Re: [PATCH 02/14] cxl/mem: Map memory device registers

[Christoph Hellwig]

Any reason not to merge a bunch of patches?  Both this one and
the previous one are rather useless on their own, making review
harder than necessary.

> + * cxl_mem_create() - Create a new &struct cxl_mem.
> + * @pdev: The pci device associated with the new &struct cxl_mem.
> + * @reg_lo: Lower 32b of the register locator
> + * @reg_hi: Upper 32b of the register locator.
> + *
> + * Return: The new &struct cxl_mem on success, NULL on failure.
> + *
> + * Map the BAR for a CXL memory device. This BAR has the memory device's
> + * registers for the device as specified in CXL specification.
> + */

A lot of text with almost no value over just reading the function.
What's that fetish with kerneldoc comments for trivial static functions?

> +		reg_type =
> +			(reg_lo >> CXL_REGLOC_RBI_SHIFT) & CXL_REGLOC_RBI_MASK;

OTOH this screams for a helper that would make the code a lot more
self documenting.

> +		if (reg_type == CXL_REGLOC_RBI_MEMDEV) {
> +			rc = 0;
> +			cxlm = cxl_mem_create(pdev, reg_lo, reg_hi);
> +			if (!cxlm)
> +				rc = -ENODEV;
> +			break;

And given that we're going to grow more types eventually, why not start
out with a switch here?  Also why return the structure when nothing
uses it?