Re: [PATCH v2 1/2] platform/x86/intel/pmt: allow user offset for PMT callbacks

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Tue, Nov 12, 2024 at 11:30:34AM -0500, Michael J. Ruhl wrote:
> Usage of the telem sysfs file allows for partial reads at
> an offset.
> 
> The current callback method returns the buffer starting
> from offset 0 only.
> 
> Include the requested offset in the callback.
> Update the necessary address calculations with the offset.
> 
> Note: offset addition is moved from the caller to the local
> usage.  For non-callback usage this unchanged behavior.

...

>  int pmt_telem_read_mmio(struct pci_dev *pdev, struct pmt_callbacks *cb, u32 guid, void *buf,
> -			void __iomem *addr, u32 count)
> +			void __iomem *addr, loff_t off, u32 count)
>  {
>  	if (cb && cb->read_telem)
> -		return cb->read_telem(pdev, guid, buf, count);
> +		return cb->read_telem(pdev, guid, buf, off, count);

Also possible instead of the below changes is to add here

	addr += off;

>  	if (guid == GUID_SPR_PUNIT)
>  		/* PUNIT on SPR only supports aligned 64-bit read */
> -		return pmt_memcpy64_fromio(buf, addr, count);
> +		return pmt_memcpy64_fromio(buf, addr + off, count);
>  
> -	memcpy_fromio(buf, addr, count);
> +	memcpy_fromio(buf, addr + off, count);
>  
>  	return count;
>  }

-- 
With Best Regards,
Andy Shevchenko