[PATCH 2/3] powerpc/85xx: Provide two functions to save/restore the core registers

[Scott Wood]

On Tue, 2014-01-14 at 15:59 +0800, Dongsheng Wang wrote:
> From: Wang Dongsheng <dongsheng.wang at freescale.com>
> 
> Add fsl_cpu_state_save/fsl_cpu_state_restore functions, used for deep
> sleep and hibernation to save/restore core registers. We abstract out
> save/restore code for use in various modules, to make them don't need
> to maintain.
> 
> Currently supported processors type are E6500, E5500, E500MC, E500v2 and
> E500v1.
> 
> Signed-off-by: Wang Dongsheng <dongsheng.wang at freescale.com>

What is there that is specfic to a particular core type that can't be
handled from C code?

> +	/*
> +	 * Need to save float-point registers if MSR[FP] = 1.
> +	 */
> +	mfmsr	r12
> +	andi.	r12, r12, MSR_FP
> +	beq	1f
> +	do_sr_fpr_regs(save)

C code should have already ensured that MSR[FP] is not 1 (and thus the
FP context has been saved).

> +/*
> + * r3 = the virtual address of buffer
> + * r4 = suspend type, 0-BASE_SAVE, 1-ALL_SAVE

#define these magic numbers, and define what is meant by "base save"
versus "all save".

-Scott