From: Nicolas Pitre Date: Thu, 12 May 2005 18:27:12 +0000 (+0100) Subject: [PATCH] ARM: 2680/1: refine TLS reg availability some more again X-Git-Tag: firefly_0821_release~42753^2~276^2~3 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=70489c88d0b7e5820ac37a039a910bb396e2a4e3;p=firefly-linux-kernel-4.4.55.git [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: Russell King --- diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 07646d25e265..48bac7da8c70 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -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.