Re: [PATCH 8/9] [HACK] ARM: imx: work around v7_cpu_resume link error

From: Shawn Guo
Date: Mon Feb 18 2013 - 20:42:44 EST


On Mon, Feb 18, 2013 at 12:06:32PM -0500, Nicolas Pitre wrote:
> Try the following instead. It makes the code simpler and easier to
> debug.
>
It works now. Thanks, Nico. Care to send a patch for it? I'd like
to apply it.

Shawn

> diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
> index 7e49deb128..27bc06e910 100644
> --- a/arch/arm/mach-imx/headsmp.S
> +++ b/arch/arm/mach-imx/headsmp.S
> @@ -73,16 +73,16 @@ ENDPROC(v7_secondary_startup)
>
> #ifdef CONFIG_PM
> /*
> - * The following code is located into the .data section. This is to
> - * allow phys_l2x0_saved_regs to be accessed with a relative load
> - * as we are running on physical address here.
> + * The following code must assume it is running from physical address
> + * where absolute virtual addresses to the data section have to be
> + * turned into relative ones.
> */
> - .data
> - .align
>
> #ifdef CONFIG_CACHE_L2X0
> .macro pl310_resume
> - ldr r2, phys_l2x0_saved_regs
> + adr r0, l2x0_saved_regs_offset
> + ldr r2, [r0]
> + add r2, r2, r0
> ldr r0, [r2, #L2X0_R_PHY_BASE] @ get physical base of l2x0
> ldr r1, [r2, #L2X0_R_AUX_CTRL] @ get aux_ctrl value
> str r1, [r0, #L2X0_AUX_CTRL] @ restore aux_ctrl
> @@ -90,9 +90,9 @@ ENDPROC(v7_secondary_startup)
> str r1, [r0, #L2X0_CTRL] @ re-enable L2
> .endm
>
> - .globl phys_l2x0_saved_regs
> -phys_l2x0_saved_regs:
> - .long 0
> +l2x0_saved_regs_offset:
> + .word l2x0_saved_regs - .
> +
> #else
> .macro pl310_resume
> .endm
> diff --git a/arch/arm/mach-imx/pm-imx6q.c b/arch/arm/mach-imx/pm-imx6q.c
> index f7b0c2b1b9..f3791f980d 100644
> --- a/arch/arm/mach-imx/pm-imx6q.c
> +++ b/arch/arm/mach-imx/pm-imx6q.c
> @@ -21,8 +21,6 @@
> #include <mach/common.h>
> #include <mach/hardware.h>
>
> -extern unsigned long phys_l2x0_saved_regs;
> -
> static int imx6q_suspend_finish(unsigned long val)
> {
> cpu_do_idle();
> @@ -55,18 +53,5 @@ static const struct platform_suspend_ops imx6q_pm_ops = {
>
> void __init imx6q_pm_init(void)
> {
> - /*
> - * The l2x0 core code provides an infrastucture to save and restore
> - * l2x0 registers across suspend/resume cycle. But because imx6q
> - * retains L2 content during suspend and needs to resume L2 before
> - * MMU is enabled, it can only utilize register saving support and
> - * have to take care of restoring on its own. So we save physical
> - * address of the data structure used by l2x0 core to save registers,
> - * and later restore the necessary ones in imx6q resume entry.
> - */
> -#ifdef CONFIG_CACHE_L2X0
> - phys_l2x0_saved_regs = __pa(&l2x0_saved_regs);
> -#endif
> -
> suspend_set_ops(&imx6q_pm_ops);
> }
>
> Nicolas

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