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-rw-r--r--arch/arc/kernel/setup.c654
1 files changed, 654 insertions, 0 deletions
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
new file mode 100644
index 0000000000..d08a5092c2
--- /dev/null
+++ b/arch/arc/kernel/setup.c
@@ -0,0 +1,654 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <linux/seq_file.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/root_dev.h>
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/sizes.h>
+#include <linux/cpu.h>
+#include <linux/of_clk.h>
+#include <linux/of_fdt.h>
+#include <linux/of.h>
+#include <linux/cache.h>
+#include <uapi/linux/mount.h>
+#include <asm/sections.h>
+#include <asm/arcregs.h>
+#include <asm/asserts.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>
+#include <asm/dsp-impl.h>
+#include <soc/arc/mcip.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 {
+ int arcver;
+ unsigned int t0:1, t1:1;
+ struct {
+ unsigned long base;
+ unsigned int sz;
+ } iccm, dccm;
+};
+
+#ifdef CONFIG_ISA_ARCV2
+
+static const struct id_to_str arc_hs_rel[] = {
+ /* ID.ARCVER, Release */
+ { 0x51, "R2.0" },
+ { 0x52, "R2.1" },
+ { 0x53, "R3.0" },
+};
+
+static const struct id_to_str arc_hs_ver54_rel[] = {
+ /* UARCH.MAJOR, Release */
+ { 0, "R3.10a"},
+ { 1, "R3.50a"},
+ { 2, "R3.60a"},
+ { 3, "R4.00a"},
+ { 0xFF, NULL }
+};
+#endif
+
+static int
+arcompact_mumbojumbo(int c, struct cpuinfo_arc *info, char *buf, int len)
+{
+ int n = 0;
+#ifdef CONFIG_ISA_ARCOMPACT
+ char *cpu_nm, *isa_nm = "ARCompact";
+ struct bcr_fp_arcompact fpu_sp, fpu_dp;
+ int atomic = 0, be, present;
+ int bpu_full, bpu_cache, bpu_pred;
+ struct bcr_bpu_arcompact bpu;
+ struct bcr_iccm_arcompact iccm;
+ struct bcr_dccm_arcompact dccm;
+ struct bcr_generic isa;
+
+ READ_BCR(ARC_REG_ISA_CFG_BCR, isa);
+
+ if (!isa.ver) /* ISA BCR absent, use Kconfig info */
+ atomic = IS_ENABLED(CONFIG_ARC_HAS_LLSC);
+ else {
+ /* ARC700_BUILD only has 2 bits of isa info */
+ atomic = isa.info & 1;
+ }
+
+ be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
+
+ if (info->arcver < 0x34)
+ cpu_nm = "ARC750";
+ else
+ cpu_nm = "ARC770";
+
+ n += scnprintf(buf + n, len - n, "processor [%d]\t: %s (%s ISA) %s%s%s\n",
+ c, cpu_nm, isa_nm,
+ IS_AVAIL2(atomic, "atomic ", CONFIG_ARC_HAS_LLSC),
+ IS_AVAIL1(be, "[Big-Endian]"));
+
+ READ_BCR(ARC_REG_FP_BCR, fpu_sp);
+ READ_BCR(ARC_REG_DPFP_BCR, fpu_dp);
+
+ if (fpu_sp.ver | fpu_dp.ver)
+ n += scnprintf(buf + n, len - n, "FPU\t\t: %s%s\n",
+ IS_AVAIL1(fpu_sp.ver, "SP "),
+ IS_AVAIL1(fpu_dp.ver, "DP "));
+
+ READ_BCR(ARC_REG_BPU_BCR, bpu);
+ bpu_full = bpu.fam ? 1 : 0;
+ bpu_cache = 256 << (bpu.ent - 1);
+ bpu_pred = 256 << (bpu.ent - 1);
+
+ n += scnprintf(buf + n, len - n,
+ "BPU\t\t: %s%s match, cache:%d, Predict Table:%d\n",
+ IS_AVAIL1(bpu_full, "full"),
+ IS_AVAIL1(!bpu_full, "partial"),
+ bpu_cache, bpu_pred);
+
+ READ_BCR(ARC_REG_ICCM_BUILD, iccm);
+ if (iccm.ver) {
+ info->iccm.sz = 4096 << iccm.sz; /* 8K to 512K */
+ info->iccm.base = iccm.base << 16;
+ }
+
+ READ_BCR(ARC_REG_DCCM_BUILD, dccm);
+ if (dccm.ver) {
+ unsigned long base;
+ info->dccm.sz = 2048 << dccm.sz; /* 2K to 256K */
+
+ base = read_aux_reg(ARC_REG_DCCM_BASE_BUILD);
+ info->dccm.base = base & ~0xF;
+ }
+
+ /* ARCompact ISA specific sanity checks */
+ present = fpu_dp.ver; /* SP has no arch visible regs */
+ CHK_OPT_STRICT(CONFIG_ARC_FPU_SAVE_RESTORE, present);
+#endif
+ return n;
+
+}
+
+static int arcv2_mumbojumbo(int c, struct cpuinfo_arc *info, char *buf, int len)
+{
+ int n = 0;
+#ifdef CONFIG_ISA_ARCV2
+ const char *release = "", *cpu_nm = "HS38", *isa_nm = "ARCv2";
+ int dual_issue = 0, dual_enb = 0, mpy_opt, present;
+ int bpu_full, bpu_cache, bpu_pred, bpu_ret_stk;
+ char mpy_nm[16], lpb_nm[32];
+ struct bcr_isa_arcv2 isa;
+ struct bcr_mpy mpy;
+ struct bcr_fp_arcv2 fpu;
+ struct bcr_bpu_arcv2 bpu;
+ struct bcr_lpb lpb;
+ struct bcr_iccm_arcv2 iccm;
+ struct bcr_dccm_arcv2 dccm;
+ struct bcr_erp erp;
+
+ /*
+ * Initial HS cores bumped AUX IDENTITY.ARCVER for each release until
+ * ARCVER 0x54 which introduced AUX MICRO_ARCH_BUILD and subsequent
+ * releases only update it.
+ */
+
+ if (info->arcver > 0x50 && info->arcver <= 0x53) {
+ release = arc_hs_rel[info->arcver - 0x51].str;
+ } else {
+ const struct id_to_str *tbl;
+ struct bcr_uarch_build uarch;
+
+ READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch);
+
+ for (tbl = &arc_hs_ver54_rel[0]; tbl->id != 0xFF; tbl++) {
+ if (uarch.maj == tbl->id) {
+ release = tbl->str;
+ break;
+ }
+ }
+ if (uarch.prod == 4) {
+ unsigned int exec_ctrl;
+
+ cpu_nm = "HS48";
+ dual_issue = 1;
+ /* if dual issue hardware, is it enabled ? */
+ READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
+ dual_enb = !(exec_ctrl & 1);
+ }
+ }
+
+ READ_BCR(ARC_REG_ISA_CFG_BCR, isa);
+
+ n += scnprintf(buf + n, len - n, "processor [%d]\t: %s %s (%s ISA) %s%s%s\n",
+ c, cpu_nm, release, isa_nm,
+ IS_AVAIL1(isa.be, "[Big-Endian]"),
+ IS_AVAIL3(dual_issue, dual_enb, " Dual-Issue "));
+
+ READ_BCR(ARC_REG_MPY_BCR, mpy);
+ mpy_opt = 2; /* stock MPY/MPYH */
+ if (mpy.dsp) /* OPT 7-9 */
+ mpy_opt = mpy.dsp + 6;
+
+ scnprintf(mpy_nm, 16, "mpy[opt %d] ", mpy_opt);
+
+ READ_BCR(ARC_REG_FP_V2_BCR, fpu);
+
+ n += scnprintf(buf + n, len - n, "ISA Extn\t: %s%s%s%s%s%s%s%s%s%s%s\n",
+ IS_AVAIL2(isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC),
+ IS_AVAIL2(isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64),
+ IS_AVAIL2(isa.unalign, "unalign ", CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS),
+ IS_AVAIL1(mpy.ver, mpy_nm),
+ IS_AVAIL1(isa.div_rem, "div_rem "),
+ IS_AVAIL1((fpu.sp | fpu.dp), " FPU:"),
+ IS_AVAIL1(fpu.sp, " sp"),
+ IS_AVAIL1(fpu.dp, " dp"));
+
+ READ_BCR(ARC_REG_BPU_BCR, bpu);
+ bpu_full = bpu.ft;
+ bpu_cache = 256 << bpu.bce;
+ bpu_pred = 2048 << bpu.pte;
+ bpu_ret_stk = 4 << bpu.rse;
+
+ READ_BCR(ARC_REG_LPB_BUILD, lpb);
+ if (lpb.ver) {
+ unsigned int ctl;
+ ctl = read_aux_reg(ARC_REG_LPB_CTRL);
+
+ scnprintf(lpb_nm, sizeof(lpb_nm), " Loop Buffer:%d %s",
+ lpb.entries, IS_DISABLED_RUN(!ctl));
+ }
+
+ n += scnprintf(buf + n, len - n,
+ "BPU\t\t: %s%s match, cache:%d, Predict Table:%d Return stk: %d%s\n",
+ IS_AVAIL1(bpu_full, "full"),
+ IS_AVAIL1(!bpu_full, "partial"),
+ bpu_cache, bpu_pred, bpu_ret_stk,
+ lpb_nm);
+
+ READ_BCR(ARC_REG_ICCM_BUILD, iccm);
+ if (iccm.ver) {
+ unsigned long base;
+ info->iccm.sz = 256 << iccm.sz00; /* 512B to 16M */
+ if (iccm.sz00 == 0xF && iccm.sz01 > 0)
+ info->iccm.sz <<= iccm.sz01;
+ base = read_aux_reg(ARC_REG_AUX_ICCM);
+ info->iccm.base = base & 0xF0000000;
+ }
+
+ READ_BCR(ARC_REG_DCCM_BUILD, dccm);
+ if (dccm.ver) {
+ unsigned long base;
+ info->dccm.sz = 256 << dccm.sz0;
+ if (dccm.sz0 == 0xF && dccm.sz1 > 0)
+ info->dccm.sz <<= dccm.sz1;
+ base = read_aux_reg(ARC_REG_AUX_DCCM);
+ info->dccm.base = base & 0xF0000000;
+ }
+
+ /* Error Protection: ECC/Parity */
+ 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 "));
+ }
+
+ /* ARCv2 ISA specific sanity checks */
+ present = fpu.sp | fpu.dp | mpy.dsp; /* DSP and/or FPU */
+ CHK_OPT_STRICT(CONFIG_ARC_HAS_ACCL_REGS, present);
+
+ dsp_config_check();
+#endif
+ return n;
+}
+
+static char *arc_cpu_mumbojumbo(int c, struct cpuinfo_arc *info, char *buf, int len)
+{
+ struct bcr_identity ident;
+ struct bcr_timer timer;
+ struct bcr_generic bcr;
+ struct mcip_bcr mp;
+ struct bcr_actionpoint ap;
+ unsigned long vec_base;
+ int ap_num, ap_full, smart, rtt, n;
+
+ memset(info, 0, sizeof(struct cpuinfo_arc));
+
+ READ_BCR(AUX_IDENTITY, ident);
+ info->arcver = ident.family;
+
+ n = scnprintf(buf, len,
+ "\nIDENTITY\t: ARCVER [%#02x] ARCNUM [%#02x] CHIPID [%#4x]\n",
+ ident.family, ident.cpu_id, ident.chip_id);
+
+ if (is_isa_arcompact()) {
+ n += arcompact_mumbojumbo(c, info, buf + n, len - n);
+ } else if (is_isa_arcv2()){
+ n += arcv2_mumbojumbo(c, info, buf + n, len - n);
+ }
+
+ n += arc_mmu_mumbojumbo(c, buf + n, len - n);
+ n += arc_cache_mumbojumbo(c, buf + n, len - n);
+
+ READ_BCR(ARC_REG_TIMERS_BCR, timer);
+ info->t0 = timer.t0;
+ info->t1 = timer.t1;
+
+ READ_BCR(ARC_REG_MCIP_BCR, mp);
+ vec_base = read_aux_reg(AUX_INTR_VEC_BASE);
+
+ n += scnprintf(buf + n, len - n,
+ "Timers\t\t: %s%s%s%s%s%s\nVector Table\t: %#lx\n",
+ IS_AVAIL1(timer.t0, "Timer0 "),
+ IS_AVAIL1(timer.t1, "Timer1 "),
+ IS_AVAIL2(timer.rtc, "RTC [UP 64-bit] ", CONFIG_ARC_TIMERS_64BIT),
+ IS_AVAIL2(mp.gfrc, "GFRC [SMP 64-bit] ", CONFIG_ARC_TIMERS_64BIT),
+ vec_base);
+
+ READ_BCR(ARC_REG_AP_BCR, ap);
+ if (ap.ver) {
+ ap_num = 2 << ap.num;
+ ap_full = !ap.min;
+ }
+
+ READ_BCR(ARC_REG_SMART_BCR, bcr);
+ smart = bcr.ver ? 1 : 0;
+
+ READ_BCR(ARC_REG_RTT_BCR, bcr);
+ rtt = bcr.ver ? 1 : 0;
+
+ if (ap.ver | smart | rtt) {
+ n += scnprintf(buf + n, len - n, "DEBUG\t\t: %s%s",
+ IS_AVAIL1(smart, "smaRT "),
+ IS_AVAIL1(rtt, "RTT "));
+ if (ap.ver) {
+ n += scnprintf(buf + n, len - n, "ActionPoint %d/%s",
+ ap_num,
+ ap_full ? "full":"min");
+ }
+ n += scnprintf(buf + n, len - n, "\n");
+ }
+
+ if (info->dccm.sz || info->iccm.sz)
+ n += scnprintf(buf + n, len - n,
+ "Extn [CCM]\t: DCCM @ %lx, %d KB / ICCM: @ %lx, %d KB\n",
+ info->dccm.base, TO_KB(info->dccm.sz),
+ info->iccm.base, TO_KB(info->iccm.sz));
+
+ return buf;
+}
+
+void chk_opt_strict(char *opt_name, bool hw_exists, bool opt_ena)
+{
+ if (hw_exists && !opt_ena)
+ pr_warn(" ! Enable %s for working apps\n", opt_name);
+ else if (!hw_exists && opt_ena)
+ panic("Disable %s, hardware NOT present\n", opt_name);
+}
+
+void chk_opt_weak(char *opt_name, bool hw_exists, bool opt_ena)
+{
+ if (!hw_exists && opt_ena)
+ panic("Disable %s, hardware NOT present\n", opt_name);
+}
+
+/*
+ * ISA agnostic sanity checks
+ */
+static void arc_chk_core_config(struct cpuinfo_arc *info)
+{
+ if (!info->t0)
+ panic("Timer0 is not present!\n");
+
+ if (!info->t1)
+ 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 != info->dccm.base)
+ panic("Linux built with incorrect DCCM Base address\n");
+
+ if (CONFIG_ARC_DCCM_SZ * SZ_1K != info->dccm.sz)
+ panic("Linux built with incorrect DCCM Size\n");
+#endif
+
+#ifdef CONFIG_ARC_HAS_ICCM
+ if (CONFIG_ARC_ICCM_SZ * SZ_1K != info->iccm.sz)
+ panic("Linux built with incorrect ICCM Size\n");
+#endif
+}
+
+/*
+ * 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)
+{
+ struct cpuinfo_arc info;
+ int c = smp_processor_id();
+ char str[512];
+
+ pr_info("%s", arc_cpu_mumbojumbo(c, &info, str, sizeof(str)));
+ pr_info("%s", arc_platform_smp_cpuinfo());
+
+ arc_chk_core_config(&info);
+
+ arc_init_IRQ();
+ arc_mmu_init();
+ arc_cache_init();
+
+}
+
+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;
+
+ 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 cpuinfo_arc info;
+ 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, &info, 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_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);