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Message-ID: <20250506050437.10264-19-darwi@linutronix.de>
Date: Tue, 6 May 2025 07:04:29 +0200
From: "Ahmed S. Darwish" <darwi@...utronix.de>
To: Ingo Molnar <mingo@...hat.com>,
Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Thomas Gleixner <tglx@...utronix.de>,
Andrew Cooper <andrew.cooper3@...rix.com>,
"H. Peter Anvin" <hpa@...or.com>,
John Ogness <john.ogness@...utronix.de>,
x86@...nel.org,
x86-cpuid@...ts.linux.dev,
LKML <linux-kernel@...r.kernel.org>,
"Ahmed S. Darwish" <darwi@...utronix.de>
Subject: [PATCH v1 18/26] x86/cpuid: Scan deterministic cache params CPUID leaves
Add CPUID scanner logic for Intel CPUID(0x4) and AMD CPUID(0x8000001d).
Define a single CPUID "deterministic cache" read function for both leaves
as both have the same subleaf cache enumeration logic.
Introduce __define_cpuid_read_function() to avoid duplication between
cpuid_read_generic(), the CPUID scanner default read function, and the
new cpuid_read_deterministic_cache().
Signed-off-by: Ahmed S. Darwish <darwi@...utronix.de>
---
arch/x86/include/asm/cpuid/types.h | 2 ++
arch/x86/kernel/cpu/cpuid_scanner.c | 40 ++++++++++++++++++++++++-----
arch/x86/kernel/cpu/cpuid_scanner.h | 4 ++-
3 files changed, 39 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/cpuid/types.h b/arch/x86/include/asm/cpuid/types.h
index b8e525725def..2ac3d05c3fe4 100644
--- a/arch/x86/include/asm/cpuid/types.h
+++ b/arch/x86/include/asm/cpuid/types.h
@@ -181,7 +181,9 @@ struct cpuid_leaves {
CPUID_LEAF(0x0, 0, 1);
CPUID_LEAF(0x1, 0, 1);
CPUID_LEAF(0x2, 0, 1);
+ CPUID_LEAF(0x4, 0, 8);
CPUID_LEAF(0x80000000, 0, 1);
+ CPUID_LEAF(0x8000001d, 0, 8);
};
/**
diff --git a/arch/x86/kernel/cpu/cpuid_scanner.c b/arch/x86/kernel/cpu/cpuid_scanner.c
index aaee1ede0472..664946ebe675 100644
--- a/arch/x86/kernel/cpu/cpuid_scanner.c
+++ b/arch/x86/kernel/cpu/cpuid_scanner.c
@@ -10,15 +10,43 @@
#include "cpuid_scanner.h"
+/**
+ * __define_cpuid_read_function() - Generate a CPUID scanner read function
+ * @_suffix: Suffix for the generated function name (full name: cpuid_read_@...ffix())
+ * @_leaf_t: Type to cast the CPUID query output storage pointer
+ * @_leaf: Name of the CPUID query storage pointer
+ * @_break_c: Condition to break the CPUID scanning loop, which may reference @_leaf,
+ * and where @_leaf stores each iteration's CPUID query output.
+ *
+ * Define a CPUID scanner read function according to the requirements stated
+ * at &struct cpuid_scan_entry->read().
+ */
+#define __define_cpuid_read_function(_suffix, _leaf_t, _leaf, _break_c) \
+static void \
+cpuid_read_##_suffix(const struct cpuid_scan_entry *e, struct cpuid_read_output *output) \
+{ \
+ struct _leaf_t *_leaf = (struct _leaf_t *)output->leaf; \
+ \
+ static_assert(sizeof(*_leaf) == 16); \
+ \
+ output->info->nr_entries = 0; \
+ for (int i = 0; i < e->maxcnt; i++, _leaf++, output->info->nr_entries++) { \
+ cpuid_subleaf(e->leaf, e->subleaf + i, _leaf); \
+ if (_break_c) \
+ break; \
+ } \
+}
+
/*
* Default CPUID scanner read function
*/
-static void cpuid_read_generic(const struct cpuid_scan_entry *e, struct cpuid_read_output *output)
-{
- output->info->nr_entries = 0;
- for (int i = 0; i < e->maxcnt; i++, output->leaf++, output->info->nr_entries++)
- cpuid_subleaf(e->leaf, e->subleaf + i, output->leaf);
-}
+__define_cpuid_read_function(generic, cpuid_regs, ignored, false);
+
+/*
+ * Shared read function for Intel CPUID leaf 0x4 and AMD CPUID leaf 0x8000001d,
+ * as both have the same subleaf enumeration logic and registers output format.
+ */
+__define_cpuid_read_function(deterministic_cache, leaf_0x4_0, leaf, leaf->cache_type == 0);
static void cpuid_read_0x2(const struct cpuid_scan_entry *e, struct cpuid_read_output *output)
{
diff --git a/arch/x86/kernel/cpu/cpuid_scanner.h b/arch/x86/kernel/cpu/cpuid_scanner.h
index dc1d518c9768..a09110a4c72c 100644
--- a/arch/x86/kernel/cpu/cpuid_scanner.h
+++ b/arch/x86/kernel/cpu/cpuid_scanner.h
@@ -93,7 +93,9 @@ struct cpuid_scan_entry {
SCAN_ENTRY(0x0, 0, generic), \
SCAN_ENTRY(0x1, 0, generic), \
SCAN_ENTRY(0x2, 0, 0x2), \
- SCAN_ENTRY(0x80000000, 0, 0x80000000),
+ SCAN_ENTRY(0x4, 0, deterministic_cache), \
+ SCAN_ENTRY(0x80000000, 0, 0x80000000), \
+ SCAN_ENTRY(0x8000001d, 0, deterministic_cache), \
/**
* struct cpuid_scan_info - Parameters for generic CPUID scan logic
--
2.49.0
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