[PATCH 2/3] arm64: cpuinfo: add human readable CPU names to /proc/cpuinfo

[ahs3@redhat.com (Al Stone)]

In the interest of making things easier for humans to use, add a
"CPU name" line to /proc/cpuinfo for each CPU that uses plain old
words instead of hex values.  For example, instead of printing only
CPU implementer 0x43 and CPU part 0x0A1, print also "CPU name :
Cavium ThunderX".

Note that this is not meant to be an exhaustive list of all possible
implementers or CPUs (I'm not even sure that is knowable); this patch
is intentionally limited to only those willing to provide info in
arch/arm64/include/asm/cputype.h

Signed-off-by: Al Stone <ahs3@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/kernel/cpuinfo.c | 84 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index e505007138eb..0b4261884862 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -75,6 +75,61 @@ static const char *const hwcap_str[] = {
 	NULL
 };
 
+struct hw_part {
+	u16	id;
+	char	*name;
+};
+
+static const struct hw_part arm_hw_part[] = {
+	{ ARM_CPU_PART_AEM_V8,		"AEMv8 Model" },
+	{ ARM_CPU_PART_FOUNDATION,	"Foundation Model" },
+	{ ARM_CPU_PART_CORTEX_A57,	"Cortex A57" },
+	{ ARM_CPU_PART_CORTEX_A53,	"Cortex A53" },
+	{ ARM_CPU_PART_CORTEX_A73,	"Cortex A73" },
+	{ (-1), "unknown" }		/* Potenza == 0, unfortunately */
+};
+
+static const struct hw_part apm_hw_part[] = {
+	{ APM_CPU_PART_POTENZA,		"Potenza" },
+	{ (-1), "unknown" }		/* Potenza == 0, unfortunately */
+};
+
+static const struct hw_part brcm_hw_part[] = {
+	{ BRCM_CPU_PART_VULCAN,		"Vulcan" },
+	{ (-1), "unknown" }		/* Potenza == 0, unfortunately */
+};
+
+static const struct hw_part cavium_hw_part[] = {
+	{ CAVIUM_CPU_PART_THUNDERX,	 "ThunderX" },
+	{ CAVIUM_CPU_PART_THUNDERX_81XX, "ThunderX 81XX" },
+	{ CAVIUM_CPU_PART_THUNDERX_83XX, "ThunderX 83XX" },
+	{ (-1), "unknown" }		/* Potenza == 0, unfortunately */
+};
+
+static const struct hw_part qcom_hw_part[] = {
+	{ QCOM_CPU_PART_FALKOR_V1,	"Falkor v1" },
+	{ (-1), "unknown" }		/* Potenza == 0, unfortunately */
+};
+
+static const struct hw_part unknown_hw_part[] = {
+	{ (-1), "unknown" }		/* Potenza == 0, unfortunately */
+};
+
+struct hw_impl {
+	u8			id;
+	const struct hw_part	*parts;
+	char			*name;
+};
+
+static const struct hw_impl hw_implementer[] = {
+	{ ARM_CPU_IMP_ARM,	arm_hw_part,	"ARM Ltd." },
+	{ ARM_CPU_IMP_APM,	apm_hw_part,	"Applied Micro" },
+	{ ARM_CPU_IMP_CAVIUM,	cavium_hw_part,	"Cavium" },
+	{ ARM_CPU_IMP_BRCM,	brcm_hw_part,	"Broadcom" },
+	{ ARM_CPU_IMP_QCOM,	qcom_hw_part,	"Qualcomm" },
+	{ 0, unknown_hw_part, "unknown" }
+};
+
 #ifdef CONFIG_COMPAT
 static const char *const compat_hwcap_str[] = {
 	"swp",
@@ -116,6 +171,9 @@ static int c_show(struct seq_file *m, void *v)
 {
 	int i, j;
 	bool compat = personality(current->personality) == PER_LINUX32;
+	u8 impl;
+	u16 part;
+	const struct hw_part *parts;
 
 	for_each_online_cpu(i) {
 		struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
@@ -132,6 +190,32 @@ static int c_show(struct seq_file *m, void *v)
 			seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
 				   MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);
 
+		impl = (u8) MIDR_IMPLEMENTOR(midr);
+		for (j = 0; hw_implementer[j].id != 0; j++) {
+			if (hw_implementer[j].id == impl) {
+				seq_printf(m, "CPU name\t: %s ",
+					   hw_implementer[j].name);
+				parts = hw_implementer[j].parts;
+				break;
+			}
+		}
+		if (hw_implementer[j].id == 0) {
+			seq_printf(m, "CPU name\t: %s ",
+				   hw_implementer[j].name);
+			parts = hw_implementer[j].parts;
+		}
+
+		part = (u16) MIDR_PARTNUM(midr);
+		for (j = 0; parts[j].id != (-1); j++) {
+			if (parts[j].id == part) {
+				seq_printf(m, "%s\n", parts[j].name);
+				break;
+			}
+		}
+		if (parts[j].id == (-1))
+			seq_printf(m, "%s", parts[j].name);
+		seq_puts(m, "\n");
+
 		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
 			   loops_per_jiffy / (500000UL/HZ),
 			   loops_per_jiffy / (5000UL/HZ) % 100);
-- 
2.13.5