1 /*
2  *  64-bit pSeries and RS/6000 setup code.
3  *
4  *  Copyright (C) 1995  Linus Torvalds
5  *  Adapted from 'alpha' version by Gary Thomas
6  *  Modified by Cort Dougan (cort@cs.nmt.edu)
7  *  Modified by PPC64 Team, IBM Corp
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14 
15 /*
16  * bootup setup stuff..
17  */
18 
19 #undef DEBUG
20 
21 #include <linux/cpu.h>
22 #include <linux/errno.h>
23 #include <linux/sched.h>
24 #include <linux/kernel.h>
25 #include <linux/mm.h>
26 #include <linux/stddef.h>
27 #include <linux/unistd.h>
28 #include <linux/slab.h>
29 #include <linux/user.h>
30 #include <linux/a.out.h>
31 #include <linux/tty.h>
32 #include <linux/major.h>
33 #include <linux/interrupt.h>
34 #include <linux/reboot.h>
35 #include <linux/init.h>
36 #include <linux/ioport.h>
37 #include <linux/console.h>
38 #include <linux/pci.h>
39 #include <linux/utsname.h>
40 #include <linux/adb.h>
41 #include <linux/module.h>
42 #include <linux/delay.h>
43 #include <linux/irq.h>
44 #include <linux/seq_file.h>
45 #include <linux/root_dev.h>
46 
47 #include <asm/mmu.h>
48 #include <asm/processor.h>
49 #include <asm/io.h>
50 #include <asm/pgtable.h>
51 #include <asm/prom.h>
52 #include <asm/rtas.h>
53 #include <asm/pci-bridge.h>
54 #include <asm/iommu.h>
55 #include <asm/dma.h>
56 #include <asm/machdep.h>
57 #include <asm/irq.h>
58 #include <asm/time.h>
59 #include <asm/nvram.h>
60 #include "xics.h"
61 #include <asm/pmc.h>
62 #include <asm/mpic.h>
63 #include <asm/ppc-pci.h>
64 #include <asm/i8259.h>
65 #include <asm/udbg.h>
66 #include <asm/smp.h>
67 #include <asm/firmware.h>
68 #include <asm/eeh.h>
69 
70 #include "plpar_wrappers.h"
71 #include "pseries.h"
72 
73 #ifdef DEBUG
74 #define DBG(fmt...) udbg_printf(fmt)
75 #else
76 #define DBG(fmt...)
77 #endif
78 
79 /* move those away to a .h */
80 extern void find_udbg_vterm(void);
81 
82 int fwnmi_active;  /* TRUE if an FWNMI handler is present */
83 
84 static void pseries_shared_idle_sleep(void);
85 static void pseries_dedicated_idle_sleep(void);
86 
87 static struct device_node *pSeries_mpic_node;
88 
89 static void pSeries_show_cpuinfo(struct seq_file *m)
90 {
91 	struct device_node *root;
92 	const char *model = "";
93 
94 	root = of_find_node_by_path("/");
95 	if (root)
96 		model = of_get_property(root, "model", NULL);
97 	seq_printf(m, "machine\t\t: CHRP %s\n", model);
98 	of_node_put(root);
99 }
100 
101 /* Initialize firmware assisted non-maskable interrupts if
102  * the firmware supports this feature.
103  */
104 static void __init fwnmi_init(void)
105 {
106 	unsigned long system_reset_addr, machine_check_addr;
107 
108 	int ibm_nmi_register = rtas_token("ibm,nmi-register");
109 	if (ibm_nmi_register == RTAS_UNKNOWN_SERVICE)
110 		return;
111 
112 	/* If the kernel's not linked at zero we point the firmware at low
113 	 * addresses anyway, and use a trampoline to get to the real code. */
114 	system_reset_addr  = __pa(system_reset_fwnmi) - PHYSICAL_START;
115 	machine_check_addr = __pa(machine_check_fwnmi) - PHYSICAL_START;
116 
117 	if (0 == rtas_call(ibm_nmi_register, 2, 1, NULL, system_reset_addr,
118 				machine_check_addr))
119 		fwnmi_active = 1;
120 }
121 
122 void pseries_8259_cascade(unsigned int irq, struct irq_desc *desc)
123 {
124 	unsigned int cascade_irq = i8259_irq();
125 	if (cascade_irq != NO_IRQ)
126 		generic_handle_irq(cascade_irq);
127 	desc->chip->eoi(irq);
128 }
129 
130 static void __init pseries_mpic_init_IRQ(void)
131 {
132 	struct device_node *np, *old, *cascade = NULL;
133         const unsigned int *addrp;
134 	unsigned long intack = 0;
135 	const unsigned int *opprop;
136 	unsigned long openpic_addr = 0;
137 	unsigned int cascade_irq;
138 	int naddr, n, i, opplen;
139 	struct mpic *mpic;
140 
141 	np = of_find_node_by_path("/");
142 	naddr = of_n_addr_cells(np);
143 	opprop = of_get_property(np, "platform-open-pic", &opplen);
144 	if (opprop != 0) {
145 		openpic_addr = of_read_number(opprop, naddr);
146 		printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
147 	}
148 	of_node_put(np);
149 
150 	BUG_ON(openpic_addr == 0);
151 
152 	/* Setup the openpic driver */
153 	mpic = mpic_alloc(pSeries_mpic_node, openpic_addr,
154 			  MPIC_PRIMARY,
155 			  16, 250, /* isu size, irq count */
156 			  " MPIC     ");
157 	BUG_ON(mpic == NULL);
158 
159 	/* Add ISUs */
160 	opplen /= sizeof(u32);
161 	for (n = 0, i = naddr; i < opplen; i += naddr, n++) {
162 		unsigned long isuaddr = of_read_number(opprop + i, naddr);
163 		mpic_assign_isu(mpic, n, isuaddr);
164 	}
165 
166 	/* All ISUs are setup, complete initialization */
167 	mpic_init(mpic);
168 
169 	/* Look for cascade */
170 	for_each_node_by_type(np, "interrupt-controller")
171 		if (of_device_is_compatible(np, "chrp,iic")) {
172 			cascade = np;
173 			break;
174 		}
175 	if (cascade == NULL)
176 		return;
177 
178 	cascade_irq = irq_of_parse_and_map(cascade, 0);
179 	if (cascade_irq == NO_IRQ) {
180 		printk(KERN_ERR "mpic: failed to map cascade interrupt");
181 		return;
182 	}
183 
184 	/* Check ACK type */
185 	for (old = of_node_get(cascade); old != NULL ; old = np) {
186 		np = of_get_parent(old);
187 		of_node_put(old);
188 		if (np == NULL)
189 			break;
190 		if (strcmp(np->name, "pci") != 0)
191 			continue;
192 		addrp = of_get_property(np, "8259-interrupt-acknowledge",
193 					    NULL);
194 		if (addrp == NULL)
195 			continue;
196 		naddr = of_n_addr_cells(np);
197 		intack = addrp[naddr-1];
198 		if (naddr > 1)
199 			intack |= ((unsigned long)addrp[naddr-2]) << 32;
200 	}
201 	if (intack)
202 		printk(KERN_DEBUG "mpic: PCI 8259 intack at 0x%016lx\n",
203 		       intack);
204 	i8259_init(cascade, intack);
205 	of_node_put(cascade);
206 	set_irq_chained_handler(cascade_irq, pseries_8259_cascade);
207 }
208 
209 static void pseries_lpar_enable_pmcs(void)
210 {
211 	unsigned long set, reset;
212 
213 	set = 1UL << 63;
214 	reset = 0;
215 	plpar_hcall_norets(H_PERFMON, set, reset);
216 
217 	/* instruct hypervisor to maintain PMCs */
218 	if (firmware_has_feature(FW_FEATURE_SPLPAR))
219 		get_lppaca()->pmcregs_in_use = 1;
220 }
221 
222 static void __init pseries_discover_pic(void)
223 {
224 	struct device_node *np;
225 	const char *typep;
226 
227 	for (np = NULL; (np = of_find_node_by_name(np,
228 						   "interrupt-controller"));) {
229 		typep = of_get_property(np, "compatible", NULL);
230 		if (strstr(typep, "open-pic")) {
231 			pSeries_mpic_node = of_node_get(np);
232 			ppc_md.init_IRQ       = pseries_mpic_init_IRQ;
233 			ppc_md.get_irq        = mpic_get_irq;
234 			setup_kexec_cpu_down_mpic();
235 			smp_init_pseries_mpic();
236 			return;
237 		} else if (strstr(typep, "ppc-xicp")) {
238 			ppc_md.init_IRQ       = xics_init_IRQ;
239 			setup_kexec_cpu_down_xics();
240 			smp_init_pseries_xics();
241 			return;
242 		}
243 	}
244 	printk(KERN_ERR "pSeries_discover_pic: failed to recognize"
245 	       " interrupt-controller\n");
246 }
247 
248 static void __init pSeries_setup_arch(void)
249 {
250 	/* Discover PIC type and setup ppc_md accordingly */
251 	pseries_discover_pic();
252 
253 	/* openpic global configuration register (64-bit format). */
254 	/* openpic Interrupt Source Unit pointer (64-bit format). */
255 	/* python0 facility area (mmio) (64-bit format) REAL address. */
256 
257 	/* init to some ~sane value until calibrate_delay() runs */
258 	loops_per_jiffy = 50000000;
259 
260 	fwnmi_init();
261 
262 	/* Find and initialize PCI host bridges */
263 	init_pci_config_tokens();
264 	find_and_init_phbs();
265 	eeh_init();
266 
267 	pSeries_nvram_init();
268 
269 	/* Choose an idle loop */
270 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
271 		vpa_init(boot_cpuid);
272 		if (get_lppaca()->shared_proc) {
273 			printk(KERN_DEBUG "Using shared processor idle loop\n");
274 			ppc_md.power_save = pseries_shared_idle_sleep;
275 		} else {
276 			printk(KERN_DEBUG "Using dedicated idle loop\n");
277 			ppc_md.power_save = pseries_dedicated_idle_sleep;
278 		}
279 	} else {
280 		printk(KERN_DEBUG "Using default idle loop\n");
281 	}
282 
283 	if (firmware_has_feature(FW_FEATURE_LPAR))
284 		ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
285 	else
286 		ppc_md.enable_pmcs = power4_enable_pmcs;
287 }
288 
289 static int __init pSeries_init_panel(void)
290 {
291 	/* Manually leave the kernel version on the panel. */
292 	ppc_md.progress("Linux ppc64\n", 0);
293 	ppc_md.progress(init_utsname()->version, 0);
294 
295 	return 0;
296 }
297 arch_initcall(pSeries_init_panel);
298 
299 static int pseries_set_dabr(unsigned long dabr)
300 {
301 	return plpar_hcall_norets(H_SET_DABR, dabr);
302 }
303 
304 static int pseries_set_xdabr(unsigned long dabr)
305 {
306 	/* We want to catch accesses from kernel and userspace */
307 	return plpar_hcall_norets(H_SET_XDABR, dabr,
308 			H_DABRX_KERNEL | H_DABRX_USER);
309 }
310 
311 /*
312  * Early initialization.  Relocation is on but do not reference unbolted pages
313  */
314 static void __init pSeries_init_early(void)
315 {
316 	DBG(" -> pSeries_init_early()\n");
317 
318 	if (firmware_has_feature(FW_FEATURE_LPAR))
319 		find_udbg_vterm();
320 
321 	if (firmware_has_feature(FW_FEATURE_DABR))
322 		ppc_md.set_dabr = pseries_set_dabr;
323 	else if (firmware_has_feature(FW_FEATURE_XDABR))
324 		ppc_md.set_dabr = pseries_set_xdabr;
325 
326 	iommu_init_early_pSeries();
327 
328 	DBG(" <- pSeries_init_early()\n");
329 }
330 
331 /*
332  * Called very early, MMU is off, device-tree isn't unflattened
333  */
334 
335 static int __init pSeries_probe_hypertas(unsigned long node,
336 					 const char *uname, int depth,
337 					 void *data)
338 {
339 	const char *hypertas;
340 	unsigned long len;
341 
342 	if (depth != 1 ||
343 	    (strcmp(uname, "rtas") != 0 && strcmp(uname, "rtas@0") != 0))
344 		return 0;
345 
346 	hypertas = of_get_flat_dt_prop(node, "ibm,hypertas-functions", &len);
347 	if (!hypertas)
348 		return 1;
349 
350 	powerpc_firmware_features |= FW_FEATURE_LPAR;
351 	fw_feature_init(hypertas, len);
352 
353 	return 1;
354 }
355 
356 static int __init pSeries_probe(void)
357 {
358 	unsigned long root = of_get_flat_dt_root();
359  	char *dtype = of_get_flat_dt_prop(root, "device_type", NULL);
360 
361  	if (dtype == NULL)
362  		return 0;
363  	if (strcmp(dtype, "chrp"))
364 		return 0;
365 
366 	/* Cell blades firmware claims to be chrp while it's not. Until this
367 	 * is fixed, we need to avoid those here.
368 	 */
369 	if (of_flat_dt_is_compatible(root, "IBM,CPBW-1.0") ||
370 	    of_flat_dt_is_compatible(root, "IBM,CBEA"))
371 		return 0;
372 
373 	DBG("pSeries detected, looking for LPAR capability...\n");
374 
375 	/* Now try to figure out if we are running on LPAR */
376 	of_scan_flat_dt(pSeries_probe_hypertas, NULL);
377 
378 	if (firmware_has_feature(FW_FEATURE_LPAR))
379 		hpte_init_lpar();
380 	else
381 		hpte_init_native();
382 
383 	DBG("Machine is%s LPAR !\n",
384 	    (powerpc_firmware_features & FW_FEATURE_LPAR) ? "" : " not");
385 
386 	return 1;
387 }
388 
389 
390 DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
391 
392 static void pseries_dedicated_idle_sleep(void)
393 {
394 	unsigned int cpu = smp_processor_id();
395 	unsigned long start_snooze;
396 
397 	/*
398 	 * Indicate to the HV that we are idle. Now would be
399 	 * a good time to find other work to dispatch.
400 	 */
401 	get_lppaca()->idle = 1;
402 	get_lppaca()->donate_dedicated_cpu = 1;
403 
404 	/*
405 	 * We come in with interrupts disabled, and need_resched()
406 	 * has been checked recently.  If we should poll for a little
407 	 * while, do so.
408 	 */
409 	if (__get_cpu_var(smt_snooze_delay)) {
410 		start_snooze = get_tb() +
411 			__get_cpu_var(smt_snooze_delay) * tb_ticks_per_usec;
412 		local_irq_enable();
413 		set_thread_flag(TIF_POLLING_NRFLAG);
414 
415 		while (get_tb() < start_snooze) {
416 			if (need_resched() || cpu_is_offline(cpu))
417 				goto out;
418 			ppc64_runlatch_off();
419 			HMT_low();
420 			HMT_very_low();
421 		}
422 
423 		HMT_medium();
424 		clear_thread_flag(TIF_POLLING_NRFLAG);
425 		smp_mb();
426 		local_irq_disable();
427 		if (need_resched() || cpu_is_offline(cpu))
428 			goto out;
429 	}
430 
431 	cede_processor();
432 
433 out:
434 	HMT_medium();
435 	get_lppaca()->donate_dedicated_cpu = 0;
436 	get_lppaca()->idle = 0;
437 }
438 
439 static void pseries_shared_idle_sleep(void)
440 {
441 	/*
442 	 * Indicate to the HV that we are idle. Now would be
443 	 * a good time to find other work to dispatch.
444 	 */
445 	get_lppaca()->idle = 1;
446 
447 	/*
448 	 * Yield the processor to the hypervisor.  We return if
449 	 * an external interrupt occurs (which are driven prior
450 	 * to returning here) or if a prod occurs from another
451 	 * processor. When returning here, external interrupts
452 	 * are enabled.
453 	 */
454 	cede_processor();
455 
456 	get_lppaca()->idle = 0;
457 }
458 
459 static int pSeries_pci_probe_mode(struct pci_bus *bus)
460 {
461 	if (firmware_has_feature(FW_FEATURE_LPAR))
462 		return PCI_PROBE_DEVTREE;
463 	return PCI_PROBE_NORMAL;
464 }
465 
466 /**
467  * pSeries_power_off - tell firmware about how to power off the system.
468  *
469  * This function calls either the power-off rtas token in normal cases
470  * or the ibm,power-off-ups token (if present & requested) in case of
471  * a power failure. If power-off token is used, power on will only be
472  * possible with power button press. If ibm,power-off-ups token is used
473  * it will allow auto poweron after power is restored.
474  */
475 void pSeries_power_off(void)
476 {
477 	int rc;
478 	int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");
479 
480 	if (rtas_flash_term_hook)
481 		rtas_flash_term_hook(SYS_POWER_OFF);
482 
483 	if (rtas_poweron_auto == 0 ||
484 		rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
485 		rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
486 		printk(KERN_INFO "RTAS power-off returned %d\n", rc);
487 	} else {
488 		rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
489 		printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
490 	}
491 	for (;;);
492 }
493 
494 #ifndef CONFIG_PCI
495 void pSeries_final_fixup(void) { }
496 #endif
497 
498 define_machine(pseries) {
499 	.name			= "pSeries",
500 	.probe			= pSeries_probe,
501 	.setup_arch		= pSeries_setup_arch,
502 	.init_early		= pSeries_init_early,
503 	.show_cpuinfo		= pSeries_show_cpuinfo,
504 	.log_error		= pSeries_log_error,
505 	.pcibios_fixup		= pSeries_final_fixup,
506 	.pci_probe_mode		= pSeries_pci_probe_mode,
507 	.restart		= rtas_restart,
508 	.power_off		= pSeries_power_off,
509 	.halt			= rtas_halt,
510 	.panic			= rtas_os_term,
511 	.get_boot_time		= rtas_get_boot_time,
512 	.get_rtc_time		= rtas_get_rtc_time,
513 	.set_rtc_time		= rtas_set_rtc_time,
514 	.calibrate_decr		= generic_calibrate_decr,
515 	.progress		= rtas_progress,
516 	.system_reset_exception = pSeries_system_reset_exception,
517 	.machine_check_exception = pSeries_machine_check_exception,
518 };
519