          -> the cpu that gets evaluated
  77  * cpu_family   -> The cpu's family (0x10, 0x12,...)
  78  * boots_states -> how much boost states the machines support
  79  *
  80  * Fills up:
  81  * pstates -> a pointer to an array of size MAX_HW_PSTATES
  82  *            must be initialized with zeros.
  83  *            All available  HW pstates (including boost states)
  84  * no      -> amount of pstates above array got filled up with
  85  *
  86  * returns zero on success, -1 on failure
  87  */
  88 int decode_pstates(unsigned int cpu, unsigned int cpu_family,
  89                    int boost_states, unsigned long *pstates, int *no)
  90 {
  91         int i, psmax, pscur;
  92         union msr_pstate pstate;
  93         unsigned long long val;
  94 
  95         /* Only read out frequencies from HW when CPU might be boostable
  96            to keep the code as short and clean as possible.
  97            Otherwise frequencies are exported via ACPI tables.
  98         */
  99         if (cpu_family < 0x10 || cpu_family == 0x14)
 100                 return -1;
 101 
 102         if (read_msr(cpu, MSR_AMD_PSTATE_LIMIT, &val))
 103                 return -1;
 104 
 105         psmax = (val >> 4) & 0x7;
 106 
 107         if (read_msr(cpu, MSR_AMD_PSTATE_STATUS, &val))
 108                 return -1;
 109 
 110         pscur = val & 0x7;
 111 
 112         pscur += boost_states;
 113         psmax += boost_states;
 114         for (i = 0; i <= psmax; i++) {
 115                 if (i >= MAX_HW_PSTATES) {
 116                         fprintf(stderr, "HW pstates [%d] exceeding max [%d]\n",
 117                                 psmax, MAX_HW_PSTATES);
 118                         return -1;
 119                 }
 120                 if (read_msr(cpu, MSR_AMD_PSTATE + i, &pstate.val))
 121                         return -1;
 122                 if ((cpu_family == 0x17) && (!pstate.fam17h_bits.en))
 123                         continue;
 124                 else if (!pstate.bits.en)
 125                         continue;
 126 
 127                 pstates[i] = get_cof(cpu_family, pstate);
 128         }
 129         *no = i;
 130         return 0;
 131 }
 132 
 133 int amd_pci_get_num_boost_states(int *active, int *states)
 134 {
 135         struct pci_access *pci_acc;
 136         struct pci_dev *device;
 137         uint8_t val = 0;
 138 
 139         *active = *states = 0;
 140 
 141         device = pci_slot_func_init(&pci_acc, 0x18, 4);
 142 
 143         if (device == NULL)
 144                 return -ENODEV;
 145 
 146         val = pci_read_byte(device, 0x15c);
 147         if (val & 3)
 148                 *active = 1;
 149         else
 150                 *active = 0;
 151         *states = (val >> 2) & 7;
 152 
 153         pci_cleanup(pci_acc);
 154         return 0;
 155 }
 156 #endif /* defined(__i386__) || defined(__x86_64__) */