281eaa8cb6
Move the get_online_cpus() and put_online_cpus() to the start and stop operation of the seqfile ops. This way there is no need to lock cpu hotplug again and again for each single cpu. This way we can also skip offline cpus early if we simply use cpumask_next() within the next operation. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
129 lines
2.8 KiB
C
129 lines
2.8 KiB
C
/*
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* Copyright IBM Corp. 2008
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
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*/
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#define KMSG_COMPONENT "cpu"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/seq_file.h>
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#include <linux/delay.h>
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#include <linux/cpu.h>
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#include <asm/diag.h>
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#include <asm/elf.h>
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#include <asm/lowcore.h>
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#include <asm/param.h>
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#include <asm/smp.h>
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static DEFINE_PER_CPU(struct cpuid, cpu_id);
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void notrace cpu_relax(void)
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{
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if (!smp_cpu_mtid && MACHINE_HAS_DIAG44) {
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diag_stat_inc(DIAG_STAT_X044);
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asm volatile("diag 0,0,0x44");
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}
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barrier();
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}
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EXPORT_SYMBOL(cpu_relax);
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/*
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* cpu_init - initializes state that is per-CPU.
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*/
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void cpu_init(void)
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{
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struct cpuid *id = this_cpu_ptr(&cpu_id);
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get_cpu_id(id);
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atomic_inc(&init_mm.mm_count);
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current->active_mm = &init_mm;
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BUG_ON(current->mm);
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enter_lazy_tlb(&init_mm, current);
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}
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/*
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* cpu_have_feature - Test CPU features on module initialization
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*/
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int cpu_have_feature(unsigned int num)
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{
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return elf_hwcap & (1UL << num);
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}
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EXPORT_SYMBOL(cpu_have_feature);
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/*
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* show_cpuinfo - Get information on one CPU for use by procfs.
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*/
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static int show_cpuinfo(struct seq_file *m, void *v)
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{
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static const char *hwcap_str[] = {
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"esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
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"edat", "etf3eh", "highgprs", "te", "vx"
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};
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static const char * const int_hwcap_str[] = {
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"sie"
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};
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unsigned long n = (unsigned long) v - 1;
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int i;
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if (!n) {
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s390_adjust_jiffies();
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seq_printf(m, "vendor_id : IBM/S390\n"
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"# processors : %i\n"
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"bogomips per cpu: %lu.%02lu\n",
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num_online_cpus(), loops_per_jiffy/(500000/HZ),
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(loops_per_jiffy/(5000/HZ))%100);
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seq_puts(m, "features\t: ");
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for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
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if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
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seq_printf(m, "%s ", hwcap_str[i]);
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for (i = 0; i < ARRAY_SIZE(int_hwcap_str); i++)
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if (int_hwcap_str[i] && (int_hwcap & (1UL << i)))
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seq_printf(m, "%s ", int_hwcap_str[i]);
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seq_puts(m, "\n");
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show_cacheinfo(m);
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}
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if (cpu_online(n)) {
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struct cpuid *id = &per_cpu(cpu_id, n);
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seq_printf(m, "processor %li: "
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"version = %02X, "
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"identification = %06X, "
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"machine = %04X\n",
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n, id->version, id->ident, id->machine);
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}
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return 0;
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}
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static inline void *c_update(loff_t *pos)
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{
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if (*pos)
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*pos = cpumask_next(*pos - 1, cpu_online_mask);
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return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
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}
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static void *c_start(struct seq_file *m, loff_t *pos)
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{
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get_online_cpus();
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return c_update(pos);
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}
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static void *c_next(struct seq_file *m, void *v, loff_t *pos)
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{
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++*pos;
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return c_update(pos);
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}
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static void c_stop(struct seq_file *m, void *v)
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{
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put_online_cpus();
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}
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const struct seq_operations cpuinfo_op = {
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.start = c_start,
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.next = c_next,
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.stop = c_stop,
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.show = show_cpuinfo,
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};
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