From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Mon, 21 Jan 2013 14:03:44 +0000
Subject: [PATCH 1/4] ARM: cache-l2x0: Manage the errata at run time
In-Reply-To: <20130121131451.GA29855@bnru10>
References: <20130121131451.GA29855@bnru10>
Message-ID: <20130121140344.GG18005@mudshark.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Jan 21, 2013 at 01:14:53PM +0000, srinidhi kasagar wrote:
> Make it possible to manage the errata by its own by using the
> l2x0 ID register. This relieves the platforms from choosing the
> Errata's at compile time
> 
> Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
> ---
>  arch/arm/include/asm/hardware/cache-l2x0.h |    2 +
>  arch/arm/mm/cache-l2x0.c                   |   77 +++++++++++++++-------------
>  2 files changed, 43 insertions(+), 36 deletions(-)
> 
> diff --git a/arch/arm/include/asm/hardware/cache-l2x0.h b/arch/arm/include/asm/hardware/cache-l2x0.h
> index 3b2c40b..d5994ac 100644
> --- a/arch/arm/include/asm/hardware/cache-l2x0.h
> +++ b/arch/arm/include/asm/hardware/cache-l2x0.h
> @@ -117,6 +117,8 @@ static inline int l2x0_of_init(u32 aux_val, u32 aux_mask)
>  }
>  #endif
>  
> +asmlinkage u32 l2x0_get_rtl_release(void);
> +
>  struct l2x0_regs {
>  	unsigned long phy_base;
>  	unsigned long aux_ctrl;
> diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
> index c2f3739..49058ac 100644
> --- a/arch/arm/mm/cache-l2x0.c
> +++ b/arch/arm/mm/cache-l2x0.c
> @@ -49,6 +49,16 @@ struct l2x0_of_data {
>  
>  static bool of_init = false;
>  
> +/*
> + * Identify ther RTL releases of l2x0 - This might help in applying
> + * the l2x0 errata's dynamically rather compile time options
> + */
> +asmlinkage u32 l2x0_get_rtl_release(void)
> +{
> +	return readl_relaxed(l2x0_base + L2X0_CACHE_ID) &
> +			L2X0_CACHE_ID_RTL_MASK;
> +}

You're calling this function all over the place, including from the flush
code. Can you read the RTL release during probe and stash it somewhere
instead please?

Will