On Wed, Sep 16, 2020 at 03:51:11PM +0100, Catalin Marinas wrote: > On Wed, Sep 16, 2020 at 12:06:58PM +0100, Lorenzo Pieralisi wrote: > > For arches that do not select CONFIG_GENERIC_IOMAP, the current > > pci_iounmap() function does nothing causing obvious memory leaks > > for mapped regions that are backed by MMIO physical space. > > > > In order to detect if a mapped pointer is IO vs MMIO, a check must made > > available to the pci_iounmap() function so that it can actually detect > > whether the pointer has to be unmapped. > > > > In configurations where CONFIG_HAS_IOPORT_MAP && !CONFIG_GENERIC_IOMAP, > > a mapped port is detected using an ioport_map() stub defined in > > asm-generic/io.h. > > > > Use the same logic to implement a stub (ie __pci_ioport_unmap()) that > > detects if the passed in pointer in pci_iounmap() is IO vs MMIO to > > iounmap conditionally and call it in pci_iounmap() fixing the issue. > > > > Leave __pci_ioport_unmap() as a NOP for all other config options. > > > > Reported-by: George Cherian <george.cherian@xxxxxxxxxxx> > > Link: https://lore.kernel.org/lkml/20200905024811.74701-1-yangyingliang@xxxxxxxxxx > > Link: https://lore.kernel.org/lkml/20200824132046.3114383-1-george.cherian@xxxxxxxxxxx > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > > Cc: Arnd Bergmann <arnd@xxxxxxxx> > > Cc: George Cherian <george.cherian@xxxxxxxxxxx> > > Cc: Will Deacon <will@xxxxxxxxxx> > > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > > Cc: Yang Yingliang <yangyingliang@xxxxxxxxxx> > > --- > > include/asm-generic/io.h | 39 +++++++++++++++++++++++++++------------ > > 1 file changed, 27 insertions(+), 12 deletions(-) > > This works for me. The only question I have is whether pci_iomap.h is > better than io.h for __pci_ioport_unmap(). These headers are really > confusing. Yes they are, in total honesty there is much more to do to make them sane, this patch is just a band-aid. I thought about moving this stuff into pci_iomap.h, though that file is included _independently_ from io.h from some arches so I tried to keep everything in io.h to minimize disruption. We can merge this patch - since it is a fix after all - and then I can try to improve the whole pci_iounmap() includes. > Either way: > > Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Thanks a lot. I'd appreciate a tested-by from the George as he is the one who reported the problem. Lorenzo
