From b4b8f770eb10a1bccaf8aa0ec1956e2dd7ed1e0a Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 10 Sep 2012 18:55:21 +0100 Subject: [PATCH] ARM: kernel: update cpuinfo to print all online CPUs features Currently, reading /proc/cpuinfo provides userspace with CPU ID of the CPU carrying out the read from the file. This is fine as long as all CPUs in the system are the same. With the advent of big.LITTLE and heterogenous ARM systems this approach provides user space with incorrect bits of information since CPU ids in the system might differ from the one provided by the CPU reading the file. This patch updates the cpuinfo show function so that a read from /proc/cpuinfo prints HW information for all online CPUs at once, mirroring x86 behaviour. Signed-off-by: Lorenzo Pieralisi Acked-by: Nicolas Pitre --- arch/arm/kernel/setup.c | 70 ++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 35 deletions(-) diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index da1d1aa20ad9..a15848f8b0ff 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -841,12 +841,9 @@ static const char *hwcap_str[] = { static int c_show(struct seq_file *m, void *v) { - int i; - - seq_printf(m, "Processor\t: %s rev %d (%s)\n", - cpu_name, read_cpuid_id() & 15, elf_platform); + int i, j; + u32 cpuid; -#if defined(CONFIG_SMP) for_each_online_cpu(i) { /* * glibc reads /proc/cpuinfo to determine the number of @@ -854,45 +851,48 @@ static int c_show(struct seq_file *m, void *v) * "processor". Give glibc what it expects. */ seq_printf(m, "processor\t: %d\n", i); - seq_printf(m, "BogoMIPS\t: %lu.%02lu\n\n", + cpuid = is_smp() ? per_cpu(cpu_data, i).cpuid : read_cpuid_id(); + seq_printf(m, "model name\t: %s rev %d (%s)\n", + cpu_name, cpuid & 15, elf_platform); + +#if defined(CONFIG_SMP) + seq_printf(m, "BogoMIPS\t: %lu.%02lu\n", per_cpu(cpu_data, i).loops_per_jiffy / (500000UL/HZ), (per_cpu(cpu_data, i).loops_per_jiffy / (5000UL/HZ)) % 100); - } -#else /* CONFIG_SMP */ - seq_printf(m, "BogoMIPS\t: %lu.%02lu\n", - loops_per_jiffy / (500000/HZ), - (loops_per_jiffy / (5000/HZ)) % 100); +#else + seq_printf(m, "BogoMIPS\t: %lu.%02lu\n", + loops_per_jiffy / (500000/HZ), + (loops_per_jiffy / (5000/HZ)) % 100); #endif + /* dump out the processor features */ + seq_puts(m, "Features\t: "); - /* dump out the processor features */ - seq_puts(m, "Features\t: "); - - for (i = 0; hwcap_str[i]; i++) - if (elf_hwcap & (1 << i)) - seq_printf(m, "%s ", hwcap_str[i]); + for (j = 0; hwcap_str[j]; j++) + if (elf_hwcap & (1 << j)) + seq_printf(m, "%s ", hwcap_str[j]); - seq_printf(m, "\nCPU implementer\t: 0x%02x\n", read_cpuid_id() >> 24); - seq_printf(m, "CPU architecture: %s\n", proc_arch[cpu_architecture()]); + seq_printf(m, "\nCPU implementer\t: 0x%02x\n", cpuid >> 24); + seq_printf(m, "CPU architecture: %s\n", + proc_arch[cpu_architecture()]); - if ((read_cpuid_id() & 0x0008f000) == 0x00000000) { - /* pre-ARM7 */ - seq_printf(m, "CPU part\t: %07x\n", read_cpuid_id() >> 4); - } else { - if ((read_cpuid_id() & 0x0008f000) == 0x00007000) { - /* ARM7 */ - seq_printf(m, "CPU variant\t: 0x%02x\n", - (read_cpuid_id() >> 16) & 127); + if ((cpuid & 0x0008f000) == 0x00000000) { + /* pre-ARM7 */ + seq_printf(m, "CPU part\t: %07x\n", cpuid >> 4); } else { - /* post-ARM7 */ - seq_printf(m, "CPU variant\t: 0x%x\n", - (read_cpuid_id() >> 20) & 15); + if ((cpuid & 0x0008f000) == 0x00007000) { + /* ARM7 */ + seq_printf(m, "CPU variant\t: 0x%02x\n", + (cpuid >> 16) & 127); + } else { + /* post-ARM7 */ + seq_printf(m, "CPU variant\t: 0x%x\n", + (cpuid >> 20) & 15); + } + seq_printf(m, "CPU part\t: 0x%03x\n", + (cpuid >> 4) & 0xfff); } - seq_printf(m, "CPU part\t: 0x%03x\n", - (read_cpuid_id() >> 4) & 0xfff); + seq_printf(m, "CPU revision\t: %d\n\n", cpuid & 15); } - seq_printf(m, "CPU revision\t: %d\n", read_cpuid_id() & 15); - - seq_puts(m, "\n"); seq_printf(m, "Hardware\t: %s\n", machine_name); seq_printf(m, "Revision\t: %04x\n", system_rev); -- 2.34.1