xref: /illumos-gate/usr/src/uts/i86pc/os/cpupm/speedstep.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright 2022 Oxide Computer Co.
24  */
25 /*
26  * Copyright (c) 2009,  Intel Corporation.
27  * All Rights Reserved.
28  */
29 
30 #include <sys/x86_archext.h>
31 #include <sys/machsystm.h>
32 #include <sys/archsystm.h>
33 #include <sys/x_call.h>
34 #include <sys/acpi/acpi.h>
35 #include <sys/acpica.h>
36 #include <sys/speedstep.h>
37 #include <sys/cpu_acpi.h>
38 #include <sys/cpupm.h>
39 #include <sys/dtrace.h>
40 #include <sys/sdt.h>
41 
42 static int speedstep_init(cpu_t *);
43 static void speedstep_fini(cpu_t *);
44 static void speedstep_power(cpuset_t, uint32_t);
45 static void speedstep_stop(cpu_t *);
46 static boolean_t speedstep_turbo_supported(void);
47 
48 /*
49  * Interfaces for modules implementing Intel's Enhanced SpeedStep.
50  */
51 cpupm_state_ops_t speedstep_ops = {
52 	"Enhanced SpeedStep Technology",
53 	speedstep_init,
54 	speedstep_fini,
55 	speedstep_power,
56 	speedstep_stop
57 };
58 
59 /*
60  * Error returns
61  */
62 #define	ESS_RET_SUCCESS		0x00
63 #define	ESS_RET_NO_PM		0x01
64 #define	ESS_RET_UNSUP_STATE	0x02
65 
66 /*
67  * MSR registers for changing and reading processor power state.
68  */
69 #define	IA32_PERF_STAT_MSR		0x198
70 #define	IA32_PERF_CTL_MSR		0x199
71 
72 #define	IA32_CPUID_TSC_CONSTANT		0xF30
73 #define	IA32_MISC_ENABLE_MSR		0x1A0
74 #define	IA32_MISC_ENABLE_EST		(1<<16)
75 #define	IA32_MISC_ENABLE_CXE		(1<<25)
76 
77 #define	CPUID_TURBO_SUPPORT		(1 << 1)
78 
79 /*
80  * Debugging support
81  */
82 #ifdef	DEBUG
83 volatile int ess_debug = 0;
84 #define	ESSDEBUG(arglist) if (ess_debug) printf arglist;
85 #else
86 #define	ESSDEBUG(arglist)
87 #endif
88 
89 /*
90  * Write the ctrl register. How it is written, depends upon the _PCT
91  * APCI object value.
92  */
93 static void
94 write_ctrl(cpu_acpi_handle_t handle, uint32_t ctrl)
95 {
96 	cpu_acpi_pct_t *pct_ctrl;
97 	uint64_t reg;
98 
99 	pct_ctrl = CPU_ACPI_PCT_CTRL(handle);
100 
101 	switch (pct_ctrl->cr_addrspace_id) {
102 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
103 		/*
104 		 * Read current power state because reserved bits must be
105 		 * preserved, compose new value, and write it.
106 		 */
107 		reg = rdmsr(IA32_PERF_CTL_MSR);
108 		reg &= ~((uint64_t)0xFFFF);
109 		reg |= ctrl;
110 		wrmsr(IA32_PERF_CTL_MSR, reg);
111 		break;
112 
113 	case ACPI_ADR_SPACE_SYSTEM_IO:
114 		(void) cpu_acpi_write_port(pct_ctrl->cr_address, ctrl,
115 		    pct_ctrl->cr_width);
116 		break;
117 
118 	default:
119 		DTRACE_PROBE1(ess_ctrl_unsupported_type, uint8_t,
120 		    pct_ctrl->cr_addrspace_id);
121 		return;
122 	}
123 
124 	DTRACE_PROBE1(ess_ctrl_write, uint32_t, ctrl);
125 }
126 
127 /*
128  * Transition the current processor to the requested state.
129  */
130 int
131 speedstep_pstate_transition(xc_arg_t arg1, xc_arg_t arg2 __unused,
132     xc_arg_t arg3 __unused)
133 {
134 	uint32_t req_state = (uint32_t)arg1;
135 	cpupm_mach_state_t *mach_state =
136 	    (cpupm_mach_state_t *)CPU->cpu_m.mcpu_pm_mach_state;
137 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
138 	cpu_acpi_pstate_t *req_pstate;
139 	uint32_t ctrl;
140 
141 	req_pstate = (cpu_acpi_pstate_t *)CPU_ACPI_PSTATES(handle);
142 	req_pstate += req_state;
143 
144 	DTRACE_PROBE1(ess_transition, uint32_t, CPU_ACPI_FREQ(req_pstate));
145 
146 	/*
147 	 * Initiate the processor p-state change.
148 	 */
149 	ctrl = CPU_ACPI_PSTATE_CTRL(req_pstate);
150 	write_ctrl(handle, ctrl);
151 
152 	if (mach_state->ms_turbo != NULL)
153 		cpupm_record_turbo_info(mach_state->ms_turbo,
154 		    mach_state->ms_pstate.cma_state.pstate, req_state);
155 
156 	mach_state->ms_pstate.cma_state.pstate = req_state;
157 	cpu_set_curr_clock(((uint64_t)CPU_ACPI_FREQ(req_pstate) * 1000000));
158 	return (0);
159 }
160 
161 static void
162 speedstep_power(cpuset_t set, uint32_t req_state)
163 {
164 	/*
165 	 * If thread is already running on target CPU then just
166 	 * make the transition request. Otherwise, we'll need to
167 	 * make a cross-call.
168 	 */
169 	kpreempt_disable();
170 	if (CPU_IN_SET(set, CPU->cpu_id)) {
171 		(void) speedstep_pstate_transition(req_state, 0, 0);
172 		CPUSET_DEL(set, CPU->cpu_id);
173 	}
174 	if (!CPUSET_ISNULL(set)) {
175 		xc_call((xc_arg_t)req_state, 0, 0, CPUSET2BV(set),
176 		    speedstep_pstate_transition);
177 	}
178 	kpreempt_enable();
179 }
180 
181 /*
182  * Validate that this processor supports Speedstep and if so,
183  * get the P-state data from ACPI and cache it.
184  */
185 static int
186 speedstep_init(cpu_t *cp)
187 {
188 	cpupm_mach_state_t *mach_state =
189 	    (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state;
190 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
191 	cpu_acpi_pct_t *pct_stat;
192 	static int logged = 0;
193 
194 	ESSDEBUG(("speedstep_init: processor %d\n", cp->cpu_id));
195 
196 	/*
197 	 * Cache the P-state specific ACPI data.
198 	 */
199 	if (cpu_acpi_cache_pstate_data(handle) != 0) {
200 		if (!logged) {
201 			cmn_err(CE_NOTE, "!SpeedStep support is being "
202 			    "disabled due to errors parsing ACPI P-state "
203 			    "objects exported by BIOS.");
204 			logged = 1;
205 		}
206 		speedstep_fini(cp);
207 		return (ESS_RET_NO_PM);
208 	}
209 
210 	pct_stat = CPU_ACPI_PCT_STATUS(handle);
211 	switch (pct_stat->cr_addrspace_id) {
212 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
213 		ESSDEBUG(("Transitions will use fixed hardware\n"));
214 		break;
215 	case ACPI_ADR_SPACE_SYSTEM_IO:
216 		ESSDEBUG(("Transitions will use system IO\n"));
217 		break;
218 	default:
219 		cmn_err(CE_WARN, "!_PCT conifgured for unsupported "
220 		    "addrspace = %d.", pct_stat->cr_addrspace_id);
221 		cmn_err(CE_NOTE, "!CPU power management will not function.");
222 		speedstep_fini(cp);
223 		return (ESS_RET_NO_PM);
224 	}
225 
226 	cpupm_alloc_domains(cp, CPUPM_P_STATES);
227 
228 	if (speedstep_turbo_supported())
229 		mach_state->ms_turbo = cpupm_turbo_init(cp);
230 
231 	ESSDEBUG(("Processor %d succeeded.\n", cp->cpu_id))
232 	return (ESS_RET_SUCCESS);
233 }
234 
235 /*
236  * Free resources allocated by speedstep_init().
237  */
238 static void
239 speedstep_fini(cpu_t *cp)
240 {
241 	cpupm_mach_state_t *mach_state =
242 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
243 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
244 
245 	cpupm_free_domains(&cpupm_pstate_domains);
246 	cpu_acpi_free_pstate_data(handle);
247 
248 	if (mach_state->ms_turbo != NULL)
249 		cpupm_turbo_fini(mach_state->ms_turbo);
250 	mach_state->ms_turbo = NULL;
251 }
252 
253 static void
254 speedstep_stop(cpu_t *cp)
255 {
256 	cpupm_mach_state_t *mach_state =
257 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
258 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
259 
260 	cpupm_remove_domains(cp, CPUPM_P_STATES, &cpupm_pstate_domains);
261 	cpu_acpi_free_pstate_data(handle);
262 
263 	if (mach_state->ms_turbo != NULL)
264 		cpupm_turbo_fini(mach_state->ms_turbo);
265 	mach_state->ms_turbo = NULL;
266 }
267 
268 boolean_t
269 speedstep_supported(uint_t family, uint_t model)
270 {
271 	struct cpuid_regs cpu_regs;
272 
273 	/* Required features */
274 	ASSERT(is_x86_feature(x86_featureset, X86FSET_CPUID));
275 	if (!is_x86_feature(x86_featureset, X86FSET_MSR)) {
276 		return (B_FALSE);
277 	}
278 
279 	/*
280 	 * We only support family/model combinations which
281 	 * are P-state TSC invariant.
282 	 */
283 	if (!((family == 0xf && model >= 0x3) ||
284 	    (family == 0x6 && model >= 0xe))) {
285 		return (B_FALSE);
286 	}
287 
288 	/*
289 	 * Enhanced SpeedStep supported?
290 	 */
291 	cpu_regs.cp_eax = 0x1;
292 	(void) __cpuid_insn(&cpu_regs);
293 	if (!(cpu_regs.cp_ecx & CPUID_INTC_ECX_EST)) {
294 		return (B_FALSE);
295 	}
296 
297 	return (B_TRUE);
298 }
299 
300 boolean_t
301 speedstep_turbo_supported(void)
302 {
303 	struct cpuid_regs cpu_regs;
304 
305 	/* Required features */
306 	ASSERT(is_x86_feature(x86_featureset, X86FSET_CPUID));
307 	if (!is_x86_feature(x86_featureset, X86FSET_MSR)) {
308 		return (B_FALSE);
309 	}
310 
311 	/*
312 	 * turbo mode supported?
313 	 */
314 	cpu_regs.cp_eax = 0x6;
315 	(void) __cpuid_insn(&cpu_regs);
316 	if (!(cpu_regs.cp_eax & CPUID_TURBO_SUPPORT)) {
317 		return (B_FALSE);
318 	}
319 
320 	return (B_TRUE);
321 }
322