diff options
Diffstat (limited to 'drivers/pci/endpoint/pci-epc-core.c')
-rw-r--r-- | drivers/pci/endpoint/pci-epc-core.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c new file mode 100644 index 0000000..caa7be1 --- /dev/null +++ b/drivers/pci/endpoint/pci-epc-core.c @@ -0,0 +1,580 @@ +/** + * PCI Endpoint *Controller* (EPC) library + * + * Copyright (C) 2017 Texas Instruments + * Author: Kishon Vijay Abraham I <kishon@ti.com> + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> +#include <linux/module.h> + +#include <linux/pci-epc.h> +#include <linux/pci-epf.h> +#include <linux/pci-ep-cfs.h> + +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; + + if (epf->epc) + return -EBUSY; + + if (IS_ERR(epc)) + return -EINVAL; + + if (epf->func_no > epc->max_functions - 1) + return -EINVAL; + + epf->epc = epc; + 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->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 <kishon@ti.com>"); +MODULE_LICENSE("GPL v2"); |