[PATCH v2 2/2] x86: Add cpu_detect_cache_sizes to init_intel() add Quark legacy_cache()

From: Bryan O'Donoghue
Date: Mon Oct 06 2014 - 20:20:46 EST


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@xxxxxxxxxxxxxxxxx>
---
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 74e804d..6fd5be3 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -382,6 +382,13 @@ 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 */
@@ -485,6 +492,13 @@ 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
@@ -686,7 +700,8 @@ 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 =
--
1.9.1

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