xref: /titanic_41/usr/src/uts/i86pc/os/cpupm/pwrnow.c (revision b509e89b2befbaa42939abad9da1d7f5a8c6aaae)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/x86_archext.h>
27 #include <sys/machsystm.h>
28 #include <sys/x_call.h>
29 #include <sys/acpi/acpi.h>
30 #include <sys/acpica.h>
31 #include <sys/pwrnow.h>
32 #include <sys/cpu_acpi.h>
33 #include <sys/cpupm.h>
34 #include <sys/dtrace.h>
35 #include <sys/sdt.h>
36 
37 static int pwrnow_init(cpu_t *);
38 static void pwrnow_fini(cpu_t *);
39 static void pwrnow_power(cpuset_t, uint32_t);
40 
41 /*
42  * Interfaces for modules implementing AMD's PowerNow!.
43  */
44 cpupm_state_ops_t pwrnow_ops = {
45 	"PowerNow! Technology",
46 	pwrnow_init,
47 	pwrnow_fini,
48 	pwrnow_power
49 };
50 
51 /*
52  * Error returns
53  */
54 #define	PWRNOW_RET_SUCCESS		0x00
55 #define	PWRNOW_RET_NO_PM		0x01
56 #define	PWRNOW_RET_UNSUP_STATE		0x02
57 #define	PWRNOW_RET_TRANS_INCOMPLETE	0x03
58 
59 #define	PWRNOW_LATENCY_WAIT		10
60 
61 /*
62  * MSR registers for changing and reading processor power state.
63  */
64 #define	PWRNOW_PERF_CTL_MSR		0xC0010062
65 #define	PWRNOW_PERF_STATUS_MSR		0xC0010063
66 
67 #define	AMD_CPUID_PSTATE_HARDWARE	(1<<7)
68 #define	AMD_CPUID_TSC_CONSTANT		(1<<8)
69 
70 /*
71  * Debugging support
72  */
73 #ifdef	DEBUG
74 volatile int pwrnow_debug = 0;
75 #define	PWRNOW_DEBUG(arglist) if (pwrnow_debug) printf arglist;
76 #else
77 #define	PWRNOW_DEBUG(arglist)
78 #endif
79 
80 /*
81  * Write the ctrl register.
82  */
83 static void
84 write_ctrl(cpu_acpi_handle_t handle, uint32_t ctrl)
85 {
86 	cpu_acpi_pct_t *pct_ctrl;
87 	uint64_t reg;
88 
89 	pct_ctrl = CPU_ACPI_PCT_CTRL(handle);
90 
91 	switch (pct_ctrl->cr_addrspace_id) {
92 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
93 		reg = ctrl;
94 		wrmsr(PWRNOW_PERF_CTL_MSR, reg);
95 		break;
96 
97 	default:
98 		DTRACE_PROBE1(pwrnow_ctrl_unsupported_type, uint8_t,
99 		    pct_ctrl->cr_addrspace_id);
100 		return;
101 	}
102 
103 	DTRACE_PROBE1(pwrnow_ctrl_write, uint32_t, ctrl);
104 }
105 
106 /*
107  * Transition the current processor to the requested state.
108  */
109 static void
110 pwrnow_pstate_transition(uint32_t req_state)
111 {
112 	cpupm_mach_state_t *mach_state =
113 	    (cpupm_mach_state_t *)CPU->cpu_m.mcpu_pm_mach_state;
114 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
115 	cpu_acpi_pstate_t *req_pstate;
116 	uint32_t ctrl;
117 
118 	req_pstate = (cpu_acpi_pstate_t *)CPU_ACPI_PSTATES(handle);
119 	req_pstate += req_state;
120 
121 	DTRACE_PROBE1(pwrnow_transition_freq, uint32_t,
122 	    CPU_ACPI_FREQ(req_pstate));
123 
124 	/*
125 	 * Initiate the processor p-state change.
126 	 */
127 	ctrl = CPU_ACPI_PSTATE_CTRL(req_pstate);
128 	write_ctrl(handle, ctrl);
129 
130 	mach_state->ms_pstate.cma_state.pstate = req_state;
131 	cpu_set_curr_clock((uint64_t)CPU_ACPI_FREQ(req_pstate) * 1000000);
132 }
133 
134 static void
135 pwrnow_power(cpuset_t set, uint32_t req_state)
136 {
137 	/*
138 	 * If thread is already running on target CPU then just
139 	 * make the transition request. Otherwise, we'll need to
140 	 * make a cross-call.
141 	 */
142 	kpreempt_disable();
143 	if (CPU_IN_SET(set, CPU->cpu_id)) {
144 		pwrnow_pstate_transition(req_state);
145 		CPUSET_DEL(set, CPU->cpu_id);
146 	}
147 	if (!CPUSET_ISNULL(set)) {
148 		xc_call((xc_arg_t)req_state, NULL, NULL,
149 		    CPUSET2BV(set), (xc_func_t)pwrnow_pstate_transition);
150 	}
151 	kpreempt_enable();
152 }
153 
154 /*
155  * Validate that this processor supports PowerNow! and if so,
156  * get the P-state data from ACPI and cache it.
157  */
158 static int
159 pwrnow_init(cpu_t *cp)
160 {
161 	cpupm_mach_state_t *mach_state =
162 	    (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state;
163 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
164 	cpu_acpi_pct_t *pct_stat;
165 
166 	PWRNOW_DEBUG(("pwrnow_init: processor %d\n", cp->cpu_id));
167 
168 	/*
169 	 * Cache the P-state specific ACPI data.
170 	 */
171 	if (cpu_acpi_cache_pstate_data(handle) != 0) {
172 		PWRNOW_DEBUG(("Failed to cache ACPI data\n"));
173 		pwrnow_fini(cp);
174 		return (PWRNOW_RET_NO_PM);
175 	}
176 
177 	pct_stat = CPU_ACPI_PCT_STATUS(handle);
178 	switch (pct_stat->cr_addrspace_id) {
179 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
180 		PWRNOW_DEBUG(("Transitions will use fixed hardware\n"));
181 		break;
182 	default:
183 		cmn_err(CE_WARN, "!_PCT configured for unsupported "
184 		    "addrspace = %d.", pct_stat->cr_addrspace_id);
185 		cmn_err(CE_NOTE, "!CPU power management will not function.");
186 		pwrnow_fini(cp);
187 		return (PWRNOW_RET_NO_PM);
188 	}
189 
190 	cpupm_alloc_domains(cp, CPUPM_P_STATES);
191 
192 	PWRNOW_DEBUG(("Processor %d succeeded.\n", cp->cpu_id))
193 	return (PWRNOW_RET_SUCCESS);
194 }
195 
196 /*
197  * Free resources allocated by pwrnow_init().
198  */
199 static void
200 pwrnow_fini(cpu_t *cp)
201 {
202 	cpupm_mach_state_t *mach_state =
203 	    (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
204 	cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
205 
206 	cpupm_free_domains(&cpupm_pstate_domains);
207 	cpu_acpi_free_pstate_data(handle);
208 }
209 
210 boolean_t
211 pwrnow_supported()
212 {
213 	struct cpuid_regs cpu_regs;
214 
215 	/* Required features */
216 	if (!(x86_feature & X86_CPUID) ||
217 	    !(x86_feature & X86_MSR)) {
218 		PWRNOW_DEBUG(("No CPUID or MSR support."));
219 		return (B_FALSE);
220 	}
221 
222 	/*
223 	 * Get the Advanced Power Management Information.
224 	 */
225 	cpu_regs.cp_eax = 0x80000007;
226 	(void) __cpuid_insn(&cpu_regs);
227 
228 	/*
229 	 * We currently only support CPU power management of
230 	 * processors that are P-state TSC invariant
231 	 */
232 	if (!(cpu_regs.cp_edx & AMD_CPUID_TSC_CONSTANT)) {
233 		PWRNOW_DEBUG(("No support for CPUs that are not P-state "
234 		    "TSC invariant.\n"));
235 		return (B_FALSE);
236 	}
237 
238 	/*
239 	 * We only support the "Fire and Forget" style of PowerNow! (i.e.,
240 	 * single MSR write to change speed).
241 	 */
242 	if (!(cpu_regs.cp_edx & AMD_CPUID_PSTATE_HARDWARE)) {
243 		PWRNOW_DEBUG(("Hardware P-State control is not supported.\n"));
244 		return (B_FALSE);
245 	}
246 	return (B_TRUE);
247 }
248