linux-kernel - [tip:x86/cache] x86/intel_cacheinfo: Enable cache id in cache info

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Date:   Wed, 26 Oct 2016 14:26:12 -0700
From:   tip-bot for Fenghua Yu <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     ravi.v.shankar@...el.com, eranian@...gle.com, mingo@...nel.org,
        tony.luck@...el.com, sai.praneeth.prakhya@...el.com,
        tglx@...utronix.de, h.peter.anvin@...el.com, mingo@...e.hu,
        davidcc@...gle.com, linux-kernel@...r.kernel.org, hpa@...or.com,
        vikas.shivappa@...ux.intel.com, nilayvaish@...il.com,
        fenghua.yu@...el.com, peterz@...radead.org, dave.hansen@...el.com,
        bp@...e.de, shli@...com
Subject: [tip:x86/cache] x86/intel_cacheinfo: Enable cache id in cache info

Commit-ID:  d57e3ab7e34c51a8badeea1b500bfb738d0af66e
Gitweb:     http://git.kernel.org/tip/d57e3ab7e34c51a8badeea1b500bfb738d0af66e
Author:     Fenghua Yu <fenghua.yu@...el.com>
AuthorDate: Sat, 22 Oct 2016 06:19:50 -0700
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Wed, 26 Oct 2016 23:12:37 +0200

x86/intel_cacheinfo: Enable cache id in cache info

Cache id is retrieved from APIC ID and CPUID leaf 4 on x86.

For more details please see the section on "Cache ID Extraction
Parameters" in "Intel 64 Architecture Processor Topology Enumeration".

Also the documentation of the CPUID instruction in the "Intel 64 and
IA-32 Architectures Software Developer's Manual"

Signed-off-by: Fenghua Yu <fenghua.yu@...el.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@...el.com>
Cc: "Tony Luck" <tony.luck@...el.com>
Cc: "David Carrillo-Cisneros" <davidcc@...gle.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@...el.com>
Cc: "Peter Zijlstra" <peterz@...radead.org>
Cc: "Stephane Eranian" <eranian@...gle.com>
Cc: "Dave Hansen" <dave.hansen@...el.com>
Cc: "Shaohua Li" <shli@...com>
Cc: "Nilay Vaish" <nilayvaish@...il.com>
Cc: "Vikas Shivappa" <vikas.shivappa@...ux.intel.com>
Cc: "Ingo Molnar" <mingo@...e.hu>
Cc: "Borislav Petkov" <bp@...e.de>
Cc: "H. Peter Anvin" <h.peter.anvin@...el.com>
Link: http://lkml.kernel.org/r/1477142405-32078-4-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>

---
 arch/x86/kernel/cpu/intel_cacheinfo.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index de6626c..8dc5720 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -153,6 +153,7 @@ struct _cpuid4_info_regs {
 	union _cpuid4_leaf_eax eax;
 	union _cpuid4_leaf_ebx ebx;
 	union _cpuid4_leaf_ecx ecx;
+	unsigned int id;
 	unsigned long size;
 	struct amd_northbridge *nb;
 };
@@ -894,6 +895,8 @@ static void __cache_cpumap_setup(unsigned int cpu, int index,
 static void ci_leaf_init(struct cacheinfo *this_leaf,
 			 struct _cpuid4_info_regs *base)
 {
+	this_leaf->id = base->id;
+	this_leaf->attributes = CACHE_ID;
 	this_leaf->level = base->eax.split.level;
 	this_leaf->type = cache_type_map[base->eax.split.type];
 	this_leaf->coherency_line_size =
@@ -920,6 +923,22 @@ static int __init_cache_level(unsigned int cpu)
 	return 0;
 }
 
+/*
+ * The max shared threads number comes from CPUID.4:EAX[25-14] with input
+ * ECX as cache index. Then right shift apicid by the number's order to get
+ * cache id for this cache node.
+ */
+static void get_cache_id(int cpu, struct _cpuid4_info_regs *id4_regs)
+{
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	unsigned long num_threads_sharing;
+	int index_msb;
+
+	num_threads_sharing = 1 + id4_regs->eax.split.num_threads_sharing;
+	index_msb = get_count_order(num_threads_sharing);
+	id4_regs->id = c->apicid >> index_msb;
+}
+
 static int __populate_cache_leaves(unsigned int cpu)
 {
 	unsigned int idx, ret;
@@ -931,6 +950,7 @@ static int __populate_cache_leaves(unsigned int cpu)
 		ret = cpuid4_cache_lookup_regs(idx, &id4_regs);
 		if (ret)
 			return ret;
+		get_cache_id(cpu, &id4_regs);
 		ci_leaf_init(this_leaf++, &id4_regs);
 		__cache_cpumap_setup(cpu, idx, &id4_regs);
 	}