From f159f4ed55bb0fa5470800641e03a13a7e0eae6e Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Mon, 5 Jul 2010 14:53:10 +0100 Subject: 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 . Also the __switch_to code is optimized out in most cases as suggested by Nicolas Pitre . Reviewed-by: Nicolas Pitre Signed-off-by: Tony Lindgren Signed-off-by: Russell King --- arch/arm/kernel/traps.c | 41 ++++++++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 11 deletions(-) (limited to 'arch/arm/kernel/traps.c') 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 #include #include +#include #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; @@ -760,6 +774,11 @@ void __init early_trap_init(void) memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); 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. -- cgit v1.2.3