lib/ioremap: ensure phys_addr actually corresponds to a physical address
authorWill Deacon <will.deacon@arm.com>
Fri, 28 Dec 2018 08:37:49 +0000 (00:37 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 28 Dec 2018 20:11:50 +0000 (12:11 -0800)
commit36ddc5a78c878e9b10c323d2fe88b0dae2f487eb
tree49e1698683500be2c4b481053af814a75922a755
parent48e178ab0d630b8b60deca64b22b22e68818777e
lib/ioremap: ensure phys_addr actually corresponds to a physical address

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.

Link: http://lkml.kernel.org/r/1544120495-17438-5-git-send-email-will.deacon@arm.com
Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/ioremap.c