1 /*
2  * PowerNV setup code.
3  *
4  * Copyright 2011 IBM Corp.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #undef DEBUG
13 
14 #include <linux/cpu.h>
15 #include <linux/errno.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/tty.h>
19 #include <linux/reboot.h>
20 #include <linux/init.h>
21 #include <linux/console.h>
22 #include <linux/delay.h>
23 #include <linux/irq.h>
24 #include <linux/seq_file.h>
25 #include <linux/of.h>
26 #include <linux/of_fdt.h>
27 #include <linux/interrupt.h>
28 #include <linux/bug.h>
29 #include <linux/pci.h>
30 
31 #include <asm/machdep.h>
32 #include <asm/firmware.h>
33 #include <asm/xics.h>
34 #include <asm/rtas.h>
35 #include <asm/opal.h>
36 #include <asm/kexec.h>
37 
38 #include "powernv.h"
39 
40 static void __init pnv_setup_arch(void)
41 {
42 	/* Initialize SMP */
43 	pnv_smp_init();
44 
45 	/* Setup PCI */
46 	pnv_pci_init();
47 
48 	/* Setup RTC and NVRAM callbacks */
49 	if (firmware_has_feature(FW_FEATURE_OPAL))
50 		opal_nvram_init();
51 
52 	/* Enable NAP mode */
53 	powersave_nap = 1;
54 
55 	/* XXX PMCS */
56 }
57 
58 static void __init pnv_init_early(void)
59 {
60 	/*
61 	 * Initialize the LPC bus now so that legacy serial
62 	 * ports can be found on it
63 	 */
64 	opal_lpc_init();
65 
66 #ifdef CONFIG_HVC_OPAL
67 	if (firmware_has_feature(FW_FEATURE_OPAL))
68 		hvc_opal_init_early();
69 	else
70 #endif
71 		add_preferred_console("hvc", 0, NULL);
72 }
73 
74 static void __init pnv_init_IRQ(void)
75 {
76 	xics_init();
77 
78 	WARN_ON(!ppc_md.get_irq);
79 }
80 
81 static void pnv_show_cpuinfo(struct seq_file *m)
82 {
83 	struct device_node *root;
84 	const char *model = "";
85 
86 	root = of_find_node_by_path("/");
87 	if (root)
88 		model = of_get_property(root, "model", NULL);
89 	seq_printf(m, "machine\t\t: PowerNV %s\n", model);
90 	if (firmware_has_feature(FW_FEATURE_OPALv3))
91 		seq_printf(m, "firmware\t: OPAL v3\n");
92 	else if (firmware_has_feature(FW_FEATURE_OPALv2))
93 		seq_printf(m, "firmware\t: OPAL v2\n");
94 	else if (firmware_has_feature(FW_FEATURE_OPAL))
95 		seq_printf(m, "firmware\t: OPAL v1\n");
96 	else
97 		seq_printf(m, "firmware\t: BML\n");
98 	of_node_put(root);
99 }
100 
101 static void  __noreturn pnv_restart(char *cmd)
102 {
103 	long rc = OPAL_BUSY;
104 
105 	opal_notifier_disable();
106 
107 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
108 		rc = opal_cec_reboot();
109 		if (rc == OPAL_BUSY_EVENT)
110 			opal_poll_events(NULL);
111 		else
112 			mdelay(10);
113 	}
114 	for (;;)
115 		opal_poll_events(NULL);
116 }
117 
118 static void __noreturn pnv_power_off(void)
119 {
120 	long rc = OPAL_BUSY;
121 
122 	opal_notifier_disable();
123 
124 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
125 		rc = opal_cec_power_down(0);
126 		if (rc == OPAL_BUSY_EVENT)
127 			opal_poll_events(NULL);
128 		else
129 			mdelay(10);
130 	}
131 	for (;;)
132 		opal_poll_events(NULL);
133 }
134 
135 static void __noreturn pnv_halt(void)
136 {
137 	pnv_power_off();
138 }
139 
140 static void pnv_progress(char *s, unsigned short hex)
141 {
142 }
143 
144 static int pnv_dma_set_mask(struct device *dev, u64 dma_mask)
145 {
146 	if (dev_is_pci(dev))
147 		return pnv_pci_dma_set_mask(to_pci_dev(dev), dma_mask);
148 	return __dma_set_mask(dev, dma_mask);
149 }
150 
151 static void pnv_shutdown(void)
152 {
153 	/* Let the PCI code clear up IODA tables */
154 	pnv_pci_shutdown();
155 
156 	/*
157 	 * Stop OPAL activity: Unregister all OPAL interrupts so they
158 	 * don't fire up while we kexec and make sure all potentially
159 	 * DMA'ing ops are complete (such as dump retrieval).
160 	 */
161 	opal_shutdown();
162 }
163 
164 #ifdef CONFIG_KEXEC
165 static void pnv_kexec_wait_secondaries_down(void)
166 {
167 	int my_cpu, i, notified = -1;
168 
169 	my_cpu = get_cpu();
170 
171 	for_each_online_cpu(i) {
172 		uint8_t status;
173 		int64_t rc;
174 
175 		if (i == my_cpu)
176 			continue;
177 
178 		for (;;) {
179 			rc = opal_query_cpu_status(get_hard_smp_processor_id(i),
180 						   &status);
181 			if (rc != OPAL_SUCCESS || status != OPAL_THREAD_STARTED)
182 				break;
183 			barrier();
184 			if (i != notified) {
185 				printk(KERN_INFO "kexec: waiting for cpu %d "
186 				       "(physical %d) to enter OPAL\n",
187 				       i, paca[i].hw_cpu_id);
188 				notified = i;
189 			}
190 		}
191 	}
192 }
193 
194 static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
195 {
196 	xics_kexec_teardown_cpu(secondary);
197 
198 	/* On OPAL v3, we return all CPUs to firmware */
199 
200 	if (!firmware_has_feature(FW_FEATURE_OPALv3))
201 		return;
202 
203 	if (secondary) {
204 		/* Return secondary CPUs to firmware on OPAL v3 */
205 		mb();
206 		get_paca()->kexec_state = KEXEC_STATE_REAL_MODE;
207 		mb();
208 
209 		/* Return the CPU to OPAL */
210 		opal_return_cpu();
211 	} else if (crash_shutdown) {
212 		/*
213 		 * On crash, we don't wait for secondaries to go
214 		 * down as they might be unreachable or hung, so
215 		 * instead we just wait a bit and move on.
216 		 */
217 		mdelay(1);
218 	} else {
219 		/* Primary waits for the secondaries to have reached OPAL */
220 		pnv_kexec_wait_secondaries_down();
221 	}
222 }
223 #endif /* CONFIG_KEXEC */
224 
225 static void __init pnv_setup_machdep_opal(void)
226 {
227 	ppc_md.get_boot_time = opal_get_boot_time;
228 	ppc_md.get_rtc_time = opal_get_rtc_time;
229 	ppc_md.set_rtc_time = opal_set_rtc_time;
230 	ppc_md.restart = pnv_restart;
231 	ppc_md.power_off = pnv_power_off;
232 	ppc_md.halt = pnv_halt;
233 	ppc_md.machine_check_exception = opal_machine_check;
234 	ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
235 }
236 
237 #ifdef CONFIG_PPC_POWERNV_RTAS
238 static void __init pnv_setup_machdep_rtas(void)
239 {
240 	if (rtas_token("get-time-of-day") != RTAS_UNKNOWN_SERVICE) {
241 		ppc_md.get_boot_time = rtas_get_boot_time;
242 		ppc_md.get_rtc_time = rtas_get_rtc_time;
243 		ppc_md.set_rtc_time = rtas_set_rtc_time;
244 	}
245 	ppc_md.restart = rtas_restart;
246 	ppc_md.power_off = rtas_power_off;
247 	ppc_md.halt = rtas_halt;
248 }
249 #endif /* CONFIG_PPC_POWERNV_RTAS */
250 
251 static int __init pnv_probe(void)
252 {
253 	unsigned long root = of_get_flat_dt_root();
254 
255 	if (!of_flat_dt_is_compatible(root, "ibm,powernv"))
256 		return 0;
257 
258 	hpte_init_native();
259 
260 	if (firmware_has_feature(FW_FEATURE_OPAL))
261 		pnv_setup_machdep_opal();
262 #ifdef CONFIG_PPC_POWERNV_RTAS
263 	else if (rtas.base)
264 		pnv_setup_machdep_rtas();
265 #endif /* CONFIG_PPC_POWERNV_RTAS */
266 
267 	pr_debug("PowerNV detected !\n");
268 
269 	return 1;
270 }
271 
272 define_machine(powernv) {
273 	.name			= "PowerNV",
274 	.probe			= pnv_probe,
275 	.init_early		= pnv_init_early,
276 	.setup_arch		= pnv_setup_arch,
277 	.init_IRQ		= pnv_init_IRQ,
278 	.show_cpuinfo		= pnv_show_cpuinfo,
279 	.progress		= pnv_progress,
280 	.machine_shutdown	= pnv_shutdown,
281 	.power_save             = power7_idle,
282 	.calibrate_decr		= generic_calibrate_decr,
283 	.dma_set_mask		= pnv_dma_set_mask,
284 #ifdef CONFIG_KEXEC
285 	.kexec_cpu_down		= pnv_kexec_cpu_down,
286 #endif
287 };
288