On Mon, Jun 09, 2025 at 12:34:13PM GMT, Frank Li wrote:
Set device ID as 'vfunc_no << 3 | func_no' and use 'device_set_of_node_from_dev()' to set 'of_node' the same as the EPC parent device.
Currently, EPF 'of_node' is NULL, but many functions depend on 'of_node' settings, such as DMA, IOMMU, and MSI. At present, all DMA allocation functions use the EPC's device node, but they should use the EPF one. For multiple function drivers, IOMMU/MSI should be different for each function driver.
We don't define OF node for any function, so device_set_of_node_from_dev() also ends up reusing the EPC node. So how can you make use of it in multi EPF setup? I don't understand.
If multiple function devices share the same EPC device, there will be no isolation between them. Setting the ID and 'of_node' prepares for proper support.
I don't know who you can provide *isolation* by reusing the EPC OF node. It is same as using the EPC node directly.
- Mani
Signed-off-by: Frank Li Frank.Li@nxp.com
change from v14 to v16
- none
change from v13 to v14 new patch
drivers/pci/endpoint/pci-epf-core.c | 4 ++++ include/linux/pci-epf.h | 2 ++ 2 files changed, 6 insertions(+)
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index 577a9e490115c..95fb3d7c1d45e 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -120,12 +120,16 @@ int pci_epf_bind(struct pci_epf *epf) epf_vf->sec_epc_func_no = epf->sec_epc_func_no; epf_vf->epc = epf->epc; epf_vf->sec_epc = epf->sec_epc;
epf_vf->dev.id = PCI_EPF_DEVID(epf->func_no, vfunc_no);device_set_of_node_from_dev(&epf_vf->dev, epc->dev.parent);
- epf->dev.id = PCI_EPF_DEVID(epf->func_no, 0);
- device_set_of_node_from_dev(&epf->dev, epc->dev.parent); ret = epf->driver->ops->bind(epf); if (ret) goto ret;
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h index 749cee0bcf2cc..c0864935c6864 100644 --- a/include/linux/pci-epf.h +++ b/include/linux/pci-epf.h @@ -216,6 +216,8 @@ static inline void *epf_get_drvdata(struct pci_epf *epf) return dev_get_drvdata(&epf->dev); } +#define PCI_EPF_DEVID(func_no, vfunc_no) ((vfunc_no) << 3 | (func_no))
struct pci_epf *pci_epf_create(const char *name); void pci_epf_destroy(struct pci_epf *epf); int __pci_epf_register_driver(struct pci_epf_driver *driver,
-- 2.34.1