[PATCH v7 010/120] x86/lib: Add CPUID(0x1) family and model calculation
"Ahmed S. Darwish" <[email protected]> Thu, 28 May 2026 17:37:32 +0200
| Newsgroups | dev.linux.lists.x86-cpuid,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
The x86 library provides x86_family() and x86_model(). They take raw CPUID(0x1) register output and calculate the CPU family and model from it. In follow-up work, the x86 subsystem will use parsed CPUID APIs instead of invoking direct CPUID queries. These new APIs force using the auto generated leaf data types at <asm/cpuid/leaf_types.h>. Introduce x86 family and model calculation functions that take these auto-generated data types. Refactor the original code so that no logic is duplicated. Signed-off-by: Ahmed S. Darwish <[email protected]> --- arch/x86/include/asm/cpu.h | 6 +++++ arch/x86/lib/cpu.c | 45 ++++++++++++++++++++++++-------------- 2 files changed, 35 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 57a0786dfd75..01313070b2da 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -7,7 +7,9 @@ #include <linux/topology.h> #include <linux/nodemask.h> #include <linux/percpu.h> + #include <asm/ibt.h> +#include <asm/cpuid/leaf_types.h> #ifndef CONFIG_SMP #define cpu_physical_id(cpu) boot_cpu_physical_apicid @@ -24,6 +26,10 @@ int mwait_usable(const struct cpuinfo_x86 *); unsigned int x86_family(unsigned int sig); unsigned int x86_model(unsigned int sig); unsigned int x86_stepping(unsigned int sig); + +unsigned int cpuid_family(const struct leaf_0x1_0 *l); +unsigned int cpuid_model(const struct leaf_0x1_0 *l); + #ifdef CONFIG_X86_BUS_LOCK_DETECT extern void __init sld_setup(struct cpuinfo_x86 *c); extern bool handle_user_split_lock(struct pt_regs *regs, long error_code); diff --git a/arch/x86/lib/cpu.c b/arch/x86/lib/cpu.c index 7ad68917a51e..4d0beeeb4885 100644 --- a/arch/x86/lib/cpu.c +++ b/arch/x86/lib/cpu.c @@ -1,33 +1,36 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/types.h> #include <linux/export.h> + #include <asm/cpu.h> +#include <asm/cpuid/leaf_types.h> -unsigned int x86_family(unsigned int sig) +static unsigned int __x86_family(unsigned int base_fam, unsigned int ext_fam) { - unsigned int x86; + if (base_fam == 0xf) + base_fam += ext_fam; - x86 = (sig >> 8) & 0xf; + return base_fam; +} - if (x86 == 0xf) - x86 += (sig >> 20) & 0xff; +static unsigned int +__x86_model(unsigned int family, unsigned int base_model, unsigned int ext_model) +{ + if (family >= 0x6) + base_model |= ext_model << 4; - return x86; + return base_model; +} + +unsigned int x86_family(unsigned int sig) +{ + return __x86_family((sig >> 8) & 0xf, (sig >> 20) & 0xff); } EXPORT_SYMBOL_GPL(x86_family); unsigned int x86_model(unsigned int sig) { - unsigned int fam, model; - - fam = x86_family(sig); - - model = (sig >> 4) & 0xf; - - if (fam >= 0x6) - model += ((sig >> 16) & 0xf) << 4; - - return model; + return __x86_model(x86_family(sig), (sig >> 4) & 0xf, (sig >> 16) & 0xf); } EXPORT_SYMBOL_GPL(x86_model); @@ -36,3 +39,13 @@ unsigned int x86_stepping(unsigned int sig) return sig & 0xf; } EXPORT_SYMBOL_GPL(x86_stepping); + +unsigned int cpuid_family(const struct leaf_0x1_0 *l) +{ + return __x86_family(l->base_family_id, l->ext_family); +} + +unsigned int cpuid_model(const struct leaf_0x1_0 *l) +{ + return __x86_model(cpuid_family(l), l->base_model, l->ext_model); +} -- 2.54.0