blob: 89c97dcfa3602b3f5e1de180c9a9b7f47a76f23b [file] [log] [blame]
/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/seq_file.h>
#include <linux/fs.h>
#include <linux/delay.h>
#include <linux/root_dev.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clocksource.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/of_fdt.h>
#include <linux/of.h>
#include <linux/cache.h>
#include <asm/sections.h>
#include <asm/arcregs.h>
#include <asm/tlb.h>
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/irq.h>
#include <asm/unwind.h>
#include <asm/mach_desc.h>
#include <asm/smp.h>
#define FIX_PTR(x) __asm__ __volatile__(";" : "+r"(x))
unsigned int intr_to_DE_cnt;
/* Part of U-boot ABI: see head.S */
int __initdata uboot_tag;
int __initdata uboot_magic;
char __initdata *uboot_arg;
const struct machine_desc *machine_desc;
struct task_struct *_current_task[NR_CPUS]; /* For stack switching */
struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
static const struct id_to_str arc_cpu_rel[] = {
#ifdef CONFIG_ISA_ARCOMPACT
{ 0x34, "R4.10"},
{ 0x35, "R4.11"},
#else
{ 0x51, "R2.0" },
{ 0x52, "R2.1" },
{ 0x53, "R3.0" },
{ 0x54, "R3.10a" },
#endif
{ 0x00, NULL }
};
static const struct id_to_str arc_cpu_nm[] = {
#ifdef CONFIG_ISA_ARCOMPACT
{ 0x20, "ARC 600" },
{ 0x30, "ARC 770" }, /* 750 identified seperately */
#else
{ 0x40, "ARC EM" },
{ 0x50, "ARC HS38" },
{ 0x54, "ARC HS48" },
#endif
{ 0x00, "Unknown" }
};
static void read_decode_ccm_bcr(struct cpuinfo_arc *cpu)
{
if (is_isa_arcompact()) {
struct bcr_iccm_arcompact iccm;
struct bcr_dccm_arcompact dccm;
READ_BCR(ARC_REG_ICCM_BUILD, iccm);
if (iccm.ver) {
cpu->iccm.sz = 4096 << iccm.sz; /* 8K to 512K */
cpu->iccm.base_addr = iccm.base << 16;
}
READ_BCR(ARC_REG_DCCM_BUILD, dccm);
if (dccm.ver) {
unsigned long base;
cpu->dccm.sz = 2048 << dccm.sz; /* 2K to 256K */
base = read_aux_reg(ARC_REG_DCCM_BASE_BUILD);
cpu->dccm.base_addr = base & ~0xF;
}
} else {
struct bcr_iccm_arcv2 iccm;
struct bcr_dccm_arcv2 dccm;
unsigned long region;
READ_BCR(ARC_REG_ICCM_BUILD, iccm);
if (iccm.ver) {
cpu->iccm.sz = 256 << iccm.sz00; /* 512B to 16M */
if (iccm.sz00 == 0xF && iccm.sz01 > 0)
cpu->iccm.sz <<= iccm.sz01;
region = read_aux_reg(ARC_REG_AUX_ICCM);
cpu->iccm.base_addr = region & 0xF0000000;
}
READ_BCR(ARC_REG_DCCM_BUILD, dccm);
if (dccm.ver) {
cpu->dccm.sz = 256 << dccm.sz0;
if (dccm.sz0 == 0xF && dccm.sz1 > 0)
cpu->dccm.sz <<= dccm.sz1;
region = read_aux_reg(ARC_REG_AUX_DCCM);
cpu->dccm.base_addr = region & 0xF0000000;
}
}
}
static void read_arc_build_cfg_regs(void)
{
struct bcr_timer timer;
struct bcr_generic bcr;
struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
const struct id_to_str *tbl;
struct bcr_isa_arcv2 isa;
FIX_PTR(cpu);
READ_BCR(AUX_IDENTITY, cpu->core);
for (tbl = &arc_cpu_rel[0]; tbl->id != 0; tbl++) {
if (cpu->core.family == tbl->id) {
cpu->details = tbl->str;
break;
}
}
for (tbl = &arc_cpu_nm[0]; tbl->id != 0; tbl++) {
if ((cpu->core.family & 0xF4) == tbl->id)
break;
}
cpu->name = tbl->str;
READ_BCR(ARC_REG_TIMERS_BCR, timer);
cpu->extn.timer0 = timer.t0;
cpu->extn.timer1 = timer.t1;
cpu->extn.rtc = timer.rtc;
cpu->vec_base = read_aux_reg(AUX_INTR_VEC_BASE);
READ_BCR(ARC_REG_MUL_BCR, cpu->extn_mpy);
cpu->extn.norm = read_aux_reg(ARC_REG_NORM_BCR) > 1 ? 1 : 0; /* 2,3 */
cpu->extn.barrel = read_aux_reg(ARC_REG_BARREL_BCR) > 1 ? 1 : 0; /* 2,3 */
cpu->extn.swap = read_aux_reg(ARC_REG_SWAP_BCR) ? 1 : 0; /* 1,3 */
cpu->extn.crc = read_aux_reg(ARC_REG_CRC_BCR) ? 1 : 0;
cpu->extn.minmax = read_aux_reg(ARC_REG_MIXMAX_BCR) > 1 ? 1 : 0; /* 2 */
cpu->extn.swape = (cpu->core.family >= 0x34) ? 1 :
IS_ENABLED(CONFIG_ARC_HAS_SWAPE);
READ_BCR(ARC_REG_XY_MEM_BCR, cpu->extn_xymem);
/* Read CCM BCRs for boot reporting even if not enabled in Kconfig */
read_decode_ccm_bcr(cpu);
read_decode_mmu_bcr();
read_decode_cache_bcr();
if (is_isa_arcompact()) {
struct bcr_fp_arcompact sp, dp;
struct bcr_bpu_arcompact bpu;
READ_BCR(ARC_REG_FP_BCR, sp);
READ_BCR(ARC_REG_DPFP_BCR, dp);
cpu->extn.fpu_sp = sp.ver ? 1 : 0;
cpu->extn.fpu_dp = dp.ver ? 1 : 0;
READ_BCR(ARC_REG_BPU_BCR, bpu);
cpu->bpu.ver = bpu.ver;
cpu->bpu.full = bpu.fam ? 1 : 0;
if (bpu.ent) {
cpu->bpu.num_cache = 256 << (bpu.ent - 1);
cpu->bpu.num_pred = 256 << (bpu.ent - 1);
}
} else {
struct bcr_fp_arcv2 spdp;
struct bcr_bpu_arcv2 bpu;
READ_BCR(ARC_REG_FP_V2_BCR, spdp);
cpu->extn.fpu_sp = spdp.sp ? 1 : 0;
cpu->extn.fpu_dp = spdp.dp ? 1 : 0;
READ_BCR(ARC_REG_BPU_BCR, bpu);
cpu->bpu.ver = bpu.ver;
cpu->bpu.full = bpu.ft;
cpu->bpu.num_cache = 256 << bpu.bce;
cpu->bpu.num_pred = 2048 << bpu.pte;
if (cpu->core.family >= 0x54) {
struct bcr_uarch_build_arcv2 uarch;
/*
* The first 0x54 core (uarch maj:min 0:1 or 0:2) was
* dual issue only (HS4x). But next uarch rev (1:0)
* allows it be configured for single issue (HS3x)
* Ensure we fiddle with dual issue only on HS4x
*/
READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch);
if (uarch.prod == 4) {
unsigned int exec_ctrl;
/* dual issue hardware always present */
cpu->extn.dual = 1;
READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
/* dual issue hardware enabled ? */
cpu->extn.dual_enb = !(exec_ctrl & 1);
}
}
}
READ_BCR(ARC_REG_AP_BCR, bcr);
cpu->extn.ap = bcr.ver ? 1 : 0;
READ_BCR(ARC_REG_SMART_BCR, bcr);
cpu->extn.smart = bcr.ver ? 1 : 0;
READ_BCR(ARC_REG_RTT_BCR, bcr);
cpu->extn.rtt = bcr.ver ? 1 : 0;
cpu->extn.debug = cpu->extn.ap | cpu->extn.smart | cpu->extn.rtt;
READ_BCR(ARC_REG_ISA_CFG_BCR, isa);
/* some hacks for lack of feature BCR info in old ARC700 cores */
if (is_isa_arcompact()) {
if (!isa.ver) /* ISA BCR absent, use Kconfig info */
cpu->isa.atomic = IS_ENABLED(CONFIG_ARC_HAS_LLSC);
else {
/* ARC700_BUILD only has 2 bits of isa info */
struct bcr_generic bcr = *(struct bcr_generic *)&isa;
cpu->isa.atomic = bcr.info & 1;
}
cpu->isa.be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
/* there's no direct way to distinguish 750 vs. 770 */
if (unlikely(cpu->core.family < 0x34 || cpu->mmu.ver < 3))
cpu->name = "ARC750";
} else {
cpu->isa = isa;
}
}
static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len)
{
struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
struct bcr_identity *core = &cpu->core;
int i, n = 0;
FIX_PTR(cpu);
n += scnprintf(buf + n, len - n,
"\nIDENTITY\t: ARCVER [%#02x] ARCNUM [%#02x] CHIPID [%#4x]\n",
core->family, core->cpu_id, core->chip_id);
n += scnprintf(buf + n, len - n, "processor [%d]\t: %s %s (%s ISA) %s%s%s\n",
cpu_id, cpu->name, cpu->details,
is_isa_arcompact() ? "ARCompact" : "ARCv2",
IS_AVAIL1(cpu->isa.be, "[Big-Endian]"),
IS_AVAIL3(cpu->extn.dual, cpu->extn.dual_enb, " Dual-Issue "));
n += scnprintf(buf + n, len - n, "Timers\t\t: %s%s%s%s%s%s\nISA Extn\t: ",
IS_AVAIL1(cpu->extn.timer0, "Timer0 "),
IS_AVAIL1(cpu->extn.timer1, "Timer1 "),
IS_AVAIL2(cpu->extn.rtc, "RTC [UP 64-bit] ", CONFIG_ARC_TIMERS_64BIT),
IS_AVAIL2(cpu->extn.gfrc, "GFRC [SMP 64-bit] ", CONFIG_ARC_TIMERS_64BIT));
n += i = scnprintf(buf + n, len - n, "%s%s%s%s%s",
IS_AVAIL2(cpu->isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC),
IS_AVAIL2(cpu->isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64),
IS_AVAIL1(cpu->isa.unalign, "unalign (not used)"));
if (i)
n += scnprintf(buf + n, len - n, "\n\t\t: ");
if (cpu->extn_mpy.ver) {
if (cpu->extn_mpy.ver <= 0x2) { /* ARCompact */
n += scnprintf(buf + n, len - n, "mpy ");
} else {
int opt = 2; /* stock MPY/MPYH */
if (cpu->extn_mpy.dsp) /* OPT 7-9 */
opt = cpu->extn_mpy.dsp + 6;
n += scnprintf(buf + n, len - n, "mpy[opt %d] ", opt);
}
}
n += scnprintf(buf + n, len - n, "%s%s%s%s%s%s%s%s\n",
IS_AVAIL1(cpu->isa.div_rem, "div_rem "),
IS_AVAIL1(cpu->extn.norm, "norm "),
IS_AVAIL1(cpu->extn.barrel, "barrel-shift "),
IS_AVAIL1(cpu->extn.swap, "swap "),
IS_AVAIL1(cpu->extn.minmax, "minmax "),
IS_AVAIL1(cpu->extn.crc, "crc "),
IS_AVAIL2(cpu->extn.swape, "swape", CONFIG_ARC_HAS_SWAPE));
if (cpu->bpu.ver)
n += scnprintf(buf + n, len - n,
"BPU\t\t: %s%s match, cache:%d, Predict Table:%d",
IS_AVAIL1(cpu->bpu.full, "full"),
IS_AVAIL1(!cpu->bpu.full, "partial"),
cpu->bpu.num_cache, cpu->bpu.num_pred);
if (is_isa_arcv2()) {
struct bcr_lpb lpb;
READ_BCR(ARC_REG_LPB_BUILD, lpb);
if (lpb.ver) {
unsigned int ctl;
ctl = read_aux_reg(ARC_REG_LPB_CTRL);
n += scnprintf(buf + n, len - n, " Loop Buffer:%d %s",
lpb.entries,
IS_DISABLED_RUN(!ctl));
}
}
n += scnprintf(buf + n, len - n, "\n");
return buf;
}
static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
{
int n = 0;
struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
FIX_PTR(cpu);
n += scnprintf(buf + n, len - n, "Vector Table\t: %#x\n", cpu->vec_base);
if (cpu->extn.fpu_sp || cpu->extn.fpu_dp)
n += scnprintf(buf + n, len - n, "FPU\t\t: %s%s\n",
IS_AVAIL1(cpu->extn.fpu_sp, "SP "),
IS_AVAIL1(cpu->extn.fpu_dp, "DP "));
if (cpu->extn.debug)
n += scnprintf(buf + n, len - n, "DEBUG\t\t: %s%s%s\n",
IS_AVAIL1(cpu->extn.ap, "ActionPoint "),
IS_AVAIL1(cpu->extn.smart, "smaRT "),
IS_AVAIL1(cpu->extn.rtt, "RTT "));
if (cpu->dccm.sz || cpu->iccm.sz)
n += scnprintf(buf + n, len - n, "Extn [CCM]\t: DCCM @ %x, %d KB / ICCM: @ %x, %d KB\n",
cpu->dccm.base_addr, TO_KB(cpu->dccm.sz),
cpu->iccm.base_addr, TO_KB(cpu->iccm.sz));
if (is_isa_arcv2()) {
/* Error Protection: ECC/Parity */
struct bcr_erp erp;
READ_BCR(ARC_REG_ERP_BUILD, erp);
if (erp.ver) {
struct ctl_erp ctl;
READ_BCR(ARC_REG_ERP_CTRL, ctl);
/* inverted bits: 0 means enabled */
n += scnprintf(buf + n, len - n, "Extn [ECC]\t: %s%s%s%s%s%s\n",
IS_AVAIL3(erp.ic, !ctl.dpi, "IC "),
IS_AVAIL3(erp.dc, !ctl.dpd, "DC "),
IS_AVAIL3(erp.mmu, !ctl.mpd, "MMU "));
}
}
n += scnprintf(buf + n, len - n, "OS ABI [v%d]\t: %s\n",
EF_ARC_OSABI_CURRENT >> 8,
EF_ARC_OSABI_CURRENT == EF_ARC_OSABI_V3 ?
"no-legacy-syscalls" : "64-bit data any register aligned");
return buf;
}
static void arc_chk_core_config(void)
{
struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
int saved = 0, present = 0;
char *opt_nm = NULL;
if (!cpu->extn.timer0)
panic("Timer0 is not present!\n");
if (!cpu->extn.timer1)
panic("Timer1 is not present!\n");
#ifdef CONFIG_ARC_HAS_DCCM
/*
* DCCM can be arbit placed in hardware.
* Make sure it's placement/sz matches what Linux is built with
*/
if ((unsigned int)__arc_dccm_base != cpu->dccm.base_addr)
panic("Linux built with incorrect DCCM Base address\n");
if (CONFIG_ARC_DCCM_SZ != cpu->dccm.sz)
panic("Linux built with incorrect DCCM Size\n");
#endif
#ifdef CONFIG_ARC_HAS_ICCM
if (CONFIG_ARC_ICCM_SZ != cpu->iccm.sz)
panic("Linux built with incorrect ICCM Size\n");
#endif
/*
* FP hardware/software config sanity
* -If hardware present, kernel needs to save/restore FPU state
* -If not, it will crash trying to save/restore the non-existant regs
*/
if (is_isa_arcompact()) {
opt_nm = "CONFIG_ARC_FPU_SAVE_RESTORE";
saved = IS_ENABLED(CONFIG_ARC_FPU_SAVE_RESTORE);
/* only DPDP checked since SP has no arch visible regs */
present = cpu->extn.fpu_dp;
} else {
opt_nm = "CONFIG_ARC_HAS_ACCL_REGS";
saved = IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS);
/* Accumulator Low:High pair (r58:59) present if DSP MPY or FPU */
present = cpu->extn_mpy.dsp | cpu->extn.fpu_sp | cpu->extn.fpu_dp;
}
if (present && !saved)
pr_warn("Enable %s for working apps\n", opt_nm);
else if (!present && saved)
panic("Disable %s, hardware NOT present\n", opt_nm);
}
/*
* Initialize and setup the processor core
* This is called by all the CPUs thus should not do special case stuff
* such as only for boot CPU etc
*/
void setup_processor(void)
{
char str[512];
int cpu_id = smp_processor_id();
read_arc_build_cfg_regs();
arc_init_IRQ();
pr_info("%s", arc_cpu_mumbojumbo(cpu_id, str, sizeof(str)));
arc_mmu_init();
arc_cache_init();
pr_info("%s", arc_extn_mumbojumbo(cpu_id, str, sizeof(str)));
pr_info("%s", arc_platform_smp_cpuinfo());
arc_chk_core_config();
}
static inline bool uboot_arg_invalid(unsigned long addr)
{
/*
* Check that it is a untranslated address (although MMU is not enabled
* yet, it being a high address ensures this is not by fluke)
*/
if (addr < PAGE_OFFSET)
return true;
/* Check that address doesn't clobber resident kernel image */
return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
}
#define IGNORE_ARGS "Ignore U-boot args: "
/* uboot_tag values for U-boot - kernel ABI revision 0; see head.S */
#define UBOOT_TAG_NONE 0
#define UBOOT_TAG_CMDLINE 1
#define UBOOT_TAG_DTB 2
/* We always pass 0 as magic from U-boot */
#define UBOOT_MAGIC_VALUE 0
void __init handle_uboot_args(void)
{
bool use_embedded_dtb = true;
bool append_cmdline = false;
/* check that we know this tag */
if (uboot_tag != UBOOT_TAG_NONE &&
uboot_tag != UBOOT_TAG_CMDLINE &&
uboot_tag != UBOOT_TAG_DTB) {
pr_warn(IGNORE_ARGS "invalid uboot tag: '%08x'\n", uboot_tag);
goto ignore_uboot_args;
}
if (uboot_magic != UBOOT_MAGIC_VALUE) {
pr_warn(IGNORE_ARGS "non zero uboot magic\n");
goto ignore_uboot_args;
}
if (uboot_tag != UBOOT_TAG_NONE &&
uboot_arg_invalid((unsigned long)uboot_arg)) {
pr_warn(IGNORE_ARGS "invalid uboot arg: '%px'\n", uboot_arg);
goto ignore_uboot_args;
}
/* see if U-boot passed an external Device Tree blob */
if (uboot_tag == UBOOT_TAG_DTB) {
machine_desc = setup_machine_fdt((void *)uboot_arg);
/* external Device Tree blob is invalid - use embedded one */
use_embedded_dtb = !machine_desc;
}
if (uboot_tag == UBOOT_TAG_CMDLINE)
append_cmdline = true;
ignore_uboot_args:
if (use_embedded_dtb) {
machine_desc = setup_machine_fdt(__dtb_start);
if (!machine_desc)
panic("Embedded DT invalid\n");
}
/*
* NOTE: @boot_command_line is populated by setup_machine_fdt() so this
* append processing can only happen after.
*/
if (append_cmdline) {
/* Ensure a whitespace between the 2 cmdlines */
strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE);
}
}
void __init setup_arch(char **cmdline_p)
{
handle_uboot_args();
/* Save unparsed command line copy for /proc/cmdline */
*cmdline_p = boot_command_line;
/* To force early parsing of things like mem=xxx */
parse_early_param();
/* Platform/board specific: e.g. early console registration */
if (machine_desc->init_early)
machine_desc->init_early();
smp_init_cpus();
setup_processor();
setup_arch_memory();
/* copy flat DT out of .init and then unflatten it */
unflatten_and_copy_device_tree();
/* Can be issue if someone passes cmd line arg "ro"
* But that is unlikely so keeping it as it is
*/
root_mountflags &= ~MS_RDONLY;
#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
conswitchp = &dummy_con;
#endif
arc_unwind_init();
}
/*
* Called from start_kernel() - boot CPU only
*/
void __init time_init(void)
{
of_clk_init(NULL);
timer_probe();
}
static int __init customize_machine(void)
{
if (machine_desc->init_machine)
machine_desc->init_machine();
return 0;
}
arch_initcall(customize_machine);
static int __init init_late_machine(void)
{
if (machine_desc->init_late)
machine_desc->init_late();
return 0;
}
late_initcall(init_late_machine);
/*
* Get CPU information for use by the procfs.
*/
#define cpu_to_ptr(c) ((void *)(0xFFFF0000 | (unsigned int)(c)))
#define ptr_to_cpu(p) (~0xFFFF0000UL & (unsigned int)(p))
static int show_cpuinfo(struct seq_file *m, void *v)
{
char *str;
int cpu_id = ptr_to_cpu(v);
struct device *cpu_dev = get_cpu_device(cpu_id);
struct clk *cpu_clk;
unsigned long freq = 0;
if (!cpu_online(cpu_id)) {
seq_printf(m, "processor [%d]\t: Offline\n", cpu_id);
goto done;
}
str = (char *)__get_free_page(GFP_KERNEL);
if (!str)
goto done;
seq_printf(m, arc_cpu_mumbojumbo(cpu_id, str, PAGE_SIZE));
cpu_clk = clk_get(cpu_dev, NULL);
if (IS_ERR(cpu_clk)) {
seq_printf(m, "CPU speed \t: Cannot get clock for processor [%d]\n",
cpu_id);
} else {
freq = clk_get_rate(cpu_clk);
}
if (freq)
seq_printf(m, "CPU speed\t: %lu.%02lu Mhz\n",
freq / 1000000, (freq / 10000) % 100);
seq_printf(m, "Bogo MIPS\t: %lu.%02lu\n",
loops_per_jiffy / (500000 / HZ),
(loops_per_jiffy / (5000 / HZ)) % 100);
seq_printf(m, arc_mmu_mumbojumbo(cpu_id, str, PAGE_SIZE));
seq_printf(m, arc_cache_mumbojumbo(cpu_id, str, PAGE_SIZE));
seq_printf(m, arc_extn_mumbojumbo(cpu_id, str, PAGE_SIZE));
seq_printf(m, arc_platform_smp_cpuinfo());
free_page((unsigned long)str);
done:
seq_printf(m, "\n");
return 0;
}
static void *c_start(struct seq_file *m, loff_t *pos)
{
/*
* Callback returns cpu-id to iterator for show routine, NULL to stop.
* However since NULL is also a valid cpu-id (0), we use a round-about
* way to pass it w/o having to kmalloc/free a 2 byte string.
* Encode cpu-id as 0xFFcccc, which is decoded by show routine.
*/
return *pos < nr_cpu_ids ? cpu_to_ptr(*pos) : NULL;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return c_start(m, pos);
}
static void c_stop(struct seq_file *m, void *v)
{
}
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = show_cpuinfo
};
static DEFINE_PER_CPU(struct cpu, cpu_topology);
static int __init topology_init(void)
{
int cpu;
for_each_present_cpu(cpu)
register_cpu(&per_cpu(cpu_topology, cpu), cpu);
return 0;
}
subsys_initcall(topology_init);