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Date:   Mon, 19 Oct 2020 10:58:36 -0600
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     Peng Fan <peng.fan@nxp.com>
Cc:     bjorn.andersson@linaro.org, o.rempel@pengutronix.de,
        robh+dt@kernel.org, linux-remoteproc@vger.kernel.org,
        linux-kernel@vger.kernel.org, shawnguo@kernel.org,
        s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com,
        linux-imx@nxp.com, linux-arm-kernel@lists.infradead.org,
        Richard Zhu <hongxing.zhu@nxp.com>
Subject: Re: [PATCH V2 1/7] remoteproc: elf: support platform specific memory
 hook
Message-ID: <20201019165836.GA496175@xps15>
References: <20200927064131.24101-1-peng.fan@nxp.com>
 <20200927064131.24101-2-peng.fan@nxp.com>
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In-Reply-To: <20200927064131.24101-2-peng.fan@nxp.com>
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Hi Peng,

On Sun, Sep 27, 2020 at 02:41:25PM +0800, Peng Fan wrote:
> To arm64, "dc      zva, dst" is used in memset.
> Per ARM DDI 0487A.j, chapter C5.3.8 DC ZVA, Data Cache Zero by VA,
> 
> "If the memory region being zeroed is any type of Device memory,
> this instruction can give an alignment fault which is prioritized
> in the same way as other alignment faults that are determined
> by the memory type."
> 
> On i.MX platforms, when elf is loaded to onchip TCM area, the region
> is ioremapped, so "dc zva, dst" will trigger abort. And ioremap_wc()
> on i.MX not able to write correct data to TCM area.
> 
> So we need to use io helpers, and extend the elf loader to support
> platform specific memory functions.
> 
> Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/remoteproc/remoteproc_elf_loader.c | 20 ++++++++++++++++++--
>  include/linux/remoteproc.h                 |  2 ++
>  2 files changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_elf_loader.c b/drivers/remoteproc/remoteproc_elf_loader.c
> index df68d87752e4..6cb71fe47261 100644
> --- a/drivers/remoteproc/remoteproc_elf_loader.c
> +++ b/drivers/remoteproc/remoteproc_elf_loader.c
> @@ -129,6 +129,22 @@ u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
>  }
>  EXPORT_SYMBOL(rproc_elf_get_boot_addr);
>  
> +static void rproc_elf_memcpy(struct rproc *rproc, void *dest, const void *src, size_t count)
> +{
> +	if (!rproc->ops->elf_memcpy)
> +		memcpy(dest, src, count);
> +
> +	rproc->ops->elf_memcpy(rproc, dest, src, count);
> +}
> +
> +static void rproc_elf_memset(struct rproc *rproc, void *s, int c, size_t count)
> +{
> +	if (!rproc->ops->elf_memset)
> +		memset(s, c, count);
> +
> +	rproc->ops->elf_memset(rproc, s, c, count);
> +}
> +
>  /**
>   * rproc_elf_load_segments() - load firmware segments to memory
>   * @rproc: remote processor which will be booted using these fw segments
> @@ -214,7 +230,7 @@ int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
>  
>  		/* put the segment where the remote processor expects it */
>  		if (filesz)
> -			memcpy(ptr, elf_data + offset, filesz);
> +			rproc_elf_memcpy(rproc, ptr, elf_data + offset, filesz);
>  
>  		/*
>  		 * Zero out remaining memory for this segment.
> @@ -224,7 +240,7 @@ int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
>  		 * this.
>  		 */
>  		if (memsz > filesz)
> -			memset(ptr + filesz, 0, memsz - filesz);
> +			rproc_elf_memset(rproc, ptr + filesz, 0, memsz - filesz);
>  	}
>  
>  	return ret;
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 2fa68bf5aa4f..1f5fa2c772df 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -392,6 +392,8 @@ struct rproc_ops {
>  	int (*load)(struct rproc *rproc, const struct firmware *fw);
>  	int (*sanity_check)(struct rproc *rproc, const struct firmware *fw);
>  	u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
> +	void (*elf_memcpy)(struct rproc *rproc, void *dest, const void *src, size_t count);
> +	void (*elf_memset)(struct rproc *rproc, void *s, int c, size_t count);

As with every other operations, the above two addition should be documented.

With that:

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

>  	unsigned long (*panic)(struct rproc *rproc);
>  };
>  
> -- 
> 2.28.0
>