From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: kirill.shutemov@linux.intel.com,pbonzini@redhat.com,tglx@linutronix.de,x86@kernel.org,bp@alien8.de,Dave
Hansen <dave.hansen@linux.intel.com>
Subject: [RFC][PATCH 21/34] x86/cpu: Consolidate CLFLUSH size setting.
Date: Thu, 22 Feb 2024 10:39:54 -0800 [thread overview]
Message-ID: <20240222183954.9A6E5428@davehans-spike.ostc.intel.com> (raw)
In-Reply-To: <20240222183926.517AFCD2@davehans-spike.ostc.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
Right now, cpu_detect() establishes ->x86_clflush_size on each CPU
that. supports CLFLUSH. As you might have guessed, that per-cpu
value is no longer used.
Move the setting to get_cpu_address_sizes() which is only called
on the boot CPU. Consolidate all of the ->x86_clflush_size logic
into a single helper.
This removes the (cap0 & (1<<19) aka X86_FEATURE_CLFLUSH check before
reading the CLFLUSH size out of CPUID[1]. Those bits are presumably
either 0 or have actual data about CLFLUSH in them.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
---
b/arch/x86/kernel/cpu/common.c | 35 ++++++++++++++++++++++++-----------
1 file changed, 24 insertions(+), 11 deletions(-)
diff -puN arch/x86/kernel/cpu/common.c~later-clflush_size-detect arch/x86/kernel/cpu/common.c
--- a/arch/x86/kernel/cpu/common.c~later-clflush_size-detect 2024-02-22 10:08:58.728856457 -0800
+++ b/arch/x86/kernel/cpu/common.c 2024-02-22 10:08:58.732856614 -0800
@@ -935,6 +935,27 @@ static void get_cpu_vendor(struct cpuinf
this_cpu = &default_cpu;
}
+static u16 detect_clflush_size(struct cpuinfo_x86 *c)
+{
+ u16 clflush_size = 0;
+
+ if (c->cpuid_level >= 0x00000001) {
+ u32 eax, ebx, ecx, edx;
+
+ cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
+
+ clflush_size = ((ebx >> 8) & 0xff) * 8;
+ }
+
+ if (clflush_size)
+ return clflush_size;
+
+ /* Return some mostly sane defaults: */
+ if (IS_ENABLED(CONFIG_X86_64))
+ return 64;
+ return 32;
+}
+
void cpu_detect(struct cpuinfo_x86 *c)
{
/* Get vendor name */
@@ -952,11 +973,6 @@ void cpu_detect(struct cpuinfo_x86 *c)
c->x86 = x86_family(tfms);
c->x86_model = x86_model(tfms);
c->x86_stepping = x86_stepping(tfms);
-
- if (cap0 & (1<<19)) {
- if (c == &boot_cpu_data)
- c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
- }
}
}
@@ -1111,17 +1127,17 @@ void get_cpu_address_sizes(struct cpuinf
if (IS_ENABLED(CONFIG_X86_64)) {
x86_config.phys_bits = 36;
x86_config.virt_bits = 48;
- c->x86_clflush_size = 64;
} else {
x86_config.phys_bits = 32;
x86_config.virt_bits = 32;
- c->x86_clflush_size = 32;
if (cpu_has(c, X86_FEATURE_PAE) ||
cpu_has(c, X86_FEATURE_PSE36))
x86_config.phys_bits = 36;
}
}
+ c->x86_clflush_size = detect_clflush_size(c);
+
c->x86_cache_bits = x86_config.phys_bits;
c->x86_cache_alignment = x86_clflush_size();
@@ -1827,11 +1843,8 @@ static void identify_cpu(struct cpuinfo_
c->topo.cu_id = 0xff;
c->topo.llc_id = BAD_APICID;
c->topo.l2c_id = BAD_APICID;
-#ifdef CONFIG_X86_64
- c->x86_clflush_size = 64;
-#else
+#ifndef CONFIG_X86_64
c->cpuid_level = -1; /* CPUID not detected */
- c->x86_clflush_size = 32;
#endif
memset(&c->x86_capability, 0, sizeof(c->x86_capability));
#ifdef CONFIG_X86_VMX_FEATURE_NAMES
_
next prev parent reply other threads:[~2024-02-22 18:39 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-22 18:39 [RFC][PATCH 00/34] [RFC] x86: Rework system-wide configuration masquerading as per-cpu data Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 01/34] x86/xen: Explain why calling get_cpu_cap() so early is a hack Dave Hansen
2024-03-07 16:27 ` Borislav Petkov
2024-02-22 18:39 ` [RFC][PATCH 02/34] x86/xen: Remove early "debug" physical address lookups Dave Hansen
2024-03-07 17:01 ` Borislav Petkov
2024-03-11 13:16 ` Jürgen Groß
2024-02-22 18:39 ` [RFC][PATCH 03/34] x86/pci: Assume that clflush size is always provided Dave Hansen
2024-03-08 8:57 ` Borislav Petkov
2024-02-22 18:39 ` [RFC][PATCH 04/34] x86/mm: Introduce physical address limit helper Dave Hansen
2024-02-27 11:05 ` Huang, Kai
2024-02-22 18:39 ` [RFC][PATCH 05/34] x86/cpu: Move /proc per-cpu ->x86_phys_bits reference to global one Dave Hansen
2024-02-27 11:05 ` Huang, Kai
2024-02-22 18:39 ` [RFC][PATCH 06/34] x86/boot: Use consistent value for iomem_resource.end Dave Hansen
2024-02-27 10:59 ` Huang, Kai
2024-02-28 14:22 ` Zhang, Rui
2024-02-22 18:39 ` [RFC][PATCH 07/34] x86/mm: Introduce virtual address space limit helper Dave Hansen
2024-02-27 11:09 ` Huang, Kai
2024-02-22 18:39 ` [RFC][PATCH 08/34] x86/cpu: Add CLFLUSH size helper Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 09/34] x86/cpu: Introduce address configuration structure Dave Hansen
2024-02-27 23:47 ` Huang, Kai
2024-02-28 17:29 ` Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 10/34] x86/cpu/amd: Use new "address configuration" infrastructure Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 11/34] x86/cpu/intel: Prepare MKTME for " Dave Hansen
2024-02-23 11:33 ` Kirill A. Shutemov
2024-02-23 16:22 ` Dave Hansen
2024-02-26 12:14 ` Kirill A. Shutemov
2024-02-27 21:48 ` Huang, Kai
2024-02-28 15:20 ` Kirill A. Shutemov
2024-02-28 16:57 ` Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 12/34] x86/cpu/intel: Actually use "address configuration" infrastructure for MKTME Dave Hansen
2024-02-23 11:41 ` Kirill A. Shutemov
2024-02-23 16:16 ` Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 13/34] x86/boot: Use address reduction config to handle erratum Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 14/34] x86/cpu: Remove default physical address space settings Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 15/34] x86/cpu: Remove default x86_phys_bits assignment Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 16/34] x86/cpu: Move physical address limit out of cpuinfo_x86 Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 17/34] x86/cpu: Move virtual " Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 18/34] x86/cpu/centaur: Move cache alignment override to BSP init Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 19/34] x86/cpu: Introduce cache alignment multiplier Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 20/34] x86/cpu: Remove superfluous cache alignment assignments Dave Hansen
2024-02-22 18:39 ` Dave Hansen [this message]
2024-02-22 18:39 ` [RFC][PATCH 22/34] x86/cpu: Move CLFLUSH size into global config Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 23/34] x86/cpu: Move cache alignment configuration to global struct Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 24/34] x86/cpu: Establish 'min_cache_bits' configuration Dave Hansen
2024-02-22 18:39 ` [RFC][PATCH 25/34] x86/cpu: Move cache bits to global config Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 26/34] x86/cpu: Zap superfluous get_cpu_address_sizes() Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 27/34] x86/cpu: Enforce read-only x86_config state (lightly) Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 28/34] x86/cpu: Return sane defaults for early x86_config reads Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 29/34] x86/xen: Remove extra get_cpu_address_sizes() call Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 30/34] x86/cpu/centaur: Mark BSP init function as __init Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 31/34] x86/cpu/intel: " Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 32/34] x86/cpu/amd: Move memory encryption detection Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 33/34] x86/cpu: Make get_cpu_address_sizes() static and __init Dave Hansen
2024-02-22 18:40 ` [RFC][PATCH 34/34] x86/cpu: Mark new boot CPU and config structures appropriately Dave Hansen
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