From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35288) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cEfhC-0002JV-Gq for qemu-devel@nongnu.org; Wed, 07 Dec 2016 12:07:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cEfhB-0000UP-I2 for qemu-devel@nongnu.org; Wed, 07 Dec 2016 12:07:54 -0500 From: vijay.kilari@gmail.com Date: Wed, 7 Dec 2016 22:36:12 +0530 Message-Id: <1481130374-5147-3-git-send-email-vijay.kilari@gmail.com> In-Reply-To: <1481130374-5147-1-git-send-email-vijay.kilari@gmail.com> References: <1481130374-5147-1-git-send-email-vijay.kilari@gmail.com> Subject: [Qemu-devel] [PATCH v5 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 | 38 ++++++++++++++++++++++++++++++++ util/Makefile.objs | 1 + util/aarch64-cpuid.c | 52 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 91 insertions(+) diff --git a/include/qemu/aarch64-cpuid.h b/include/qemu/aarch64-cpuid.h new file mode 100644 index 0000000..fb88ed8 --- /dev/null +++ b/include/qemu/aarch64-cpuid.h @@ -0,0 +1,38 @@ +#ifndef QEMU_AARCH64_CPUID_H +#define QEMU_AARCH64_CPUID_H + +#if defined(__aarch64__) && defined(CONFIG_LINUX) +#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) + +uint64_t get_aarch64_cpu_id(void); +bool is_thunderx_pass2_cpu(void); +#else +static inline uint64_t get_aarch64_cpu_id(void) +{ + return 0; +} + +static inline bool is_thunderx_pass2_cpu(void) +{ + return false; +} +#endif +#endif diff --git a/util/Makefile.objs b/util/Makefile.objs index ad0f9c7..a9585c9 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -36,3 +36,4 @@ util-obj-y += log.o util-obj-y += qdist.o util-obj-y += qht.o util-obj-y += range.o +util-obj-$(CONFIG_LINUX) += aarch64-cpuid.o diff --git a/util/aarch64-cpuid.c b/util/aarch64-cpuid.c new file mode 100644 index 0000000..575f52e --- /dev/null +++ b/util/aarch64-cpuid.c @@ -0,0 +1,52 @@ +/* + * 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 "qemu/osdep.h" +#include "qemu/cutils.h" +#include "qemu/aarch64-cpuid.h" + +#if defined(__aarch64__) +static uint64_t qemu_read_aarch64_midr_el1(void) +{ + const char *file = "/sys/devices/system/cpu/cpu0/regs/identification/midr_el1"; + char *buf; + uint64_t midr = 0; + + if (!g_file_get_contents(file, &buf, 0, NULL)) { + goto out; + } + + if (qemu_strtoull(buf, NULL, 0, &midr) < 0) { + midr = 0; + goto out; + } + +out: + g_free(buf); + + return midr; +} + +static uint64_t aarch64_midr_val; +uint64_t get_aarch64_cpu_id(void) +{ + aarch64_midr_val = qemu_read_aarch64_midr_el1(); + aarch64_midr_val &= CPU_MODEL_MASK; + + return aarch64_midr_val; +} + +bool is_thunderx_pass2_cpu(void) +{ + return aarch64_midr_val == MIDR_THUNDERX_PASS2; +} +#endif -- 1.9.1