On Mon, Sep 13, 2021, at 20:25, Marc Zyngier wrote: > The Apple PCIe controller doesn't directly feed the endpoint's > Requester ID to the IOMMU (DART), but instead maps RIDs onto > Stream IDs (SIDs). The DART and the PCIe controller must thus > agree on the SIDs that are used for translation (by using > the 'iommu-map' property). > > For this purpose, parse the 'iommu-map' property each time a > device gets added, and use the resulting translation to configure > the PCIe RID-to-SID mapper. Similarily, remove the translation > if/when the device gets removed. > > This is all driven from a bus notifier which gets registered at > probe time. Hopefully this is the only PCI controller driver > in the whole system. > > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> > --- > drivers/pci/controller/pcie-apple.c | 158 +++++++++++++++++++++++++++- > 1 file changed, 156 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/pcie-apple.c > b/drivers/pci/controller/pcie-apple.c > index 76344223245d..68d71eabe708 100644 > --- a/drivers/pci/controller/pcie-apple.c > +++ b/drivers/pci/controller/pcie-apple.c > @@ -23,8 +23,10 @@ > #include <linux/iopoll.h> > #include <linux/irqchip/chained_irq.h> > #include <linux/irqdomain.h> > +#include <linux/list.h> > #include <linux/module.h> > #include <linux/msi.h> > +#include <linux/notifier.h> > #include <linux/of_irq.h> > #include <linux/pci-ecam.h> > > @@ -116,6 +118,8 @@ > #define PORT_TUNSTAT_PERST_ACK_PEND BIT(1) > #define PORT_PREFMEM_ENABLE 0x00994 > > +#define MAX_RID2SID 64 Do these actually have 64 slots? I thought that was only for the Thunderbolt controllers and that these only had 16. I never checked it myself though and it doesn't make much of a difference for now since only four different RIDs will ever be connected anyway. Sven
