[PATCH 6/8] x86: require minimum 64 byte cache lines

[Arnd Bergmann]

From: Arnd Bergmann <arnd at arndb.de>

Later x86-32 CPUs like Pentium-M, K7 and Atom use 64 byte cache lines
and are incompatible with kernels built for smaller values of
X86_L1_CACHE_SHIFT.

Pentium-4 CPUs have 128 byte cache lines but are compatible with
cache operations that expect the lines to be 64 bytes.

Older CPUs have smaller cache lines of 16 or 32 bytes but work
correctly when X86_L1_CACHE_SHIFT is set to a larger value.

Remove the per-CPU tuning and always build for 64 or 128 byte
cache lines that work correctly in any CPU.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
 arch/x86/Kconfig.cpu | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 65d887274dd8..4991b633047e 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -180,8 +180,8 @@ config MVIAC7
 	bool "VIA C7"
 	depends on X86_32
 	help
-	  Select this for a VIA C7.  Selecting this uses the correct cache
-	  shift and tells gcc to treat the CPU as a 686.
+	  Select this for a VIA C7.  Selecting this tells gcc to treat the
+	  CPU as a 686.
 
 config MATOM
 	bool "Intel Atom"
@@ -239,9 +239,7 @@ config X86_INTERNODE_CACHE_SHIFT
 config X86_L1_CACHE_SHIFT
 	int
 	default "7" if MPENTIUM4
-	default "6" if MK7 || MPENTIUMM || MATOM || MVIAC7 || X86_GENERIC || X86_64
-	default "4" if MGEODEGX1
-	default "5" if MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MVIAC3_2 || MGEODE_LX
+	default "6"
 
 config X86_F00F_BUG
 	def_bool y
-- 
2.39.5