xref: /illumos-gate/usr/src/uts/i86pc/os/cpupm/pwrnow.c (revision e982f11fb2fc266a3d04a69ea3edcf51f44b1e0f)
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 void
114 pwrnow_pstate_transition(uint32_t req_state)
115 {
116 	cpupm_mach_state_t *mach_state =
117 	    (cpupm_mach_state_t *)CPU->cpu_m.mcpu_pm_mach_state;
118 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
119 	cpu_acpi_pstate_t *req_pstate;
120 	uint32_t ctrl;
121 
122 	req_pstate = (cpu_acpi_pstate_t *)CPU_ACPI_PSTATES(handle);
123 	req_pstate += req_state;
124 
125 	DTRACE_PROBE1(pwrnow_transition_freq, uint32_t,
126 	    CPU_ACPI_FREQ(req_pstate));
127 
128 	/*
129 	 * Initiate the processor p-state change.
130 	 */
131 	ctrl = CPU_ACPI_PSTATE_CTRL(req_pstate);
132 	write_ctrl(handle, ctrl);
133 
134 	if (mach_state->ms_turbo != NULL)
135 		cpupm_record_turbo_info(mach_state->ms_turbo,
136 		    mach_state->ms_pstate.cma_state.pstate, req_state);
137 
138 	mach_state->ms_pstate.cma_state.pstate = req_state;
139 	cpu_set_curr_clock((uint64_t)CPU_ACPI_FREQ(req_pstate) * 1000000);
140 }
141 
142 static void
143 pwrnow_power(cpuset_t set, uint32_t req_state)
144 {
145 	/*
146 	 * If thread is already running on target CPU then just
147 	 * make the transition request. Otherwise, we'll need to
148 	 * make a cross-call.
149 	 */
150 	kpreempt_disable();
151 	if (CPU_IN_SET(set, CPU->cpu_id)) {
152 		pwrnow_pstate_transition(req_state);
153 		CPUSET_DEL(set, CPU->cpu_id);
154 	}
155 	if (!CPUSET_ISNULL(set)) {
156 		xc_call((xc_arg_t)req_state, 0, 0,
157 		    CPUSET2BV(set), (xc_func_t)pwrnow_pstate_transition);
158 	}
159 	kpreempt_enable();
160 }
161 
162 /*
163  * Validate that this processor supports PowerNow! and if so,
164  * get the P-state data from ACPI and cache it.
165  */
166 static int
167 pwrnow_init(cpu_t *cp)
168 {
169 	cpupm_mach_state_t *mach_state =
170 	    (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state;
171 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
172 	cpu_acpi_pct_t *pct_stat;
173 	static int logged = 0;
174 
175 	PWRNOW_DEBUG(("pwrnow_init: processor %d\n", cp->cpu_id));
176 
177 	/*
178 	 * Cache the P-state specific ACPI data.
179 	 */
180 	if (cpu_acpi_cache_pstate_data(handle) != 0) {
181 		if (!logged) {
182 			cmn_err(CE_NOTE, "!PowerNow! support is being "
183 			    "disabled due to errors parsing ACPI P-state "
184 			    "objects exported by BIOS.");
185 			logged = 1;
186 		}
187 		pwrnow_fini(cp);
188 		return (PWRNOW_RET_NO_PM);
189 	}
190 
191 	pct_stat = CPU_ACPI_PCT_STATUS(handle);
192 	switch (pct_stat->cr_addrspace_id) {
193 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
194 		PWRNOW_DEBUG(("Transitions will use fixed hardware\n"));
195 		break;
196 	default:
197 		cmn_err(CE_WARN, "!_PCT configured for unsupported "
198 		    "addrspace = %d.", pct_stat->cr_addrspace_id);
199 		cmn_err(CE_NOTE, "!CPU power management will not function.");
200 		pwrnow_fini(cp);
201 		return (PWRNOW_RET_NO_PM);
202 	}
203 
204 	cpupm_alloc_domains(cp, CPUPM_P_STATES);
205 
206 	/*
207 	 * Check for Core Performance Boost support
208 	 */
209 	if (pwrnow_cpb_supported())
210 		mach_state->ms_turbo = cpupm_turbo_init(cp);
211 
212 	PWRNOW_DEBUG(("Processor %d succeeded.\n", cp->cpu_id))
213 	return (PWRNOW_RET_SUCCESS);
214 }
215 
216 /*
217  * Free resources allocated by pwrnow_init().
218  */
219 static void
220 pwrnow_fini(cpu_t *cp)
221 {
222 	cpupm_mach_state_t *mach_state =
223 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
224 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
225 
226 	cpupm_free_domains(&cpupm_pstate_domains);
227 	cpu_acpi_free_pstate_data(handle);
228 
229 	if (mach_state->ms_turbo != NULL)
230 		cpupm_turbo_fini(mach_state->ms_turbo);
231 	mach_state->ms_turbo = NULL;
232 }
233 
234 boolean_t
235 pwrnow_supported()
236 {
237 	struct cpuid_regs cpu_regs;
238 
239 	/* Required features */
240 	if (!is_x86_feature(x86_featureset, X86FSET_CPUID) ||
241 	    !is_x86_feature(x86_featureset, X86FSET_MSR)) {
242 		PWRNOW_DEBUG(("No CPUID or MSR support."));
243 		return (B_FALSE);
244 	}
245 
246 	/*
247 	 * Get the Advanced Power Management Information.
248 	 */
249 	cpu_regs.cp_eax = 0x80000007;
250 	(void) __cpuid_insn(&cpu_regs);
251 
252 	/*
253 	 * We currently only support CPU power management of
254 	 * processors that are P-state TSC invariant
255 	 */
256 	if (!(cpu_regs.cp_edx & AMD_CPUID_TSC_CONSTANT)) {
257 		PWRNOW_DEBUG(("No support for CPUs that are not P-state "
258 		    "TSC invariant.\n"));
259 		return (B_FALSE);
260 	}
261 
262 	/*
263 	 * We only support the "Fire and Forget" style of PowerNow! (i.e.,
264 	 * single MSR write to change speed).
265 	 */
266 	if (!(cpu_regs.cp_edx & AMD_CPUID_PSTATE_HARDWARE)) {
267 		PWRNOW_DEBUG(("Hardware P-State control is not supported.\n"));
268 		return (B_FALSE);
269 	}
270 	return (B_TRUE);
271 }
272 
273 static boolean_t
274 pwrnow_cpb_supported(void)
275 {
276 	struct cpuid_regs cpu_regs;
277 
278 	/* Required features */
279 	if (!is_x86_feature(x86_featureset, X86FSET_CPUID) ||
280 	    !is_x86_feature(x86_featureset, X86FSET_MSR)) {
281 		PWRNOW_DEBUG(("No CPUID or MSR support."));
282 		return (B_FALSE);
283 	}
284 
285 	/*
286 	 * Get the Advanced Power Management Information.
287 	 */
288 	cpu_regs.cp_eax = 0x80000007;
289 	(void) __cpuid_insn(&cpu_regs);
290 
291 	if (!(cpu_regs.cp_edx & AMD_CPUID_CPB))
292 		return (B_FALSE);
293 
294 	return (B_TRUE);
295 }
296 
297 static void
298 pwrnow_stop(cpu_t *cp)
299 {
300 	cpupm_mach_state_t *mach_state =
301 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
302 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
303 
304 	cpupm_remove_domains(cp, CPUPM_P_STATES, &cpupm_pstate_domains);
305 	cpu_acpi_free_pstate_data(handle);
306 
307 	if (mach_state->ms_turbo != NULL)
308 		cpupm_turbo_fini(mach_state->ms_turbo);
309 	mach_state->ms_turbo = NULL;
310 }
311