• Herve Codina's avatar
    of: address: Fix address translation when address-size is greater than 2 · 42604f8e
    Herve Codina authored
    With the recent addition of of_pci_prop_ranges() in commit 407d1a51
    ("PCI: Create device tree node for bridge"), the ranges property can
    have a 3 cells child address, a 3 cells parent address and a 2 cells
    child size.
    
    A range item property for a PCI device is filled as follow:
      <BAR_nbr> 0 0 <phys.hi> <phys.mid> <phys.low> <BAR_sizeh> <BAR_sizel>
      <-- Child --> <-- Parent (PCI definition) --> <- BAR size (64bit) -->
    
    This allow to translate BAR addresses from the DT. For instance:
    pci@0,0 {
      #address-cells = <0x03>;
      #size-cells = <0x02>;
      device_type = "pci";
      compatible = "pci11ab,100", "pciclass,060400", "pciclass,0604";
      ranges = <0x82000000 0x00 0xe8000000
                0x82000000 0x00 0xe8000000
    	    0x00 0x4400000>;
      ...
      dev@0,0 {
        #address-cells = <0x03>;
        #size-cells = <0x02>;
        compatible = "pci1055,9660", "pciclass,020000", "pciclass,0200";
        /* Translations for BAR0 to BAR5 */
        ranges = <0x00 0x00 0x00 0x82010000 0x00 0xe8000000 0x00 0x2000000
                  0x01 0x00 0x00 0x82010000 0x00 0xea000000 0x00 0x1000000
                  0x02 0x00 0x00 0x82010000 0x00 0xeb000000 0x00 0x800000
                  0x03 0x00 0x00 0x82010000 0x00 0xeb800000 0x00 0x800000
                  0x04 0x00 0x00 0x82010000 0x00 0xec000000 0x00 0x20000
                  0x05 0x00 0x00 0x82010000 0x00 0xec020000 0x00 0x2000>;
        ...
        pci-ep-bus@0 {
          #address-cells = <0x01>;
          #size-cells = <0x01>;
          compatible = "simple-bus";
          /* Translate 0xe2000000 to BAR0 and 0xe0000000 to BAR1 */
          ranges = <0xe2000000 0x00 0x00 0x00 0x2000000
                    0xe0000000 0x01 0x00 0x00 0x1000000>;
          ...
        };
      };
    };
    
    During the translation process, the "default-flags" map() function is
    used to select the matching item in the ranges table and determine the
    address offset from this matching item.
    This map() function simply calls of_read_number() and when address-size
    is greater than 2, the map() function skips the extra high address part
    (ie part over 64bit). This lead to a wrong matching item and a wrong
    offset computation.
    Also during the translation itself, the extra high part related to the
    parent address is not present in the translated address.
    
    Fix the "default-flags" map() and translate() in order to take into
    account the child extra high address part in map() and the parent extra
    high address part in translate() and so having a correct address
    translation for ranges patterns such as the one given in the example
    above.
    Signed-off-by: default avatarHerve Codina <herve.codina@bootlin.com>
    Link: https://lore.kernel.org/r/20231017110221.189299-2-herve.codina@bootlin.comSigned-off-by: default avatarRob Herring <robh@kernel.org>
    42604f8e
address.c 30.8 KB