arch/powerpc/platforms/85xx/smp.c

   1 /*
   2  * Author: Andy Fleming <afleming@freescale.com>
   3  *         Kumar Gala <galak@kernel.crashing.org>
   4  *
   5  * Copyright 2006-2008 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 static void __init
 115 smp_85xx_setup_cpu(int cpu_nr)
 116 {
 117         mpic_setup_this_cpu();
 118         if (cpu_has_feature(CPU_FTR_DBELL))
 119                 doorbell_setup_this_cpu();
 120 }
 121
 122 struct smp_ops_t smp_85xx_ops = {
 123         .kick_cpu = smp_85xx_kick_cpu,
 124 #ifdef CONFIG_KEXEC
 125         .give_timebase  = smp_generic_give_timebase,
 126         .take_timebase  = smp_generic_take_timebase,
 127 #endif
 128 };
 129
 130 #ifdef CONFIG_KEXEC
 131 atomic_t kexec_down_cpus = ATOMIC_INIT(0);
 132
 133 void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
 134 {
 135         local_irq_disable();
 136
 137         if (secondary) {
 138                 atomic_inc(&kexec_down_cpus);
 139                 /* loop forever */
 140                 while (1);
 141         }
 142 }
 143
 144 static void mpc85xx_smp_kexec_down(void *arg)
 145 {
 146         if (ppc_md.kexec_cpu_down)
 147                 ppc_md.kexec_cpu_down(0,1);
 148 }
 149
 150 static void map_and_flush(unsigned long paddr)
 151 {
 152         struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
 153         unsigned long kaddr  = (unsigned long)kmap(page);
 154
 155         flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
 156         kunmap(page);
 157 }
 158
 159 /**
 160  * Before we reset the other cores, we need to flush relevant cache
 161  * out to memory so we don't get anything corrupted, some of these flushes
 162  * are performed out of an overabundance of caution as interrupts are not
 163  * disabled yet and we can switch cores
 164  */
 165 static void mpc85xx_smp_flush_dcache_kexec(struct kimage *image)
 166 {
 167         kimage_entry_t *ptr, entry;
 168         unsigned long paddr;
 169         int i;
 170
 171         if (image->type == KEXEC_TYPE_DEFAULT) {
 172                 /* normal kexec images are stored in temporary pages */
 173                 for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
 174                      ptr = (entry & IND_INDIRECTION) ?
 175                                 phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
 176                         if (!(entry & IND_DESTINATION)) {
 177                                 map_and_flush(entry);
 178                         }
 179                 }
 180                 /* flush out last IND_DONE page */
 181                 map_and_flush(entry);
 182         } else {
 183                 /* crash type kexec images are copied to the crash region */
 184                 for (i = 0; i < image->nr_segments; i++) {
 185                         struct kexec_segment *seg = &image->segment[i];
 186                         for (paddr = seg->mem; paddr < seg->mem + seg->memsz;
 187                              paddr += PAGE_SIZE) {
 188                                 map_and_flush(paddr);
 189                         }
 190                 }
 191         }
 192
 193         /* also flush the kimage struct to be passed in as well */
 194         flush_dcache_range((unsigned long)image,
 195                            (unsigned long)image + sizeof(*image));
 196 }
 197
 198 static void mpc85xx_smp_machine_kexec(struct kimage *image)
 199 {
 200         int timeout = INT_MAX;
 201         int i, num_cpus = num_present_cpus();
 202
 203         mpc85xx_smp_flush_dcache_kexec(image);
 204
 205         if (image->type == KEXEC_TYPE_DEFAULT)
 206                 smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);
 207
 208         while ( (atomic_read(&kexec_down_cpus) != (num_cpus - 1)) &&
 209                 ( timeout > 0 ) )
 210         {
 211                 timeout--;
 212         }
 213
 214         if ( !timeout )
 215                 printk(KERN_ERR "Unable to bring down secondary cpu(s)");
 216
 217         for (i = 0; i < num_cpus; i++)
 218         {
 219                 if ( i == smp_processor_id() ) continue;
 220                 mpic_reset_core(i);
 221         }
 222
 223         default_machine_kexec(image);
 224 }
 225 #endif /* CONFIG_KEXEC */
 226
 227 void __init mpc85xx_smp_init(void)
 228 {
 229         struct device_node *np;
 230
 231         np = of_find_node_by_type(NULL, "open-pic");
 232         if (np) {
 233                 smp_85xx_ops.probe = smp_mpic_probe;
 234                 smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
 235                 smp_85xx_ops.message_pass = smp_mpic_message_pass;
 236         }
 237
 238         if (cpu_has_feature(CPU_FTR_DBELL)) {
 239                 smp_85xx_ops.message_pass = smp_muxed_ipi_message_pass;
 240                 smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
 241         }
 242
 243         BUG_ON(!smp_85xx_ops.message_pass);
 244
 245         smp_ops = &smp_85xx_ops;
 246
 247 #ifdef CONFIG_KEXEC
 248         ppc_md.kexec_cpu_down = mpc85xx_smp_kexec_cpu_down;
 249         ppc_md.machine_kexec = mpc85xx_smp_machine_kexec;
 250 #endif
 251 }