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 	if (ROOT_DEV == 0) {
261 		printk("No ramdisk, default root is /dev/sda2\n");
262 		ROOT_DEV = Root_SDA2;
263 	}
264 
265 	fwnmi_init();
266 
267 	/* Find and initialize PCI host bridges */
268 	init_pci_config_tokens();
269 	find_and_init_phbs();
270 	eeh_init();
271 
272 	pSeries_nvram_init();
273 
274 	/* Choose an idle loop */
275 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
276 		vpa_init(boot_cpuid);
277 		if (get_lppaca()->shared_proc) {
278 			printk(KERN_DEBUG "Using shared processor idle loop\n");
279 			ppc_md.power_save = pseries_shared_idle_sleep;
280 		} else {
281 			printk(KERN_DEBUG "Using dedicated idle loop\n");
282 			ppc_md.power_save = pseries_dedicated_idle_sleep;
283 		}
284 	} else {
285 		printk(KERN_DEBUG "Using default idle loop\n");
286 	}
287 
288 	if (firmware_has_feature(FW_FEATURE_LPAR))
289 		ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
290 	else
291 		ppc_md.enable_pmcs = power4_enable_pmcs;
292 }
293 
294 static int __init pSeries_init_panel(void)
295 {
296 	/* Manually leave the kernel version on the panel. */
297 	ppc_md.progress("Linux ppc64\n", 0);
298 	ppc_md.progress(init_utsname()->version, 0);
299 
300 	return 0;
301 }
302 arch_initcall(pSeries_init_panel);
303 
304 static int pseries_set_dabr(unsigned long dabr)
305 {
306 	return plpar_hcall_norets(H_SET_DABR, dabr);
307 }
308 
309 static int pseries_set_xdabr(unsigned long dabr)
310 {
311 	/* We want to catch accesses from kernel and userspace */
312 	return plpar_hcall_norets(H_SET_XDABR, dabr,
313 			H_DABRX_KERNEL | H_DABRX_USER);
314 }
315 
316 /*
317  * Early initialization.  Relocation is on but do not reference unbolted pages
318  */
319 static void __init pSeries_init_early(void)
320 {
321 	DBG(" -> pSeries_init_early()\n");
322 
323 	if (firmware_has_feature(FW_FEATURE_LPAR))
324 		find_udbg_vterm();
325 
326 	if (firmware_has_feature(FW_FEATURE_DABR))
327 		ppc_md.set_dabr = pseries_set_dabr;
328 	else if (firmware_has_feature(FW_FEATURE_XDABR))
329 		ppc_md.set_dabr = pseries_set_xdabr;
330 
331 	iommu_init_early_pSeries();
332 
333 	DBG(" <- pSeries_init_early()\n");
334 }
335 
336 /*
337  * Called very early, MMU is off, device-tree isn't unflattened
338  */
339 
340 static int __init pSeries_probe_hypertas(unsigned long node,
341 					 const char *uname, int depth,
342 					 void *data)
343 {
344 	const char *hypertas;
345 	unsigned long len;
346 
347 	if (depth != 1 ||
348 	    (strcmp(uname, "rtas") != 0 && strcmp(uname, "rtas@0") != 0))
349 		return 0;
350 
351 	hypertas = of_get_flat_dt_prop(node, "ibm,hypertas-functions", &len);
352 	if (!hypertas)
353 		return 1;
354 
355 	powerpc_firmware_features |= FW_FEATURE_LPAR;
356 	fw_feature_init(hypertas, len);
357 
358 	return 1;
359 }
360 
361 static int __init pSeries_probe(void)
362 {
363 	unsigned long root = of_get_flat_dt_root();
364  	char *dtype = of_get_flat_dt_prop(root, "device_type", NULL);
365 
366  	if (dtype == NULL)
367  		return 0;
368  	if (strcmp(dtype, "chrp"))
369 		return 0;
370 
371 	/* Cell blades firmware claims to be chrp while it's not. Until this
372 	 * is fixed, we need to avoid those here.
373 	 */
374 	if (of_flat_dt_is_compatible(root, "IBM,CPBW-1.0") ||
375 	    of_flat_dt_is_compatible(root, "IBM,CBEA"))
376 		return 0;
377 
378 	DBG("pSeries detected, looking for LPAR capability...\n");
379 
380 	/* Now try to figure out if we are running on LPAR */
381 	of_scan_flat_dt(pSeries_probe_hypertas, NULL);
382 
383 	if (firmware_has_feature(FW_FEATURE_LPAR))
384 		hpte_init_lpar();
385 	else
386 		hpte_init_native();
387 
388 	DBG("Machine is%s LPAR !\n",
389 	    (powerpc_firmware_features & FW_FEATURE_LPAR) ? "" : " not");
390 
391 	return 1;
392 }
393 
394 
395 DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
396 
397 static void pseries_dedicated_idle_sleep(void)
398 {
399 	unsigned int cpu = smp_processor_id();
400 	unsigned long start_snooze;
401 
402 	/*
403 	 * Indicate to the HV that we are idle. Now would be
404 	 * a good time to find other work to dispatch.
405 	 */
406 	get_lppaca()->idle = 1;
407 	get_lppaca()->donate_dedicated_cpu = 1;
408 
409 	/*
410 	 * We come in with interrupts disabled, and need_resched()
411 	 * has been checked recently.  If we should poll for a little
412 	 * while, do so.
413 	 */
414 	if (__get_cpu_var(smt_snooze_delay)) {
415 		start_snooze = get_tb() +
416 			__get_cpu_var(smt_snooze_delay) * tb_ticks_per_usec;
417 		local_irq_enable();
418 		set_thread_flag(TIF_POLLING_NRFLAG);
419 
420 		while (get_tb() < start_snooze) {
421 			if (need_resched() || cpu_is_offline(cpu))
422 				goto out;
423 			ppc64_runlatch_off();
424 			HMT_low();
425 			HMT_very_low();
426 		}
427 
428 		HMT_medium();
429 		clear_thread_flag(TIF_POLLING_NRFLAG);
430 		smp_mb();
431 		local_irq_disable();
432 		if (need_resched() || cpu_is_offline(cpu))
433 			goto out;
434 	}
435 
436 	cede_processor();
437 
438 out:
439 	HMT_medium();
440 	get_lppaca()->donate_dedicated_cpu = 0;
441 	get_lppaca()->idle = 0;
442 }
443 
444 static void pseries_shared_idle_sleep(void)
445 {
446 	/*
447 	 * Indicate to the HV that we are idle. Now would be
448 	 * a good time to find other work to dispatch.
449 	 */
450 	get_lppaca()->idle = 1;
451 
452 	/*
453 	 * Yield the processor to the hypervisor.  We return if
454 	 * an external interrupt occurs (which are driven prior
455 	 * to returning here) or if a prod occurs from another
456 	 * processor. When returning here, external interrupts
457 	 * are enabled.
458 	 */
459 	cede_processor();
460 
461 	get_lppaca()->idle = 0;
462 }
463 
464 static int pSeries_pci_probe_mode(struct pci_bus *bus)
465 {
466 	if (firmware_has_feature(FW_FEATURE_LPAR))
467 		return PCI_PROBE_DEVTREE;
468 	return PCI_PROBE_NORMAL;
469 }
470 
471 /**
472  * pSeries_power_off - tell firmware about how to power off the system.
473  *
474  * This function calls either the power-off rtas token in normal cases
475  * or the ibm,power-off-ups token (if present & requested) in case of
476  * a power failure. If power-off token is used, power on will only be
477  * possible with power button press. If ibm,power-off-ups token is used
478  * it will allow auto poweron after power is restored.
479  */
480 void pSeries_power_off(void)
481 {
482 	int rc;
483 	int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");
484 
485 	if (rtas_flash_term_hook)
486 		rtas_flash_term_hook(SYS_POWER_OFF);
487 
488 	if (rtas_poweron_auto == 0 ||
489 		rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
490 		rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
491 		printk(KERN_INFO "RTAS power-off returned %d\n", rc);
492 	} else {
493 		rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
494 		printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
495 	}
496 	for (;;);
497 }
498 
499 #ifndef CONFIG_PCI
500 void pSeries_final_fixup(void) { }
501 #endif
502 
503 define_machine(pseries) {
504 	.name			= "pSeries",
505 	.probe			= pSeries_probe,
506 	.setup_arch		= pSeries_setup_arch,
507 	.init_early		= pSeries_init_early,
508 	.show_cpuinfo		= pSeries_show_cpuinfo,
509 	.log_error		= pSeries_log_error,
510 	.pcibios_fixup		= pSeries_final_fixup,
511 	.pci_probe_mode		= pSeries_pci_probe_mode,
512 	.restart		= rtas_restart,
513 	.power_off		= pSeries_power_off,
514 	.halt			= rtas_halt,
515 	.panic			= rtas_os_term,
516 	.get_boot_time		= rtas_get_boot_time,
517 	.get_rtc_time		= rtas_get_rtc_time,
518 	.set_rtc_time		= rtas_set_rtc_time,
519 	.calibrate_decr		= generic_calibrate_decr,
520 	.progress		= rtas_progress,
521 	.system_reset_exception = pSeries_system_reset_exception,
522 	.machine_check_exception = pSeries_machine_check_exception,
523 };
524