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[PATCH] ARM: 2663/1: straightify TLS register emulation a bit more

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Patch from Nicolas Pitre

This better express things, and should cover RMK's weird SMP toys.

Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Nicolas Pitre
2005-05-05 23:24:45 +01:00
committed by Russell King
parent f7e68bbf40
commit 4b0e07a556
3 changed files with 25 additions and 20 deletions
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10
arch/arm/kernel/entry-armv.S
View File

@@ -505,9 +505,9 @@ ENTRY(__switch_to)
mra r4, r5, acc0
stmia ip, {r4, r5}
#endif
#ifdef CONFIG_HAS_TLS_REG
#if defined(CONFIG_HAS_TLS_REG)
mcr p15, 0, r3, c13, c0, 3 @ set TLS register
#else
#elif !defined(CONFIG_TLS_REG_EMUL)
mov r4, #0xffff0fff
str r3, [r4, #-15] @ TLS val at 0xffff0ff0
#endif
@@ -690,11 +690,7 @@ __kuser_cmpxchg: @ 0xffff0fc0
__kuser_get_tls: @ 0xffff0fe0
#ifndef CONFIG_HAS_TLS_REG
#ifdef CONFIG_SMP /* sanity check */
#error "CONFIG_SMP without CONFIG_HAS_TLS_REG is wrong"
#endif
#if !defined(CONFIG_HAS_TLS_REG) && !defined(CONFIG_TLS_REG_EMUL)
ldr r0, [pc, #(16 - 8)] @ TLS stored at 0xffff0ff0
mov pc, lr

11
arch/arm/kernel/traps.c
View File

@@ -451,9 +451,9 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
case NR(set_tls):
thread->tp_value = regs->ARM_r0;
#ifdef CONFIG_HAS_TLS_REG
#if defined(CONFIG_HAS_TLS_REG)
asm ("mcr p15, 0, %0, c13, c0, 3" : : "r" (regs->ARM_r0) );
#else
#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.
@@ -498,11 +498,14 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
return 0;
}
#if defined(CONFIG_CPU_32v6) && !defined(CONFIG_HAS_TLS_REG)
#ifdef CONFIG_TLS_REG_EMUL
/*
* We might be running on an ARMv6+ processor which should have the TLS
* register, but for some reason we can't use it and have to emulate it.
* 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.
*/
static int get_tp_trap(struct pt_regs *regs, unsigned int instr)