[PATCH v10 03/10] mtd: intel-dg: implement access functions

[Raag Jadav]

On Thu, May 15, 2025 at 04:33:38PM +0300, Alexander Usyskin wrote:
> Implement read(), erase() and write() functions.

...

> +__maybe_unused
> +static ssize_t idg_write(struct intel_dg_nvm *nvm, u8 region,
> +			 loff_t to, size_t len, const unsigned char *buf)
> +{
> +	size_t i;
> +	size_t len8;
> +	size_t len4;
> +	size_t to4;
> +	size_t to_shift;
> +	size_t len_s = len;
> +	ssize_t ret;
> +
> +	idg_nvm_set_region_id(nvm, region);
> +
> +	to4 = ALIGN_DOWN(to, sizeof(u32));
> +	to_shift = min(sizeof(u32) - ((size_t)to - to4), len);
> +	if (to - to4) {
> +		ret = idg_nvm_rewrite_partial(nvm, to4, to - to4, to_shift, (uint32_t *)&buf[0]);

Forgot to add, you're using both uint32_t and u32.
Perhaps make it consistent?

> +		if (ret < 0)
> +			return ret;
> +
> +		buf += to_shift;
> +		to += to_shift;
> +		len_s -= to_shift;
> +	}
> +
> +	len8 = ALIGN_DOWN(len_s, sizeof(u64));
> +	for (i = 0; i < len8; i += sizeof(u64)) {
> +		u64 data;
> +
> +		memcpy(&data, &buf[i], sizeof(u64));
> +		idg_nvm_write64(nvm, to + i, data);
> +		if (idg_nvm_error(nvm))
> +			return -EIO;
> +	}
> +
> +	len4 = len_s - len8;
> +	if (len4 >= sizeof(u32)) {
> +		u32 data;
> +
> +		memcpy(&data, &buf[i], sizeof(u32));
> +		idg_nvm_write32(nvm, to + i, data);
> +		if (idg_nvm_error(nvm))
> +			return -EIO;
> +		i += sizeof(u32);
> +		len4 -= sizeof(u32);
> +	}
> +
> +	if (len4 > 0) {
> +		ret = idg_nvm_rewrite_partial(nvm, to + i, 0, len4, (uint32_t *)&buf[i]);

Ditto (and also in all other places if any).

> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	return len;
> +}

Raag