On Mon, Jun 09, 2025 at 12:34:14PM GMT, Frank Li wrote: > Doorbell feature is implemented by mapping the EP's MSI interrupt > controller message address to a dedicated BAR in the EPC core. It is the > responsibility of the EPF driver to pass the actual message data to be > written by the host to the doorbell BAR region through its own logic. > > Tested-by: Niklas Cassel <cassel@xxxxxxxxxx> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx> > --- > Change from v15 to v16 > - fix rebase conflict > > Change from v14 to v15 > - check CONFIG_GENERIC_MSI > > Fix below build error > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > | Closes: https://lore.kernel.org/oe-kbuild-all/202502082204.6PRR3cfG-lkp@xxxxxxxxx/ > > All errors (new ones prefixed by >>): > > drivers/pci/endpoint/pci-ep-msi.c: In function 'pci_epf_alloc_doorbell': > >> drivers/pci/endpoint/pci-ep-msi.c:53:15: error: implicit declaration of function 'platform_device_msi_init_and_alloc_irqs' [-Werror=implicit-function-declaration] > 53 | ret = platform_device_msi_init_and_alloc_irqs(&epf->dev, num_db, pci_epf_write_msi_msg); > > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > | Closes: https://lore.kernel.org/oe-kbuild-all/202502082242.pOq1hB1d-lkp@xxxxxxxxx/ > > All errors (new ones prefixed by >>): > > drivers/pci/endpoint/pci-ep-msi.c: In function 'pci_epf_alloc_doorbell': > >> drivers/pci/endpoint/pci-ep-msi.c:49:14: error: implicit declaration of function 'irq_domain_is_msi_immutable'; did you mean 'irq_domain_is_msi_device'? [-Werror=implicit-function-declaration] > 49 | if (!irq_domain_is_msi_immutable(dom)) { > > Change from v13 to v14 > - basic roll back to v9 > - use device:id as msi-map input, its will handle it > - use existed platform_device_msi_init_and_alloc_irqs() > - pass down epf->dev point, because epf->dev of-node will be the same as > epc's parent. > > Change from v12 to v13 > - Use DOMAIN_BUS_DEVICE_PCI_EP_MSI > > Change from v10 to v12 > - none > > Change from v9 to v10 > - Create msi domain for each function device. > - Remove only function support limiation. My hardware only support one > function, so not test more than one case. > - use "msi-map" descript msi information > > msi-map = <func_no << 8 | vfunc_no, &its, start_stream_id, size>; > > Chagne from v8 to v9 > - sort header file > - use pci_epc_get(dev_name(msi_desc_to_dev(desc))); > - check epf number at pci_epf_alloc_doorbell > - Add comments for miss msi-parent case > > change from v5 to v8 > -none > > Change from v4 to v5 > - Remove request_irq() in pci_epc_alloc_doorbell() and leave to EP function > driver, so ep function driver can register differece call back function for > difference doorbell events and set irq affinity to differece CPU core. > - Improve error message when MSI allocate failure. > > Change from v3 to v4 > - msi change to use msi_get_virq() avoid use msi_for_each_desc(). > - add new struct for pci_epf_doorbell_msg to msi msg,virq and irq name. > - move mutex lock to epc function > - initialize variable at declear place. > - passdown epf to epc*() function to simplify code. > --- > drivers/pci/endpoint/Makefile | 1 + > drivers/pci/endpoint/pci-ep-msi.c | 82 +++++++++++++++++++++++++++++++++++++++ > include/linux/pci-ep-msi.h | 28 +++++++++++++ > include/linux/pci-epf.h | 16 ++++++++ > 4 files changed, 127 insertions(+) > > diff --git a/drivers/pci/endpoint/Makefile b/drivers/pci/endpoint/Makefile > index 95b2fe47e3b06..c502ea7ef367c 100644 > --- a/drivers/pci/endpoint/Makefile > +++ b/drivers/pci/endpoint/Makefile > @@ -6,3 +6,4 @@ > obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS) += pci-ep-cfs.o > obj-$(CONFIG_PCI_ENDPOINT) += pci-epc-core.o pci-epf-core.o\ > pci-epc-mem.o functions/ > +obj-$(CONFIG_GENERIC_MSI_IRQ) += pci-ep-msi.o I don't think we should build this driver for generic CONFIG_GENERIC_MSI_IRQ Kconfig. You should create a new EP specific Kconfig and make it depend on CONFIG_GENERIC_MSI_IRQ. > diff --git a/drivers/pci/endpoint/pci-ep-msi.c b/drivers/pci/endpoint/pci-ep-msi.c > new file mode 100644 > index 0000000000000..549b55b864d0e > --- /dev/null > +++ b/drivers/pci/endpoint/pci-ep-msi.c > @@ -0,0 +1,82 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * PCI Endpoint *Controller* (EPC) MSI library > + * > + * Copyright (C) 2025 NXP > + * Author: Frank Li <Frank.Li@xxxxxxx> > + */ > + > +#include <linux/device.h> > +#include <linux/irqdomain.h> > +#include <linux/module.h> > +#include <linux/msi.h> > +#include <linux/of_irq.h> > +#include <linux/pci-epc.h> > +#include <linux/pci-epf.h> > +#include <linux/pci-ep-cfs.h> > +#include <linux/pci-ep-msi.h> > +#include <linux/slab.h> > + > +static void pci_epf_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg) > +{ > + struct pci_epf *epf = to_pci_epf(desc->dev); > + > + if (epf && epf->db_msg && desc->msi_index < epf->num_db) > + memcpy(&epf->db_msg[desc->msi_index].msg, msg, sizeof(*msg)); > +} > + > +int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db) > +{ > + struct pci_epc *epc = epf->epc; > + struct device *dev = &epf->dev; > + struct irq_domain *dom; > + void *msg; > + u32 rid; > + int ret; > + int i; > + > + rid = PCI_EPF_DEVID(epf->func_no, epf->vfunc_no); > + dom = of_msi_map_get_device_domain(epc->dev.parent, rid, DOMAIN_BUS_PLATFORM_MSI); > + if (!dom) { > + dev_err(dev, "Can't find msi domain\n"); s/msi/MSI Perhaps, "Can't find MSI domain for parent device" to be more explicit that we are searching for MSI domain in parent device? > + return -EINVAL; -ENODATA > + } > + > + dev_set_msi_domain(dev, dom); > + > + msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + epf->num_db = num_db; > + epf->db_msg = msg; > + > + ret = platform_device_msi_init_and_alloc_irqs(&epf->dev, num_db, pci_epf_write_msi_msg); > + if (ret) { > + /* > + * The pcie_ep DT node has to specify 'msi-parent' for EP > + * doorbell support to work. Right now only GIC ITS is > + * supported. If you have GIC ITS and reached this print, > + * perhaps you are missing 'msi-map' in DT. > + */ msi-map is a generic property, no need to tie it with GIC ITS. Also, this API could fail for different reasons. So please get rid of this comment. > + dev_err(dev, "Failed to allocate MSI\n"); > + kfree(msg); > + return -ENOMEM; Why are you overriding the errno and not using 'ret'? > + } > + > + for (i = 0; i < num_db; i++) > + epf->db_msg[i].virq = msi_get_virq(dev, i); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(pci_epf_alloc_doorbell); > + > +void pci_epf_free_doorbell(struct pci_epf *epf) > +{ > + platform_device_msi_free_irqs_all(&epf->dev); > + > + kfree(epf->db_msg); > + epf->db_msg = NULL; > + epf->num_db = 0; > +} > +EXPORT_SYMBOL_GPL(pci_epf_free_doorbell); > diff --git a/include/linux/pci-ep-msi.h b/include/linux/pci-ep-msi.h > new file mode 100644 > index 0000000000000..6dfbe9353f0d8 > --- /dev/null > +++ b/include/linux/pci-ep-msi.h > @@ -0,0 +1,28 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * PCI Endpoint *Function* side MSI header file > + * > + * Copyright (C) 2024 NXP > + * Author: Frank Li <Frank.Li@xxxxxxx> > + */ > + > +#ifndef __PCI_EP_MSI__ > +#define __PCI_EP_MSI__ > + > +struct pci_epf; > + > +#ifdef CONFIG_GENERIC_MSI_IRQ > +int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 nums); > +void pci_epf_free_doorbell(struct pci_epf *epf); > +#else > +static inline int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 nums) > +{ > + return -EINVAL; -ENODATA > +} > + > +static inline void pci_epf_free_doorbell(struct pci_epf *epf) > +{ > +} > +#endif /* CONFIG_GENERIC_MSI_IRQ */ > + > +#endif /* __PCI_EP_MSI__ */ > diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h > index c0864935c6864..9634bf2c1ac06 100644 > --- a/include/linux/pci-epf.h > +++ b/include/linux/pci-epf.h > @@ -12,6 +12,7 @@ > #include <linux/configfs.h> > #include <linux/device.h> > #include <linux/mod_devicetable.h> > +#include <linux/msi.h> > #include <linux/pci.h> > > struct pci_epf; > @@ -128,6 +129,17 @@ struct pci_epf_bar { > int flags; > }; > > +/** > + * struct pci_epf_doorbell_msg - represents doorbell message > + * @msi_msg: MSI message > + * @virq: irq number of this doorbell MSI message > + * @name: irq name for doorbell interrupt 'name' is not present in the struct. - Mani -- மணிவண்ணன் சதாசிவம்
