Commit 70489c88 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Russell King
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[PATCH] ARM: 2680/1: refine TLS reg availability some more again 



Patch from Nicolas Pitre

Not all ARMv6 processors implement the TLS register.

Signed-off-by: Nicolas Pitre
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent d7def6c2

arch/arm/mm/Kconfig

+10 −11
Original line number Diff line number Diff line
@@ -412,21 +412,20 @@ config CPU_BPREDICT_DISABLE 


config TLS_REG_EMUL

	bool

	default y if (SMP || CPU_32v6) && (CPU_32v5 || CPU_32v4 || CPU_32v3)

	default y if SMP && (CPU_32v5 || CPU_32v4 || CPU_32v3)

	help

	  We might be running on an ARMv6+ processor which should have the TLS

	  register but for some reason we can't use it, or maybe an SMP system

	  using a pre-ARMv6 processor (there are apparently a few prototypes

	  like that in existence) and therefore access to that register must

	  be emulated.

	  An SMP system using a pre-ARMv6 processor (there are apparently

	  a few prototypes like that in existence) and therefore access to

	  that required register must be emulated.



config HAS_TLS_REG

	bool

	depends on CPU_32v6

	default y if !TLS_REG_EMUL

	depends on !TLS_REG_EMUL

	default y if SMP || CPU_32v7

	help

	  This selects support for the CP15 thread register.

	  It is defined to be available on ARMv6 or later.  If a particular

	  ARMv6 or later CPU doesn't support it then it must include "select

	  TLS_REG_EMUL" along with its other characteristics.

	  It is defined to be available on some ARMv6 processors (including

	  all SMP capable ARMv6's) or later processors.  User space may

	  assume directly accessing that register and always obtain the

	  expected value only on ARMv7 and above.