1 files changed, 74 insertions, 24 deletions

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 055cfb80e05c..24bf1563c3bd 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -41,6 +41,7 @@
 #include <linux/memblock.h>
 #include <linux/of_fdt.h>
 #include <linux/of_platform.h>
+#include <linux/personality.h>
 
 #include <asm/cputype.h>
 #include <asm/elf.h>
@@ -97,6 +98,19 @@ void __init early_print(const char *str, ...)
 	printk("%s", buf);
 }
 
+struct cpuinfo_arm64 {
+	struct cpu	cpu;
+	u32		reg_midr;
+};
+
+static DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
+
+void cpuinfo_store_cpu(void)
+{
+	struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
+	info->reg_midr = read_cpuid_id();
+}
+
 static void __init setup_processor(void)
 {
 	struct cpu_info *cpu_info;
@@ -127,6 +141,8 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys)
 	struct boot_param_header *devtree;
 	unsigned long dt_root;
 
+	cpuinfo_store_cpu();
+
 	/* Check we have a non-NULL DT pointer */
 	if (!dt_phys) {
 		early_print("\n"
@@ -285,14 +301,12 @@ static int __init arm64_device_init(void)
 }
 arch_initcall(arm64_device_init);
 
-static DEFINE_PER_CPU(struct cpu, cpu_data);
-
 static int __init topology_init(void)
 {
 	int i;
 
 	for_each_possible_cpu(i) {
-		struct cpu *cpu = &per_cpu(cpu_data, i);
+		struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
 		cpu->hotpluggable = 1;
 		register_cpu(cpu, i);
 	}
@@ -307,14 +321,41 @@ static const char *hwcap_str[] = {
 	NULL
 };
 
+#ifdef CONFIG_COMPAT
+static const char *compat_hwcap_str[] = {
+	"swp",
+	"half",
+	"thumb",
+	"26bit",
+	"fastmult",
+	"fpa",
+	"vfp",
+	"edsp",
+	"java",
+	"iwmmxt",
+	"crunch",
+	"thumbee",
+	"neon",
+	"vfpv3",
+	"vfpv3d16",
+	"tls",
+	"vfpv4",
+	"idiva",
+	"idivt",
+	"vfpd32",
+	"lpae",
+	"evtstrm"
+};
+#endif /* CONFIG_COMPAT */
+
 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;
 
 	for_each_online_cpu(i) {
+		struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
+		u32 midr = cpuinfo->reg_midr;
+
 		/*
 		 * glibc reads /proc/cpuinfo to determine the number of
 		 * online processors, looking for lines beginning with
@@ -323,24 +364,33 @@ static int c_show(struct seq_file *m, void *v)
 #ifdef CONFIG_SMP
 		seq_printf(m, "processor\t: %d\n", i);
 #endif
-	}
-
-	/* 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]);
 
-	seq_printf(m, "\nCPU implementer\t: 0x%02x\n", read_cpuid_id() >> 24);
-	seq_printf(m, "CPU architecture: AArch64\n");
-	seq_printf(m, "CPU variant\t: 0x%x\n", (read_cpuid_id() >> 20) & 15);
-	seq_printf(m, "CPU part\t: 0x%03x\n", (read_cpuid_id() >> 4) & 0xfff);
-	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);
+		/*
+		 * Dump out the common processor features in a single line.
+		 * Userspace should read the hwcaps with getauxval(AT_HWCAP)
+		 * rather than attempting to parse this, but there's a body of
+		 * software which does already (at least for 32-bit).
+		 */
+		seq_puts(m, "Features\t:");
+		if (personality(current->personality) == PER_LINUX32) {
+#ifdef CONFIG_COMPAT
+			for (j = 0; compat_hwcap_str[j]; j++)
+				if (COMPAT_ELF_HWCAP & (1 << j))
+					seq_printf(m, " %s", compat_hwcap_str[j]);
+#endif /* CONFIG_COMPAT */
+		} else {
+			for (j = 0; hwcap_str[j]; j++)
+				if (elf_hwcap & (1 << j))
+					seq_printf(m, " %s", hwcap_str[j]);
+		}
+		seq_puts(m, "\n");
+
+		seq_printf(m, "CPU implementer\t: 0x%02x\n", (midr >> 24));
+		seq_printf(m, "CPU architecture: 8\n");
+		seq_printf(m, "CPU variant\t: 0x%x\n", ((midr >> 20) & 0xf));
+		seq_printf(m, "CPU part\t: 0x%03x\n", ((midr >> 4) & 0xfff));
+		seq_printf(m, "CPU revision\t: %d\n\n", (midr & 0xf));
+	}
 
 	return 0;
 }