xref: /openbmc/linux/arch/powerpc/platforms/85xx/smp.c (revision cff4fa84)
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 
31 extern void __early_start(void);
32 
33 #define BOOT_ENTRY_ADDR_UPPER	0
34 #define BOOT_ENTRY_ADDR_LOWER	1
35 #define BOOT_ENTRY_R3_UPPER	2
36 #define BOOT_ENTRY_R3_LOWER	3
37 #define BOOT_ENTRY_RESV		4
38 #define BOOT_ENTRY_PIR		5
39 #define BOOT_ENTRY_R6_UPPER	6
40 #define BOOT_ENTRY_R6_LOWER	7
41 #define NUM_BOOT_ENTRY		8
42 #define SIZE_BOOT_ENTRY		(NUM_BOOT_ENTRY * sizeof(u32))
43 
44 static int __init
45 smp_85xx_kick_cpu(int nr)
46 {
47 	unsigned long flags;
48 	const u64 *cpu_rel_addr;
49 	__iomem u32 *bptr_vaddr;
50 	struct device_node *np;
51 	int n = 0;
52 	int ioremappable;
53 
54 	WARN_ON (nr < 0 || nr >= NR_CPUS);
55 
56 	pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
57 
58 	np = of_get_cpu_node(nr, NULL);
59 	cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
60 
61 	if (cpu_rel_addr == NULL) {
62 		printk(KERN_ERR "No cpu-release-addr for cpu %d\n", nr);
63 		return -ENOENT;
64 	}
65 
66 	/*
67 	 * A secondary core could be in a spinloop in the bootpage
68 	 * (0xfffff000), somewhere in highmem, or somewhere in lowmem.
69 	 * The bootpage and highmem can be accessed via ioremap(), but
70 	 * we need to directly access the spinloop if its in lowmem.
71 	 */
72 	ioremappable = *cpu_rel_addr > virt_to_phys(high_memory);
73 
74 	/* Map the spin table */
75 	if (ioremappable)
76 		bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
77 	else
78 		bptr_vaddr = phys_to_virt(*cpu_rel_addr);
79 
80 	local_irq_save(flags);
81 
82 	out_be32(bptr_vaddr + BOOT_ENTRY_PIR, nr);
83 #ifdef CONFIG_PPC32
84 	out_be32(bptr_vaddr + BOOT_ENTRY_ADDR_LOWER, __pa(__early_start));
85 
86 	if (!ioremappable)
87 		flush_dcache_range((ulong)bptr_vaddr,
88 				(ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
89 
90 	/* Wait a bit for the CPU to ack. */
91 	while ((__secondary_hold_acknowledge != nr) && (++n < 1000))
92 		mdelay(1);
93 #else
94 	smp_generic_kick_cpu(nr);
95 
96 	out_be64((u64 *)(bptr_vaddr + BOOT_ENTRY_ADDR_UPPER),
97 		__pa((u64)*((unsigned long long *) generic_secondary_smp_init)));
98 
99 	if (!ioremappable)
100 		flush_dcache_range((ulong)bptr_vaddr,
101 				(ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
102 #endif
103 
104 	local_irq_restore(flags);
105 
106 	if (ioremappable)
107 		iounmap(bptr_vaddr);
108 
109 	pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
110 
111 	return 0;
112 }
113 
114 struct smp_ops_t smp_85xx_ops = {
115 	.kick_cpu = smp_85xx_kick_cpu,
116 #ifdef CONFIG_KEXEC
117 	.give_timebase	= smp_generic_give_timebase,
118 	.take_timebase	= smp_generic_take_timebase,
119 #endif
120 };
121 
122 #ifdef CONFIG_KEXEC
123 atomic_t kexec_down_cpus = ATOMIC_INIT(0);
124 
125 void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
126 {
127 	local_irq_disable();
128 
129 	if (secondary) {
130 		atomic_inc(&kexec_down_cpus);
131 		/* loop forever */
132 		while (1);
133 	}
134 }
135 
136 static void mpc85xx_smp_kexec_down(void *arg)
137 {
138 	if (ppc_md.kexec_cpu_down)
139 		ppc_md.kexec_cpu_down(0,1);
140 }
141 
142 static void map_and_flush(unsigned long paddr)
143 {
144 	struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
145 	unsigned long kaddr  = (unsigned long)kmap(page);
146 
147 	flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
148 	kunmap(page);
149 }
150 
151 /**
152  * Before we reset the other cores, we need to flush relevant cache
153  * out to memory so we don't get anything corrupted, some of these flushes
154  * are performed out of an overabundance of caution as interrupts are not
155  * disabled yet and we can switch cores
156  */
157 static void mpc85xx_smp_flush_dcache_kexec(struct kimage *image)
158 {
159 	kimage_entry_t *ptr, entry;
160 	unsigned long paddr;
161 	int i;
162 
163 	if (image->type == KEXEC_TYPE_DEFAULT) {
164 		/* normal kexec images are stored in temporary pages */
165 		for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
166 		     ptr = (entry & IND_INDIRECTION) ?
167 				phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
168 			if (!(entry & IND_DESTINATION)) {
169 				map_and_flush(entry);
170 			}
171 		}
172 		/* flush out last IND_DONE page */
173 		map_and_flush(entry);
174 	} else {
175 		/* crash type kexec images are copied to the crash region */
176 		for (i = 0; i < image->nr_segments; i++) {
177 			struct kexec_segment *seg = &image->segment[i];
178 			for (paddr = seg->mem; paddr < seg->mem + seg->memsz;
179 			     paddr += PAGE_SIZE) {
180 				map_and_flush(paddr);
181 			}
182 		}
183 	}
184 
185 	/* also flush the kimage struct to be passed in as well */
186 	flush_dcache_range((unsigned long)image,
187 			   (unsigned long)image + sizeof(*image));
188 }
189 
190 static void mpc85xx_smp_machine_kexec(struct kimage *image)
191 {
192 	int timeout = INT_MAX;
193 	int i, num_cpus = num_present_cpus();
194 
195 	mpc85xx_smp_flush_dcache_kexec(image);
196 
197 	if (image->type == KEXEC_TYPE_DEFAULT)
198 		smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);
199 
200 	while ( (atomic_read(&kexec_down_cpus) != (num_cpus - 1)) &&
201 		( timeout > 0 ) )
202 	{
203 		timeout--;
204 	}
205 
206 	if ( !timeout )
207 		printk(KERN_ERR "Unable to bring down secondary cpu(s)");
208 
209 	for (i = 0; i < num_cpus; i++)
210 	{
211 		if ( i == smp_processor_id() ) continue;
212 		mpic_reset_core(i);
213 	}
214 
215 	default_machine_kexec(image);
216 }
217 #endif /* CONFIG_KEXEC */
218 
219 static void __init
220 smp_85xx_setup_cpu(int cpu_nr)
221 {
222 	if (smp_85xx_ops.probe == smp_mpic_probe)
223 		mpic_setup_this_cpu();
224 
225 	if (cpu_has_feature(CPU_FTR_DBELL))
226 		doorbell_setup_this_cpu();
227 }
228 
229 void __init mpc85xx_smp_init(void)
230 {
231 	struct device_node *np;
232 
233 	smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
234 
235 	np = of_find_node_by_type(NULL, "open-pic");
236 	if (np) {
237 		smp_85xx_ops.probe = smp_mpic_probe;
238 		smp_85xx_ops.message_pass = smp_mpic_message_pass;
239 	}
240 
241 	if (cpu_has_feature(CPU_FTR_DBELL)) {
242 		/*
243 		 * If left NULL, .message_pass defaults to
244 		 * smp_muxed_ipi_message_pass
245 		 */
246 		smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
247 	}
248 
249 	smp_ops = &smp_85xx_ops;
250 
251 #ifdef CONFIG_KEXEC
252 	ppc_md.kexec_cpu_down = mpc85xx_smp_kexec_cpu_down;
253 	ppc_md.machine_kexec = mpc85xx_smp_machine_kexec;
254 #endif
255 }
256