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    Subject[PATCH 5.10 417/545] powerpc/pci: Prefer PCI domain assignment via DT linux,pci-domain and alias
    Date
    From: Pali Rohár <pali@kernel.org>

    [ Upstream commit 0fe1e96fef0a5c53b4c0d1500d356f3906000f81 ]

    Other Linux architectures use DT property 'linux,pci-domain' for
    specifying fixed PCI domain of PCI controller specified in Device-Tree.

    And lot of Freescale powerpc boards have defined numbered pci alias in
    Device-Tree for every PCIe controller which number specify preferred PCI
    domain.

    So prefer usage of DT property 'linux,pci-domain' (via function
    of_get_pci_domain_nr()) and DT pci alias (via function
    of_alias_get_id()) on powerpc architecture for assigning PCI domain to
    PCI controller.

    Fixes: 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties")
    Signed-off-by: Pali Rohár <pali@kernel.org>
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
    Link: https://lore.kernel.org/r/20220706102148.5060-2-pali@kernel.org
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    arch/powerpc/kernel/pci-common.c | 27 +++++++++++++++++++--------
    1 file changed, 19 insertions(+), 8 deletions(-)

    diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
    index 7920559a1ca8..7af00a880e16 100644
    --- a/arch/powerpc/kernel/pci-common.c
    +++ b/arch/powerpc/kernel/pci-common.c
    @@ -73,16 +73,30 @@ void set_pci_dma_ops(const struct dma_map_ops *dma_ops)
    static int get_phb_number(struct device_node *dn)
    {
    int ret, phb_id = -1;
    - u32 prop_32;
    u64 prop;

    /*
    * Try fixed PHB numbering first, by checking archs and reading
    - * the respective device-tree properties. Firstly, try powernv by
    - * reading "ibm,opal-phbid", only present in OPAL environment.
    + * the respective device-tree properties. Firstly, try reading
    + * standard "linux,pci-domain", then try reading "ibm,opal-phbid"
    + * (only present in powernv OPAL environment), then try device-tree
    + * alias and as the last try to use lower bits of "reg" property.
    */
    - ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop);
    + ret = of_get_pci_domain_nr(dn);
    + if (ret >= 0) {
    + prop = ret;
    + ret = 0;
    + }
    + if (ret)
    + ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop);
    + if (ret)
    + ret = of_alias_get_id(dn, "pci");
    + if (ret >= 0) {
    + prop = ret;
    + ret = 0;
    + }
    if (ret) {
    + u32 prop_32;
    ret = of_property_read_u32_index(dn, "reg", 1, &prop_32);
    prop = prop_32;
    }
    @@ -94,10 +108,7 @@ static int get_phb_number(struct device_node *dn)
    if ((phb_id >= 0) && !test_and_set_bit(phb_id, phb_bitmap))
    return phb_id;

    - /*
    - * If not pseries nor powernv, or if fixed PHB numbering tried to add
    - * the same PHB number twice, then fallback to dynamic PHB numbering.
    - */
    + /* If everything fails then fallback to dynamic PHB numbering. */
    phb_id = find_first_zero_bit(phb_bitmap, MAX_PHBS);
    BUG_ON(phb_id >= MAX_PHBS);
    set_bit(phb_id, phb_bitmap);
    --
    2.35.1


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