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x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption

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Some features (Intel MKTME, AMD SME) reduce the number of effectively
available physical address bits. cpuinfo_x86::x86_phys_bits is adjusted
accordingly during the early cpu feature detection.

Though if get_cpu_cap() is called later again then this adjustement is
overwritten. That happens in setup_pku(), which is called after
detect_tme().

To address this, extract the address sizes enumeration into a separate
function, which is only called only from early_identify_cpu() and from
generic_identify().

This makes get_cpu_cap() safe to be called later during boot proccess
without overwriting cpuinfo_x86::x86_phys_bits.

[ tglx: Massaged changelog ]

Fixes: cb06d8e3d0 ("x86/tme: Detect if TME and MKTME is activated by BIOS")
Reported-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: linux-mm@kvack.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180410092704.41106-1-kirill.shutemov@linux.intel.com
This commit is contained in:
Kirill A. Shutemov 2018-04-10 12:27:04 +03:00 committed by Thomas Gleixner
parent 92e830f25f
commit d94a155c59
1 changed files with 20 additions and 12 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

32
arch/x86/kernel/cpu/common.c
View file

@ -848,18 +848,6 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
c->x86_power = edx; c->x86_power = edx;
} }
if (c->extended_cpuid_level >= 0x80000008) {
cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
c->x86_virt_bits = (eax >> 8) & 0xff;
c->x86_phys_bits = eax & 0xff;
c->x86_capability[CPUID_8000_0008_EBX] = ebx;
}
#ifdef CONFIG_X86_32
else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
c->x86_phys_bits = 36;
#endif
if (c->extended_cpuid_level >= 0x8000000a) if (c->extended_cpuid_level >= 0x8000000a)
c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a); c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
@ -874,6 +862,23 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
apply_forced_caps(c); apply_forced_caps(c);
} }
static void get_cpu_address_sizes(struct cpuinfo_x86 *c)
{
u32 eax, ebx, ecx, edx;
if (c->extended_cpuid_level >= 0x80000008) {
cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
c->x86_virt_bits = (eax >> 8) & 0xff;
c->x86_phys_bits = eax & 0xff;
c->x86_capability[CPUID_8000_0008_EBX] = ebx;
}
#ifdef CONFIG_X86_32
else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
c->x86_phys_bits = 36;
#endif
}
static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c) static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
{ {
#ifdef CONFIG_X86_32 #ifdef CONFIG_X86_32
@ -965,6 +970,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
cpu_detect(c); cpu_detect(c);
get_cpu_vendor(c); get_cpu_vendor(c);
get_cpu_cap(c); get_cpu_cap(c);
get_cpu_address_sizes(c);
setup_force_cpu_cap(X86_FEATURE_CPUID); setup_force_cpu_cap(X86_FEATURE_CPUID);
if (this_cpu->c_early_init) if (this_cpu->c_early_init)
@ -1097,6 +1103,8 @@ static void generic_identify(struct cpuinfo_x86 *c)
get_cpu_cap(c); get_cpu_cap(c);
get_cpu_address_sizes(c);
if (c->cpuid_level >= 0x00000001) { if (c->cpuid_level >= 0x00000001) {
c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF; c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
#ifdef CONFIG_X86_32 #ifdef CONFIG_X86_32