/** * PCI Endpoint *Controller* (EPC) library * * Copyright (C) 2017 Texas Instruments * Author: Kishon Vijay Abraham I * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 of * the License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include #include #include #include #include #include #include #include static struct class *pci_epc_class; static void devm_pci_epc_release(struct device *dev, void *res) { struct pci_epc *epc = *(struct pci_epc **)res; pci_epc_destroy(epc); } static int devm_pci_epc_match(struct device *dev, void *res, void *match_data) { struct pci_epc **epc = res; return *epc == match_data; } /** * pci_epc_put() - release the PCI endpoint controller * @epc: epc returned by pci_epc_get() * * release the refcount the caller obtained by invoking pci_epc_get() */ void pci_epc_put(struct pci_epc *epc) { if (!epc || IS_ERR(epc)) return; module_put(epc->ops->owner); put_device(&epc->dev); } EXPORT_SYMBOL_GPL(pci_epc_put); /** * pci_epc_get() - get the PCI endpoint controller * @epc_name: device name of the endpoint controller * * Invoke to get struct pci_epc * corresponding to the device name of the * endpoint controller */ struct pci_epc *pci_epc_get(const char *epc_name) { int ret = -EINVAL; struct pci_epc *epc; struct device *dev; struct class_dev_iter iter; class_dev_iter_init(&iter, pci_epc_class, NULL, NULL); while ((dev = class_dev_iter_next(&iter))) { if (strcmp(epc_name, dev_name(dev))) continue; epc = to_pci_epc(dev); if (!try_module_get(epc->ops->owner)) { ret = -EINVAL; goto err; } class_dev_iter_exit(&iter); get_device(&epc->dev); return epc; } err: class_dev_iter_exit(&iter); return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(pci_epc_get); /** * pci_epc_stop() - stop the PCI link * @epc: the link of the EPC device that has to be stopped * * Invoke to stop the PCI link */ void pci_epc_stop(struct pci_epc *epc) { unsigned long flags; if (IS_ERR(epc) || !epc->ops->stop) return; spin_lock_irqsave(&epc->lock, flags); epc->ops->stop(epc); spin_unlock_irqrestore(&epc->lock, flags); } EXPORT_SYMBOL_GPL(pci_epc_stop); /** * pci_epc_start() - start the PCI link * @epc: the link of *this* EPC device has to be started * * Invoke to start the PCI link */ int pci_epc_start(struct pci_epc *epc) { int ret; unsigned long flags; if (IS_ERR(epc)) return -EINVAL; if (!epc->ops->start) return 0; spin_lock_irqsave(&epc->lock, flags); ret = epc->ops->start(epc); spin_unlock_irqrestore(&epc->lock, flags); return ret; } EXPORT_SYMBOL_GPL(pci_epc_start); /** * pci_epc_raise_irq() - interrupt the host system * @epc: the EPC device which has to interrupt the host * @type: specify the type of interrupt; legacy or MSI * @interrupt_num: the MSI interrupt number * * Invoke to raise an MSI or legacy interrupt */ int pci_epc_raise_irq(struct pci_epc *epc, enum pci_epc_irq_type type, u8 interrupt_num) { int ret; unsigned long flags; if (IS_ERR(epc)) return -EINVAL; if (!epc->ops->raise_irq) return 0; spin_lock_irqsave(&epc->lock, flags); ret = epc->ops->raise_irq(epc, type, interrupt_num); spin_unlock_irqrestore(&epc->lock, flags); return ret; } EXPORT_SYMBOL_GPL(pci_epc_raise_irq); /** * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated * @epc: the EPC device to which MSI interrupts was requested * * Invoke to get the number of MSI interrupts allocated by the RC */ int pci_epc_get_msi(struct pci_epc *epc) { int interrupt; unsigned long flags; if (IS_ERR(epc)) return 0; if (!epc->ops->get_msi) return 0; spin_lock_irqsave(&epc->lock, flags); interrupt = epc->ops->get_msi(epc); spin_unlock_irqrestore(&epc->lock, flags); if (interrupt < 0) return 0; interrupt = 1 << interrupt; return interrupt; } EXPORT_SYMBOL_GPL(pci_epc_get_msi); /** * pci_epc_set_msi() - set the number of MSI interrupt numbers required * @epc: the EPC device on which MSI has to be configured * @interrupts: number of MSI interrupts required by the EPF * * Invoke to set the required number of MSI interrupts. */ int pci_epc_set_msi(struct pci_epc *epc, u8 interrupts) { int ret; u8 encode_int; unsigned long flags; if (IS_ERR(epc)) return -EINVAL; if (!epc->ops->set_msi) return 0; encode_int = order_base_2(interrupts); spin_lock_irqsave(&epc->lock, flags); ret = epc->ops->set_msi(epc, encode_int); spin_unlock_irqrestore(&epc->lock, flags); return ret; } EXPORT_SYMBOL_GPL(pci_epc_set_msi); /** * pci_epc_unmap_addr() - unmap CPU address from PCI address * @epc: the EPC device on which address is allocated * @phys_addr: physical address of the local system * * Invoke to unmap the CPU address from PCI address. */ void pci_epc_unmap_addr(struct pci_epc *epc, phys_addr_t phys_addr) { unsigned long flags; if (IS_ERR(epc)) return; if (!epc->ops->unmap_addr) return; spin_lock_irqsave(&epc->lock, flags); epc->ops->unmap_addr(epc, phys_addr); spin_unlock_irqrestore(&epc->lock, flags); } EXPORT_SYMBOL_GPL(pci_epc_unmap_addr); /** * pci_epc_map_addr() - map CPU address to PCI address * @epc: the EPC device on which address is allocated * @phys_addr: physical address of the local system * @pci_addr: PCI address to which the physical address should be mapped * @size: the size of the allocation * * Invoke to map CPU address with PCI address. */ int pci_epc_map_addr(struct pci_epc *epc, phys_addr_t phys_addr, u64 pci_addr, size_t size) { int ret; unsigned long flags; if (IS_ERR(epc)) return -EINVAL; if (!epc->ops->map_addr) return 0; spin_lock_irqsave(&epc->lock, flags); ret = epc->ops->map_addr(epc, phys_addr, pci_addr, size); spin_unlock_irqrestore(&epc->lock, flags); return ret; } EXPORT_SYMBOL_GPL(pci_epc_map_addr); /** * pci_epc_clear_bar() - reset the BAR * @epc: the EPC device for which the BAR has to be cleared * @bar: the BAR number that has to be reset * * Invoke to reset the BAR of the endpoint device. */ void pci_epc_clear_bar(struct pci_epc *epc, int bar) { unsigned long flags; if (IS_ERR(epc)) return; if (!epc->ops->clear_bar) return; spin_lock_irqsave(&epc->lock, flags); epc->ops->clear_bar(epc, bar); spin_unlock_irqrestore(&epc->lock, flags); } EXPORT_SYMBOL_GPL(pci_epc_clear_bar); /** * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space * @epc: the EPC device on which BAR has to be configured * @bar: the BAR number that has to be configured * @size: the size of the addr space * @flags: specify memory allocation/io allocation/32bit address/64 bit address * * Invoke to configure the BAR of the endpoint device. */ int pci_epc_set_bar(struct pci_epc *epc, enum pci_barno bar, dma_addr_t bar_phys, size_t size, int flags) { int ret; unsigned long irq_flags; if (IS_ERR(epc)) return -EINVAL; if (!epc->ops->set_bar) return 0; spin_lock_irqsave(&epc->lock, irq_flags); ret = epc->ops->set_bar(epc, bar, bar_phys, size, flags); spin_unlock_irqrestore(&epc->lock, irq_flags); return ret; } EXPORT_SYMBOL_GPL(pci_epc_set_bar); /** * pci_epc_write_header() - write standard configuration header * @epc: the EPC device to which the configuration header should be written * @header: standard configuration header fields * * Invoke to write the configuration header to the endpoint controller. Every * endpoint controller will have a dedicated location to which the standard * configuration header would be written. The callback function should write * the header fields to this dedicated location. */ int pci_epc_write_header(struct pci_epc *epc, struct pci_epf_header *header) { int ret; unsigned long flags; if (IS_ERR(epc)) return -EINVAL; if (!epc->ops->write_header) return 0; spin_lock_irqsave(&epc->lock, flags); ret = epc->ops->write_header(epc, header); spin_unlock_irqrestore(&epc->lock, flags); return ret; } EXPORT_SYMBOL_GPL(pci_epc_write_header); /** * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller * @epc: the EPC device to which the endpoint function should be added * @epf: the endpoint function to be added * * A PCI endpoint device can have one or more functions. In the case of PCIe, * the specification allows up to 8 PCIe endpoint functions. Invoke * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller. */ int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf) { unsigned long flags; struct device *dev = epc->dev.parent; if (epf->epc) return -EBUSY; if (IS_ERR(epc)) return -EINVAL; if (epf->func_no > epc->max_functions - 1) return -EINVAL; epf->epc = epc; if (dev->of_node) { of_dma_configure(&epf->dev, dev->of_node); } else { dma_set_coherent_mask(&epf->dev, epc->dev.coherent_dma_mask); epf->dev.dma_mask = epc->dev.dma_mask; } spin_lock_irqsave(&epc->lock, flags); list_add_tail(&epf->list, &epc->pci_epf); spin_unlock_irqrestore(&epc->lock, flags); return 0; } EXPORT_SYMBOL_GPL(pci_epc_add_epf); /** * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller * @epc: the EPC device from which the endpoint function should be removed * @epf: the endpoint function to be removed * * Invoke to remove PCI endpoint function from the endpoint controller. */ void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf) { unsigned long flags; if (!epc || IS_ERR(epc)) return; spin_lock_irqsave(&epc->lock, flags); list_del(&epf->list); spin_unlock_irqrestore(&epc->lock, flags); } EXPORT_SYMBOL_GPL(pci_epc_remove_epf); /** * pci_epc_linkup() - Notify the EPF device that EPC device has established a * connection with the Root Complex. * @epc: the EPC device which has established link with the host * * Invoke to Notify the EPF device that the EPC device has established a * connection with the Root Complex. */ void pci_epc_linkup(struct pci_epc *epc) { unsigned long flags; struct pci_epf *epf; if (!epc || IS_ERR(epc)) return; spin_lock_irqsave(&epc->lock, flags); list_for_each_entry(epf, &epc->pci_epf, list) pci_epf_linkup(epf); spin_unlock_irqrestore(&epc->lock, flags); } EXPORT_SYMBOL_GPL(pci_epc_linkup); /** * pci_epc_destroy() - destroy the EPC device * @epc: the EPC device that has to be destroyed * * Invoke to destroy the PCI EPC device */ void pci_epc_destroy(struct pci_epc *epc) { pci_ep_cfs_remove_epc_group(epc->group); device_unregister(&epc->dev); kfree(epc); } EXPORT_SYMBOL_GPL(pci_epc_destroy); /** * devm_pci_epc_destroy() - destroy the EPC device * @dev: device that wants to destroy the EPC * @epc: the EPC device that has to be destroyed * * Invoke to destroy the devres associated with this * pci_epc and destroy the EPC device. */ void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc) { int r; r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match, epc); dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n"); } EXPORT_SYMBOL_GPL(devm_pci_epc_destroy); /** * __pci_epc_create() - create a new endpoint controller (EPC) device * @dev: device that is creating the new EPC * @ops: function pointers for performing EPC operations * @owner: the owner of the module that creates the EPC device * * Invoke to create a new EPC device and add it to pci_epc class. */ struct pci_epc * __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, struct module *owner) { int ret; struct pci_epc *epc; if (WARN_ON(!dev)) { ret = -EINVAL; goto err_ret; } epc = kzalloc(sizeof(*epc), GFP_KERNEL); if (!epc) { ret = -ENOMEM; goto err_ret; } spin_lock_init(&epc->lock); INIT_LIST_HEAD(&epc->pci_epf); device_initialize(&epc->dev); dma_set_coherent_mask(&epc->dev, dev->coherent_dma_mask); epc->dev.class = pci_epc_class; epc->dev.dma_mask = dev->dma_mask; epc->dev.parent = dev; epc->ops = ops; ret = dev_set_name(&epc->dev, "%s", dev_name(dev)); if (ret) goto put_dev; ret = device_add(&epc->dev); if (ret) goto put_dev; epc->group = pci_ep_cfs_add_epc_group(dev_name(dev)); return epc; put_dev: put_device(&epc->dev); kfree(epc); err_ret: return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(__pci_epc_create); /** * __devm_pci_epc_create() - create a new endpoint controller (EPC) device * @dev: device that is creating the new EPC * @ops: function pointers for performing EPC operations * @owner: the owner of the module that creates the EPC device * * Invoke to create a new EPC device and add it to pci_epc class. * While at that, it also associates the device with the pci_epc using devres. * On driver detach, release function is invoked on the devres data, * then, devres data is freed. */ struct pci_epc * __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, struct module *owner) { struct pci_epc **ptr, *epc; ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return ERR_PTR(-ENOMEM); epc = __pci_epc_create(dev, ops, owner); if (!IS_ERR(epc)) { *ptr = epc; devres_add(dev, ptr); } else { devres_free(ptr); } return epc; } EXPORT_SYMBOL_GPL(__devm_pci_epc_create); static int __init pci_epc_init(void) { pci_epc_class = class_create(THIS_MODULE, "pci_epc"); if (IS_ERR(pci_epc_class)) { pr_err("failed to create pci epc class --> %ld\n", PTR_ERR(pci_epc_class)); return PTR_ERR(pci_epc_class); } return 0; } module_init(pci_epc_init); static void __exit pci_epc_exit(void) { class_destroy(pci_epc_class); } module_exit(pci_epc_exit); MODULE_DESCRIPTION("PCI EPC Library"); MODULE_AUTHOR("Kishon Vijay Abraham I "); MODULE_LICENSE("GPL v2");