On Mon, Nov 30, 2020 at 09:06:56AM +0000, David Laight wrote: > From: Krzysztof Wilczynski > > Sent: 29 November 2020 23:08 > > > > Use "void __iomem" instead "char __iomem" pointer type when working with > > the accessor functions (with names like readb() or writel(), etc.) to > > better match a given accessor function signature where commonly the > > address pointing to an I/O memory region would be a "void __iomem" > > pointer. > > ISTM that is heading in the wrong direction. > > I think (form the variable names etc) that these are pointers > to specific registers. > > So what you ought to have is a type for that register block. > Typically this is actually a structure - to give some type > checking that the offsets are being used with the correct > base address. In this case, "cfgbar" is not really a pointer to a register; it's the address of memory-mapped config space. The VMD hardware turns accesses to that space into PCI config transactions on its secondary side. xgene_pcie_get_cfg_base() and brcm_pcie_map_conf() are similar situations and use "void *". Bjorn
