ARM: 6207/1: Replace CONFIG_HAS_TLS_REG with HWCAP_TLS and check for it on V6
The TLS register is only available on ARM1136 r1p0 and later.
Set HWCAP_TLS flags if hardware TLS is available and test for
it if CONFIG_CPU_32v6K is not set for V6.
Note that we set the TLS instruction in __kuser_get_tls
dynamically as suggested by Jamie Lokier <jamie@shareable.org>.
Also the __switch_to code is optimized out in most cases as
suggested by Nicolas Pitre <nico@fluxnic.net>.
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 346ae14..71d5d5e 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -717,17 +717,6 @@
a few prototypes like that in existence) and therefore access to
that required register must be emulated.
-config HAS_TLS_REG
- bool
- 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 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.
-
config NEEDS_SYSCALL_FOR_CMPXCHG
bool
help
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 7a5337e..2f5a3c2 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -239,7 +239,8 @@
b __v6_setup
.long cpu_arch_name
.long cpu_elf_name
- .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA
+ /* See also feat_v6_fixup() for HWCAP_TLS */
+ .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA|HWCAP_TLS
.long cpu_v6_name
.long v6_processor_functions
.long v6wbi_tlb_fns
@@ -262,7 +263,7 @@
b __v6_setup
.long cpu_arch_name
.long cpu_elf_name
- .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP
+ .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_TLS
.long cpu_pj4_name
.long v6_processor_functions
.long v6wbi_tlb_fns
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 7aaf88a..8071bcd 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -344,7 +344,7 @@
b __v7_setup
.long cpu_arch_name
.long cpu_elf_name
- .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP
+ .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_TLS
.long cpu_v7_name
.long v7_processor_functions
.long v7wbi_tlb_fns
