[3.16.y-ckt stable] Patch "x86: Add cpu_detect_cache_sizes to init_intel() add Quark legacy_cache()" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    x86: Add cpu_detect_cache_sizes to init_intel() add Quark legacy_cache()

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 03d7090ea16fc3864ceb0ca92680ed9be4bd4a4c Mon Sep 17 00:00:00 2001
From: Bryan O'Donoghue <pure.logic at nexus-software.ie>
Date: Tue, 7 Oct 2014 01:19:49 +0100
Subject: x86: Add cpu_detect_cache_sizes to init_intel() add Quark
 legacy_cache()

commit aece118e487a744eafcdd0c77fe32b55ee2092a1 upstream.

Intel processors which don't report cache information via cpuid(2)
or cpuid(4) need quirk code in the legacy_cache_size callback to
report this data. For Intel that callback is is intel_size_cache().

This patch enables calling of cpu_detect_cache_sizes() inside of
init_intel() and hence the calling of the legacy_cache callback in
intel_size_cache(). Adding this call will ensure that PIII Tualatin
currently in intel_size_cache() and Quark SoC X1000 being added to
intel_size_cache() in this patch will report their respective cache
sizes.

This model of calling cpu_detect_cache_sizes() is consistent with
AMD/Via/Cirix/Transmeta and Centaur.

Also added is a string to idenitfy the Quark as Quark SoC X1000
giving better and more descriptive output via /proc/cpuinfo

Adding cpu_detect_cache_sizes to init_intel() will enable calling
of intel_size_cache() on Intel processors which currently no code
can reach. Therefore this patch will also re-enable reporting
of PIII Tualatin cache size information as well as add
Quark SoC X1000 support.

Comment text and cache flow logic suggested by Thomas Gleixner

Signed-off-by: Bryan O'Donoghue <pure.logic at nexus-software.ie>
Cc: davej at redhat.com
Cc: hmh at hmh.eng.br
Link: http://lkml.kernel.org/r/1412641189-12415-3-git-send-email-pure.logic@nexus-software.ie
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/x86/kernel/cpu/intel.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 21337cd58b6b..df64630d8053 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -397,6 +397,13 @@ static void init_intel(struct cpuinfo_x86 *c)
 	}

 	l2 = init_intel_cacheinfo(c);
+
+	/* Detect legacy cache sizes if init_intel_cacheinfo did not */
+	if (l2 == 0) {
+		cpu_detect_cache_sizes(c);
+		l2 = c->x86_cache_size;
+	}
+
 	if (c->cpuid_level > 9) {
 		unsigned eax = cpuid_eax(10);
 		/* Check for version and the number of counters */
@@ -500,6 +507,13 @@ static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 	 */
 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 		size = 256;
+
+	/*
+	 * Intel Quark SoC X1000 contains a 4-way set associative
+	 * 16K cache with a 16 byte cache line and 256 lines per tag
+	 */
+	if ((c->x86 == 5) && (c->x86_model == 9))
+		size = 16;
 	return size;
 }
 #endif
@@ -727,7 +741,8 @@ static const struct cpu_dev intel_cpu_dev = {
 			  [3] = "OverDrive PODP5V83",
 			  [4] = "Pentium MMX",
 			  [7] = "Mobile Pentium 75 - 200",
-			  [8] = "Mobile Pentium MMX"
+			  [8] = "Mobile Pentium MMX",
+			  [9] = "Quark SoC X1000",
 		  }
 		},
 		{ .family = 6, .model_names =
--
2.1.0