v4.19.13 snapshot.
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
new file mode 100644
index 0000000..b2cae79
--- /dev/null
+++ b/arch/arc/kernel/setup.c
@@ -0,0 +1,639 @@
+/*
+ * 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;
+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) {
+ unsigned int exec_ctrl;
+
+ READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
+ cpu->extn.dual_enb = !(exec_ctrl & 1);
+
+ /* dual issue always present for this core */
+ cpu->extn.dual = 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 int is_kernel(unsigned long addr)
+{
+ if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
+ return 1;
+ return 0;
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+#ifdef CONFIG_ARC_UBOOT_SUPPORT
+ /* make sure that uboot passed pointer to cmdline/dtb is valid */
+ if (uboot_tag && is_kernel((unsigned long)uboot_arg))
+ panic("Invalid uboot arg\n");
+
+ /* See if u-boot passed an external Device Tree blob */
+ machine_desc = setup_machine_fdt(uboot_arg); /* uboot_tag == 2 */
+ if (!machine_desc)
+#endif
+ {
+ /* No, so try the embedded one */
+ machine_desc = setup_machine_fdt(__dtb_start);
+ if (!machine_desc)
+ panic("Embedded DT invalid\n");
+
+ /*
+ * If we are here, it is established that @uboot_arg didn't
+ * point to DT blob. Instead if u-boot says it is cmdline,
+ * append to embedded DT cmdline.
+ * setup_machine_fdt() would have populated @boot_command_line
+ */
+ if (uboot_tag == 1) {
+ /* Ensure a whitespace between the 2 cmdlines */
+ strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
+ strlcat(boot_command_line, uboot_arg,
+ COMMAND_LINE_SIZE);
+ }
+ }
+
+ /* 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);