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__) */
157