1 /*
2  * PowerNV OPAL high level interfaces
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/types.h>
15 #include <linux/of.h>
16 #include <linux/of_platform.h>
17 #include <linux/interrupt.h>
18 #include <asm/opal.h>
19 #include <asm/firmware.h>
20 
21 #include "powernv.h"
22 
23 struct opal {
24 	u64 base;
25 	u64 entry;
26 } opal;
27 
28 static struct device_node *opal_node;
29 static DEFINE_SPINLOCK(opal_write_lock);
30 extern u64 opal_mc_secondary_handler[];
31 
early_init_dt_scan_opal(unsigned long node,const char * uname,int depth,void * data)32 int __init early_init_dt_scan_opal(unsigned long node,
33 				   const char *uname, int depth, void *data)
34 {
35 	const void *basep, *entryp;
36 	unsigned long basesz, entrysz;
37 	u64 glue;
38 
39 	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
40 		return 0;
41 
42 	basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
43 	entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
44 
45 	if (!basep || !entryp)
46 		return 1;
47 
48 	opal.base = of_read_number(basep, basesz/4);
49 	opal.entry = of_read_number(entryp, entrysz/4);
50 
51 	pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%ld)\n",
52 		 opal.base, basep, basesz);
53 	pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%ld)\n",
54 		 opal.entry, entryp, entrysz);
55 
56 	powerpc_firmware_features |= FW_FEATURE_OPAL;
57 	if (of_flat_dt_is_compatible(node, "ibm,opal-v2")) {
58 		powerpc_firmware_features |= FW_FEATURE_OPALv2;
59 		printk("OPAL V2 detected !\n");
60 	} else {
61 		printk("OPAL V1 detected !\n");
62 	}
63 
64 	/* Hookup some exception handlers. We use the fwnmi area at 0x7000
65 	 * to provide the glue space to OPAL
66 	 */
67 	glue = 0x7000;
68 	opal_register_exception_handler(OPAL_MACHINE_CHECK_HANDLER,
69 					__pa(opal_mc_secondary_handler[0]),
70 					glue);
71 	glue += 128;
72 	opal_register_exception_handler(OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
73 					0, glue);
74 	glue += 128;
75 	opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
76 
77 	return 1;
78 }
79 
opal_get_chars(uint32_t vtermno,char * buf,int count)80 int opal_get_chars(uint32_t vtermno, char *buf, int count)
81 {
82 	s64 len, rc;
83 	u64 evt;
84 
85 	if (!opal.entry)
86 		return -ENODEV;
87 	opal_poll_events(&evt);
88 	if ((evt & OPAL_EVENT_CONSOLE_INPUT) == 0)
89 		return 0;
90 	len = count;
91 	rc = opal_console_read(vtermno, &len, buf);
92 	if (rc == OPAL_SUCCESS)
93 		return len;
94 	return 0;
95 }
96 
opal_put_chars(uint32_t vtermno,const char * data,int total_len)97 int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
98 {
99 	int written = 0;
100 	s64 len, rc;
101 	unsigned long flags;
102 	u64 evt;
103 
104 	if (!opal.entry)
105 		return -ENODEV;
106 
107 	/* We want put_chars to be atomic to avoid mangling of hvsi
108 	 * packets. To do that, we first test for room and return
109 	 * -EAGAIN if there isn't enough.
110 	 *
111 	 * Unfortunately, opal_console_write_buffer_space() doesn't
112 	 * appear to work on opal v1, so we just assume there is
113 	 * enough room and be done with it
114 	 */
115 	spin_lock_irqsave(&opal_write_lock, flags);
116 	if (firmware_has_feature(FW_FEATURE_OPALv2)) {
117 		rc = opal_console_write_buffer_space(vtermno, &len);
118 		if (rc || len < total_len) {
119 			spin_unlock_irqrestore(&opal_write_lock, flags);
120 			/* Closed -> drop characters */
121 			if (rc)
122 				return total_len;
123 			opal_poll_events(&evt);
124 			return -EAGAIN;
125 		}
126 	}
127 
128 	/* We still try to handle partial completions, though they
129 	 * should no longer happen.
130 	 */
131 	rc = OPAL_BUSY;
132 	while(total_len > 0 && (rc == OPAL_BUSY ||
133 				rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
134 		len = total_len;
135 		rc = opal_console_write(vtermno, &len, data);
136 		if (rc == OPAL_SUCCESS) {
137 			total_len -= len;
138 			data += len;
139 			written += len;
140 		}
141 		/* This is a bit nasty but we need that for the console to
142 		 * flush when there aren't any interrupts. We will clean
143 		 * things a bit later to limit that to synchronous path
144 		 * such as the kernel console and xmon/udbg
145 		 */
146 		do
147 			opal_poll_events(&evt);
148 		while(rc == OPAL_SUCCESS && (evt & OPAL_EVENT_CONSOLE_OUTPUT));
149 	}
150 	spin_unlock_irqrestore(&opal_write_lock, flags);
151 	return written;
152 }
153 
opal_machine_check(struct pt_regs * regs)154 int opal_machine_check(struct pt_regs *regs)
155 {
156 	struct opal_machine_check_event *opal_evt = get_paca()->opal_mc_evt;
157 	struct opal_machine_check_event evt;
158 	const char *level, *sevstr, *subtype;
159 	static const char *opal_mc_ue_types[] = {
160 		"Indeterminate",
161 		"Instruction fetch",
162 		"Page table walk ifetch",
163 		"Load/Store",
164 		"Page table walk Load/Store",
165 	};
166 	static const char *opal_mc_slb_types[] = {
167 		"Indeterminate",
168 		"Parity",
169 		"Multihit",
170 	};
171 	static const char *opal_mc_erat_types[] = {
172 		"Indeterminate",
173 		"Parity",
174 		"Multihit",
175 	};
176 	static const char *opal_mc_tlb_types[] = {
177 		"Indeterminate",
178 		"Parity",
179 		"Multihit",
180 	};
181 
182 	/* Copy the event structure and release the original */
183 	evt = *opal_evt;
184 	opal_evt->in_use = 0;
185 
186 	/* Print things out */
187 	if (evt.version != OpalMCE_V1) {
188 		pr_err("Machine Check Exception, Unknown event version %d !\n",
189 		       evt.version);
190 		return 0;
191 	}
192 	switch(evt.severity) {
193 	case OpalMCE_SEV_NO_ERROR:
194 		level = KERN_INFO;
195 		sevstr = "Harmless";
196 		break;
197 	case OpalMCE_SEV_WARNING:
198 		level = KERN_WARNING;
199 		sevstr = "";
200 		break;
201 	case OpalMCE_SEV_ERROR_SYNC:
202 		level = KERN_ERR;
203 		sevstr = "Severe";
204 		break;
205 	case OpalMCE_SEV_FATAL:
206 	default:
207 		level = KERN_ERR;
208 		sevstr = "Fatal";
209 		break;
210 	}
211 
212 	printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
213 	       evt.disposition == OpalMCE_DISPOSITION_RECOVERED ?
214 	       "Recovered" : "[Not recovered");
215 	printk("%s  Initiator: %s\n", level,
216 	       evt.initiator == OpalMCE_INITIATOR_CPU ? "CPU" : "Unknown");
217 	switch(evt.error_type) {
218 	case OpalMCE_ERROR_TYPE_UE:
219 		subtype = evt.u.ue_error.ue_error_type <
220 			ARRAY_SIZE(opal_mc_ue_types) ?
221 			opal_mc_ue_types[evt.u.ue_error.ue_error_type]
222 			: "Unknown";
223 		printk("%s  Error type: UE [%s]\n", level, subtype);
224 		if (evt.u.ue_error.effective_address_provided)
225 			printk("%s    Effective address: %016llx\n",
226 			       level, evt.u.ue_error.effective_address);
227 		if (evt.u.ue_error.physical_address_provided)
228 			printk("%s      Physial address: %016llx\n",
229 			       level, evt.u.ue_error.physical_address);
230 		break;
231 	case OpalMCE_ERROR_TYPE_SLB:
232 		subtype = evt.u.slb_error.slb_error_type <
233 			ARRAY_SIZE(opal_mc_slb_types) ?
234 			opal_mc_slb_types[evt.u.slb_error.slb_error_type]
235 			: "Unknown";
236 		printk("%s  Error type: SLB [%s]\n", level, subtype);
237 		if (evt.u.slb_error.effective_address_provided)
238 			printk("%s    Effective address: %016llx\n",
239 			       level, evt.u.slb_error.effective_address);
240 		break;
241 	case OpalMCE_ERROR_TYPE_ERAT:
242 		subtype = evt.u.erat_error.erat_error_type <
243 			ARRAY_SIZE(opal_mc_erat_types) ?
244 			opal_mc_erat_types[evt.u.erat_error.erat_error_type]
245 			: "Unknown";
246 		printk("%s  Error type: ERAT [%s]\n", level, subtype);
247 		if (evt.u.erat_error.effective_address_provided)
248 			printk("%s    Effective address: %016llx\n",
249 			       level, evt.u.erat_error.effective_address);
250 		break;
251 	case OpalMCE_ERROR_TYPE_TLB:
252 		subtype = evt.u.tlb_error.tlb_error_type <
253 			ARRAY_SIZE(opal_mc_tlb_types) ?
254 			opal_mc_tlb_types[evt.u.tlb_error.tlb_error_type]
255 			: "Unknown";
256 		printk("%s  Error type: TLB [%s]\n", level, subtype);
257 		if (evt.u.tlb_error.effective_address_provided)
258 			printk("%s    Effective address: %016llx\n",
259 			       level, evt.u.tlb_error.effective_address);
260 		break;
261 	default:
262 	case OpalMCE_ERROR_TYPE_UNKNOWN:
263 		printk("%s  Error type: Unknown\n", level);
264 		break;
265 	}
266 	return evt.severity == OpalMCE_SEV_FATAL ? 0 : 1;
267 }
268 
opal_interrupt(int irq,void * data)269 static irqreturn_t opal_interrupt(int irq, void *data)
270 {
271 	uint64_t events;
272 
273 	opal_handle_interrupt(virq_to_hw(irq), &events);
274 
275 	/* XXX TODO: Do something with the events */
276 
277 	return IRQ_HANDLED;
278 }
279 
opal_init(void)280 static int __init opal_init(void)
281 {
282 	struct device_node *np, *consoles;
283 	const u32 *irqs;
284 	int rc, i, irqlen;
285 
286 	opal_node = of_find_node_by_path("/ibm,opal");
287 	if (!opal_node) {
288 		pr_warn("opal: Node not found\n");
289 		return -ENODEV;
290 	}
291 	if (firmware_has_feature(FW_FEATURE_OPALv2))
292 		consoles = of_find_node_by_path("/ibm,opal/consoles");
293 	else
294 		consoles = of_node_get(opal_node);
295 
296 	/* Register serial ports */
297 	for_each_child_of_node(consoles, np) {
298 		if (strcmp(np->name, "serial"))
299 			continue;
300 		of_platform_device_create(np, NULL, NULL);
301 	}
302 	of_node_put(consoles);
303 
304 	/* Find all OPAL interrupts and request them */
305 	irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
306 	pr_debug("opal: Found %d interrupts reserved for OPAL\n",
307 		 irqs ? (irqlen / 4) : 0);
308 	for (i = 0; irqs && i < (irqlen / 4); i++, irqs++) {
309 		unsigned int hwirq = be32_to_cpup(irqs);
310 		unsigned int irq = irq_create_mapping(NULL, hwirq);
311 		if (irq == NO_IRQ) {
312 			pr_warning("opal: Failed to map irq 0x%x\n", hwirq);
313 			continue;
314 		}
315 		rc = request_irq(irq, opal_interrupt, 0, "opal", NULL);
316 		if (rc)
317 			pr_warning("opal: Error %d requesting irq %d"
318 				   " (0x%x)\n", rc, irq, hwirq);
319 	}
320 	return 0;
321 }
322 subsys_initcall(opal_init);
323