Hi Paolo, On Tue, Aug 2, 2016 at 4:18 PM, Paolo Bonzini <pbonz...@redhat.com> wrote: > ----- Original Message ----- >> From: "vijay kilari" <vijay.kil...@gmail.com> >> To: qemu-...@nongnu.org, "peter maydell" <peter.mayd...@linaro.org>, >> pbonz...@redhat.com >> Cc: qemu-devel@nongnu.org, "Prasun Kapoor" <prasun.kap...@cavium.com>, >> "vijay kilari" <vijay.kil...@gmail.com>, >> "Vijaya Kumar K" <vijaya.ku...@cavium.com> >> Sent: Tuesday, August 2, 2016 12:20:15 PM >> Subject: [RFC PATCH v1 1/2] utils: Add helper to read arm MIDR_EL1 register >> >> From: Vijaya Kumar K <vijaya.ku...@cavium.com> >> >> 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 <vijaya.ku...@cavium.com> >> --- >> include/qemu-common.h | 1 + >> util/Makefile.objs | 1 + >> util/cpuinfo.c | 52 >> +++++++++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 54 insertions(+) >> >> diff --git a/include/qemu-common.h b/include/qemu-common.h >> index 1f2cb94..62ad674 100644 >> --- a/include/qemu-common.h >> +++ b/include/qemu-common.h >> @@ -134,4 +134,5 @@ void page_size_init(void); >> * returned. */ >> bool dump_in_progress(void); >> >> +long int qemu_read_cpuid_info(void); > > First, please avoid adding to include/qemu-common.h (it really should > go away). > > Second, this is too generic a name. Please call it something like > qemu_read_aarch64_midr_el1.
OK > > Third, it's probably a bad idea to call this function from generic code, so > make it static and add the detection function from patch 2/2 already here. > By making it static, it's also possible to define it only if CONFIG_LINUX > is defined; the ThunderX detection will then return false if !CONFIG_LINUX. > You mean to say, move contents of this patch to util/cutils.c and make it static and define under __aarch64__ and CONFIG_LINUX?. > Thanks, > > Paolo > >> #endif >> diff --git a/util/Makefile.objs b/util/Makefile.objs >> index 96cb1e0..9d25a72 100644 >> --- a/util/Makefile.objs >> +++ b/util/Makefile.objs >> @@ -35,3 +35,4 @@ util-obj-y += log.o >> util-obj-y += qdist.o >> util-obj-y += qht.o >> util-obj-y += range.o >> +util-obj-y += cpuinfo.o >> diff --git a/util/cpuinfo.c b/util/cpuinfo.c >> new file mode 100644 >> index 0000000..3ba7194 >> --- /dev/null >> +++ b/util/cpuinfo.c >> @@ -0,0 +1,52 @@ >> +/* >> + * Dealing with arm cpu identification information. >> + * >> + * Copyright (C) 2016 Cavium, Inc. >> + * >> + * Authors: >> + * Vijaya Kumar K <vijaya.ku...@cavium.com> >> + * >> + * 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-common.h" >> +#include "qemu/cutils.h" >> + >> +#if defined(__aarch64__) >> + >> +long int qemu_read_cpuid_info(void) >> +{ >> + FILE *fp; >> + char *buf; >> + long int midr = 0; >> +#define BUF_SIZE 32 >> + >> + fp = fopen("/sys/devices/system/cpu/cpu0/regs/identification/midr_el1", >> + "r"); >> + if (!fp) { >> + return 0; >> + } >> + >> + buf = g_malloc0(BUF_SIZE); >> + if (!buf) { >> + fclose(fp); >> + return 0; >> + } >> + >> + if (buf != fgets(buf, BUF_SIZE - 1, fp)) { >> + goto out; >> + } >> + >> + if (qemu_strtol(buf, NULL, 0, &midr) < 0) { >> + goto out; >> + } >> + >> +out: >> + g_free(buf); >> + fclose(fp); >> + >> + return midr; >> +} >> +#endif >> -- >> 1.7.9.5 >> >>