x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption

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: cb06d8e3d020 ("x86/tme: Detect if TME and MKTME is activated by BIOS")
Reported-by: Kai Huang <[e-mail]>
Signed-off-by: Kirill A. Shutemov <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Cc: Tom Lendacky <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: [e-mail]
Cc: "H. Peter Anvin" <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]

arch/x86/kernel/cpu/common.c

···
 		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)
 		c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
 
···
 	 * several times during CPU initialization.
 	 */
 	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)
···
 		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)
···
 	get_cpu_vendor(c);
 
 	get_cpu_cap(c);
+
+	get_cpu_address_sizes(c);
 
 	if (c->cpuid_level >= 0x00000001) {
 		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;