xref: /netbsd-src/sys/arch/arm/fdt/psci_fdt.c (revision 16ab290372fc95ade1a04be624f607b3949adb0c)
1 /* $NetBSD: psci_fdt.c,v 1.1 2017/06/28 23:48:22 jmcneill Exp $ */
2 
3 /*-
4  * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: psci_fdt.c,v 1.1 2017/06/28 23:48:22 jmcneill Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/device.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 
38 #include <dev/fdt/fdtvar.h>
39 
40 #include <arm/locore.h>
41 #include <arm/armreg.h>
42 
43 #include <arm/arm/psci.h>
44 #include <arm/fdt/psci_fdt.h>
45 
46 static int	psci_fdt_match(device_t, cfdata_t, void *);
47 static void	psci_fdt_attach(device_t, device_t, void *);
48 
49 static int	psci_fdt_init(const int);
50 
51 static const char * const compatible[] = {
52 	"arm,psci",
53 	"arm,psci-0.2",
54 	"arm,psci-1.0",
55 	NULL
56 };
57 
58 CFATTACH_DECL_NEW(psci_fdt, 0, psci_fdt_match, psci_fdt_attach, NULL, NULL);
59 
60 static int
61 psci_fdt_match(device_t parent, cfdata_t cf, void *aux)
62 {
63 	struct fdt_attach_args * const faa = aux;
64 
65 	return of_match_compatible(faa->faa_phandle, compatible);
66 }
67 
68 static void
69 psci_fdt_attach(device_t parent, device_t self, void *aux)
70 {
71 	struct fdt_attach_args * const faa = aux;
72 	const int phandle = faa->faa_phandle;
73 
74 	psci_fdt_init(phandle);
75 
76 	const uint32_t ver = psci_version();
77 	const u_int ver_maj = __SHIFTOUT(ver, PSCI_VERSION_MAJOR);
78 	const u_int ver_min = __SHIFTOUT(ver, PSCI_VERSION_MINOR);
79 
80 	aprint_naive("\n");
81 	aprint_normal(": PSCI %u.%u\n", ver_maj, ver_min);
82 }
83 
84 static int
85 psci_fdt_init(const int phandle)
86 {
87 	char method[4];
88 	uint32_t val;
89 
90 	if (!of_hasprop(phandle, "method")) {
91 		aprint_error("PSCI: missing 'method' property\n");
92 		return EINVAL;
93 	}
94 
95 	OF_getprop(phandle, "method", method, sizeof(method));
96 	if (strcmp(method, "smc") == 0)
97 		psci_init(psci_call_smc);
98 	else if (strcmp(method, "hvc") == 0)
99 		psci_init(psci_call_hvc);
100 	else {
101 		aprint_error("PSCI: unsupported method '%s'\n", method);
102 		return EINVAL;
103 	}
104 
105 	const char * const compat_0_1[] = { "arm,psci", NULL };
106 	if (of_match_compatible(phandle, compat_0_1)) {
107 		psci_clearfunc();
108 		if (of_getprop_uint32(phandle, "cpu_on", &val) == 0)
109 			psci_setfunc(PSCI_FUNC_CPU_ON, val);
110 	}
111 
112 	return 0;
113 }
114 
115 void
116 psci_fdt_bootstrap(void)
117 {
118 	extern void cortex_mpstart(void);
119 	bus_addr_t mpidr;
120 	uint32_t bp_mpidr;
121 	int child;
122 
123 	const int cpus = OF_finddevice("/cpus");
124 	if (cpus == -1) {
125 		aprint_error("PSCI: no /cpus node found\n");
126 		arm_cpu_max = 1;
127 		return;
128 	}
129 
130 	/* Count CPUs */
131 	arm_cpu_max = 0;
132 	for (child = OF_child(cpus); child; child = OF_peer(child))
133 		if (fdtbus_status_okay(child))
134 			arm_cpu_max++;
135 
136 	const int phandle = OF_finddevice("/psci");
137 	if (phandle == -1) {
138 		aprint_error("PSCI: no /psci node found\n");
139 		return;
140 	}
141 
142 	if (psci_fdt_init(phandle) != 0)
143 		return;
144 
145 	/* MPIDR affinity levels of boot processor. */
146 	bp_mpidr = armreg_mpidr_read() & (MPIDR_AFF2|MPIDR_AFF1|MPIDR_AFF0);
147 
148 	/* Boot APs */
149 	uint32_t started = 0;
150 	for (child = OF_child(cpus); child; child = OF_peer(child)) {
151 		if (!fdtbus_status_okay(child))
152 			continue;
153 		if (fdtbus_get_reg(child, 0, &mpidr, NULL) != 0)
154 			continue;
155 		if (mpidr == bp_mpidr)
156 			continue; 	/* BP already started */
157 
158 		/* XXX NetBSD requires all CPUs to be in the same cluster */
159 		const u_int bp_clid = __SHIFTOUT(bp_mpidr, CORTEXA9_MPIDR_CLID);
160 		const u_int clid = __SHIFTOUT(mpidr, CORTEXA9_MPIDR_CLID);
161 		if (bp_clid != clid)
162 			continue;
163 
164 		const u_int cpuid = __SHIFTOUT(mpidr, CORTEXA9_MPIDR_CPUID);
165 		int ret = psci_cpu_on(cpuid, (register_t)cortex_mpstart, 0);
166 		if (ret == PSCI_SUCCESS)
167 			started |= __BIT(cpuid);
168 	}
169 
170 	/* Wait for APs to start */
171 	for (u_int i = 0x10000000; i > 0; i--) {
172 		arm_dmb();
173 		if (arm_cpu_hatched == started)
174 			break;
175 	}
176 }
177