1 // SPDX-License-Identifier: GPL-2.0
3 * PCI Endpoint *Controller* (EPC) library
5 * Copyright (C) 2017 Texas Instruments
6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
9 #include <linux/device.h>
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/of_device.h>
14 #include <linux/pci-epc.h>
15 #include <linux/pci-epf.h>
16 #include <linux/pci-ep-cfs.h>
18 static struct class *pci_epc_class;
20 static void devm_pci_epc_release(struct device *dev, void *res)
22 struct pci_epc *epc = *(struct pci_epc **)res;
27 static int devm_pci_epc_match(struct device *dev, void *res, void *match_data)
29 struct pci_epc **epc = res;
31 return *epc == match_data;
35 * pci_epc_put() - release the PCI endpoint controller
36 * @epc: epc returned by pci_epc_get()
38 * release the refcount the caller obtained by invoking pci_epc_get()
40 void pci_epc_put(struct pci_epc *epc)
42 if (!epc || IS_ERR(epc))
45 module_put(epc->ops->owner);
46 put_device(&epc->dev);
48 EXPORT_SYMBOL_GPL(pci_epc_put);
51 * pci_epc_get() - get the PCI endpoint controller
52 * @epc_name: device name of the endpoint controller
54 * Invoke to get struct pci_epc * corresponding to the device name of the
57 struct pci_epc *pci_epc_get(const char *epc_name)
62 struct class_dev_iter iter;
64 class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
65 while ((dev = class_dev_iter_next(&iter))) {
66 if (strcmp(epc_name, dev_name(dev)))
69 epc = to_pci_epc(dev);
70 if (!try_module_get(epc->ops->owner)) {
75 class_dev_iter_exit(&iter);
76 get_device(&epc->dev);
81 class_dev_iter_exit(&iter);
84 EXPORT_SYMBOL_GPL(pci_epc_get);
87 * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
88 * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
90 * Invoke to get the first unreserved BAR that can be used by the endpoint
91 * function. For any incorrect value in reserved_bar return '0'.
94 pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features)
96 return pci_epc_get_next_free_bar(epc_features, BAR_0);
98 EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
101 * pci_epc_get_next_free_bar() - helper to get unreserved BAR starting from @bar
102 * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
103 * @bar: the starting BAR number from where unreserved BAR should be searched
105 * Invoke to get the next unreserved BAR starting from @bar that can be used
106 * for endpoint function. For any incorrect value in reserved_bar return '0'.
108 enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
109 *epc_features, enum pci_barno bar)
111 unsigned long free_bar;
116 /* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
117 if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
120 /* Find if the reserved BAR is also a 64-bit BAR */
121 free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
123 /* Set the adjacent bit if the reserved BAR is also a 64-bit BAR */
125 free_bar |= epc_features->reserved_bar;
127 free_bar = find_next_zero_bit(&free_bar, 6, bar);
133 EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar);
136 * pci_epc_get_features() - get the features supported by EPC
137 * @epc: the features supported by *this* EPC device will be returned
138 * @func_no: the features supported by the EPC device specific to the
139 * endpoint function with func_no will be returned
141 * Invoke to get the features provided by the EPC which may be
142 * specific to an endpoint function. Returns pci_epc_features on success
143 * and NULL for any failures.
145 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
148 const struct pci_epc_features *epc_features;
150 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
153 if (!epc->ops->get_features)
156 mutex_lock(&epc->lock);
157 epc_features = epc->ops->get_features(epc, func_no);
158 mutex_unlock(&epc->lock);
162 EXPORT_SYMBOL_GPL(pci_epc_get_features);
165 * pci_epc_stop() - stop the PCI link
166 * @epc: the link of the EPC device that has to be stopped
168 * Invoke to stop the PCI link
170 void pci_epc_stop(struct pci_epc *epc)
172 if (IS_ERR(epc) || !epc->ops->stop)
175 mutex_lock(&epc->lock);
177 mutex_unlock(&epc->lock);
179 EXPORT_SYMBOL_GPL(pci_epc_stop);
182 * pci_epc_start() - start the PCI link
183 * @epc: the link of *this* EPC device has to be started
185 * Invoke to start the PCI link
187 int pci_epc_start(struct pci_epc *epc)
194 if (!epc->ops->start)
197 mutex_lock(&epc->lock);
198 ret = epc->ops->start(epc);
199 mutex_unlock(&epc->lock);
203 EXPORT_SYMBOL_GPL(pci_epc_start);
206 * pci_epc_raise_irq() - interrupt the host system
207 * @epc: the EPC device which has to interrupt the host
208 * @func_no: the endpoint function number in the EPC device
209 * @type: specify the type of interrupt; legacy, MSI or MSI-X
210 * @interrupt_num: the MSI or MSI-X interrupt number
212 * Invoke to raise an legacy, MSI or MSI-X interrupt
214 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
215 enum pci_epc_irq_type type, u16 interrupt_num)
219 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
222 if (!epc->ops->raise_irq)
225 mutex_lock(&epc->lock);
226 ret = epc->ops->raise_irq(epc, func_no, type, interrupt_num);
227 mutex_unlock(&epc->lock);
231 EXPORT_SYMBOL_GPL(pci_epc_raise_irq);
234 * pci_epc_map_msi_irq() - Map physical address to MSI address and return
236 * @epc: the EPC device which has the MSI capability
237 * @func_no: the physical endpoint function number in the EPC device
238 * @phys_addr: the physical address of the outbound region
239 * @interrupt_num: the MSI interrupt number
240 * @entry_size: Size of Outbound address region for each interrupt
241 * @msi_data: the data that should be written in order to raise MSI interrupt
242 * with interrupt number as 'interrupt num'
243 * @msi_addr_offset: Offset of MSI address from the aligned outbound address
244 * to which the MSI address is mapped
246 * Invoke to map physical address to MSI address and return MSI data. The
247 * physical address should be an address in the outbound region. This is
248 * required to implement doorbell functionality of NTB wherein EPC on either
249 * side of the interface (primary and secondary) can directly write to the
250 * physical address (in outbound region) of the other interface to ring
253 int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no, phys_addr_t phys_addr,
254 u8 interrupt_num, u32 entry_size, u32 *msi_data,
255 u32 *msi_addr_offset)
259 if (IS_ERR_OR_NULL(epc))
262 if (!epc->ops->map_msi_irq)
265 mutex_lock(&epc->lock);
266 ret = epc->ops->map_msi_irq(epc, func_no, phys_addr, interrupt_num,
267 entry_size, msi_data, msi_addr_offset);
268 mutex_unlock(&epc->lock);
272 EXPORT_SYMBOL_GPL(pci_epc_map_msi_irq);
275 * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated
276 * @epc: the EPC device to which MSI interrupts was requested
277 * @func_no: the endpoint function number in the EPC device
279 * Invoke to get the number of MSI interrupts allocated by the RC
281 int pci_epc_get_msi(struct pci_epc *epc, u8 func_no)
285 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
288 if (!epc->ops->get_msi)
291 mutex_lock(&epc->lock);
292 interrupt = epc->ops->get_msi(epc, func_no);
293 mutex_unlock(&epc->lock);
298 interrupt = 1 << interrupt;
302 EXPORT_SYMBOL_GPL(pci_epc_get_msi);
305 * pci_epc_set_msi() - set the number of MSI interrupt numbers required
306 * @epc: the EPC device on which MSI has to be configured
307 * @func_no: the endpoint function number in the EPC device
308 * @interrupts: number of MSI interrupts required by the EPF
310 * Invoke to set the required number of MSI interrupts.
312 int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts)
317 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
321 if (!epc->ops->set_msi)
324 encode_int = order_base_2(interrupts);
326 mutex_lock(&epc->lock);
327 ret = epc->ops->set_msi(epc, func_no, encode_int);
328 mutex_unlock(&epc->lock);
332 EXPORT_SYMBOL_GPL(pci_epc_set_msi);
335 * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated
336 * @epc: the EPC device to which MSI-X interrupts was requested
337 * @func_no: the endpoint function number in the EPC device
339 * Invoke to get the number of MSI-X interrupts allocated by the RC
341 int pci_epc_get_msix(struct pci_epc *epc, u8 func_no)
345 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
348 if (!epc->ops->get_msix)
351 mutex_lock(&epc->lock);
352 interrupt = epc->ops->get_msix(epc, func_no);
353 mutex_unlock(&epc->lock);
358 return interrupt + 1;
360 EXPORT_SYMBOL_GPL(pci_epc_get_msix);
363 * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required
364 * @epc: the EPC device on which MSI-X has to be configured
365 * @func_no: the endpoint function number in the EPC device
366 * @interrupts: number of MSI-X interrupts required by the EPF
367 * @bir: BAR where the MSI-X table resides
368 * @offset: Offset pointing to the start of MSI-X table
370 * Invoke to set the required number of MSI-X interrupts.
372 int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts,
373 enum pci_barno bir, u32 offset)
377 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
378 interrupts < 1 || interrupts > 2048)
381 if (!epc->ops->set_msix)
384 mutex_lock(&epc->lock);
385 ret = epc->ops->set_msix(epc, func_no, interrupts - 1, bir, offset);
386 mutex_unlock(&epc->lock);
390 EXPORT_SYMBOL_GPL(pci_epc_set_msix);
393 * pci_epc_unmap_addr() - unmap CPU address from PCI address
394 * @epc: the EPC device on which address is allocated
395 * @func_no: the endpoint function number in the EPC device
396 * @phys_addr: physical address of the local system
398 * Invoke to unmap the CPU address from PCI address.
400 void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,
401 phys_addr_t phys_addr)
403 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
406 if (!epc->ops->unmap_addr)
409 mutex_lock(&epc->lock);
410 epc->ops->unmap_addr(epc, func_no, phys_addr);
411 mutex_unlock(&epc->lock);
413 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);
416 * pci_epc_map_addr() - map CPU address to PCI address
417 * @epc: the EPC device on which address is allocated
418 * @func_no: the endpoint function number in the EPC device
419 * @phys_addr: physical address of the local system
420 * @pci_addr: PCI address to which the physical address should be mapped
421 * @size: the size of the allocation
423 * Invoke to map CPU address with PCI address.
425 int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
426 phys_addr_t phys_addr, u64 pci_addr, size_t size)
430 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
433 if (!epc->ops->map_addr)
436 mutex_lock(&epc->lock);
437 ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size);
438 mutex_unlock(&epc->lock);
442 EXPORT_SYMBOL_GPL(pci_epc_map_addr);
445 * pci_epc_clear_bar() - reset the BAR
446 * @epc: the EPC device for which the BAR has to be cleared
447 * @func_no: the endpoint function number in the EPC device
448 * @epf_bar: the struct epf_bar that contains the BAR information
450 * Invoke to reset the BAR of the endpoint device.
452 void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,
453 struct pci_epf_bar *epf_bar)
455 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
456 (epf_bar->barno == BAR_5 &&
457 epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
460 if (!epc->ops->clear_bar)
463 mutex_lock(&epc->lock);
464 epc->ops->clear_bar(epc, func_no, epf_bar);
465 mutex_unlock(&epc->lock);
467 EXPORT_SYMBOL_GPL(pci_epc_clear_bar);
470 * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space
471 * @epc: the EPC device on which BAR has to be configured
472 * @func_no: the endpoint function number in the EPC device
473 * @epf_bar: the struct epf_bar that contains the BAR information
475 * Invoke to configure the BAR of the endpoint device.
477 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no,
478 struct pci_epf_bar *epf_bar)
481 int flags = epf_bar->flags;
483 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
484 (epf_bar->barno == BAR_5 &&
485 flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ||
486 (flags & PCI_BASE_ADDRESS_SPACE_IO &&
487 flags & PCI_BASE_ADDRESS_IO_MASK) ||
488 (upper_32_bits(epf_bar->size) &&
489 !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64)))
492 if (!epc->ops->set_bar)
495 mutex_lock(&epc->lock);
496 ret = epc->ops->set_bar(epc, func_no, epf_bar);
497 mutex_unlock(&epc->lock);
501 EXPORT_SYMBOL_GPL(pci_epc_set_bar);
504 * pci_epc_write_header() - write standard configuration header
505 * @epc: the EPC device to which the configuration header should be written
506 * @func_no: the endpoint function number in the EPC device
507 * @header: standard configuration header fields
509 * Invoke to write the configuration header to the endpoint controller. Every
510 * endpoint controller will have a dedicated location to which the standard
511 * configuration header would be written. The callback function should write
512 * the header fields to this dedicated location.
514 int pci_epc_write_header(struct pci_epc *epc, u8 func_no,
515 struct pci_epf_header *header)
519 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
522 if (!epc->ops->write_header)
525 mutex_lock(&epc->lock);
526 ret = epc->ops->write_header(epc, func_no, header);
527 mutex_unlock(&epc->lock);
531 EXPORT_SYMBOL_GPL(pci_epc_write_header);
534 * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller
535 * @epc: the EPC device to which the endpoint function should be added
536 * @epf: the endpoint function to be added
537 * @type: Identifies if the EPC is connected to the primary or secondary
540 * A PCI endpoint device can have one or more functions. In the case of PCIe,
541 * the specification allows up to 8 PCIe endpoint functions. Invoke
542 * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller.
544 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
545 enum pci_epc_interface_type type)
547 struct list_head *list;
551 if (IS_ERR_OR_NULL(epc))
554 if (type == PRIMARY_INTERFACE && epf->epc)
557 if (type == SECONDARY_INTERFACE && epf->sec_epc)
560 mutex_lock(&epc->lock);
561 func_no = find_first_zero_bit(&epc->function_num_map,
563 if (func_no >= BITS_PER_LONG) {
568 if (func_no > epc->max_functions - 1) {
569 dev_err(&epc->dev, "Exceeding max supported Function Number\n");
574 set_bit(func_no, &epc->function_num_map);
575 if (type == PRIMARY_INTERFACE) {
576 epf->func_no = func_no;
580 epf->sec_epc_func_no = func_no;
582 list = &epf->sec_epc_list;
585 list_add_tail(list, &epc->pci_epf);
587 mutex_unlock(&epc->lock);
591 EXPORT_SYMBOL_GPL(pci_epc_add_epf);
594 * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller
595 * @epc: the EPC device from which the endpoint function should be removed
596 * @epf: the endpoint function to be removed
597 * @type: identifies if the EPC is connected to the primary or secondary
600 * Invoke to remove PCI endpoint function from the endpoint controller.
602 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
603 enum pci_epc_interface_type type)
605 struct list_head *list;
608 if (!epc || IS_ERR(epc) || !epf)
611 if (type == PRIMARY_INTERFACE) {
612 func_no = epf->func_no;
615 func_no = epf->sec_epc_func_no;
616 list = &epf->sec_epc_list;
619 mutex_lock(&epc->lock);
620 clear_bit(func_no, &epc->function_num_map);
623 mutex_unlock(&epc->lock);
625 EXPORT_SYMBOL_GPL(pci_epc_remove_epf);
628 * pci_epc_linkup() - Notify the EPF device that EPC device has established a
629 * connection with the Root Complex.
630 * @epc: the EPC device which has established link with the host
632 * Invoke to Notify the EPF device that the EPC device has established a
633 * connection with the Root Complex.
635 void pci_epc_linkup(struct pci_epc *epc)
637 if (!epc || IS_ERR(epc))
640 atomic_notifier_call_chain(&epc->notifier, LINK_UP, NULL);
642 EXPORT_SYMBOL_GPL(pci_epc_linkup);
645 * pci_epc_init_notify() - Notify the EPF device that EPC device's core
646 * initialization is completed.
647 * @epc: the EPC device whose core initialization is completeds
649 * Invoke to Notify the EPF device that the EPC device's initialization
652 void pci_epc_init_notify(struct pci_epc *epc)
654 if (!epc || IS_ERR(epc))
657 atomic_notifier_call_chain(&epc->notifier, CORE_INIT, NULL);
659 EXPORT_SYMBOL_GPL(pci_epc_init_notify);
662 * pci_epc_destroy() - destroy the EPC device
663 * @epc: the EPC device that has to be destroyed
665 * Invoke to destroy the PCI EPC device
667 void pci_epc_destroy(struct pci_epc *epc)
669 pci_ep_cfs_remove_epc_group(epc->group);
670 device_unregister(&epc->dev);
673 EXPORT_SYMBOL_GPL(pci_epc_destroy);
676 * devm_pci_epc_destroy() - destroy the EPC device
677 * @dev: device that wants to destroy the EPC
678 * @epc: the EPC device that has to be destroyed
680 * Invoke to destroy the devres associated with this
681 * pci_epc and destroy the EPC device.
683 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc)
687 r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match,
689 dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n");
691 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy);
694 * __pci_epc_create() - create a new endpoint controller (EPC) device
695 * @dev: device that is creating the new EPC
696 * @ops: function pointers for performing EPC operations
697 * @owner: the owner of the module that creates the EPC device
699 * Invoke to create a new EPC device and add it to pci_epc class.
702 __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
703 struct module *owner)
713 epc = kzalloc(sizeof(*epc), GFP_KERNEL);
719 mutex_init(&epc->lock);
720 INIT_LIST_HEAD(&epc->pci_epf);
721 ATOMIC_INIT_NOTIFIER_HEAD(&epc->notifier);
723 device_initialize(&epc->dev);
724 epc->dev.class = pci_epc_class;
725 epc->dev.parent = dev;
728 ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
732 ret = device_add(&epc->dev);
736 epc->group = pci_ep_cfs_add_epc_group(dev_name(dev));
741 put_device(&epc->dev);
747 EXPORT_SYMBOL_GPL(__pci_epc_create);
750 * __devm_pci_epc_create() - create a new endpoint controller (EPC) device
751 * @dev: device that is creating the new EPC
752 * @ops: function pointers for performing EPC operations
753 * @owner: the owner of the module that creates the EPC device
755 * Invoke to create a new EPC device and add it to pci_epc class.
756 * While at that, it also associates the device with the pci_epc using devres.
757 * On driver detach, release function is invoked on the devres data,
758 * then, devres data is freed.
761 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
762 struct module *owner)
764 struct pci_epc **ptr, *epc;
766 ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL);
768 return ERR_PTR(-ENOMEM);
770 epc = __pci_epc_create(dev, ops, owner);
773 devres_add(dev, ptr);
780 EXPORT_SYMBOL_GPL(__devm_pci_epc_create);
782 static int __init pci_epc_init(void)
784 pci_epc_class = class_create(THIS_MODULE, "pci_epc");
785 if (IS_ERR(pci_epc_class)) {
786 pr_err("failed to create pci epc class --> %ld\n",
787 PTR_ERR(pci_epc_class));
788 return PTR_ERR(pci_epc_class);
793 module_init(pci_epc_init);
795 static void __exit pci_epc_exit(void)
797 class_destroy(pci_epc_class);
799 module_exit(pci_epc_exit);
801 MODULE_DESCRIPTION("PCI EPC Library");
802 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
803 MODULE_LICENSE("GPL v2");