Re: [PATCH v4 4/5] lib/ioremap: Ensure phys_addr actually corresponds to a physical address

[Sean Christopherson]

On Mon, Nov 26, 2018 at 05:07:46PM +0000, Will Deacon wrote:
> The current ioremap() code uses a phys_addr variable at each level of
> page table, which is confusingly offset by subtracting the base virtual
> address being mapped so that adding the current virtual address back on
> when iterating through the page table entries gives back the corresponding
> physical address.
> 
> This is fairly confusing and results in all users of phys_addr having to
> add the current virtual address back on. Instead, this patch just updates
> phys_addr when iterating over the page table entries, ensuring that it's
> always up-to-date and doesn't require explicit offsetting.
> 
> Cc: Chintan Pandya <cpandya@xxxxxxxxxxxxxx>
> Cc: Toshi Kani <toshi.kani@xxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Signed-off-by: Will Deacon <will.deacon@xxxxxxx>

Tested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>