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 #include <linux/cpu.h>
20 #include <linux/errno.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/stddef.h>
25 #include <linux/unistd.h>
26 #include <linux/slab.h>
27 #include <linux/user.h>
28 #include <linux/a.out.h>
29 #include <linux/tty.h>
30 #include <linux/major.h>
31 #include <linux/interrupt.h>
32 #include <linux/reboot.h>
33 #include <linux/init.h>
34 #include <linux/ioport.h>
35 #include <linux/console.h>
36 #include <linux/pci.h>
37 #include <linux/utsname.h>
38 #include <linux/adb.h>
39 #include <linux/module.h>
40 #include <linux/delay.h>
41 #include <linux/irq.h>
42 #include <linux/seq_file.h>
43 #include <linux/root_dev.h>
44 
45 #include <asm/mmu.h>
46 #include <asm/processor.h>
47 #include <asm/io.h>
48 #include <asm/pgtable.h>
49 #include <asm/prom.h>
50 #include <asm/rtas.h>
51 #include <asm/pci-bridge.h>
52 #include <asm/iommu.h>
53 #include <asm/dma.h>
54 #include <asm/machdep.h>
55 #include <asm/irq.h>
56 #include <asm/time.h>
57 #include <asm/nvram.h>
58 #include "xics.h"
59 #include <asm/pmc.h>
60 #include <asm/mpic.h>
61 #include <asm/ppc-pci.h>
62 #include <asm/i8259.h>
63 #include <asm/udbg.h>
64 #include <asm/smp.h>
65 #include <asm/firmware.h>
66 #include <asm/eeh.h>
67 
68 #include "plpar_wrappers.h"
69 #include "pseries.h"
70 
71 
72 int fwnmi_active;  /* TRUE if an FWNMI handler is present */
73 
74 static void pseries_shared_idle_sleep(void);
75 static void pseries_dedicated_idle_sleep(void);
76 
77 static struct device_node *pSeries_mpic_node;
78 
79 static void pSeries_show_cpuinfo(struct seq_file *m)
80 {
81 	struct device_node *root;
82 	const char *model = "";
83 
84 	root = of_find_node_by_path("/");
85 	if (root)
86 		model = of_get_property(root, "model", NULL);
87 	seq_printf(m, "machine\t\t: CHRP %s\n", model);
88 	of_node_put(root);
89 }
90 
91 /* Initialize firmware assisted non-maskable interrupts if
92  * the firmware supports this feature.
93  */
94 static void __init fwnmi_init(void)
95 {
96 	unsigned long system_reset_addr, machine_check_addr;
97 
98 	int ibm_nmi_register = rtas_token("ibm,nmi-register");
99 	if (ibm_nmi_register == RTAS_UNKNOWN_SERVICE)
100 		return;
101 
102 	/* If the kernel's not linked at zero we point the firmware at low
103 	 * addresses anyway, and use a trampoline to get to the real code. */
104 	system_reset_addr  = __pa(system_reset_fwnmi) - PHYSICAL_START;
105 	machine_check_addr = __pa(machine_check_fwnmi) - PHYSICAL_START;
106 
107 	if (0 == rtas_call(ibm_nmi_register, 2, 1, NULL, system_reset_addr,
108 				machine_check_addr))
109 		fwnmi_active = 1;
110 }
111 
112 static void pseries_8259_cascade(unsigned int irq, struct irq_desc *desc)
113 {
114 	unsigned int cascade_irq = i8259_irq();
115 	if (cascade_irq != NO_IRQ)
116 		generic_handle_irq(cascade_irq);
117 	desc->chip->eoi(irq);
118 }
119 
120 static void __init pseries_setup_i8259_cascade(void)
121 {
122 	struct device_node *np, *old, *found = NULL;
123 	unsigned int cascade;
124 	const u32 *addrp;
125 	unsigned long intack = 0;
126 	int naddr;
127 
128 	for_each_node_by_type(np, "interrupt-controller") {
129 		if (of_device_is_compatible(np, "chrp,iic")) {
130 			found = np;
131 			break;
132 		}
133 	}
134 
135 	if (found == NULL) {
136 		printk(KERN_DEBUG "pic: no ISA interrupt controller\n");
137 		return;
138 	}
139 
140 	cascade = irq_of_parse_and_map(found, 0);
141 	if (cascade == NO_IRQ) {
142 		printk(KERN_ERR "pic: failed to map cascade interrupt");
143 		return;
144 	}
145 	pr_debug("pic: cascade mapped to irq %d\n", cascade);
146 
147 	for (old = of_node_get(found); old != NULL ; old = np) {
148 		np = of_get_parent(old);
149 		of_node_put(old);
150 		if (np == NULL)
151 			break;
152 		if (strcmp(np->name, "pci") != 0)
153 			continue;
154 		addrp = of_get_property(np, "8259-interrupt-acknowledge", NULL);
155 		if (addrp == NULL)
156 			continue;
157 		naddr = of_n_addr_cells(np);
158 		intack = addrp[naddr-1];
159 		if (naddr > 1)
160 			intack |= ((unsigned long)addrp[naddr-2]) << 32;
161 	}
162 	if (intack)
163 		printk(KERN_DEBUG "pic: PCI 8259 intack at 0x%016lx\n", intack);
164 	i8259_init(found, intack);
165 	of_node_put(found);
166 	set_irq_chained_handler(cascade, pseries_8259_cascade);
167 }
168 
169 static void __init pseries_mpic_init_IRQ(void)
170 {
171 	struct device_node *np;
172 	const unsigned int *opprop;
173 	unsigned long openpic_addr = 0;
174 	int naddr, n, i, opplen;
175 	struct mpic *mpic;
176 
177 	np = of_find_node_by_path("/");
178 	naddr = of_n_addr_cells(np);
179 	opprop = of_get_property(np, "platform-open-pic", &opplen);
180 	if (opprop != 0) {
181 		openpic_addr = of_read_number(opprop, naddr);
182 		printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
183 	}
184 	of_node_put(np);
185 
186 	BUG_ON(openpic_addr == 0);
187 
188 	/* Setup the openpic driver */
189 	mpic = mpic_alloc(pSeries_mpic_node, openpic_addr,
190 			  MPIC_PRIMARY,
191 			  16, 250, /* isu size, irq count */
192 			  " MPIC     ");
193 	BUG_ON(mpic == NULL);
194 
195 	/* Add ISUs */
196 	opplen /= sizeof(u32);
197 	for (n = 0, i = naddr; i < opplen; i += naddr, n++) {
198 		unsigned long isuaddr = of_read_number(opprop + i, naddr);
199 		mpic_assign_isu(mpic, n, isuaddr);
200 	}
201 
202 	/* All ISUs are setup, complete initialization */
203 	mpic_init(mpic);
204 
205 	/* Look for cascade */
206 	pseries_setup_i8259_cascade();
207 }
208 
209 static void __init pseries_xics_init_IRQ(void)
210 {
211 	xics_init_IRQ();
212 	pseries_setup_i8259_cascade();
213 }
214 
215 static void pseries_lpar_enable_pmcs(void)
216 {
217 	unsigned long set, reset;
218 
219 	set = 1UL << 63;
220 	reset = 0;
221 	plpar_hcall_norets(H_PERFMON, set, reset);
222 
223 	/* instruct hypervisor to maintain PMCs */
224 	if (firmware_has_feature(FW_FEATURE_SPLPAR))
225 		get_lppaca()->pmcregs_in_use = 1;
226 }
227 
228 static void __init pseries_discover_pic(void)
229 {
230 	struct device_node *np;
231 	const char *typep;
232 
233 	for (np = NULL; (np = of_find_node_by_name(np,
234 						   "interrupt-controller"));) {
235 		typep = of_get_property(np, "compatible", NULL);
236 		if (strstr(typep, "open-pic")) {
237 			pSeries_mpic_node = of_node_get(np);
238 			ppc_md.init_IRQ       = pseries_mpic_init_IRQ;
239 			ppc_md.get_irq        = mpic_get_irq;
240 			setup_kexec_cpu_down_mpic();
241 			smp_init_pseries_mpic();
242 			return;
243 		} else if (strstr(typep, "ppc-xicp")) {
244 			ppc_md.init_IRQ       = pseries_xics_init_IRQ;
245 			setup_kexec_cpu_down_xics();
246 			smp_init_pseries_xics();
247 			return;
248 		}
249 	}
250 	printk(KERN_ERR "pSeries_discover_pic: failed to recognize"
251 	       " interrupt-controller\n");
252 }
253 
254 static void __init pSeries_setup_arch(void)
255 {
256 	/* Discover PIC type and setup ppc_md accordingly */
257 	pseries_discover_pic();
258 
259 	/* openpic global configuration register (64-bit format). */
260 	/* openpic Interrupt Source Unit pointer (64-bit format). */
261 	/* python0 facility area (mmio) (64-bit format) REAL address. */
262 
263 	/* init to some ~sane value until calibrate_delay() runs */
264 	loops_per_jiffy = 50000000;
265 
266 	fwnmi_init();
267 
268 	/* Find and initialize PCI host bridges */
269 	init_pci_config_tokens();
270 	find_and_init_phbs();
271 	eeh_init();
272 
273 	pSeries_nvram_init();
274 
275 	/* Choose an idle loop */
276 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
277 		vpa_init(boot_cpuid);
278 		if (get_lppaca()->shared_proc) {
279 			printk(KERN_DEBUG "Using shared processor idle loop\n");
280 			ppc_md.power_save = pseries_shared_idle_sleep;
281 		} else {
282 			printk(KERN_DEBUG "Using dedicated idle loop\n");
283 			ppc_md.power_save = pseries_dedicated_idle_sleep;
284 		}
285 	} else {
286 		printk(KERN_DEBUG "Using default idle loop\n");
287 	}
288 
289 	if (firmware_has_feature(FW_FEATURE_LPAR))
290 		ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
291 	else
292 		ppc_md.enable_pmcs = power4_enable_pmcs;
293 }
294 
295 static int __init pSeries_init_panel(void)
296 {
297 	/* Manually leave the kernel version on the panel. */
298 	ppc_md.progress("Linux ppc64\n", 0);
299 	ppc_md.progress(init_utsname()->version, 0);
300 
301 	return 0;
302 }
303 arch_initcall(pSeries_init_panel);
304 
305 static int pseries_set_dabr(unsigned long dabr)
306 {
307 	return plpar_hcall_norets(H_SET_DABR, dabr);
308 }
309 
310 static int pseries_set_xdabr(unsigned long dabr)
311 {
312 	/* We want to catch accesses from kernel and userspace */
313 	return plpar_hcall_norets(H_SET_XDABR, dabr,
314 			H_DABRX_KERNEL | H_DABRX_USER);
315 }
316 
317 /*
318  * Early initialization.  Relocation is on but do not reference unbolted pages
319  */
320 static void __init pSeries_init_early(void)
321 {
322 	pr_debug(" -> pSeries_init_early()\n");
323 
324 	if (firmware_has_feature(FW_FEATURE_LPAR))
325 		find_udbg_vterm();
326 
327 	if (firmware_has_feature(FW_FEATURE_DABR))
328 		ppc_md.set_dabr = pseries_set_dabr;
329 	else if (firmware_has_feature(FW_FEATURE_XDABR))
330 		ppc_md.set_dabr = pseries_set_xdabr;
331 
332 	iommu_init_early_pSeries();
333 
334 	pr_debug(" <- pSeries_init_early()\n");
335 }
336 
337 /*
338  * Called very early, MMU is off, device-tree isn't unflattened
339  */
340 
341 static int __init pSeries_probe_hypertas(unsigned long node,
342 					 const char *uname, int depth,
343 					 void *data)
344 {
345 	const char *hypertas;
346 	unsigned long len;
347 
348 	if (depth != 1 ||
349 	    (strcmp(uname, "rtas") != 0 && strcmp(uname, "rtas@0") != 0))
350 		return 0;
351 
352 	hypertas = of_get_flat_dt_prop(node, "ibm,hypertas-functions", &len);
353 	if (!hypertas)
354 		return 1;
355 
356 	powerpc_firmware_features |= FW_FEATURE_LPAR;
357 	fw_feature_init(hypertas, len);
358 
359 	return 1;
360 }
361 
362 static int __init pSeries_probe(void)
363 {
364 	unsigned long root = of_get_flat_dt_root();
365  	char *dtype = of_get_flat_dt_prop(root, "device_type", NULL);
366 
367  	if (dtype == NULL)
368  		return 0;
369  	if (strcmp(dtype, "chrp"))
370 		return 0;
371 
372 	/* Cell blades firmware claims to be chrp while it's not. Until this
373 	 * is fixed, we need to avoid those here.
374 	 */
375 	if (of_flat_dt_is_compatible(root, "IBM,CPBW-1.0") ||
376 	    of_flat_dt_is_compatible(root, "IBM,CBEA"))
377 		return 0;
378 
379 	pr_debug("pSeries detected, looking for LPAR capability...\n");
380 
381 	/* Now try to figure out if we are running on LPAR */
382 	of_scan_flat_dt(pSeries_probe_hypertas, NULL);
383 
384 	if (firmware_has_feature(FW_FEATURE_LPAR))
385 		hpte_init_lpar();
386 	else
387 		hpte_init_native();
388 
389 	pr_debug("Machine is%s LPAR !\n",
390 	         (powerpc_firmware_features & FW_FEATURE_LPAR) ? "" : " not");
391 
392 	return 1;
393 }
394 
395 
396 DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
397 
398 static void pseries_dedicated_idle_sleep(void)
399 {
400 	unsigned int cpu = smp_processor_id();
401 	unsigned long start_snooze;
402 	unsigned long in_purr, out_purr;
403 
404 	/*
405 	 * Indicate to the HV that we are idle. Now would be
406 	 * a good time to find other work to dispatch.
407 	 */
408 	get_lppaca()->idle = 1;
409 	get_lppaca()->donate_dedicated_cpu = 1;
410 	in_purr = mfspr(SPRN_PURR);
411 
412 	/*
413 	 * We come in with interrupts disabled, and need_resched()
414 	 * has been checked recently.  If we should poll for a little
415 	 * while, do so.
416 	 */
417 	if (__get_cpu_var(smt_snooze_delay)) {
418 		start_snooze = get_tb() +
419 			__get_cpu_var(smt_snooze_delay) * tb_ticks_per_usec;
420 		local_irq_enable();
421 		set_thread_flag(TIF_POLLING_NRFLAG);
422 
423 		while (get_tb() < start_snooze) {
424 			if (need_resched() || cpu_is_offline(cpu))
425 				goto out;
426 			ppc64_runlatch_off();
427 			HMT_low();
428 			HMT_very_low();
429 		}
430 
431 		HMT_medium();
432 		clear_thread_flag(TIF_POLLING_NRFLAG);
433 		smp_mb();
434 		local_irq_disable();
435 		if (need_resched() || cpu_is_offline(cpu))
436 			goto out;
437 	}
438 
439 	cede_processor();
440 
441 out:
442 	HMT_medium();
443 	out_purr = mfspr(SPRN_PURR);
444 	get_lppaca()->wait_state_cycles += out_purr - in_purr;
445 	get_lppaca()->donate_dedicated_cpu = 0;
446 	get_lppaca()->idle = 0;
447 }
448 
449 static void pseries_shared_idle_sleep(void)
450 {
451 	/*
452 	 * Indicate to the HV that we are idle. Now would be
453 	 * a good time to find other work to dispatch.
454 	 */
455 	get_lppaca()->idle = 1;
456 
457 	/*
458 	 * Yield the processor to the hypervisor.  We return if
459 	 * an external interrupt occurs (which are driven prior
460 	 * to returning here) or if a prod occurs from another
461 	 * processor. When returning here, external interrupts
462 	 * are enabled.
463 	 */
464 	cede_processor();
465 
466 	get_lppaca()->idle = 0;
467 }
468 
469 static int pSeries_pci_probe_mode(struct pci_bus *bus)
470 {
471 	if (firmware_has_feature(FW_FEATURE_LPAR))
472 		return PCI_PROBE_DEVTREE;
473 	return PCI_PROBE_NORMAL;
474 }
475 
476 /**
477  * pSeries_power_off - tell firmware about how to power off the system.
478  *
479  * This function calls either the power-off rtas token in normal cases
480  * or the ibm,power-off-ups token (if present & requested) in case of
481  * a power failure. If power-off token is used, power on will only be
482  * possible with power button press. If ibm,power-off-ups token is used
483  * it will allow auto poweron after power is restored.
484  */
485 static void pSeries_power_off(void)
486 {
487 	int rc;
488 	int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");
489 
490 	if (rtas_flash_term_hook)
491 		rtas_flash_term_hook(SYS_POWER_OFF);
492 
493 	if (rtas_poweron_auto == 0 ||
494 		rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
495 		rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
496 		printk(KERN_INFO "RTAS power-off returned %d\n", rc);
497 	} else {
498 		rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
499 		printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
500 	}
501 	for (;;);
502 }
503 
504 #ifndef CONFIG_PCI
505 void pSeries_final_fixup(void) { }
506 #endif
507 
508 define_machine(pseries) {
509 	.name			= "pSeries",
510 	.probe			= pSeries_probe,
511 	.setup_arch		= pSeries_setup_arch,
512 	.init_early		= pSeries_init_early,
513 	.show_cpuinfo		= pSeries_show_cpuinfo,
514 	.log_error		= pSeries_log_error,
515 	.pcibios_fixup		= pSeries_final_fixup,
516 	.pci_probe_mode		= pSeries_pci_probe_mode,
517 	.restart		= rtas_restart,
518 	.power_off		= pSeries_power_off,
519 	.halt			= rtas_halt,
520 	.panic			= rtas_os_term,
521 	.get_boot_time		= rtas_get_boot_time,
522 	.get_rtc_time		= rtas_get_rtc_time,
523 	.set_rtc_time		= rtas_set_rtc_time,
524 	.calibrate_decr		= generic_calibrate_decr,
525 	.progress		= rtas_progress,
526 	.system_reset_exception = pSeries_system_reset_exception,
527 	.machine_check_exception = pSeries_machine_check_exception,
528 };
529