[PATCH v19 01/10] PCI: endpoint: Set ID and of_node for function driver
Manivannan Sadhasivam
mani at kernel.org
Wed Jul 2 04:00:48 PDT 2025
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 at 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);
> ret = epf_vf->driver->ops->bind(epf_vf);
> if (ret)
> goto ret;
> epf_vf->is_bound = true;
> }
>
> + 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
>
>
--
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