From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752682AbaBVTKP (ORCPT ); Sat, 22 Feb 2014 14:10:15 -0500 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:33204 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752605AbaBVTJs (ORCPT ); Sat, 22 Feb 2014 14:09:48 -0500 X-Originating-IP: 50.43.14.201 Date: Sat, 22 Feb 2014 11:09:30 -0800 From: Josh Triplett To: Andi Kleen , Andrew Morton , Borislav Petkov , Feng Tang , "H. Peter Anvin" , Ingo Molnar , Jacob Shin , Jan Beulich , "Kirill A. Shutemov" , Paul Gortmaker , Peter Zijlstra , Qiaowei Ren , Rob Landley , Seiji Aguchi , Stephane Eranian , Suravee Suthikulpanit , Thomas Gleixner , Thomas Renninger , linux-kernel@vger.kernel.org, x86@kernel.org Subject: [PATCH 2/2] x86: Support compiling out human-friendly processor feature names Message-ID: <33fa63a2b441f81f2ddb3ee2edff4deda60e50ac.1393096111.git.josh@joshtriplett.org> References: <296de15c8addece6dada4ddac982b3934d8ff6fa.1393096111.git.josh@joshtriplett.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <296de15c8addece6dada4ddac982b3934d8ff6fa.1393096111.git.josh@joshtriplett.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The table mapping CPUID bits to human-readable strings takes up a non-trivial amount of space, and only exists to support /proc/cpuinfo and a couple of kernel messages. Since programs depend on the format of /proc/cpuinfo, force inclusion of the table when building with /proc support; otherwise, support omitting that table to save space, in which case the kernel messages will print features numerically instead. In addition to saving 1408 bytes out of vmlinux, this also saves 1373 bytes out of the uncompressed setup code, which contributes directly to the size of bzImage. Signed-off-by: Josh Triplett --- arch/x86/Kconfig | 12 +++++++ arch/x86/boot/Makefile | 5 ++- arch/x86/boot/cpu.c | 68 +++++++++++++++++++++++---------------- arch/x86/include/asm/cpufeature.h | 13 ++++++++ arch/x86/kernel/cpu/Makefile | 5 ++- arch/x86/kernel/cpu/common.c | 4 +-- 6 files changed, 76 insertions(+), 31 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0af5250..4dfdbdc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -127,6 +127,7 @@ config X86 select HAVE_DEBUG_STACKOVERFLOW select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 select HAVE_CC_STACKPROTECTOR + select X86_FEATURE_NAMES if PROC_FS config INSTRUCTION_DECODER def_bool y @@ -304,6 +305,17 @@ config SMP If you don't know what to do here, say N. +config X86_FEATURE_NAMES + bool "Processor feature human-readable names" + default y + ---help--- + This option compiles in a table of x86 feature bits and corresponding + names. This is required to support /proc/cpuinfo and a few kernel + messages. You can disable this to save space, at the expense of + making those few kernel messages show numeric feature bits instead. + + If in doubt, say Y. + config X86_X2APIC bool "Support x2apic" depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 878df7e..ca6f7ed 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -35,7 +35,7 @@ setup-y += video-vesa.o setup-y += video-bios.o targets += $(setup-y) -hostprogs-y := mkcpustr tools/build +hostprogs-y := tools/build HOST_EXTRACFLAGS += -I$(srctree)/tools/include \ -include include/generated/autoconf.h \ @@ -43,11 +43,14 @@ HOST_EXTRACFLAGS += -I$(srctree)/tools/include \ $(obj)/cpu.o: $(obj)/cpustr.h +ifdef CONFIG_X86_FEATURE_NAMES +hostprogs-y += mkcpustr quiet_cmd_cpustr = CPUSTR $@ cmd_cpustr = $(obj)/mkcpustr > $@ targets += cpustr.h $(obj)/cpustr.h: $(obj)/mkcpustr FORCE $(call if_changed,cpustr) +endif # --------------------------------------------------------------------------- diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c index 6ec6bb6..29207f6 100644 --- a/arch/x86/boot/cpu.c +++ b/arch/x86/boot/cpu.c @@ -16,7 +16,9 @@ */ #include "boot.h" +#ifdef CONFIG_X86_FEATURE_NAMES #include "cpustr.h" +#endif static char *cpu_name(int level) { @@ -32,11 +34,48 @@ static char *cpu_name(int level) } } +static void show_cap_strs(u32 *err_flags) +{ + int i, j; +#ifdef CONFIG_X86_FEATURE_NAMES + const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs; + for (i = 0; i < NCAPINTS; i++) { + u32 e = err_flags[i]; + for (j = 0; j < 32; j++) { + if (msg_strs[0] < i || + (msg_strs[0] == i && msg_strs[1] < j)) { + /* Skip to the next string */ + msg_strs += 2; + while (*msg_strs++) + ; + } + if (e & 1) { + if (msg_strs[0] == i && + msg_strs[1] == j && + msg_strs[2]) + printf("%s ", msg_strs+2); + else + printf("%d:%d ", i, j); + } + e >>= 1; + } + } +#else + for (i = 0; i < NCAPINTS; i++) { + u32 e = err_flags[i]; + for (j = 0; j < 32; j++) { + if (e & 1) + printf("%d:%d ", i, j); + e >>= 1; + } + } +#endif +} + int validate_cpu(void) { u32 *err_flags; int cpu_level, req_level; - const unsigned char *msg_strs; check_cpu(&cpu_level, &req_level, &err_flags); @@ -49,34 +88,9 @@ int validate_cpu(void) } if (err_flags) { - int i, j; puts("This kernel requires the following features " "not present on the CPU:\n"); - - msg_strs = (const unsigned char *)x86_cap_strs; - - for (i = 0; i < NCAPINTS; i++) { - u32 e = err_flags[i]; - - for (j = 0; j < 32; j++) { - if (msg_strs[0] < i || - (msg_strs[0] == i && msg_strs[1] < j)) { - /* Skip to the next string */ - msg_strs += 2; - while (*msg_strs++) - ; - } - if (e & 1) { - if (msg_strs[0] == i && - msg_strs[1] == j && - msg_strs[2]) - printf("%s ", msg_strs+2); - else - printf("%d:%d ", i, j); - } - e >>= 1; - } - } + show_cap_strs(err_flags); putchar('\n'); return -1; } else { diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index e099f95..af6d7d5 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -237,8 +237,21 @@ #include #include +#ifdef CONFIG_X86_FEATURE_NAMES extern const char * const x86_cap_flags[NCAPINTS*32]; extern const char * const x86_power_flags[32]; +#define X86_CAP_FMT "%s" +static inline const char *x86_cap_flag(u32 flag) +{ + return x86_cap_flags[flag]; +} +#else +#define X86_CAP_FMT "%x" +static inline u32 x86_cap_flag(u32 flag) +{ + return flag; +} +#endif #define test_cpu_cap(c, bit) \ test_bit(bit, (unsigned long *)((c)->x86_capability)) diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 64038d8..77dcab2 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -13,11 +13,12 @@ nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_common.o := $(nostackp) obj-y := intel_cacheinfo.o scattered.o topology.o -obj-y += capflags.o powerflags.o common.o +obj-y += common.o obj-y += rdrand.o obj-y += match.o obj-$(CONFIG_PROC_FS) += proc.o +obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o obj-$(CONFIG_X86_32) += bugs.o obj-$(CONFIG_X86_64) += bugs_64.o @@ -50,6 +51,7 @@ obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o perf_event_amd_ibs.o obj-$(CONFIG_HYPERVISOR_GUEST) += vmware.o hypervisor.o mshyperv.o +ifdef CONFIG_X86_FEATURE_NAMES quiet_cmd_mkcapflags = MKCAP $@ cmd_mkcapflags = $(CONFIG_SHELL) $(srctree)/$(src)/mkcapflags.sh $< $@ @@ -58,3 +60,4 @@ cpufeature = $(src)/../../include/asm/cpufeature.h targets += capflags.c $(obj)/capflags.c: $(cpufeature) $(src)/mkcapflags.sh FORCE $(call if_changed,mkcapflags) +endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8e28bf2..3991a81 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -336,8 +336,8 @@ static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn) continue; printk(KERN_WARNING - "CPU: CPU feature %s disabled, no CPUID level 0x%x\n", - x86_cap_flags[df->feature], df->level); + "CPU: CPU feature " X86_CAP_FMT " disabled, no CPUID level 0x%x\n", + x86_cap_flag(df->feature), df->level); } } -- 1.9.0