[PATCH v2 14/33] x86/intel_rdt: Intel Code Data Prioritization detection

[Fenghua Yu]

From: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>

This patch adds enumeration support for Code Data Prioritization(CDP)
feature found in future Intel Xeon processors. It includes CPUID
enumeration routines for CDP.

CDP is an extension to Cache Allocation and lets threads allocate subset
of L3 cache for code and data separately. The allocation is represented
by the code or data cache capacity bit mask(cbm) MSRs
IA32_L3_QOS_MASK_n. Each Class of service would be associated with one
dcache_cbm and one icache_cbm MSR and hence the number of available
CLOSids is halved with CDP. The association for a CLOSid 'n' is shown
below :

data_cbm_address (n) = base + (n <<1)
code_cbm_address (n) = base + (n <<1) +1.
During scheduling the kernel writes the CLOSid
of the thread to IA32_PQR_ASSOC_MSR.

Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
 arch/x86/include/asm/cpufeature.h        | 6 ++++--
 arch/x86/include/asm/cpufeatures.h       | 5 ++++-
 arch/x86/include/asm/disabled-features.h | 3 ++-
 arch/x86/include/asm/required-features.h | 3 ++-
 arch/x86/kernel/cpu/intel_rdt.c          | 2 ++
 5 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 9985b4cf..7a54f87 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -81,8 +81,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) ||	\
+	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) ||	\
 	   REQUIRED_MASK_CHECK					  ||	\
-	   BUILD_BUG_ON_ZERO(NCAPINTS != 19))
+	   BUILD_BUG_ON_ZERO(NCAPINTS != 20))
 
 #define DISABLED_MASK_BIT_SET(feature_bit)				\
 	 ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  0, feature_bit) ||	\
@@ -104,8 +105,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) ||	\
+	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) ||	\
 	   DISABLED_MASK_CHECK					  ||	\
-	   BUILD_BUG_ON_ZERO(NCAPINTS != 19))
+	   BUILD_BUG_ON_ZERO(NCAPINTS != 20))
 
 #define cpu_has(c, bit)							\
 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 62d979b9..03f5d39 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -12,7 +12,7 @@
 /*
  * Defines x86 CPU feature bits
  */
-#define NCAPINTS	19	/* N 32-bit words worth of info */
+#define NCAPINTS	20	/* N 32-bit words worth of info */
 #define NBUGINTS	1	/* N 32-bit bug flags */
 
 /*
@@ -290,6 +290,9 @@
 /* Intel-defined CPU features, CPUID level 0x00000010:0 (ebx), word 18 */
 #define X86_FEATURE_CAT_L3      (18*32+ 1) /* Cache Allocation L3 */
 
+/* Intel-defined CPU QoS Sub-leaf, CPUID level 0x00000010:1 (ecx), word 19 */
+#define X86_FEATURE_CDP_L3	(19*32+ 2) /* Code Data Prioritization L3 */
+
 /*
  * BUG word(s)
  */
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 8b45e08..49d3c9f 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -58,6 +58,7 @@
 #define DISABLED_MASK16	(DISABLE_PKU|DISABLE_OSPKE)
 #define DISABLED_MASK17	0
 #define DISABLED_MASK18	0
-#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
+#define DISABLED_MASK19	0
+#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)
 
 #endif /* _ASM_X86_DISABLED_FEATURES_H */
diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h
index 6847d85..fa57000 100644
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h
@@ -101,6 +101,7 @@
 #define REQUIRED_MASK16	0
 #define REQUIRED_MASK17	0
 #define REQUIRED_MASK18	0
-#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
+#define REQUIRED_MASK19	0
+#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)
 
 #endif /* _ASM_X86_REQUIRED_FEATURES_H */
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index fb5a9a9..a4937d4 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -292,6 +292,8 @@ static int __init intel_rdt_late_init(void)
 		goto out_err;
 
 	pr_info("Intel cache allocation enabled\n");
+	if (cpu_has(c, X86_FEATURE_CDP_L3))
+		pr_info("Intel code data prioritization detected\n");
 out_err:
 
 	return err;
-- 
2.5.0