diff options
Diffstat (limited to 'drivers/pci/endpoint/pci-epf-core.c')
| -rw-r--r-- | drivers/pci/endpoint/pci-epf-core.c | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c new file mode 100644 index 000000000000..9a505c796370 --- /dev/null +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -0,0 +1,699 @@ +// 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 DEFINE_MUTEX(pci_epf_mutex); + +static const struct bus_type pci_epf_bus_type; +static const struct device_type pci_epf_type; + +/** + * 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) +{ + struct pci_epf *epf_vf; + + if (!epf->driver) { + dev_WARN(&epf->dev, "epf device not bound to driver\n"); + return; + } + + mutex_lock(&epf->lock); + list_for_each_entry(epf_vf, &epf->pci_vepf, list) { + if (epf_vf->is_bound) + epf_vf->driver->ops->unbind(epf_vf); + } + if (epf->is_bound) + epf->driver->ops->unbind(epf); + mutex_unlock(&epf->lock); + 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) +{ + struct device *dev = &epf->dev; + struct pci_epf *epf_vf; + u8 func_no, vfunc_no; + struct pci_epc *epc; + int ret; + + if (!epf->driver) { + dev_WARN(dev, "epf device not bound to driver\n"); + return -EINVAL; + } + + if (!try_module_get(epf->driver->owner)) + return -EAGAIN; + + mutex_lock(&epf->lock); + list_for_each_entry(epf_vf, &epf->pci_vepf, list) { + vfunc_no = epf_vf->vfunc_no; + + if (vfunc_no < 1) { + dev_err(dev, "Invalid virtual function number\n"); + ret = -EINVAL; + goto ret; + } + + epc = epf->epc; + func_no = epf->func_no; + if (!IS_ERR_OR_NULL(epc)) { + if (!epc->max_vfs) { + dev_err(dev, "No support for virt function\n"); + ret = -EINVAL; + goto ret; + } + + if (vfunc_no > epc->max_vfs[func_no]) { + dev_err(dev, "PF%d: Exceeds max vfunc number\n", + func_no); + ret = -EINVAL; + goto ret; + } + } + + epc = epf->sec_epc; + func_no = epf->sec_epc_func_no; + if (!IS_ERR_OR_NULL(epc)) { + if (!epc->max_vfs) { + dev_err(dev, "No support for virt function\n"); + ret = -EINVAL; + goto ret; + } + + if (vfunc_no > epc->max_vfs[func_no]) { + dev_err(dev, "PF%d: Exceeds max vfunc number\n", + func_no); + ret = -EINVAL; + goto ret; + } + } + + epf_vf->func_no = epf->func_no; + epf_vf->sec_epc_func_no = epf->sec_epc_func_no; + epf_vf->epc = epf->epc; + epf_vf->sec_epc = epf->sec_epc; + ret = epf_vf->driver->ops->bind(epf_vf); + if (ret) + goto ret; + epf_vf->is_bound = true; + } + + ret = epf->driver->ops->bind(epf); + if (ret) + goto ret; + epf->is_bound = true; + + mutex_unlock(&epf->lock); + return 0; + +ret: + mutex_unlock(&epf->lock); + pci_epf_unbind(epf); + + return ret; +} +EXPORT_SYMBOL_GPL(pci_epf_bind); + +/** + * pci_epf_add_vepf() - associate virtual EP function to physical EP function + * @epf_pf: the physical EP function to which the virtual EP function should be + * associated + * @epf_vf: the virtual EP function to be added + * + * A physical endpoint function can be associated with multiple virtual + * endpoint functions. Invoke pci_epf_add_epf() to add a virtual PCI endpoint + * function to a physical PCI endpoint function. + */ +int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf) +{ + u32 vfunc_no; + + if (IS_ERR_OR_NULL(epf_pf) || IS_ERR_OR_NULL(epf_vf)) + return -EINVAL; + + if (epf_pf->epc || epf_vf->epc || epf_vf->epf_pf) + return -EBUSY; + + if (epf_pf->sec_epc || epf_vf->sec_epc) + return -EBUSY; + + mutex_lock(&epf_pf->lock); + vfunc_no = find_first_zero_bit(&epf_pf->vfunction_num_map, + BITS_PER_LONG); + if (vfunc_no >= BITS_PER_LONG) { + mutex_unlock(&epf_pf->lock); + return -EINVAL; + } + + set_bit(vfunc_no, &epf_pf->vfunction_num_map); + epf_vf->vfunc_no = vfunc_no; + + epf_vf->epf_pf = epf_pf; + epf_vf->is_vf = true; + + list_add_tail(&epf_vf->list, &epf_pf->pci_vepf); + mutex_unlock(&epf_pf->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_epf_add_vepf); + +/** + * pci_epf_remove_vepf() - remove virtual EP function from physical EP function + * @epf_pf: the physical EP function from which the virtual EP function should + * be removed + * @epf_vf: the virtual EP function to be removed + * + * Invoke to remove a virtual endpoint function from the physical endpoint + * function. + */ +void pci_epf_remove_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf) +{ + if (IS_ERR_OR_NULL(epf_pf) || IS_ERR_OR_NULL(epf_vf)) + return; + + mutex_lock(&epf_pf->lock); + clear_bit(epf_vf->vfunc_no, &epf_pf->vfunction_num_map); + epf_vf->epf_pf = NULL; + list_del(&epf_vf->list); + mutex_unlock(&epf_pf->lock); +} +EXPORT_SYMBOL_GPL(pci_epf_remove_vepf); + +static int pci_epf_get_required_bar_size(struct pci_epf *epf, size_t *bar_size, + size_t *aligned_mem_size, + enum pci_barno bar, + const struct pci_epc_features *epc_features, + enum pci_epc_interface_type type) +{ + u64 bar_fixed_size = epc_features->bar[bar].fixed_size; + size_t align = epc_features->align; + size_t size = *bar_size; + + if (size < 128) + size = 128; + + /* According to PCIe base spec, min size for a resizable BAR is 1 MB. */ + if (epc_features->bar[bar].type == BAR_RESIZABLE && size < SZ_1M) + size = SZ_1M; + + if (epc_features->bar[bar].type == BAR_FIXED && bar_fixed_size) { + if (size > bar_fixed_size) { + dev_err(&epf->dev, + "requested BAR size is larger than fixed size\n"); + return -ENOMEM; + } + size = bar_fixed_size; + } else { + /* BAR size must be power of two */ + size = roundup_pow_of_two(size); + } + + *bar_size = size; + + /* + * The EPC's BAR start address must meet alignment requirements. In most + * cases, the alignment will match the BAR size. However, differences + * can occur—for example, when the fixed BAR size (e.g., 128 bytes) is + * smaller than the required alignment (e.g., 4 KB). + */ + *aligned_mem_size = align ? ALIGN(size, align) : size; + + return 0; +} + +/** + * pci_epf_free_space() - free the allocated PCI EPF register space + * @epf: the EPF device from whom to free the memory + * @addr: the virtual address of the PCI EPF register space + * @bar: the BAR number corresponding to the register space + * @type: Identifies if the allocated space is for primary EPC or secondary EPC + * + * Invoke to free the allocated PCI EPF register space. + */ +void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar, + enum pci_epc_interface_type type) +{ + struct device *dev; + struct pci_epf_bar *epf_bar; + struct pci_epc *epc; + + if (!addr) + return; + + if (type == PRIMARY_INTERFACE) { + epc = epf->epc; + epf_bar = epf->bar; + } else { + epc = epf->sec_epc; + epf_bar = epf->sec_epc_bar; + } + + dev = epc->dev.parent; + dma_free_coherent(dev, epf_bar[bar].mem_size, addr, + epf_bar[bar].phys_addr); + + epf_bar[bar].phys_addr = 0; + epf_bar[bar].addr = NULL; + epf_bar[bar].size = 0; + epf_bar[bar].mem_size = 0; + epf_bar[bar].barno = 0; + epf_bar[bar].flags = 0; +} +EXPORT_SYMBOL_GPL(pci_epf_free_space); + +/** + * pci_epf_alloc_space() - allocate memory for the PCI EPF register space + * @epf: the EPF device to whom allocate the memory + * @size: the size of the memory that has to be allocated + * @bar: the BAR number corresponding to the allocated register space + * @epc_features: the features provided by the EPC specific to this EPF + * @type: Identifies if the allocation is for primary EPC or secondary EPC + * + * Invoke to allocate memory for the PCI EPF register space. + * Flag PCI_BASE_ADDRESS_MEM_TYPE_64 will automatically get set if the BAR + * can only be a 64-bit BAR, or if the requested size is larger than 2 GB. + */ +void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, + const struct pci_epc_features *epc_features, + enum pci_epc_interface_type type) +{ + struct pci_epf_bar *epf_bar; + dma_addr_t phys_addr; + struct pci_epc *epc; + struct device *dev; + size_t mem_size; + void *space; + + if (pci_epf_get_required_bar_size(epf, &size, &mem_size, bar, + epc_features, type)) + return NULL; + + if (type == PRIMARY_INTERFACE) { + epc = epf->epc; + epf_bar = epf->bar; + } else { + epc = epf->sec_epc; + epf_bar = epf->sec_epc_bar; + } + + dev = epc->dev.parent; + space = dma_alloc_coherent(dev, mem_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].addr = space; + epf_bar[bar].size = size; + epf_bar[bar].mem_size = mem_size; + epf_bar[bar].barno = bar; + if (upper_32_bits(size) || epc_features->bar[bar].only_64bit) + epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_64; + else + epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_32; + + return space; +} +EXPORT_SYMBOL_GPL(pci_epf_alloc_space); + +/** + * pci_epf_assign_bar_space() - Assign PCI EPF BAR space + * @epf: EPF device to assign the BAR memory + * @size: Size of the memory that has to be assigned + * @bar: BAR number for which the memory is assigned + * @epc_features: Features provided by the EPC specific to this EPF + * @type: Identifies if the assignment is for primary EPC or secondary EPC + * @bar_addr: Address to be assigned for the @bar + * + * Invoke to assign memory for the PCI EPF BAR. + * Flag PCI_BASE_ADDRESS_MEM_TYPE_64 will automatically get set if the BAR + * can only be a 64-bit BAR, or if the requested size is larger than 2 GB. + */ +int pci_epf_assign_bar_space(struct pci_epf *epf, size_t size, + enum pci_barno bar, + const struct pci_epc_features *epc_features, + enum pci_epc_interface_type type, + dma_addr_t bar_addr) +{ + size_t bar_size, aligned_mem_size; + struct pci_epf_bar *epf_bar; + dma_addr_t limit; + int pos; + + if (!size) + return -EINVAL; + + limit = bar_addr + size - 1; + + /* + * Bits: 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + * bar_addr: U U U U U U 0 X X X X X X X X X + * limit: U U U U U U 1 X X X X X X X X X + * + * bar_addr^limit 0 0 0 0 0 0 1 X X X X X X X X X + * + * U: unchanged address bits in range [bar_addr, limit] + * X: bit 0 or 1 + * + * (bar_addr^limit) & BIT_ULL(pos) will find the first set bit from MSB + * (pos). And value of (2 ^ pos) should be able to cover the BAR range. + */ + for (pos = 8 * sizeof(dma_addr_t) - 1; pos > 0; pos--) + if ((limit ^ bar_addr) & BIT_ULL(pos)) + break; + + if (pos == 8 * sizeof(dma_addr_t) - 1) + return -EINVAL; + + bar_size = BIT_ULL(pos + 1); + if (pci_epf_get_required_bar_size(epf, &bar_size, &aligned_mem_size, + bar, epc_features, type)) + return -ENOMEM; + + if (type == PRIMARY_INTERFACE) + epf_bar = epf->bar; + else + epf_bar = epf->sec_epc_bar; + + epf_bar[bar].phys_addr = ALIGN_DOWN(bar_addr, aligned_mem_size); + + if (epf_bar[bar].phys_addr + bar_size < limit) + return -ENOMEM; + + epf_bar[bar].addr = NULL; + epf_bar[bar].size = bar_size; + epf_bar[bar].mem_size = aligned_mem_size; + epf_bar[bar].barno = bar; + if (upper_32_bits(size) || epc_features->bar[bar].only_64bit) + epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_64; + else + epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_32; + + return 0; +} +EXPORT_SYMBOL_GPL(pci_epf_assign_bar_space); + +static void pci_epf_remove_cfs(struct pci_epf_driver *driver) +{ + struct config_group *group, *tmp; + + if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS)) + return; + + mutex_lock(&pci_epf_mutex); + list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry) + pci_ep_cfs_remove_epf_group(group); + WARN_ON(!list_empty(&driver->epf_group)); + mutex_unlock(&pci_epf_mutex); +} + +/** + * 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_epf_remove_cfs(driver); + driver_unregister(&driver->driver); +} +EXPORT_SYMBOL_GPL(pci_epf_unregister_driver); + +static int pci_epf_add_cfs(struct pci_epf_driver *driver) +{ + struct config_group *group; + const struct pci_epf_device_id *id; + + if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS)) + return 0; + + INIT_LIST_HEAD(&driver->epf_group); + + id = driver->id_table; + while (id->name[0]) { + group = pci_ep_cfs_add_epf_group(id->name); + if (IS_ERR(group)) { + pci_epf_remove_cfs(driver); + return PTR_ERR(group); + } + + mutex_lock(&pci_epf_mutex); + list_add_tail(&group->group_entry, &driver->epf_group); + mutex_unlock(&pci_epf_mutex); + id++; + } + + return 0; +} + +/** + * __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) + return -EINVAL; + + driver->driver.bus = &pci_epf_bus_type; + driver->driver.owner = owner; + + ret = driver_register(&driver->driver); + if (ret) + return ret; + + pci_epf_add_cfs(driver); + + 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 + * 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; + int len; + + epf = kzalloc(sizeof(*epf), GFP_KERNEL); + if (!epf) + return ERR_PTR(-ENOMEM); + + len = strchrnul(name, '.') - name; + epf->name = kstrndup(name, len, GFP_KERNEL); + if (!epf->name) { + kfree(epf); + return ERR_PTR(-ENOMEM); + } + + /* VFs are numbered starting with 1. So set BIT(0) by default */ + epf->vfunction_num_map = 1; + INIT_LIST_HEAD(&epf->pci_vepf); + + dev = &epf->dev; + device_initialize(dev); + dev->bus = &pci_epf_bus_type; + dev->type = &pci_epf_type; + mutex_init(&epf->lock); + + ret = dev_set_name(dev, "%s", name); + if (ret) { + put_device(dev); + return ERR_PTR(ret); + } + + ret = device_add(dev); + if (ret) { + put_device(dev); + return ERR_PTR(ret); + } + + return epf; +} +EXPORT_SYMBOL_GPL(pci_epf_create); + +/** + * pci_epf_align_inbound_addr() - Align the given address based on the BAR + * alignment requirement + * @epf: the EPF device + * @addr: inbound address to be aligned + * @bar: the BAR number corresponding to the given addr + * @base: base address matching the @bar alignment requirement + * @off: offset to be added to the @base address + * + * Helper function to align input @addr based on BAR's alignment requirement. + * The aligned base address and offset are returned via @base and @off. + * + * NOTE: The pci_epf_alloc_space() function already accounts for alignment. + * This API is primarily intended for use with other memory regions not + * allocated by pci_epf_alloc_space(), such as peripheral register spaces or + * the message address of a platform MSI controller. + * + * Return: 0 on success, errno otherwise. + */ +int pci_epf_align_inbound_addr(struct pci_epf *epf, enum pci_barno bar, + u64 addr, dma_addr_t *base, size_t *off) +{ + /* + * Most EP controllers require the BAR start address to be aligned to + * the BAR size, because they mask off the lower bits. + * + * Alignment to BAR size also works for controllers that support + * unaligned addresses. + */ + u64 align = epf->bar[bar].size; + + *base = round_down(addr, align); + *off = addr & (align - 1); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_epf_align_inbound_addr); + +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 const struct pci_epf_device_id * +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 id; + id++; + } + + return NULL; +} + +static int pci_epf_device_match(struct device *dev, const struct device_driver *drv) +{ + struct pci_epf *epf = to_pci_epf(dev); + const 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, pci_epf_match_id(driver->id_table, epf)); +} + +static void pci_epf_device_remove(struct device *dev) +{ + struct pci_epf *epf = to_pci_epf(dev); + struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver); + + if (driver->remove) + driver->remove(epf); + epf->driver = NULL; +} + +static const 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>"); |