Il 29/09/2014 10:24, Alexander Graf ha scritto: > > > On 26.09.14 14:44, Paolo Bonzini wrote: >> Il 26/09/2014 14:26, Alexander Graf ha scritto: >>> >>> Are you sure? Imagine one sysbus device includes another. We only want >>> to look at the region the lowest sysbus device exposes, no? >> >> IIUC this function is used to build the device tree. > > Yes, it's used to figure out the map of "start of region x of my device" > to "offset y in the platform bus mmio space". > >> Say you have 2 >> consecutive memory regions and the device tree requires separate "reg" >> entries for them. But because they are consecutive (or perhaps because >> you have a PCI version of the same device that sticks them in a single >> BAR) you use a single MMIO area at the sysbus level. >> >> In that case, you will use platform_bus_get_mmio_addr on the two inner >> regions, not the outer one. > > In that case, you will use platform_bus_get_mmio_addr on the outer > region because that's what the device model exposes. The parameter to > this function that tells us which region we want is the "mmio region > number" that sysbus exposes. > > If in device tree there are 2 reg properties, the device tree assembling > code has to do the conversion from sysbus granularity to device tree > granularity :).
Thanks for the clarification. Series Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
