Commit 32e55a77 authored Jun 09, 2015 by Stephen Boyd Committed by Russell King Jun 12, 2015

ARM: 8389/1: Add cpu_resume_arm() for firmwares that resume in ARM state



Some platforms always enter the kernel in the ARM state even if
the kernel is compiled for THUMB2. Add a small wrapper on top of
cpu_resume() that switches into THUMB2 state.

This provides the functionality to fix a problem reported by Kevin
Hilman on next-20150601 where the ifc6410 fails to boot a THUMB2
kernel because the platform's firmware always enters the kernel in
ARM mode from deep idle states.

(rmk: tweaked to work without BSYM->badr changes.)

Reported-by: Kevin Hilman <khilman@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 02b4e275

arch/arm/include/asm/suspend.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@ struct sleep_save_sp {
		};

		extern void cpu_resume(void);
		extern void cpu_resume_arm(void);
		extern int cpu_suspend(unsigned long, int (*)(unsigned long));

		#endif

arch/arm/kernel/sleep.S

+7 −0

Original line number	Diff line number	Diff line
		@@ -118,6 +118,12 @@ ENDPROC(cpu_resume_after_mmu)

		.text
		.align
		.arm
		ENTRY(cpu_resume_arm)
		THUMB( adr r9, BSYM(1f) ) @ Kernel is entered in ARM.
		THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
		THUMB( .thumb ) @ switch to Thumb now.
		THUMB(1: )
		ENTRY(cpu_resume)
		ARM_BE8(setend be) @ ensure we are in BE mode
		#ifdef CONFIG_ARM_VIRT_EXT
		@@ -149,6 +155,7 @@ THUMB( ldmia r0!, {r1, r2, r3} )
		THUMB( mov sp, r2 )
		THUMB( bx r3 )
		ENDPROC(cpu_resume)
		ENDPROC(cpu_resume_arm)

		.align 2
		_sleep_save_sp: