[PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation detection
From: Fenghua Yu
Date: Thu Sep 08 2016 - 03:03:29 EST
From: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
This patch includes CPUID enumeration routines for Cache allocation and
new values to track resources to the cpuinfo_x86 structure.
Cache allocation provides a way for the Software (OS/VMM) to restrict
cache allocation to a defined 'subset' of cache which may be overlapping
with other 'subsets'. This feature is used when allocating a line in
cache ie when pulling new data into the cache. The programming of the
hardware is done via programming MSRs (model specific registers).
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 | 8 +++++--
arch/x86/include/asm/cpufeatures.h | 6 +++++-
arch/x86/include/asm/disabled-features.h | 3 ++-
arch/x86/include/asm/processor.h | 3 +++
arch/x86/include/asm/required-features.h | 3 ++-
arch/x86/kernel/cpu/common.c | 19 ++++++++++++++++
arch/x86/kernel/cpu/intel_rdt.c | 37 ++++++++++++++++++++++++++++++++
7 files changed, 74 insertions(+), 5 deletions(-)
create mode 100644 arch/x86/kernel/cpu/intel_rdt.c
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 1d2b69f..9985b4cf 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -28,6 +28,8 @@ enum cpuid_leafs
CPUID_8000_000A_EDX,
CPUID_7_ECX,
CPUID_8000_0007_EBX,
+ CPUID_10_0_EBX,
+ CPUID_10_1_ECX,
};
#ifdef CONFIG_X86_FEATURE_NAMES
@@ -78,8 +80,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \
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) || \
REQUIRED_MASK_CHECK || \
- BUILD_BUG_ON_ZERO(NCAPINTS != 18))
+ BUILD_BUG_ON_ZERO(NCAPINTS != 19))
#define DISABLED_MASK_BIT_SET(feature_bit) \
( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
@@ -100,8 +103,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \
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) || \
DISABLED_MASK_CHECK || \
- BUILD_BUG_ON_ZERO(NCAPINTS != 18))
+ BUILD_BUG_ON_ZERO(NCAPINTS != 19))
#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 92a8308..62d979b9 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 18 /* N 32-bit words worth of info */
+#define NCAPINTS 19 /* N 32-bit words worth of info */
#define NBUGINTS 1 /* N 32-bit bug flags */
/*
@@ -220,6 +220,7 @@
#define X86_FEATURE_RTM ( 9*32+11) /* Restricted Transactional Memory */
#define X86_FEATURE_CQM ( 9*32+12) /* Cache QoS Monitoring */
#define X86_FEATURE_MPX ( 9*32+14) /* Memory Protection Extension */
+#define X86_FEATURE_RDT ( 9*32+15) /* Resource Director Technology */
#define X86_FEATURE_AVX512F ( 9*32+16) /* AVX-512 Foundation */
#define X86_FEATURE_AVX512DQ ( 9*32+17) /* AVX-512 DQ (Double/Quad granular) Instructions */
#define X86_FEATURE_RDSEED ( 9*32+18) /* The RDSEED instruction */
@@ -286,6 +287,9 @@
#define X86_FEATURE_SUCCOR (17*32+1) /* Uncorrectable error containment and recovery */
#define X86_FEATURE_SMCA (17*32+3) /* Scalable MCA */
+/* Intel-defined CPU features, CPUID level 0x00000010:0 (ebx), word 18 */
+#define X86_FEATURE_CAT_L3 (18*32+ 1) /* Cache Allocation L3 */
+
/*
* BUG word(s)
*/
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 85599ad..8b45e08 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -57,6 +57,7 @@
#define DISABLED_MASK15 0
#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE)
#define DISABLED_MASK17 0
-#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
+#define DISABLED_MASK18 0
+#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
#endif /* _ASM_X86_DISABLED_FEATURES_H */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 63def95..e940b2d 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -119,6 +119,9 @@ struct cpuinfo_x86 {
int x86_cache_occ_scale; /* scale to bytes */
int x86_power;
unsigned long loops_per_jiffy;
+ /* Cache Allocation values: */
+ u16 x86_l3_max_cbm_len;
+ u16 x86_l3_max_closid;
/* cpuid returned max cores value: */
u16 x86_max_cores;
u16 apicid;
diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h
index fac9a5c..6847d85 100644
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h
@@ -100,6 +100,7 @@
#define REQUIRED_MASK15 0
#define REQUIRED_MASK16 0
#define REQUIRED_MASK17 0
-#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
+#define REQUIRED_MASK18 0
+#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
#endif /* _ASM_X86_REQUIRED_FEATURES_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 809eda0..997d1d5 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -711,6 +711,25 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
}
}
+ /* Additional Intel-defined flags: level 0x00000010 */
+ if (c->cpuid_level >= 0x00000010) {
+ u32 eax, ebx, ecx, edx;
+
+ cpuid_count(0x00000010, 0, &eax, &ebx, &ecx, &edx);
+ c->x86_capability[CPUID_10_0_EBX] = ebx;
+
+ if (cpu_has(c, X86_FEATURE_CAT_L3)) {
+
+ cpuid_count(0x00000010, 1, &eax, &ebx, &ecx, &edx);
+ c->x86_l3_max_closid = edx + 1;
+ c->x86_l3_max_cbm_len = eax + 1;
+ c->x86_capability[CPUID_10_1_ECX] = ecx;
+ } else {
+ c->x86_l3_max_closid = -1;
+ c->x86_l3_max_cbm_len = -1;
+ }
+ }
+
/* AMD-defined flags: level 0x80000001 */
eax = cpuid_eax(0x80000000);
c->extended_cpuid_level = eax;
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
new file mode 100644
index 0000000..fcd0642
--- /dev/null
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -0,0 +1,37 @@
+/*
+ * Resource Director Technology(RDT)
+ * - Cache Allocation code.
+ *
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * 2015-05-25 Written by
+ * Vikas Shivappa <vikas.shivappa@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * More information about RDT be found in the Intel (R) x86 Architecture
+ * Software Developer Manual June 2015, volume 3, section 17.15.
+ */
+#include <linux/slab.h>
+#include <linux/err.h>
+
+static int __init intel_rdt_late_init(void)
+{
+ struct cpuinfo_x86 *c = &boot_cpu_data;
+
+ if (!cpu_has(c, X86_FEATURE_CAT_L3))
+ return -ENODEV;
+
+ pr_info("Intel cache allocation detected\n");
+
+ return 0;
+}
+
+late_initcall(intel_rdt_late_init);
--
2.5.0