From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51088) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1byYEs-000338-8u for qemu-devel@nongnu.org; Mon, 24 Oct 2016 01:56:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1byYEr-0004jK-EL for qemu-devel@nongnu.org; Mon, 24 Oct 2016 01:56:02 -0400 From: vijay.kilari@gmail.com Date: Mon, 24 Oct 2016 11:25:22 +0530 Message-Id: <1477288523-10819-3-git-send-email-vijay.kilari@gmail.com> In-Reply-To: <1477288523-10819-1-git-send-email-vijay.kilari@gmail.com> References: <1477288523-10819-1-git-send-email-vijay.kilari@gmail.com> Subject: [Qemu-devel] [PATCH v3 2/3] utils: Add helper to read arm MIDR_EL1 register List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-arm@nongnu.org, peter.maydell@linaro.org, pbonzini@redhat.com, rth@twiddle.net Cc: qemu-devel@nongnu.org, vijay.kilari@gmail.com, Vijaya Kumar K From: Vijaya Kumar K Add helper API to read MIDR_EL1 registers to fetch cpu identification information. This helps in adding errata's and architecture specific features. This is implemented only for arm architecture. Signed-off-by: Vijaya Kumar K --- include/qemu/aarch64-cpuid.h | 9 +++++ util/Makefile.objs | 1 + util/aarch64-cpuid.c | 87 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 97 insertions(+) diff --git a/include/qemu/aarch64-cpuid.h b/include/qemu/aarch64-cpuid.h new file mode 100644 index 0000000..dbcb5ff --- /dev/null +++ b/include/qemu/aarch64-cpuid.h @@ -0,0 +1,9 @@ +#ifndef QEMU_AARCH64_CPUID_H +#define QEMU_AARCH64_CPUID_H + +#if defined(__aarch64__) +uint64_t get_aarch64_cpu_id(void); +bool is_thunderx_pass2_cpu(void); +#endif + +#endif diff --git a/util/Makefile.objs b/util/Makefile.objs index 36c7dcc..d14a455 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -37,3 +37,4 @@ util-obj-y += log.o util-obj-y += qdist.o util-obj-y += qht.o util-obj-y += range.o +util-obj-y += aarch64-cpuid.o diff --git a/util/aarch64-cpuid.c b/util/aarch64-cpuid.c new file mode 100644 index 0000000..a6352ad --- /dev/null +++ b/util/aarch64-cpuid.c @@ -0,0 +1,87 @@ +/* + * Dealing with arm cpu identification information. + * + * Copyright (C) 2016 Cavium, Inc. + * + * Authors: + * Vijaya Kumar K + * + * This work is licensed under the terms of the GNU LGPL, version 2.1 + * or later. See the COPYING.LIB file in the top-level directory. + */ + +#include +#include "qemu/osdep.h" +#include "qemu-common.h" +#include "qemu/cutils.h" +#include "qemu/aarch64-cpuid.h" + +#if defined(__aarch64__) +#define MIDR_IMPLEMENTER_SHIFT 24 +#define MIDR_IMPLEMENTER_MASK (0xffULL << MIDR_IMPLEMENTER_SHIFT) +#define MIDR_ARCHITECTURE_SHIFT 16 +#define MIDR_ARCHITECTURE_MASK (0xf << MIDR_ARCHITECTURE_SHIFT) +#define MIDR_PARTNUM_SHIFT 4 +#define MIDR_PARTNUM_MASK (0xfff << MIDR_PARTNUM_SHIFT) + +#define MIDR_CPU_PART(imp, partnum) \ + (((imp) << MIDR_IMPLEMENTER_SHIFT) | \ + (0xf << MIDR_ARCHITECTURE_SHIFT) | \ + ((partnum) << MIDR_PARTNUM_SHIFT)) + +#define ARM_CPU_IMP_CAVIUM 0x43 +#define CAVIUM_CPU_PART_THUNDERX 0x0A1 + +#define MIDR_THUNDERX_PASS2 \ + MIDR_CPU_PART(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX) +#define CPU_MODEL_MASK (MIDR_IMPLEMENTER_MASK | MIDR_ARCHITECTURE_MASK | \ + MIDR_PARTNUM_MASK) + +static uint64_t qemu_read_aarch64_midr_el1(void) +{ +#ifdef CONFIG_LINUX + const char *file = "/sys/devices/system/cpu/cpu0/regs/identification/midr_el1"; + char *buf; + uint64_t midr = 0; + +#define BUF_SIZE 32 + buf = g_malloc0(BUF_SIZE); + if (!buf) { + return 0; + } + + if (!g_file_get_contents(file, &buf, 0, NULL)) { + goto out; + } + + if (qemu_strtoull(buf, NULL, 0, &midr) < 0) { + goto out; + } + +out: + g_free(buf); + + return midr; +#else + return 0; +#endif +} + +static uint64_t aarch64_midr_val; +uint64_t get_aarch64_cpu_id(void) +{ +#ifdef CONFIG_LINUX + aarch64_midr_val = qemu_read_aarch64_midr_el1(); + aarch64_midr_val &= CPU_MODEL_MASK; + + return aarch64_midr_val; +#else + return 0; +#endif +} + +bool is_thunderx_pass2_cpu(void) +{ + return aarch64_midr_val == MIDR_THUNDERX_PASS2; +} +#endif -- 1.9.1