Commit cd849ae9 authored Dec 01, 2010 by Dave Martin Committed by Russell King Dec 04, 2010

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>

parent 0946b8c5

arch/arm/include/asm/kexec.h

+14 −4

Original line number	Diff line number	Diff line
		@@ -33,10 +33,20 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
		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"
		);
		}
		}

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