linux-kernel - [RFC][PATCH 14/34] x86/cpu: Remove default physical address space settings

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Date: Thu, 22 Feb 2024 10:39:45 -0800
From: Dave Hansen <dave.hansen@...ux.intel.com>
To: linux-kernel@...r.kernel.org
Cc: kirill.shutemov@...ux.intel.com,pbonzini@...hat.com,tglx@...utronix.de,x86@...nel.org,bp@...en8.de,Dave Hansen <dave.hansen@...ux.intel.com>
Subject: [RFC][PATCH 14/34] x86/cpu: Remove default physical address space settings


From: Dave Hansen <dave.hansen@...ux.intel.com>

At this point, the secondary CPUs' c->x86_phys_bits should be unused.  The boot
CPU values were also established long before reaching here.  This can only
serve to sow chaos.  Remove the twiddling.

Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
---

 b/arch/x86/kernel/cpu/common.c |    2 --
 1 file changed, 2 deletions(-)

diff -puN arch/x86/kernel/cpu/common.c~no-default-bit-setting-phys arch/x86/kernel/cpu/common.c
--- a/arch/x86/kernel/cpu/common.c~no-default-bit-setting-phys	2024-02-22 10:08:55.256720151 -0800
+++ b/arch/x86/kernel/cpu/common.c	2024-02-22 10:08:55.260720308 -0800
@@ -1827,12 +1827,10 @@ static void identify_cpu(struct cpuinfo_
 	c->topo.l2c_id = BAD_APICID;
 #ifdef CONFIG_X86_64
 	c->x86_clflush_size = 64;
-	c->x86_phys_bits = 36;
 	c->x86_virt_bits = 48;
 #else
 	c->cpuid_level = -1;	/* CPUID not detected */
 	c->x86_clflush_size = 32;
-	c->x86_phys_bits = 32;
 	c->x86_virt_bits = 32;
 #endif
 	c->x86_cache_alignment = x86_clflush_size();
_