mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-25 19:42:19 +00:00
129f6af747
dw_pcie_prog_ep_inbound_atu() is used to program an inbound iATU in "BAR Match Mode". A memory address returned by e.g. kmalloc() is guaranteed to have natural alignment (aligned to the size of the allocation). It is however not guaranteed that pci_epc_set_bar() (and thus dw_pcie_prog_ep_inbound_atu()) is supplied an address that has natural alignment. (An EPF driver can send in an arbitrary physical address to pci_epc_set_bar().) The DWC Databook description for the LWR_TARGET_RW and LWR_TARGET_HW fields in the IATU_LWR_TARGET_ADDR_OFF_INBOUND_i registers state that: "Field size depends on log2(BAR_MASK+1) in BAR match mode." I.e. only the upper bits are writable, and the number of writable bits is dependent on the configured BAR_MASK. Add a check to ensure that the physical address programmed in the iATU is aligned to the size of the BAR (BAR_MASK+1), as without this, we can get hard to debug errors, as we could write to bits that are read-only (without getting a write error), which could cause the iATU to end up redirecting to a physical address that is different from the address that we intended. Link: https://lore.kernel.org/r/20241213143301.4158431-11-cassel@kernel.org Signed-off-by: Niklas Cassel <cassel@kernel.org> Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>