[RFC PATCH 13/23] x86/cpufeatures: Add the Intel Thread Director feature definitions

Ricardo Neri
2022-09-09T23:07:12Z

Intel Thread Director (ITD) provides hardware resources to categorize
the currently running task with a classification value. The classification
reflects the type of instructions that a task executes.

ITD extends the Hardware Feedback Interface table to provide performance
and energy efficiency capabilities for each of the supported classes of
tasks.

Cc: Ben Segall <bsegall@google.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim C. Chen <tim.c.chen@intel.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/disabled-features.h | 8 +++++++-
arch/x86/kernel/cpu/cpuid-deps.c | 1 +
3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index ef4775c6db01..d3202d665ac0 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -339,6 +339,7 @@
#define X86_FEATURE_HWP_EPP (14*32+10) /* HWP Energy Perf. Preference */
#define X86_FEATURE_HWP_PKG_REQ (14*32+11) /* HWP Package Level Request */
#define X86_FEATURE_HFI (14*32+19) /* Hardware Feedback Interface */
+#define X86_FEATURE_ITD (14*32+23) /* Intel Thread Director */

/* AMD SVM Feature Identification, CPUID level 0x8000000a (EDX), word 15 */
#define X86_FEATURE_NPT (15*32+ 0) /* Nested Page Table support */
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 33d2cd04d254..225657aff476 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -87,6 +87,12 @@
# define DISABLE_TDX_GUEST (1 << (X86_FEATURE_TDX_GUEST & 31))
#endif

+#ifdef CONFIG_INTEL_THREAD_DIRECTOR
+# define DISABLE_ITD 0
+#else
+# define DISABLE_ITD (1 << (X86_FEATURE_ITD & 31))
+#endif
+
/*
* Make sure to add features to the correct mask
*/
@@ -103,7 +109,7 @@
#define DISABLED_MASK10 0
#define DISABLED_MASK11 (DISABLE_RETPOLINE|DISABLE_RETHUNK|DISABLE_UNRET)
#define DISABLED_MASK12 0
-#define DISABLED_MASK13 0
+#define DISABLED_MASK13 (DISABLE_ITD)
#define DISABLED_MASK14 0
#define DISABLED_MASK15 0
#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP| \
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index c881bcafba7d..f6f8a3cd4f2c 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -78,6 +78,7 @@ static const struct cpuid_dep cpuid_deps[] = {
{ X86_FEATURE_XFD, X86_FEATURE_XSAVES },
{ X86_FEATURE_XFD, X86_FEATURE_XGETBV1 },
{ X86_FEATURE_AMX_TILE, X86_FEATURE_XFD },
+ { X86_FEATURE_ITD, X86_FEATURE_HFI },
{}
};

--
2.25.1