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Date: Tue, 5 Jun 2018 13:19:43 +0300
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Ingo Molnar <mingo@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>, x86@...nel.org,
"H. Peter Anvin" <hpa@...or.com>, Hugh Dickins <hughd@...gle.com>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 5/7] x86/cpu: Move early cpu initialization into a
separate translation unit
On Sat, May 19, 2018 at 08:47:33AM +0000, Thomas Gleixner wrote:
> On Fri, 18 May 2018, Kirill A. Shutemov wrote:
>
> > __pgtable_l5_enabled shouldn't be needed after system has booted, we can
> > mark it as __initdata, but it requires preparation.
> >
> > This patch moves early cpu initialization into a separate translation
> > unit. This limits effect of USE_EARLY_PGTABLE_L5 to less code.
> >
> > Without the change cpu_init() uses __pgtable_l5_enabled. cpu_init() is
> > not __init function and it leads to section mismatch.
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
>
> This makes a lot of sense independent of 5level changes.
>
> Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
Ingo, I've just noticed that this patch wasn't applied.
Below is rebased version. It applies cleanly on current tip/master and
Linus' tree.
---------------------8<----------------------------------
>From ff84fea44db72d09890dd69f4afb82060e6633a1 Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Date: Fri, 18 May 2018 13:35:26 +0300
Subject: [PATCH] x86/cpu: Move early cpu initialization into a separate
translation unit
__pgtable_l5_enabled shouldn't be needed after system has booted, we can
mark it as __initdata, but it requires preparation.
This patch moves early cpu initialization into a separate translation
unit. This limits effect of USE_EARLY_PGTABLE_L5 to less code.
Without the change cpu_init() uses __pgtable_l5_enabled. cpu_init() is
not __init function and it leads to section mismatch.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
---
arch/x86/kernel/cpu/Makefile | 1 +
arch/x86/kernel/cpu/common.c | 215 ++++-------------------------------
arch/x86/kernel/cpu/cpu.h | 7 ++
arch/x86/kernel/cpu/early.c | 183 +++++++++++++++++++++++++++++
4 files changed, 213 insertions(+), 193 deletions(-)
create mode 100644 arch/x86/kernel/cpu/early.c
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 7a40196967cb..b1da5a7c145c 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -19,6 +19,7 @@ CFLAGS_common.o := $(nostackp)
obj-y := cacheinfo.o scattered.o topology.o
obj-y += common.o
+obj-y += early.o
obj-y += rdrand.o
obj-y += match.o
obj-y += bugs.o
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 95c8e507580d..fa3dcbb7d4d8 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -47,7 +47,6 @@
#include <asm/pat.h>
#include <asm/microcode.h>
#include <asm/microcode_intel.h>
-#include <asm/intel-family.h>
#include <asm/cpu_device_id.h>
#ifdef CONFIG_X86_LOCAL_APIC
@@ -105,7 +104,7 @@ static const struct cpu_dev default_cpu = {
.c_x86_vendor = X86_VENDOR_UNKNOWN,
};
-static const struct cpu_dev *this_cpu = &default_cpu;
+const struct cpu_dev *this_cpu_dev = &default_cpu;
DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
#ifdef CONFIG_X86_64
@@ -426,7 +425,7 @@ cpuid_dependent_features[] = {
{ 0, 0 }
};
-static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
+void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
{
const struct cpuid_dependent_feature *df;
@@ -471,10 +470,10 @@ static const char *table_lookup_model(struct cpuinfo_x86 *c)
if (c->x86_model >= 16)
return NULL; /* Range check */
- if (!this_cpu)
+ if (!this_cpu_dev)
return NULL;
- info = this_cpu->legacy_models;
+ info = this_cpu_dev->legacy_models;
while (info->family) {
if (info->family == c->x86)
@@ -551,7 +550,7 @@ void switch_to_new_gdt(int cpu)
load_percpu_segment(cpu);
}
-static const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
+const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
static void get_model_name(struct cpuinfo_x86 *c)
{
@@ -622,8 +621,8 @@ void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
#else
/* do processor-specific cache resizing */
- if (this_cpu->legacy_cache_size)
- l2size = this_cpu->legacy_cache_size(c, l2size);
+ if (this_cpu_dev->legacy_cache_size)
+ l2size = this_cpu_dev->legacy_cache_size(c, l2size);
/* Allow user to override all this if necessary. */
if (cachesize_override != -1)
@@ -646,8 +645,8 @@ u16 __read_mostly tlb_lld_1g[NR_INFO];
static void cpu_detect_tlb(struct cpuinfo_x86 *c)
{
- if (this_cpu->c_detect_tlb)
- this_cpu->c_detect_tlb(c);
+ if (this_cpu_dev->c_detect_tlb)
+ this_cpu_dev->c_detect_tlb(c);
pr_info("Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n",
tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
@@ -709,7 +708,7 @@ void detect_ht(struct cpuinfo_x86 *c)
#endif
}
-static void get_cpu_vendor(struct cpuinfo_x86 *c)
+void get_cpu_vendor(struct cpuinfo_x86 *c)
{
char *v = c->x86_vendor_id;
int i;
@@ -722,8 +721,8 @@ static void get_cpu_vendor(struct cpuinfo_x86 *c)
(cpu_devs[i]->c_ident[1] &&
!strcmp(v, cpu_devs[i]->c_ident[1]))) {
- this_cpu = cpu_devs[i];
- c->x86_vendor = this_cpu->c_x86_vendor;
+ this_cpu_dev = cpu_devs[i];
+ c->x86_vendor = this_cpu_dev->c_x86_vendor;
return;
}
}
@@ -732,7 +731,7 @@ static void get_cpu_vendor(struct cpuinfo_x86 *c)
"CPU: Your system may be unstable.\n", v);
c->x86_vendor = X86_VENDOR_UNKNOWN;
- this_cpu = &default_cpu;
+ this_cpu_dev = &default_cpu;
}
void cpu_detect(struct cpuinfo_x86 *c)
@@ -902,7 +901,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
apply_forced_caps(c);
}
-static void get_cpu_address_sizes(struct cpuinfo_x86 *c)
+void get_cpu_address_sizes(struct cpuinfo_x86 *c)
{
u32 eax, ebx, ecx, edx;
@@ -918,7 +917,7 @@ static void get_cpu_address_sizes(struct cpuinfo_x86 *c)
#endif
}
-static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
+void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_32
int i;
@@ -944,176 +943,6 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
#endif
}
-static const __initconst struct x86_cpu_id cpu_no_speculation[] = {
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PINEVIEW, X86_FEATURE_ANY },
- { X86_VENDOR_CENTAUR, 5 },
- { X86_VENDOR_INTEL, 5 },
- { X86_VENDOR_NSC, 5 },
- { X86_VENDOR_ANY, 4 },
- {}
-};
-
-static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
- { X86_VENDOR_AMD },
- {}
-};
-
-/* Only list CPUs which speculate but are non susceptible to SSB */
-static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT1 },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT2 },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_MERRIFIELD },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_CORE_YONAH },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM },
- { X86_VENDOR_AMD, 0x12, },
- { X86_VENDOR_AMD, 0x11, },
- { X86_VENDOR_AMD, 0x10, },
- { X86_VENDOR_AMD, 0xf, },
- {}
-};
-
-static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
-{
- u64 ia32_cap = 0;
-
- if (x86_match_cpu(cpu_no_speculation))
- return;
-
- setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
- setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
-
- if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
- rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
-
- if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
- !(ia32_cap & ARCH_CAP_SSB_NO))
- setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
-
- if (x86_match_cpu(cpu_no_meltdown))
- return;
-
- /* Rogue Data Cache Load? No! */
- if (ia32_cap & ARCH_CAP_RDCL_NO)
- return;
-
- setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
-}
-
-/*
- * Do minimum CPU detection early.
- * Fields really needed: vendor, cpuid_level, family, model, mask,
- * cache alignment.
- * The others are not touched to avoid unwanted side effects.
- *
- * WARNING: this function is only called on the boot CPU. Don't add code
- * here that is supposed to run on all CPUs.
- */
-static void __init early_identify_cpu(struct cpuinfo_x86 *c)
-{
-#ifdef CONFIG_X86_64
- c->x86_clflush_size = 64;
- c->x86_phys_bits = 36;
- c->x86_virt_bits = 48;
-#else
- c->x86_clflush_size = 32;
- c->x86_phys_bits = 32;
- c->x86_virt_bits = 32;
-#endif
- c->x86_cache_alignment = c->x86_clflush_size;
-
- memset(&c->x86_capability, 0, sizeof c->x86_capability);
- c->extended_cpuid_level = 0;
-
- /* cyrix could have cpuid enabled via c_identify()*/
- if (have_cpuid_p()) {
- cpu_detect(c);
- get_cpu_vendor(c);
- get_cpu_cap(c);
- get_cpu_address_sizes(c);
- setup_force_cpu_cap(X86_FEATURE_CPUID);
-
- if (this_cpu->c_early_init)
- this_cpu->c_early_init(c);
-
- c->cpu_index = 0;
- filter_cpuid_features(c, false);
-
- if (this_cpu->c_bsp_init)
- this_cpu->c_bsp_init(c);
- } else {
- identify_cpu_without_cpuid(c);
- setup_clear_cpu_cap(X86_FEATURE_CPUID);
- }
-
- setup_force_cpu_cap(X86_FEATURE_ALWAYS);
-
- cpu_set_bug_bits(c);
-
- fpu__init_system(c);
-
-#ifdef CONFIG_X86_32
- /*
- * Regardless of whether PCID is enumerated, the SDM says
- * that it can't be enabled in 32-bit mode.
- */
- setup_clear_cpu_cap(X86_FEATURE_PCID);
-#endif
-
- /*
- * Later in the boot process pgtable_l5_enabled() relies on
- * cpu_feature_enabled(X86_FEATURE_LA57). If 5-level paging is not
- * enabled by this point we need to clear the feature bit to avoid
- * false-positives at the later stage.
- *
- * pgtable_l5_enabled() can be false here for several reasons:
- * - 5-level paging is disabled compile-time;
- * - it's 32-bit kernel;
- * - machine doesn't support 5-level paging;
- * - user specified 'no5lvl' in kernel command line.
- */
- if (!pgtable_l5_enabled())
- setup_clear_cpu_cap(X86_FEATURE_LA57);
-}
-
-void __init early_cpu_init(void)
-{
- const struct cpu_dev *const *cdev;
- int count = 0;
-
-#ifdef CONFIG_PROCESSOR_SELECT
- pr_info("KERNEL supported cpus:\n");
-#endif
-
- for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
- const struct cpu_dev *cpudev = *cdev;
-
- if (count >= X86_VENDOR_NUM)
- break;
- cpu_devs[count] = cpudev;
- count++;
-
-#ifdef CONFIG_PROCESSOR_SELECT
- {
- unsigned int j;
-
- for (j = 0; j < 2; j++) {
- if (!cpudev->c_ident[j])
- continue;
- pr_info(" %s %s\n", cpudev->c_vendor,
- cpudev->c_ident[j]);
- }
- }
-#endif
- }
- early_identify_cpu(&boot_cpu_data);
-}
-
/*
* The NOPL instruction is supposed to exist on all CPUs of family >= 6;
* unfortunately, that's not true in practice because of early VIA
@@ -1290,8 +1119,8 @@ static void identify_cpu(struct cpuinfo_x86 *c)
generic_identify(c);
- if (this_cpu->c_identify)
- this_cpu->c_identify(c);
+ if (this_cpu_dev->c_identify)
+ this_cpu_dev->c_identify(c);
/* Clear/Set all flags overridden by options, after probe */
apply_forced_caps(c);
@@ -1310,8 +1139,8 @@ static void identify_cpu(struct cpuinfo_x86 *c)
* At the end of this section, c->x86_capability better
* indicate the features this CPU genuinely supports!
*/
- if (this_cpu->c_init)
- this_cpu->c_init(c);
+ if (this_cpu_dev->c_init)
+ this_cpu_dev->c_init(c);
/* Disable the PN if appropriate */
squash_the_stupid_serial_number(c);
@@ -1446,7 +1275,7 @@ void print_cpu_info(struct cpuinfo_x86 *c)
const char *vendor = NULL;
if (c->x86_vendor < X86_VENDOR_NUM) {
- vendor = this_cpu->c_vendor;
+ vendor = this_cpu_dev->c_vendor;
} else {
if (c->cpuid_level >= 0)
vendor = c->x86_vendor_id;
@@ -1820,8 +1649,8 @@ void cpu_init(void)
static void bsp_resume(void)
{
- if (this_cpu->c_bsp_resume)
- this_cpu->c_bsp_resume(&boot_cpu_data);
+ if (this_cpu_dev->c_bsp_resume)
+ this_cpu_dev->c_bsp_resume(&boot_cpu_data);
}
static struct syscore_ops cpu_syscore_ops = {
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index 38216f678fc3..959529a61f9b 100644
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -45,8 +45,15 @@ struct _tlb_table {
extern const struct cpu_dev *const __x86_cpu_dev_start[],
*const __x86_cpu_dev_end[];
+extern const struct cpu_dev *cpu_devs[];
+extern const struct cpu_dev *this_cpu_dev;
+
extern void get_cpu_cap(struct cpuinfo_x86 *c);
+extern void get_cpu_vendor(struct cpuinfo_x86 *c);
+extern void get_cpu_address_sizes(struct cpuinfo_x86 *c);
extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
+extern void identify_cpu_without_cpuid(struct cpuinfo_x86 *c);
+extern void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn);
extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
extern u32 get_scattered_cpuid_leaf(unsigned int level,
unsigned int sub_leaf,
diff --git a/arch/x86/kernel/cpu/early.c b/arch/x86/kernel/cpu/early.c
new file mode 100644
index 000000000000..3014203b684c
--- /dev/null
+++ b/arch/x86/kernel/cpu/early.c
@@ -0,0 +1,183 @@
+/* cpu_feature_enabled() cannot be used this early */
+#define USE_EARLY_PGTABLE_L5
+
+#include <linux/linkage.h>
+#include <linux/kernel.h>
+
+#include <asm/processor.h>
+#include <asm/cpu.h>
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+#include <asm/fpu/internal.h>
+
+#include "cpu.h"
+
+static const __initconst struct x86_cpu_id cpu_no_speculation[] = {
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW, X86_FEATURE_ANY },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW, X86_FEATURE_ANY },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT, X86_FEATURE_ANY },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL, X86_FEATURE_ANY },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PINEVIEW, X86_FEATURE_ANY },
+ { X86_VENDOR_CENTAUR, 5 },
+ { X86_VENDOR_INTEL, 5 },
+ { X86_VENDOR_NSC, 5 },
+ { X86_VENDOR_ANY, 4 },
+ {}
+};
+
+static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
+ { X86_VENDOR_AMD },
+ {}
+};
+
+/* Only list CPUs which speculate but are non susceptible to SSB */
+static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT1 },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT2 },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_MERRIFIELD },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_CORE_YONAH },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL },
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM },
+ { X86_VENDOR_AMD, 0x12, },
+ { X86_VENDOR_AMD, 0x11, },
+ { X86_VENDOR_AMD, 0x10, },
+ { X86_VENDOR_AMD, 0xf, },
+ {}
+};
+
+static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
+{
+ u64 ia32_cap = 0;
+
+ if (x86_match_cpu(cpu_no_speculation))
+ return;
+
+ setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+ setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
+ if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
+ rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
+
+ if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
+ !(ia32_cap & ARCH_CAP_SSB_NO))
+ setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
+
+ if (x86_match_cpu(cpu_no_meltdown))
+ return;
+
+ /* Rogue Data Cache Load? No! */
+ if (ia32_cap & ARCH_CAP_RDCL_NO)
+ return;
+
+ setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
+}
+
+/*
+ * Do minimum CPU detection early.
+ * Fields really needed: vendor, cpuid_level, family, model, mask,
+ * cache alignment.
+ * The others are not touched to avoid unwanted side effects.
+ *
+ * WARNING: this function is only called on the boot CPU. Don't add code
+ * here that is supposed to run on all CPUs.
+ */
+static void __init early_identify_cpu(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_X86_64
+ c->x86_clflush_size = 64;
+ c->x86_phys_bits = 36;
+ c->x86_virt_bits = 48;
+#else
+ c->x86_clflush_size = 32;
+ c->x86_phys_bits = 32;
+ c->x86_virt_bits = 32;
+#endif
+ c->x86_cache_alignment = c->x86_clflush_size;
+
+ memset(&c->x86_capability, 0, sizeof c->x86_capability);
+ c->extended_cpuid_level = 0;
+
+ /* cyrix could have cpuid enabled via c_identify()*/
+ if (have_cpuid_p()) {
+ cpu_detect(c);
+ get_cpu_vendor(c);
+ get_cpu_cap(c);
+ get_cpu_address_sizes(c);
+ setup_force_cpu_cap(X86_FEATURE_CPUID);
+
+ if (this_cpu_dev->c_early_init)
+ this_cpu_dev->c_early_init(c);
+
+ c->cpu_index = 0;
+ filter_cpuid_features(c, false);
+
+ if (this_cpu_dev->c_bsp_init)
+ this_cpu_dev->c_bsp_init(c);
+ } else {
+ identify_cpu_without_cpuid(c);
+ setup_clear_cpu_cap(X86_FEATURE_CPUID);
+ }
+
+ setup_force_cpu_cap(X86_FEATURE_ALWAYS);
+
+ cpu_set_bug_bits(c);
+
+ fpu__init_system(c);
+
+#ifdef CONFIG_X86_32
+ /*
+ * Regardless of whether PCID is enumerated, the SDM says
+ * that it can't be enabled in 32-bit mode.
+ */
+ setup_clear_cpu_cap(X86_FEATURE_PCID);
+#endif
+
+ /*
+ * Later in the boot process pgtable_l5_enabled() relies on
+ * cpu_feature_enabled(X86_FEATURE_LA57). If 5-level paging is not
+ * enabled by this point we need to clear the feature bit to avoid
+ * false-positives at the later stage.
+ *
+ * pgtable_l5_enabled() can be false here for several reasons:
+ * - 5-level paging is disabled compile-time;
+ * - it's 32-bit kernel;
+ * - machine doesn't support 5-level paging;
+ * - user specified 'no5lvl' in kernel command line.
+ */
+ if (!pgtable_l5_enabled())
+ setup_clear_cpu_cap(X86_FEATURE_LA57);
+}
+
+void __init early_cpu_init(void)
+{
+ const struct cpu_dev *const *cdev;
+ int count = 0;
+
+#ifdef CONFIG_PROCESSOR_SELECT
+ pr_info("KERNEL supported cpus:\n");
+#endif
+
+ for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
+ const struct cpu_dev *cpudev = *cdev;
+
+ if (count >= X86_VENDOR_NUM)
+ break;
+ cpu_devs[count] = cpudev;
+ count++;
+
+#ifdef CONFIG_PROCESSOR_SELECT
+ {
+ unsigned int j;
+
+ for (j = 0; j < 2; j++) {
+ if (!cpudev->c_ident[j])
+ continue;
+ pr_info(" %s %s\n", cpudev->c_vendor,
+ cpudev->c_ident[j]);
+ }
+ }
+#endif
+ }
+ early_identify_cpu(&boot_cpu_data);
+}
--
Kirill A. Shutemov
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