Re: [RFC PATCH 3/4] powerpc: drop redundant unmaps of failed vmap mappings

[Uladzislau Rezki <urezki@gmail.com>]

On Tue, Oct 13, 2026 at 03:23:41PM +0400, Suren Baghdasaryan wrote:
> On Fri, Oct 9, 2026 at 10:36 AM Hao Ge <hao.ge@linux.dev> wrote:
> >
> > vmap_page_range() and ioremap_page_range() clear the PTEs they
> > installed when they fail, so the vunmap_range() in remap_isa_base()
> > and ioremap_phb() has nothing left to remove.
> >
> > Signed-off-by: Hao Ge <hao.ge@linux.dev>
> 
> Reviewed-by: Suren Baghdasaryan <surenb@google.com>
> 
> 
> > ---
> >  arch/powerpc/kernel/isa-bridge.c | 5 ++---
> >  arch/powerpc/kernel/pci_64.c     | 4 +---
> >  2 files changed, 3 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/isa-bridge.c b/arch/powerpc/kernel/isa-bridge.c
> > index 5c064485197a..93029d85e6ea 100644
> > --- a/arch/powerpc/kernel/isa-bridge.c
> > +++ b/arch/powerpc/kernel/isa-bridge.c
> > @@ -46,9 +46,8 @@ static void remap_isa_base(phys_addr_t pa, unsigned long size)
> >         WARN_ON_ONCE(size & ~PAGE_MASK);
> >
> >         if (slab_is_available()) {
> > -               if (vmap_page_range(ISA_IO_BASE, ISA_IO_BASE + size, pa,
> > -                                   pgprot_noncached(PAGE_KERNEL)))
> > -                       vunmap_range(ISA_IO_BASE, ISA_IO_BASE + size);
> > +               vmap_page_range(ISA_IO_BASE, ISA_IO_BASE + size, pa,
> > +                               pgprot_noncached(PAGE_KERNEL));
> >         } else {
> >                 early_ioremap_range(ISA_IO_BASE, pa, size,
> >                                 pgprot_noncached(PAGE_KERNEL));
> > diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
> > index e27342ef128b..f74269636d5e 100644
> > --- a/arch/powerpc/kernel/pci_64.c
> > +++ b/arch/powerpc/kernel/pci_64.c
> > @@ -139,10 +139,8 @@ void __iomem *ioremap_phb(phys_addr_t paddr, unsigned long size)
> >
> >         addr = (unsigned long)area->addr;
> >         if (ioremap_page_range(addr, addr + size, paddr,
> > -                       pgprot_noncached(PAGE_KERNEL))) {
> > -               vunmap_range(addr, addr + size);
> > +                       pgprot_noncached(PAGE_KERNEL)))
> >                 return NULL;
> > -       }
> >
> >         return (void __iomem *)addr;
> >  }
> > --
> > 2.25.1
> >
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

--
Uladzislau Rezki