xref: /titanic_41/usr/src/uts/i86pc/os/cpupm/pwrnow.c (revision e5803b76927480e8f9b67b22201c484ccf4c2bcf)
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, NULL, NULL,
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 
174 	PWRNOW_DEBUG(("pwrnow_init: processor %d\n", cp->cpu_id));
175 
176 	/*
177 	 * Cache the P-state specific ACPI data.
178 	 */
179 	if (cpu_acpi_cache_pstate_data(handle) != 0) {
180 		cmn_err(CE_NOTE, "!PowerNow! support is being "
181 		    "disabled due to errors parsing ACPI P-state objects "
182 		    "exported by BIOS.");
183 		pwrnow_fini(cp);
184 		return (PWRNOW_RET_NO_PM);
185 	}
186 
187 	pct_stat = CPU_ACPI_PCT_STATUS(handle);
188 	switch (pct_stat->cr_addrspace_id) {
189 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
190 		PWRNOW_DEBUG(("Transitions will use fixed hardware\n"));
191 		break;
192 	default:
193 		cmn_err(CE_WARN, "!_PCT configured for unsupported "
194 		    "addrspace = %d.", pct_stat->cr_addrspace_id);
195 		cmn_err(CE_NOTE, "!CPU power management will not function.");
196 		pwrnow_fini(cp);
197 		return (PWRNOW_RET_NO_PM);
198 	}
199 
200 	cpupm_alloc_domains(cp, CPUPM_P_STATES);
201 
202 	/*
203 	 * Check for Core Performance Boost support
204 	 */
205 	if (pwrnow_cpb_supported())
206 		mach_state->ms_turbo = cpupm_turbo_init(cp);
207 
208 	PWRNOW_DEBUG(("Processor %d succeeded.\n", cp->cpu_id))
209 	return (PWRNOW_RET_SUCCESS);
210 }
211 
212 /*
213  * Free resources allocated by pwrnow_init().
214  */
215 static void
216 pwrnow_fini(cpu_t *cp)
217 {
218 	cpupm_mach_state_t *mach_state =
219 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
220 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
221 
222 	cpupm_free_domains(&cpupm_pstate_domains);
223 	cpu_acpi_free_pstate_data(handle);
224 
225 	if (mach_state->ms_turbo != NULL)
226 		cpupm_turbo_fini(mach_state->ms_turbo);
227 	mach_state->ms_turbo = NULL;
228 }
229 
230 boolean_t
231 pwrnow_supported()
232 {
233 	struct cpuid_regs cpu_regs;
234 
235 	/* Required features */
236 	if (!is_x86_feature(x86_featureset, X86FSET_CPUID) ||
237 	    !is_x86_feature(x86_featureset, X86FSET_MSR)) {
238 		PWRNOW_DEBUG(("No CPUID or MSR support."));
239 		return (B_FALSE);
240 	}
241 
242 	/*
243 	 * Get the Advanced Power Management Information.
244 	 */
245 	cpu_regs.cp_eax = 0x80000007;
246 	(void) __cpuid_insn(&cpu_regs);
247 
248 	/*
249 	 * We currently only support CPU power management of
250 	 * processors that are P-state TSC invariant
251 	 */
252 	if (!(cpu_regs.cp_edx & AMD_CPUID_TSC_CONSTANT)) {
253 		PWRNOW_DEBUG(("No support for CPUs that are not P-state "
254 		    "TSC invariant.\n"));
255 		return (B_FALSE);
256 	}
257 
258 	/*
259 	 * We only support the "Fire and Forget" style of PowerNow! (i.e.,
260 	 * single MSR write to change speed).
261 	 */
262 	if (!(cpu_regs.cp_edx & AMD_CPUID_PSTATE_HARDWARE)) {
263 		PWRNOW_DEBUG(("Hardware P-State control is not supported.\n"));
264 		return (B_FALSE);
265 	}
266 	return (B_TRUE);
267 }
268 
269 static boolean_t
270 pwrnow_cpb_supported(void)
271 {
272 	struct cpuid_regs cpu_regs;
273 
274 	/* Required features */
275 	if (!is_x86_feature(x86_featureset, X86FSET_CPUID) ||
276 	    !is_x86_feature(x86_featureset, X86FSET_MSR)) {
277 		PWRNOW_DEBUG(("No CPUID or MSR support."));
278 		return (B_FALSE);
279 	}
280 
281 	/*
282 	 * Get the Advanced Power Management Information.
283 	 */
284 	cpu_regs.cp_eax = 0x80000007;
285 	(void) __cpuid_insn(&cpu_regs);
286 
287 	if (!(cpu_regs.cp_edx & AMD_CPUID_CPB))
288 		return (B_FALSE);
289 
290 	return (B_TRUE);
291 }
292 
293 static void
294 pwrnow_stop(cpu_t *cp)
295 {
296 	cpupm_mach_state_t *mach_state =
297 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
298 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
299 
300 	cpupm_remove_domains(cp, CPUPM_P_STATES, &cpupm_pstate_domains);
301 	cpu_acpi_free_pstate_data(handle);
302 
303 	if (mach_state->ms_turbo != NULL)
304 		cpupm_turbo_fini(mach_state->ms_turbo);
305 	mach_state->ms_turbo = NULL;
306 }
307