linux-kernel - Re: [PATCH v10 02/10] mtd: intel-dg: implement region enumeration

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Message-ID: <aCe6hlGFG3v0cav9@black.fi.intel.com>
Date: Sat, 17 May 2025 01:21:58 +0300
From: Raag Jadav <raag.jadav@...el.com>
To: Alexander Usyskin <alexander.usyskin@...el.com>
Cc: Miquel Raynal <miquel.raynal@...tlin.com>,
	Richard Weinberger <richard@....at>,
	Vignesh Raghavendra <vigneshr@...com>,
	Lucas De Marchi <lucas.demarchi@...el.com>,
	Thomas Hellström <thomas.hellstrom@...ux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Jani Nikula <jani.nikula@...ux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
	Tvrtko Ursulin <tursulin@...ulin.net>,
	Karthik Poosa <karthik.poosa@...el.com>,
	Reuven Abliyev <reuven.abliyev@...el.com>,
	Oren Weil <oren.jer.weil@...el.com>, linux-mtd@...ts.infradead.org,
	intel-xe@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
	intel-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
	Tomas Winkler <tomasw@...il.com>
Subject: Re: [PATCH v10 02/10] mtd: intel-dg: implement region enumeration

On Thu, May 15, 2025 at 04:33:37PM +0300, Alexander Usyskin wrote:
> In intel-dg, there is no access to the spi controller,
> the information is extracted from the descriptor region.

...

> +static int intel_dg_nvm_init(struct intel_dg_nvm *nvm, struct device *device)
> +{
> +	int ret;
> +	unsigned int i, n;
> +	u32 access_map = 0;

Reverse xmas order (along with all other places) and

Reviewed-by: Raag Jadav <raag.jadav@...el.com>

> +	/* clean error register, previous errors are ignored */
> +	idg_nvm_error(nvm);
> +
> +	ret = idg_nvm_is_valid(nvm);
> +	if (ret) {
> +		dev_err(device, "The MEM is not valid %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (idg_nvm_get_access_map(nvm, &access_map))
> +		return -EIO;
> +
> +	for (i = 0, n = 0; i < nvm->nregions; i++) {
> +		u32 address, base, limit, region;
> +		u8 id = nvm->regions[i].id;
> +
> +		address = NVM_FLREG(id);
> +		region = idg_nvm_read32(nvm, address);
> +
> +		base = FIELD_GET(NVM_FREG_BASE_MASK, region) << NVM_FREG_ADDR_SHIFT;
> +		limit = (FIELD_GET(NVM_FREG_ADDR_MASK, region) << NVM_FREG_ADDR_SHIFT) |
> +			NVM_FREG_MIN_REGION_SIZE;
> +
> +		dev_dbg(device, "[%d] %s: region: 0x%08X base: 0x%08x limit: 0x%08x\n",
> +			id, nvm->regions[i].name, region, base, limit);
> +
> +		if (base >= limit || (i > 0 && limit == 0)) {
> +			dev_dbg(device, "[%d] %s: disabled\n",
> +				id, nvm->regions[i].name);
> +			nvm->regions[i].is_readable = 0;
> +			continue;
> +		}
> +
> +		if (nvm->size < limit)
> +			nvm->size = limit;
> +
> +		nvm->regions[i].offset = base;
> +		nvm->regions[i].size = limit - base + 1;
> +		/* No write access to descriptor; mask it out*/
> +		nvm->regions[i].is_writable = idg_nvm_region_writable(access_map, id);
> +
> +		nvm->regions[i].is_readable = idg_nvm_region_readable(access_map, id);
> +		dev_dbg(device, "Registered, %s id=%d offset=%lld size=%lld rd=%d wr=%d\n",
> +			nvm->regions[i].name,
> +			nvm->regions[i].id,
> +			nvm->regions[i].offset,
> +			nvm->regions[i].size,
> +			nvm->regions[i].is_readable,
> +			nvm->regions[i].is_writable);
> +
> +		if (nvm->regions[i].is_readable)
> +			n++;
> +	}
> +
> +	dev_dbg(device, "Registered %d regions\n", n);
> +
> +	/* Need to add 1 to the amount of memory
> +	 * so it is reported as an even block
> +	 */
> +	nvm->size += 1;
> +
> +	return n;
> +}
> +
>  static void intel_dg_nvm_release(struct kref *kref)
>  {
>  	struct intel_dg_nvm *nvm = container_of(kref, struct intel_dg_nvm, refcnt);
> @@ -85,6 +285,12 @@ static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
>  		goto err;
>  	}
>  
> +	ret = intel_dg_nvm_init(nvm, device);
> +	if (ret < 0) {
> +		dev_err(device, "cannot initialize nvm %d\n", ret);
> +		goto err;
> +	}
> +
>  	dev_set_drvdata(&aux_dev->dev, nvm);
>  
>  	return 0;
> -- 
> 2.43.0
>