xref: /illumos-gate/usr/src/uts/i86pc/os/cpupm/pwrnow.c (revision 7b34a9a5df26271af0da06974fc361c468cd48d3)
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  */
24 
25 #include <sys/x86_archext.h>
26 #include <sys/machsystm.h>
27 #include <sys/x_call.h>
28 #include <sys/acpi/acpi.h>
29 #include <sys/acpica.h>
30 #include <sys/pwrnow.h>
31 #include <sys/cpu_acpi.h>
32 #include <sys/cpupm.h>
33 #include <sys/dtrace.h>
34 #include <sys/sdt.h>
35 
36 static int pwrnow_init(cpu_t *);
37 static void pwrnow_fini(cpu_t *);
38 static void pwrnow_power(cpuset_t, uint32_t);
39 static void pwrnow_stop(cpu_t *);
40 
41 static boolean_t pwrnow_cpb_supported(void);
42 
43 /*
44  * Interfaces for modules implementing AMD's PowerNow!.
45  */
46 cpupm_state_ops_t pwrnow_ops = {
47 	"PowerNow! Technology",
48 	pwrnow_init,
49 	pwrnow_fini,
50 	pwrnow_power,
51 	pwrnow_stop
52 };
53 
54 /*
55  * Error returns
56  */
57 #define	PWRNOW_RET_SUCCESS		0x00
58 #define	PWRNOW_RET_NO_PM		0x01
59 #define	PWRNOW_RET_UNSUP_STATE		0x02
60 #define	PWRNOW_RET_TRANS_INCOMPLETE	0x03
61 
62 #define	PWRNOW_LATENCY_WAIT		10
63 
64 /*
65  * MSR registers for changing and reading processor power state.
66  */
67 #define	PWRNOW_PERF_CTL_MSR		0xC0010062
68 #define	PWRNOW_PERF_STATUS_MSR		0xC0010063
69 
70 #define	AMD_CPUID_PSTATE_HARDWARE	(1<<7)
71 #define	AMD_CPUID_TSC_CONSTANT		(1<<8)
72 #define	AMD_CPUID_CPB			(1<<9)
73 
74 /*
75  * Debugging support
76  */
77 #ifdef	DEBUG
78 volatile int pwrnow_debug = 0;
79 #define	PWRNOW_DEBUG(arglist) if (pwrnow_debug) printf arglist;
80 #else
81 #define	PWRNOW_DEBUG(arglist)
82 #endif
83 
84 /*
85  * Write the ctrl register.
86  */
87 static void
88 write_ctrl(cpu_acpi_handle_t handle, uint32_t ctrl)
89 {
90 	cpu_acpi_pct_t *pct_ctrl;
91 	uint64_t reg;
92 
93 	pct_ctrl = CPU_ACPI_PCT_CTRL(handle);
94 
95 	switch (pct_ctrl->cr_addrspace_id) {
96 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
97 		reg = ctrl;
98 		wrmsr(PWRNOW_PERF_CTL_MSR, reg);
99 		break;
100 
101 	default:
102 		DTRACE_PROBE1(pwrnow_ctrl_unsupported_type, uint8_t,
103 		    pct_ctrl->cr_addrspace_id);
104 		return;
105 	}
106 
107 	DTRACE_PROBE1(pwrnow_ctrl_write, uint32_t, ctrl);
108 }
109 
110 /*
111  * Transition the current processor to the requested state.
112  */
113 static int
114 pwrnow_pstate_transition(xc_arg_t arg1, xc_arg_t arg2 __unused,
115     xc_arg_t arg3 __unused)
116 {
117 	uint32_t req_state = (uint32_t)arg1;
118 	cpupm_mach_state_t *mach_state =
119 	    (cpupm_mach_state_t *)CPU->cpu_m.mcpu_pm_mach_state;
120 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
121 	cpu_acpi_pstate_t *req_pstate;
122 	uint32_t ctrl;
123 
124 	req_pstate = (cpu_acpi_pstate_t *)CPU_ACPI_PSTATES(handle);
125 	req_pstate += req_state;
126 
127 	DTRACE_PROBE1(pwrnow_transition_freq, uint32_t,
128 	    CPU_ACPI_FREQ(req_pstate));
129 
130 	/*
131 	 * Initiate the processor p-state change.
132 	 */
133 	ctrl = CPU_ACPI_PSTATE_CTRL(req_pstate);
134 	write_ctrl(handle, ctrl);
135 
136 	if (mach_state->ms_turbo != NULL)
137 		cpupm_record_turbo_info(mach_state->ms_turbo,
138 		    mach_state->ms_pstate.cma_state.pstate, req_state);
139 
140 	mach_state->ms_pstate.cma_state.pstate = req_state;
141 	cpu_set_curr_clock((uint64_t)CPU_ACPI_FREQ(req_pstate) * 1000000);
142 	return (0);
143 }
144 
145 static void
146 pwrnow_power(cpuset_t set, uint32_t req_state)
147 {
148 	/*
149 	 * If thread is already running on target CPU then just
150 	 * make the transition request. Otherwise, we'll need to
151 	 * make a cross-call.
152 	 */
153 	kpreempt_disable();
154 	if (CPU_IN_SET(set, CPU->cpu_id)) {
155 		(void) pwrnow_pstate_transition(req_state, 0, 0);
156 		CPUSET_DEL(set, CPU->cpu_id);
157 	}
158 	if (!CPUSET_ISNULL(set)) {
159 		xc_call((xc_arg_t)req_state, 0, 0,
160 		    CPUSET2BV(set), pwrnow_pstate_transition);
161 	}
162 	kpreempt_enable();
163 }
164 
165 /*
166  * Validate that this processor supports PowerNow! and if so,
167  * get the P-state data from ACPI and cache it.
168  */
169 static int
170 pwrnow_init(cpu_t *cp)
171 {
172 	cpupm_mach_state_t *mach_state =
173 	    (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state;
174 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
175 	cpu_acpi_pct_t *pct_stat;
176 	static int logged = 0;
177 
178 	PWRNOW_DEBUG(("pwrnow_init: processor %d\n", cp->cpu_id));
179 
180 	/*
181 	 * Cache the P-state specific ACPI data.
182 	 */
183 	if (cpu_acpi_cache_pstate_data(handle) != 0) {
184 		if (!logged) {
185 			cmn_err(CE_NOTE, "!PowerNow! support is being "
186 			    "disabled due to errors parsing ACPI P-state "
187 			    "objects exported by BIOS.");
188 			logged = 1;
189 		}
190 		pwrnow_fini(cp);
191 		return (PWRNOW_RET_NO_PM);
192 	}
193 
194 	pct_stat = CPU_ACPI_PCT_STATUS(handle);
195 	switch (pct_stat->cr_addrspace_id) {
196 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
197 		PWRNOW_DEBUG(("Transitions will use fixed hardware\n"));
198 		break;
199 	default:
200 		cmn_err(CE_WARN, "!_PCT configured for unsupported "
201 		    "addrspace = %d.", pct_stat->cr_addrspace_id);
202 		cmn_err(CE_NOTE, "!CPU power management will not function.");
203 		pwrnow_fini(cp);
204 		return (PWRNOW_RET_NO_PM);
205 	}
206 
207 	cpupm_alloc_domains(cp, CPUPM_P_STATES);
208 
209 	/*
210 	 * Check for Core Performance Boost support
211 	 */
212 	if (pwrnow_cpb_supported())
213 		mach_state->ms_turbo = cpupm_turbo_init(cp);
214 
215 	PWRNOW_DEBUG(("Processor %d succeeded.\n", cp->cpu_id))
216 	return (PWRNOW_RET_SUCCESS);
217 }
218 
219 /*
220  * Free resources allocated by pwrnow_init().
221  */
222 static void
223 pwrnow_fini(cpu_t *cp)
224 {
225 	cpupm_mach_state_t *mach_state =
226 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
227 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
228 
229 	cpupm_free_domains(&cpupm_pstate_domains);
230 	cpu_acpi_free_pstate_data(handle);
231 
232 	if (mach_state->ms_turbo != NULL)
233 		cpupm_turbo_fini(mach_state->ms_turbo);
234 	mach_state->ms_turbo = NULL;
235 }
236 
237 boolean_t
238 pwrnow_supported()
239 {
240 	struct cpuid_regs cpu_regs;
241 
242 	/* Required features */
243 	if (!is_x86_feature(x86_featureset, X86FSET_CPUID) ||
244 	    !is_x86_feature(x86_featureset, X86FSET_MSR)) {
245 		PWRNOW_DEBUG(("No CPUID or MSR support."));
246 		return (B_FALSE);
247 	}
248 
249 	/*
250 	 * Get the Advanced Power Management Information.
251 	 */
252 	cpu_regs.cp_eax = 0x80000007;
253 	(void) __cpuid_insn(&cpu_regs);
254 
255 	/*
256 	 * We currently only support CPU power management of
257 	 * processors that are P-state TSC invariant
258 	 */
259 	if (!(cpu_regs.cp_edx & AMD_CPUID_TSC_CONSTANT)) {
260 		PWRNOW_DEBUG(("No support for CPUs that are not P-state "
261 		    "TSC invariant.\n"));
262 		return (B_FALSE);
263 	}
264 
265 	/*
266 	 * We only support the "Fire and Forget" style of PowerNow! (i.e.,
267 	 * single MSR write to change speed).
268 	 */
269 	if (!(cpu_regs.cp_edx & AMD_CPUID_PSTATE_HARDWARE)) {
270 		PWRNOW_DEBUG(("Hardware P-State control is not supported.\n"));
271 		return (B_FALSE);
272 	}
273 	return (B_TRUE);
274 }
275 
276 static boolean_t
277 pwrnow_cpb_supported(void)
278 {
279 	struct cpuid_regs cpu_regs;
280 
281 	/* Required features */
282 	if (!is_x86_feature(x86_featureset, X86FSET_CPUID) ||
283 	    !is_x86_feature(x86_featureset, X86FSET_MSR)) {
284 		PWRNOW_DEBUG(("No CPUID or MSR support."));
285 		return (B_FALSE);
286 	}
287 
288 	/*
289 	 * Get the Advanced Power Management Information.
290 	 */
291 	cpu_regs.cp_eax = 0x80000007;
292 	(void) __cpuid_insn(&cpu_regs);
293 
294 	if (!(cpu_regs.cp_edx & AMD_CPUID_CPB))
295 		return (B_FALSE);
296 
297 	return (B_TRUE);
298 }
299 
300 static void
301 pwrnow_stop(cpu_t *cp)
302 {
303 	cpupm_mach_state_t *mach_state =
304 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
305 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
306 
307 	cpupm_remove_domains(cp, CPUPM_P_STATES, &cpupm_pstate_domains);
308 	cpu_acpi_free_pstate_data(handle);
309 
310 	if (mach_state->ms_turbo != NULL)
311 		cpupm_turbo_fini(mach_state->ms_turbo);
312 	mach_state->ms_turbo = NULL;
313 }
314