linux/drivers/pci/endpoint/pci-epf-core.c

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// SPDX-License-Identifier: GPL-2.0
/**
* PCI Endpoint *Function* (EPF) library
*
* Copyright (C) 2017 Texas Instruments
* Author: Kishon Vijay Abraham I <kishon@ti.com>
*/
#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 bus_type pci_epf_bus_type;
static const struct device_type pci_epf_type;
/**
* pci_epf_linkup() - Notify the function driver that EPC device has
* established a connection with the Root Complex.
* @epf: the EPF device bound to the EPC device which has established
* the connection with the host
*
* Invoke to notify the function driver that EPC device has established
* a connection with the Root Complex.
*/
void pci_epf_linkup(struct pci_epf *epf)
{
if (!epf->driver) {
dev_WARN(&epf->dev, "epf device not bound to driver\n");
return;
}
epf->driver->ops->linkup(epf);
}
EXPORT_SYMBOL_GPL(pci_epf_linkup);
/**
* pci_epf_unbind() - Notify the function driver that the binding between the
* EPF device and EPC device has been lost
* @epf: the EPF device which has lost the binding with the EPC device
*
* Invoke to notify the function driver that the binding between the EPF device
* and EPC device has been lost.
*/
void pci_epf_unbind(struct pci_epf *epf)
{
if (!epf->driver) {
dev_WARN(&epf->dev, "epf device not bound to driver\n");
return;
}
epf->driver->ops->unbind(epf);
module_put(epf->driver->owner);
}
EXPORT_SYMBOL_GPL(pci_epf_unbind);
/**
* pci_epf_bind() - Notify the function driver that the EPF device has been
* bound to a EPC device
* @epf: the EPF device which has been bound to the EPC device
*
* Invoke to notify the function driver that it has been bound to a EPC device
*/
int pci_epf_bind(struct pci_epf *epf)
{
if (!epf->driver) {
dev_WARN(&epf->dev, "epf device not bound to driver\n");
return -EINVAL;
}
if (!try_module_get(epf->driver->owner))
return -EAGAIN;
return epf->driver->ops->bind(epf);
}
EXPORT_SYMBOL_GPL(pci_epf_bind);
/**
* pci_epf_free_space() - free the allocated PCI EPF register space
* @addr: the virtual address of the PCI EPF register space
* @bar: the BAR number corresponding to the register space
*
* Invoke to free the allocated PCI EPF register space.
*/
void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar)
{
struct device *dev = epf->epc->dev.parent;
if (!addr)
return;
dma_free_coherent(dev, epf->bar[bar].size, addr,
epf->bar[bar].phys_addr);
epf->bar[bar].phys_addr = 0;
epf->bar[bar].size = 0;
}
EXPORT_SYMBOL_GPL(pci_epf_free_space);
/**
* pci_epf_alloc_space() - allocate memory for the PCI EPF register space
* @size: the size of the memory that has to be allocated
* @bar: the BAR number corresponding to the allocated register space
*
* Invoke to allocate memory for the PCI EPF register space.
*/
void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar)
{
void *space;
struct device *dev = epf->epc->dev.parent;
dma_addr_t phys_addr;
if (size < 128)
size = 128;
size = roundup_pow_of_two(size);
space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL);
if (!space) {
dev_err(dev, "failed to allocate mem space\n");
return NULL;
}
epf->bar[bar].phys_addr = phys_addr;
epf->bar[bar].size = size;
return space;
}
EXPORT_SYMBOL_GPL(pci_epf_alloc_space);
/**
* pci_epf_unregister_driver() - unregister the PCI EPF driver
* @driver: the PCI EPF driver that has to be unregistered
*
* Invoke to unregister the PCI EPF driver.
*/
void pci_epf_unregister_driver(struct pci_epf_driver *driver)
{
pci_ep_cfs_remove_epf_group(driver->group);
driver_unregister(&driver->driver);
}
EXPORT_SYMBOL_GPL(pci_epf_unregister_driver);
/**
* __pci_epf_register_driver() - register a new PCI EPF driver
* @driver: structure representing PCI EPF driver
* @owner: the owner of the module that registers the PCI EPF driver
*
* Invoke to register a new PCI EPF driver.
*/
int __pci_epf_register_driver(struct pci_epf_driver *driver,
struct module *owner)
{
int ret;
if (!driver->ops)
return -EINVAL;
if (!driver->ops->bind || !driver->ops->unbind || !driver->ops->linkup)
return -EINVAL;
driver->driver.bus = &pci_epf_bus_type;
driver->driver.owner = owner;
ret = driver_register(&driver->driver);
if (ret)
return ret;
driver->group = pci_ep_cfs_add_epf_group(driver->driver.name);
return 0;
}
EXPORT_SYMBOL_GPL(__pci_epf_register_driver);
/**
* pci_epf_destroy() - destroy the created PCI EPF device
* @epf: the PCI EPF device that has to be destroyed.
*
* Invoke to destroy the PCI EPF device created by invoking pci_epf_create().
*/
void pci_epf_destroy(struct pci_epf *epf)
{
device_unregister(&epf->dev);
}
EXPORT_SYMBOL_GPL(pci_epf_destroy);
/**
* pci_epf_create() - create a new PCI EPF device
* @name: the name of the PCI EPF device. This name will be used to bind the
* the EPF device to a EPF driver
*
* Invoke to create a new PCI EPF device by providing the name of the function
* device.
*/
struct pci_epf *pci_epf_create(const char *name)
{
int ret;
struct pci_epf *epf;
struct device *dev;
char *func_name;
char *buf;
epf = kzalloc(sizeof(*epf), GFP_KERNEL);
if (!epf) {
ret = -ENOMEM;
goto err_ret;
}
buf = kstrdup(name, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto free_epf;
}
func_name = buf;
buf = strchrnul(buf, '.');
*buf = '\0';
epf->name = kstrdup(func_name, GFP_KERNEL);
if (!epf->name) {
ret = -ENOMEM;
goto free_func_name;
}
dev = &epf->dev;
device_initialize(dev);
dev->bus = &pci_epf_bus_type;
dev->type = &pci_epf_type;
ret = dev_set_name(dev, "%s", name);
if (ret)
goto put_dev;
ret = device_add(dev);
if (ret)
goto put_dev;
kfree(func_name);
return epf;
put_dev:
put_device(dev);
kfree(epf->name);
free_func_name:
kfree(func_name);
free_epf:
kfree(epf);
err_ret:
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(pci_epf_create);
const struct pci_epf_device_id *
pci_epf_match_device(const struct pci_epf_device_id *id, struct pci_epf *epf)
{
if (!id || !epf)
return NULL;
while (*id->name) {
if (strcmp(epf->name, id->name) == 0)
return id;
id++;
}
return NULL;
}
EXPORT_SYMBOL_GPL(pci_epf_match_device);
static void pci_epf_dev_release(struct device *dev)
{
struct pci_epf *epf = to_pci_epf(dev);
kfree(epf->name);
kfree(epf);
}
static const struct device_type pci_epf_type = {
.release = pci_epf_dev_release,
};
static int
pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
{
while (id->name[0]) {
if (strcmp(epf->name, id->name) == 0)
return true;
id++;
}
return false;
}
static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
{
struct pci_epf *epf = to_pci_epf(dev);
struct pci_epf_driver *driver = to_pci_epf_driver(drv);
if (driver->id_table)
return pci_epf_match_id(driver->id_table, epf);
return !strcmp(epf->name, drv->name);
}
static int pci_epf_device_probe(struct device *dev)
{
struct pci_epf *epf = to_pci_epf(dev);
struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
if (!driver->probe)
return -ENODEV;
epf->driver = driver;
return driver->probe(epf);
}
static int pci_epf_device_remove(struct device *dev)
{
int ret = 0;
struct pci_epf *epf = to_pci_epf(dev);
struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
if (driver->remove)
ret = driver->remove(epf);
epf->driver = NULL;
return ret;
}
static struct bus_type pci_epf_bus_type = {
.name = "pci-epf",
.match = pci_epf_device_match,
.probe = pci_epf_device_probe,
.remove = pci_epf_device_remove,
};
static int __init pci_epf_init(void)
{
int ret;
ret = bus_register(&pci_epf_bus_type);
if (ret) {
pr_err("failed to register pci epf bus --> %d\n", ret);
return ret;
}
return 0;
}
module_init(pci_epf_init);
static void __exit pci_epf_exit(void)
{
bus_unregister(&pci_epf_bus_type);
}
module_exit(pci_epf_exit);
MODULE_DESCRIPTION("PCI EPF Library");
MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
MODULE_LICENSE("GPL v2");