Subject: Re: [PATCH] powerpc/powernv: Correctly set hypervisor interrupt little endian bit on POWER8

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 13 May 2014 07:40:00 +1000

On Thu, 2014-05-08 at 22:31 +1000, Anton Blanchard wrote:
> HID0 IBM bit 19 is the HILE bit on POWER8. Set it to 0 to take
> exceptions in big endian and to 1 to take them in little endian.
> 
> Signed-off-by: Anton Blanchard <[email-masked]>
> ---

Let's stick to the variant involving a FW call instead.

Cheers,
Ben.

> 
> Index: b/arch/powerpc/include/asm/reg.h
> ===================================================================
> --- a/arch/powerpc/include/asm/reg.h
> +++ b/arch/powerpc/include/asm/reg.h
> @@ -397,6 +397,7 @@
>  #define SPRN_HASH1	0x3D2		/* Primary Hash Address Register */
>  #define SPRN_HASH2	0x3D3		/* Secondary Hash Address Resgister */
>  #define SPRN_HID0	0x3F0		/* Hardware Implementation Register 0 */
> +#define HID0_HILE_SH	(63 - 19)	/* Hypervisor interrupt little endian */
>  #define HID0_HDICE_SH	(63 - 23)	/* 970 HDEC interrupt enable */
>  #define HID0_EMCP	(1<<31)		/* Enable Machine Check pin */
>  #define HID0_EBA	(1<<29)		/* Enable Bus Address Parity */
> Index: b/arch/powerpc/kernel/cpu_setup_power.S
> ===================================================================
> --- a/arch/powerpc/kernel/cpu_setup_power.S
> +++ b/arch/powerpc/kernel/cpu_setup_power.S
> @@ -60,6 +60,7 @@ _GLOBAL(__setup_cpu_power8)
>  	bl	__init_HFSCR
>  	bl	__init_tlb_power8
>  	bl	__init_PMU_HV
> +	bl	__init_HILE
>  	mtlr	r11
>  	blr
>  
> @@ -78,6 +79,7 @@ _GLOBAL(__restore_cpu_power8)
>  	bl	__init_HFSCR
>  	bl	__init_tlb_power8
>  	bl	__init_PMU_HV
> +	bl	__init_HILE
>  	mtlr	r11
>  	blr
>  
> @@ -132,6 +134,26 @@ __init_HFSCR:
>  	mtspr	SPRN_HFSCR,r3
>  	blr
>  
> +__init_HILE:
> +	mfspr	r3,SPRN_HID0
> +	li	r4,1
> +	sldi	r4,r4,HID0_HILE_SH
> +#ifdef __LITTLE_ENDIAN__
> +	or	r3,r3,r4
> +#else
> +	andc	r3,r3,r4
> +#endif
> +	sync
> +	mtspr	SPRN_HID0,r3
> +	mfspr	r3,SPRN_HID0
> +	mfspr	r3,SPRN_HID0
> +	mfspr	r3,SPRN_HID0
> +	mfspr	r3,SPRN_HID0
> +	mfspr	r3,SPRN_HID0
> +	mfspr	r3,SPRN_HID0
> +	isync
> +	blr
> +
>  /*
>   * Clear the TLB using the specified IS form of tlbiel instruction
>   * (invalidate by congruence class). P7 has 128 CCs., P8 has 512.