linux/arch/powerpc/kernel/setup_32.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Common prep/pmac/chrp boot and setup code.
   4 */
   5
   6#include <linux/module.h>
   7#include <linux/string.h>
   8#include <linux/sched.h>
   9#include <linux/init.h>
  10#include <linux/kernel.h>
  11#include <linux/reboot.h>
  12#include <linux/delay.h>
  13#include <linux/initrd.h>
  14#include <linux/tty.h>
  15#include <linux/seq_file.h>
  16#include <linux/root_dev.h>
  17#include <linux/cpu.h>
  18#include <linux/console.h>
  19#include <linux/memblock.h>
  20#include <linux/export.h>
  21#include <linux/nvram.h>
  22#include <linux/pgtable.h>
  23
  24#include <asm/io.h>
  25#include <asm/prom.h>
  26#include <asm/processor.h>
  27#include <asm/setup.h>
  28#include <asm/smp.h>
  29#include <asm/elf.h>
  30#include <asm/cputable.h>
  31#include <asm/bootx.h>
  32#include <asm/btext.h>
  33#include <asm/machdep.h>
  34#include <linux/uaccess.h>
  35#include <asm/pmac_feature.h>
  36#include <asm/sections.h>
  37#include <asm/nvram.h>
  38#include <asm/xmon.h>
  39#include <asm/time.h>
  40#include <asm/serial.h>
  41#include <asm/udbg.h>
  42#include <asm/code-patching.h>
  43#include <asm/cpu_has_feature.h>
  44#include <asm/asm-prototypes.h>
  45#include <asm/kdump.h>
  46#include <asm/feature-fixups.h>
  47#include <asm/early_ioremap.h>
  48
  49#include "setup.h"
  50
  51#define DBG(fmt...)
  52
  53extern void bootx_init(unsigned long r4, unsigned long phys);
  54
  55int boot_cpuid_phys;
  56EXPORT_SYMBOL_GPL(boot_cpuid_phys);
  57
  58int smp_hw_index[NR_CPUS];
  59EXPORT_SYMBOL(smp_hw_index);
  60
  61unsigned int DMA_MODE_READ;
  62unsigned int DMA_MODE_WRITE;
  63
  64EXPORT_SYMBOL(DMA_MODE_READ);
  65EXPORT_SYMBOL(DMA_MODE_WRITE);
  66
  67/*
  68 * This is run before start_kernel(), the kernel has been relocated
  69 * and we are running with enough of the MMU enabled to have our
  70 * proper kernel virtual addresses
  71 *
  72 * We do the initial parsing of the flat device-tree and prepares
  73 * for the MMU to be fully initialized.
  74 */
  75notrace void __init machine_init(u64 dt_ptr)
  76{
  77        u32 *addr = (u32 *)patch_site_addr(&patch__memset_nocache);
  78        struct ppc_inst insn;
  79
  80        /* Configure static keys first, now that we're relocated. */
  81        setup_feature_keys();
  82
  83        early_ioremap_init();
  84
  85        /* Enable early debugging if any specified (see udbg.h) */
  86        udbg_early_init();
  87
  88        patch_instruction_site(&patch__memcpy_nocache, ppc_inst(PPC_RAW_NOP()));
  89
  90        create_cond_branch(&insn, addr, branch_target(addr), 0x820000);
  91        patch_instruction(addr, insn);  /* replace b by bne cr0 */
  92
  93        /* Do some early initialization based on the flat device tree */
  94        early_init_devtree(__va(dt_ptr));
  95
  96        early_init_mmu();
  97
  98        setup_kdump_trampoline();
  99}
 100
 101/* Checks "l2cr=xxxx" command-line option */
 102static int __init ppc_setup_l2cr(char *str)
 103{
 104        if (cpu_has_feature(CPU_FTR_L2CR)) {
 105                unsigned long val = simple_strtoul(str, NULL, 0);
 106                printk(KERN_INFO "l2cr set to %lx\n", val);
 107                _set_L2CR(0);           /* force invalidate by disable cache */
 108                _set_L2CR(val);         /* and enable it */
 109        }
 110        return 1;
 111}
 112__setup("l2cr=", ppc_setup_l2cr);
 113
 114/* Checks "l3cr=xxxx" command-line option */
 115static int __init ppc_setup_l3cr(char *str)
 116{
 117        if (cpu_has_feature(CPU_FTR_L3CR)) {
 118                unsigned long val = simple_strtoul(str, NULL, 0);
 119                printk(KERN_INFO "l3cr set to %lx\n", val);
 120                _set_L3CR(val);         /* and enable it */
 121        }
 122        return 1;
 123}
 124__setup("l3cr=", ppc_setup_l3cr);
 125
 126static int __init ppc_init(void)
 127{
 128        /* clear the progress line */
 129        if (ppc_md.progress)
 130                ppc_md.progress("             ", 0xffff);
 131
 132        /* call platform init */
 133        if (ppc_md.init != NULL) {
 134                ppc_md.init();
 135        }
 136        return 0;
 137}
 138arch_initcall(ppc_init);
 139
 140static void *__init alloc_stack(void)
 141{
 142        void *ptr = memblock_alloc(THREAD_SIZE, THREAD_ALIGN);
 143
 144        if (!ptr)
 145                panic("cannot allocate %d bytes for stack at %pS\n",
 146                      THREAD_SIZE, (void *)_RET_IP_);
 147
 148        return ptr;
 149}
 150
 151void __init irqstack_early_init(void)
 152{
 153        unsigned int i;
 154
 155        if (IS_ENABLED(CONFIG_VMAP_STACK))
 156                return;
 157
 158        /* interrupt stacks must be in lowmem, we get that for free on ppc32
 159         * as the memblock is limited to lowmem by default */
 160        for_each_possible_cpu(i) {
 161                softirq_ctx[i] = alloc_stack();
 162                hardirq_ctx[i] = alloc_stack();
 163        }
 164}
 165
 166#ifdef CONFIG_VMAP_STACK
 167void *emergency_ctx[NR_CPUS] __ro_after_init = {[0] = &init_stack};
 168
 169void __init emergency_stack_init(void)
 170{
 171        unsigned int i;
 172
 173        for_each_possible_cpu(i)
 174                emergency_ctx[i] = alloc_stack();
 175}
 176#endif
 177
 178#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 179void __init exc_lvl_early_init(void)
 180{
 181        unsigned int i, hw_cpu;
 182
 183        /* interrupt stacks must be in lowmem, we get that for free on ppc32
 184         * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
 185        for_each_possible_cpu(i) {
 186#ifdef CONFIG_SMP
 187                hw_cpu = get_hard_smp_processor_id(i);
 188#else
 189                hw_cpu = 0;
 190#endif
 191
 192                critirq_ctx[hw_cpu] = alloc_stack();
 193#ifdef CONFIG_BOOKE
 194                dbgirq_ctx[hw_cpu] = alloc_stack();
 195                mcheckirq_ctx[hw_cpu] = alloc_stack();
 196#endif
 197        }
 198}
 199#endif
 200
 201void __init setup_power_save(void)
 202{
 203#ifdef CONFIG_PPC_BOOK3S_32
 204        if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
 205            cpu_has_feature(CPU_FTR_CAN_NAP))
 206                ppc_md.power_save = ppc6xx_idle;
 207#endif
 208
 209#ifdef CONFIG_E500
 210        if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
 211            cpu_has_feature(CPU_FTR_CAN_NAP))
 212                ppc_md.power_save = e500_idle;
 213#endif
 214}
 215
 216__init void initialize_cache_info(void)
 217{
 218        /*
 219         * Set cache line size based on type of cpu as a default.
 220         * Systems with OF can look in the properties on the cpu node(s)
 221         * for a possibly more accurate value.
 222         */
 223        dcache_bsize = cur_cpu_spec->dcache_bsize;
 224        icache_bsize = cur_cpu_spec->icache_bsize;
 225}
 226