ARM: 6518/1: kexec: Fix crash_setup_regs() for ARMv7 and CONFIG_THUMB2_KERNEL
* Fix kexec build failure with CONFIG_THUMB2_KERNEL.
* Avoids deprecated/forbidden sp and pc usage in for ARMv7
onwards, retaining compatibility with older architecture
versions.
* The pc value saved to newregs is now aligned on a predictable
instruction boundary.
(stmia { ... pc } or str pc has implementation-defined results
in most versions of the ARM architecutre, and is prohibited
(unpredictable) in Thumb-2.)
* Switch to named inline asm arguments (else I get readily
confused ...)
The resulting code should be compatible with all architecture
versions >= v3, with or without CONFIG_THUMB2_KERNEL.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/kexec.h b/arch/arm/include/asm/kexec.h
index b37e02c..c0094d8 100644
--- a/arch/arm/include/asm/kexec.h
+++ b/arch/arm/include/asm/kexec.h
@@ -33,10 +33,20 @@
if (oldregs) {
memcpy(newregs, oldregs, sizeof(*newregs));
} else {
- __asm__ __volatile__ ("stmia %0, {r0 - r15}"
- : : "r" (&newregs->ARM_r0) : "memory");
- __asm__ __volatile__ ("mrs %0, cpsr"
- : "=r" (newregs->ARM_cpsr));
+ __asm__ __volatile__ (
+ "stmia %[regs_base], {r0-r12}\n\t"
+ "mov %[_ARM_sp], sp\n\t"
+ "str lr, %[_ARM_lr]\n\t"
+ "adr %[_ARM_pc], 1f\n\t"
+ "mrs %[_ARM_cpsr], cpsr\n\t"
+ "1:"
+ : [_ARM_pc] "=r" (newregs->ARM_pc),
+ [_ARM_cpsr] "=r" (newregs->ARM_cpsr),
+ [_ARM_sp] "=r" (newregs->ARM_sp),
+ [_ARM_lr] "=o" (newregs->ARM_lr)
+ : [regs_base] "r" (&newregs->ARM_r0)
+ : "memory"
+ );
}
}