diff options
| author | Tony Lindgren <tony@atomide.com> | 2010-07-05 14:53:10 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-07-09 14:41:35 +0100 |
| commit | f159f4ed55bb0fa5470800641e03a13a7e0eae6e (patch) | |
| tree | c2ed54b103c2a1c58fa4b50740fec462ccfeec74 /arch/arm/kernel/traps.c | |
| parent | c1b2d9704c77ddaec46d5d681e1360ac40268743 (diff) | |
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>
Diffstat (limited to 'arch/arm/kernel/traps.c')
| -rw-r--r-- | arch/arm/kernel/traps.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 1621e5327b2a..cda78d59aa31 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -30,6 +30,7 @@ #include <asm/unistd.h> #include <asm/traps.h> #include <asm/unwind.h> +#include <asm/tls.h> #include "ptrace.h" #include "signal.h" @@ -518,17 +519,20 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs) case NR(set_tls): thread->tp_value = regs->ARM_r0; -#if defined(CONFIG_HAS_TLS_REG) - asm ("mcr p15, 0, %0, c13, c0, 3" : : "r" (regs->ARM_r0) ); -#elif !defined(CONFIG_TLS_REG_EMUL) - /* - * User space must never try to access this directly. - * Expect your app to break eventually if you do so. - * The user helper at 0xffff0fe0 must be used instead. - * (see entry-armv.S for details) - */ - *((unsigned int *)0xffff0ff0) = regs->ARM_r0; -#endif + if (tls_emu) + return 0; + if (has_tls_reg) { + asm ("mcr p15, 0, %0, c13, c0, 3" + : : "r" (regs->ARM_r0)); + } else { + /* + * User space must never try to access this directly. + * Expect your app to break eventually if you do so. + * The user helper at 0xffff0fe0 must be used instead. + * (see entry-armv.S for details) + */ + *((unsigned int *)0xffff0ff0) = regs->ARM_r0; + } return 0; #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG @@ -743,6 +747,16 @@ void __init trap_init(void) return; } +static void __init kuser_get_tls_init(unsigned long vectors) +{ + /* + * vectors + 0xfe0 = __kuser_get_tls + * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 + */ + if (tls_emu || has_tls_reg) + memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); +} + void __init early_trap_init(void) { unsigned long vectors = CONFIG_VECTORS_BASE; @@ -761,6 +775,11 @@ void __init early_trap_init(void) memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); /* + * Do processor specific fixups for the kuser helpers + */ + kuser_get_tls_init(vectors); + + /* * Copy signal return handlers into the vector page, and * set sigreturn to be a pointer to these. */ |