[+cc Marc, Alyssa, Sven for RID-to-SID mapping insight. The patch at https://lore.kernel.org/all/20211130062137.GD205712@thinkpad/ merely fixes a warning. My meta-question is about the qcom BDF-to-SID mapping.] On Tue, Nov 30, 2021 at 11:51:37AM +0530, Manivannan Sadhasivam wrote: > On Mon, Nov 29, 2021 at 09:36:14PM -0600, Bjorn Helgaas wrote: > > ... > > I'm also curious why pcie-qcom.c is the only driver that does this. > > "iommu-map" is not specific to qcom, but no other drivers do similar > > things with it. > > Yes, on the recent qcom platforms starting from sm8250 we need to program > the BDF to SID mapping in the controller and that's the reason we are > extracting the "iommu-map" property in DT. This sounds like something that may not really be specific to sm8250. It looks vaguely similar to apple_pcie_add_device(). Compare the qcom code at [1] with the Apple code at [2]. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/dwc/pcie-qcom.c?id=v5.16-rc1#n1308 [2] https://git.kernel.org/linus/468c8d52c332 > > > sparse warnings: (new ones prefixed by >>) > > > >> drivers/pci/controller/dwc/pcie-qcom.c:1305:30: sparse: sparse: incorrect type in initializer (different base types) @@ expected unsigned short [usertype] bdf_be @@ got restricted __be16 [usertype] @@ > > > drivers/pci/controller/dwc/pcie-qcom.c:1305:30: sparse: expected unsigned short [usertype] bdf_be > > > drivers/pci/controller/dwc/pcie-qcom.c:1305:30: sparse: got restricted __be16 [usertype] > > > > > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> > > > --- > > > drivers/pci/controller/dwc/pcie-qcom.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > > > index 8a7a300163e5..6c3b034e9946 100644 > > > --- a/drivers/pci/controller/dwc/pcie-qcom.c > > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > > > @@ -1312,7 +1312,7 @@ static int qcom_pcie_config_sid_sm8250(struct qcom_pcie *pcie) > > > > > > /* Look for an available entry to hold the mapping */ > > > for (i = 0; i < nr_map; i++) { > > > - u16 bdf_be = cpu_to_be16(map[i].bdf); > > > + __be16 bdf_be = cpu_to_be16(map[i].bdf); > > > u32 val; > > > u8 hash; > > > > > > -- > > > 2.25.1 > > >
