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  1/*
  2 * Author: Andy Fleming <afleming@freescale.com>
  3 * 	   Kumar Gala <galak@kernel.crashing.org>
  4 *
  5 * Copyright 2006-2008, 2011 Freescale Semiconductor Inc.
  6 *
  7 * This program is free software; you can redistribute  it and/or modify it
  8 * under  the terms of  the GNU General  Public License as published by the
  9 * Free Software Foundation;  either version 2 of the  License, or (at your
 10 * option) any later version.
 11 */
 12
 13#include <linux/stddef.h>
 14#include <linux/kernel.h>
 15#include <linux/init.h>
 16#include <linux/delay.h>
 17#include <linux/of.h>
 18#include <linux/kexec.h>
 19#include <linux/highmem.h>
 20
 21#include <asm/machdep.h>
 22#include <asm/pgtable.h>
 23#include <asm/page.h>
 24#include <asm/mpic.h>
 25#include <asm/cacheflush.h>
 26#include <asm/dbell.h>
 27
 28#include <sysdev/fsl_soc.h>
 29#include <sysdev/mpic.h>
 30#include "smp.h"
 31
 32extern void __early_start(void);
 33
 34#define BOOT_ENTRY_ADDR_UPPER	0
 35#define BOOT_ENTRY_ADDR_LOWER	1
 36#define BOOT_ENTRY_R3_UPPER	2
 37#define BOOT_ENTRY_R3_LOWER	3
 38#define BOOT_ENTRY_RESV		4
 39#define BOOT_ENTRY_PIR		5
 40#define BOOT_ENTRY_R6_UPPER	6
 41#define BOOT_ENTRY_R6_LOWER	7
 42#define NUM_BOOT_ENTRY		8
 43#define SIZE_BOOT_ENTRY		(NUM_BOOT_ENTRY * sizeof(u32))
 44
 45static int __init
 46smp_85xx_kick_cpu(int nr)
 47{
 48	unsigned long flags;
 49	const u64 *cpu_rel_addr;
 50	__iomem u32 *bptr_vaddr;
 51	struct device_node *np;
 52	int n = 0, hw_cpu = get_hard_smp_processor_id(nr);
 53	int ioremappable;
 54
 55	WARN_ON(nr < 0 || nr >= NR_CPUS);
 56	WARN_ON(hw_cpu < 0 || hw_cpu >= NR_CPUS);
 57
 58	pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
 59
 60	np = of_get_cpu_node(nr, NULL);
 61	cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
 62
 63	if (cpu_rel_addr == NULL) {
 64		printk(KERN_ERR "No cpu-release-addr for cpu %d\n", nr);
 65		return -ENOENT;
 66	}
 67
 68	/*
 69	 * A secondary core could be in a spinloop in the bootpage
 70	 * (0xfffff000), somewhere in highmem, or somewhere in lowmem.
 71	 * The bootpage and highmem can be accessed via ioremap(), but
 72	 * we need to directly access the spinloop if its in lowmem.
 73	 */
 74	ioremappable = *cpu_rel_addr > virt_to_phys(high_memory);
 75
 76	/* Map the spin table */
 77	if (ioremappable)
 78		bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
 79	else
 80		bptr_vaddr = phys_to_virt(*cpu_rel_addr);
 81
 82	local_irq_save(flags);
 83
 84	out_be32(bptr_vaddr + BOOT_ENTRY_PIR, hw_cpu);
 85#ifdef CONFIG_PPC32
 86	out_be32(bptr_vaddr + BOOT_ENTRY_ADDR_LOWER, __pa(__early_start));
 87
 88	if (!ioremappable)
 89		flush_dcache_range((ulong)bptr_vaddr,
 90				(ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
 91
 92	/* Wait a bit for the CPU to ack. */
 93	while ((__secondary_hold_acknowledge != hw_cpu) && (++n < 1000))
 94		mdelay(1);
 95#else
 96	smp_generic_kick_cpu(nr);
 97
 98	out_be64((u64 *)(bptr_vaddr + BOOT_ENTRY_ADDR_UPPER),
 99		__pa((u64)*((unsigned long long *) generic_secondary_smp_init)));
100
101	if (!ioremappable)
102		flush_dcache_range((ulong)bptr_vaddr,
103				(ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
104#endif
105
106	local_irq_restore(flags);
107
108	if (ioremappable)
109		iounmap(bptr_vaddr);
110
111	pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
112
113	return 0;
114}
115
116struct smp_ops_t smp_85xx_ops = {
117	.kick_cpu = smp_85xx_kick_cpu,
118#ifdef CONFIG_KEXEC
119	.give_timebase	= smp_generic_give_timebase,
120	.take_timebase	= smp_generic_take_timebase,
121#endif
122};
123
124#ifdef CONFIG_KEXEC
125atomic_t kexec_down_cpus = ATOMIC_INIT(0);
126
127void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
128{
129	local_irq_disable();
130
131	if (secondary) {
132		atomic_inc(&kexec_down_cpus);
133		/* loop forever */
134		while (1);
135	}
136}
137
138static void mpc85xx_smp_kexec_down(void *arg)
139{
140	if (ppc_md.kexec_cpu_down)
141		ppc_md.kexec_cpu_down(0,1);
142}
143
144static void map_and_flush(unsigned long paddr)
145{
146	struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
147	unsigned long kaddr  = (unsigned long)kmap(page);
148
149	flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
150	kunmap(page);
151}
152
153/**
154 * Before we reset the other cores, we need to flush relevant cache
155 * out to memory so we don't get anything corrupted, some of these flushes
156 * are performed out of an overabundance of caution as interrupts are not
157 * disabled yet and we can switch cores
158 */
159static void mpc85xx_smp_flush_dcache_kexec(struct kimage *image)
160{
161	kimage_entry_t *ptr, entry;
162	unsigned long paddr;
163	int i;
164
165	if (image->type == KEXEC_TYPE_DEFAULT) {
166		/* normal kexec images are stored in temporary pages */
167		for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
168		     ptr = (entry & IND_INDIRECTION) ?
169				phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
170			if (!(entry & IND_DESTINATION)) {
171				map_and_flush(entry);
172			}
173		}
174		/* flush out last IND_DONE page */
175		map_and_flush(entry);
176	} else {
177		/* crash type kexec images are copied to the crash region */
178		for (i = 0; i < image->nr_segments; i++) {
179			struct kexec_segment *seg = &image->segment[i];
180			for (paddr = seg->mem; paddr < seg->mem + seg->memsz;
181			     paddr += PAGE_SIZE) {
182				map_and_flush(paddr);
183			}
184		}
185	}
186
187	/* also flush the kimage struct to be passed in as well */
188	flush_dcache_range((unsigned long)image,
189			   (unsigned long)image + sizeof(*image));
190}
191
192static void mpc85xx_smp_machine_kexec(struct kimage *image)
193{
194	int timeout = INT_MAX;
195	int i, num_cpus = num_present_cpus();
196
197	mpc85xx_smp_flush_dcache_kexec(image);
198
199	if (image->type == KEXEC_TYPE_DEFAULT)
200		smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);
201
202	while ( (atomic_read(&kexec_down_cpus) != (num_cpus - 1)) &&
203		( timeout > 0 ) )
204	{
205		timeout--;
206	}
207
208	if ( !timeout )
209		printk(KERN_ERR "Unable to bring down secondary cpu(s)");
210
211	for_each_online_cpu(i)
212	{
213		if ( i == smp_processor_id() ) continue;
214		mpic_reset_core(i);
215	}
216
217	default_machine_kexec(image);
218}
219#endif /* CONFIG_KEXEC */
220
221static void __init
222smp_85xx_setup_cpu(int cpu_nr)
223{
224	if (smp_85xx_ops.probe == smp_mpic_probe)
225		mpic_setup_this_cpu();
226
227	if (cpu_has_feature(CPU_FTR_DBELL))
228		doorbell_setup_this_cpu();
229}
230
231void __init mpc85xx_smp_init(void)
232{
233	struct device_node *np;
234
235	smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
236
237	np = of_find_node_by_type(NULL, "open-pic");
238	if (np) {
239		smp_85xx_ops.probe = smp_mpic_probe;
240		smp_85xx_ops.message_pass = smp_mpic_message_pass;
241	}
242
243	if (cpu_has_feature(CPU_FTR_DBELL)) {
244		/*
245		 * If left NULL, .message_pass defaults to
246		 * smp_muxed_ipi_message_pass
247		 */
248		smp_85xx_ops.message_pass = NULL;
249		smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
250	}
251
252	smp_ops = &smp_85xx_ops;
253
254#ifdef CONFIG_KEXEC
255	ppc_md.kexec_cpu_down = mpc85xx_smp_kexec_cpu_down;
256	ppc_md.machine_kexec = mpc85xx_smp_machine_kexec;
257#endif
258}