On Sat, Sep 02, 2023 at 10:22:25AM +0530, Manivannan Sadhasivam wrote: > On Wed, Apr 26, 2023 at 04:34:34PM -0400, Frank Li wrote: > > This commit introduces a common method for sending messages from the Root Complex > > (RC) to the Endpoint (EP) by utilizing the platform MSI interrupt controller, > > such as ARM GIC, as an EP doorbell. Maps the memory assigned for the BAR region > > by the PCI host to the message address of the platform MSI interrupt controller > > in the PCI EP. As a result, when the PCI RC writes to the BAR region, it triggers > > an IRQ at the EP. This implementation serves as a common method for all endpoint > > function drivers. > > > > However, it currently supports only one EP physical function due to limitations > > in ARM MSI/IMS readiness. > > > > I've provided generic comments below, but I will do one more thorough review > after seeing epf-test driver patch. > > > Signed-off-by: Frank Li <Frank.Li@xxxxxxx> > > --- > > drivers/pci/endpoint/pci-epf-core.c | 109 ++++++++++++++++++++++++++++ > > include/linux/pci-epf.h | 16 ++++ > > 2 files changed, 125 insertions(+) > > > > diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c > > index 355a6f56fcea..94ac82bf84c5 100644 > > --- a/drivers/pci/endpoint/pci-epf-core.c > > +++ b/drivers/pci/endpoint/pci-epf-core.c > > @@ -6,10 +6,12 @@ > > * Author: Kishon Vijay Abraham I <kishon@xxxxxx> > > */ > > > > +#include <linux/irqreturn.h> > > Why is this needed? > > > #include <linux/device.h> > > #include <linux/dma-mapping.h> > > #include <linux/slab.h> > > #include <linux/module.h> > > +#include <linux/msi.h> > > > > #include <linux/pci-epc.h> > > #include <linux/pci-epf.h> > > @@ -300,6 +302,113 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, > > } > > EXPORT_SYMBOL_GPL(pci_epf_alloc_space); > > > > +static enum irqreturn pci_epf_interrupt_handler(int irq, void *data) > > static irqreturn_t > > s/pci_epf_interrupt_handler/pci_epf_doorbell_handler > > > +{ > > + struct pci_epf *epf = data; > > + > > + if (epf->event_ops && epf->event_ops->doorbell) > > + epf->event_ops->doorbell(epf, irq - epf->virq_base); > > + > > + return IRQ_HANDLED; > > +} > > + > > +static void pci_epf_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg) > > +{ > > + struct pci_epc *epc = container_of(desc->dev, struct pci_epc, dev); > > + struct pci_epf *epf; > > + > > + /* Todo: Need check correct epf if multi epf supported */ > > + list_for_each_entry(epf, &epc->pci_epf, list) { > > + if (epf->msg && desc->msi_index < epf->num_msgs) > > + epf->msg[desc->msi_index] = *msg; > > + } > > +} > > + > > +int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_msgs) > > +{ > > + struct irq_domain *domain; > > + struct pci_epc *epc; > > + struct device *dev; > > + int virq; > > + int ret; > > + int i; > > + > > + epc = epf->epc; > > + dev = &epc->dev; > > "epc_dev" to make it explicit > > > + > > + /* > > + * Current only support 1 function. > > What does this mean exactly? Even a single EPC can support multiple EPFs > Please ignore above comment. - Mani > > + * PCI IMS(interrupt message store) ARM support have not been > > + * ready yet. > > No need to mention platform irq controller name. > > > + */ > > + if (epc->function_num_map != 1) > > Why can't you use, epf->func_no? > > > + return -EOPNOTSUPP; > > + > > + domain = dev_get_msi_domain(dev->parent); > > + if (!domain) > > + return -EOPNTSUPP; > > Newline > > > + dev_set_msi_domain(dev, domain); > > + > > + /* use parent of_node to get device id information */ > > + dev->of_node = dev->parent->of_node; > > + > > Why do you need of_node assignment inside EPF core? > > > + epf->msg = kcalloc(num_msgs, sizeof(struct msi_msg), GFP_KERNEL); > > + if (!epf->msg) > > + return -ENOMEM; > > + > > + epf->num_msgs = num_msgs; > > + > > Move this to the start of the function, after checks. > > > + ret = platform_msi_domain_alloc_irqs(dev, num_msgs, pci_epf_write_msi_msg); > > + if (ret) { > > + dev_err(dev, "Can't allocate MSI from system MSI controller\n"); > > "Failed to allocate MSI" > > > + goto err_mem; > > err_free_mem > > > + } > > + > > + for (i = 0; i < num_msgs; i++) { > > + virq = msi_get_virq(dev, i); > > + if (i == 0) > > + epf->virq_base = virq; > > + > > + ret = request_irq(virq, pci_epf_interrupt_handler, 0, > > + "pci-epf-doorbell", epf); > > IRQ name should have an index, otherwise all of them will have the same name. > > > + > > + if (ret) { > > + dev_err(dev, "Failure request doorbell IRQ\n"); > > "Failed to request doorbell" > > > + goto err_irq; > > err_free_irq > > > + } > > + } > > + > > + epf->num_msgs = num_msgs; > > Newline > > > + return ret; > > + > > +err_irq: > > + platform_msi_domain_free_irqs(dev); > > +err_mem: > > + kfree(epf->msg); > > + epf->msg = NULL; > > + epf->num_msgs = 0; > > + > > + return ret; > > +} > > +EXPORT_SYMBOL_GPL(pci_epf_alloc_doorbell); > > + > > +void pci_epf_free_doorbell(struct pci_epf *epf) > > +{ > > + struct pci_epc *epc; > > + int i; > > + > > + epc = epf->epc; > > + > > + for (i = 0; i < epf->num_msgs; i++) > > + free_irq(epf->virq_base + i, epf); > > + > > + platform_msi_domain_free_irqs(&epc->dev); > > + kfree(epf->msg); > > + epf->msg = NULL; > > + epf->num_msgs = 0; > > +} > > +EXPORT_SYMBOL_GPL(pci_epf_free_doorbell); > > + > > static void pci_epf_remove_cfs(struct pci_epf_driver *driver) > > { > > struct config_group *group, *tmp; > > diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h > > index b8441db2fa52..e187e3ee48d2 100644 > > --- a/include/linux/pci-epf.h > > +++ b/include/linux/pci-epf.h > > @@ -75,6 +75,7 @@ struct pci_epf_ops { > > struct pci_epc_event_ops { > > int (*core_init)(struct pci_epf *epf); > > int (*link_up)(struct pci_epf *epf); > > + int (*doorbell)(struct pci_epf *epf, int index); > > }; > > > > /** > > @@ -173,6 +174,9 @@ struct pci_epf { > > unsigned long vfunction_num_map; > > struct list_head pci_vepf; > > const struct pci_epc_event_ops *event_ops; > > + struct msi_msg *msg; > > + u16 num_msgs; > > + int virq_base; > > }; > > > > /** > > @@ -216,4 +220,16 @@ int pci_epf_bind(struct pci_epf *epf); > > void pci_epf_unbind(struct pci_epf *epf); > > int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf); > > void pci_epf_remove_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf); > > +int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 nums); > > +void pci_epf_free_doorbell(struct pci_epf *epf); > > + > > +static inline struct msi_msg *epf_get_msg(struct pci_epf *epf) > > +{ > > + return epf->msg; > > +} > > + > > +static inline u16 epf_get_msg_num(struct pci_epf *epf) > > +{ > > + return epf->num_msgs; > > +} > > I don't see a need for these two functions as they are doing just dereferences. > > - Mani > > > #endif /* __LINUX_PCI_EPF_H */ > > -- > > 2.34.1 > > > > -- > மணிவண்ணன் சதாசிவம் -- மணிவண்ணன் சதாசிவம்