Commit d7467991 authored by Kishon Vijay Abraham I's avatar Kishon Vijay Abraham I Committed by Bjorn Helgaas
Browse files

PCI: endpoint: Introduce configfs entry for configuring EP functions 



Introduce a new configfs entry to configure the EP function (like
configuring the standard configuration header entries) and to bind the EP
function with EP controller.

Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent a8a5be09

drivers/pci/endpoint/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -17,4 +17,13 @@ config PCI_ENDPOINT 


	   If in doubt, say "N" to disable Endpoint support.



config PCI_ENDPOINT_CONFIGFS

	bool "PCI Endpoint Configfs Support"

	depends on PCI_ENDPOINT

	select CONFIGFS_FS

	help

	   This will enable the configfs entry that can be used to

	   configure the endpoint function and used to bind the

	   function with a endpoint controller.



endmenu

drivers/pci/endpoint/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -2,5 +2,6 @@ 
# Makefile for PCI Endpoint Support

#



obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS)	+= pci-ep-cfs.o

obj-$(CONFIG_PCI_ENDPOINT)		+= pci-epc-core.o pci-epf-core.o\

					   pci-epc-mem.o

drivers/pci/endpoint/pci-ep-cfs.c

0 → 100644
+509 −0
Original line number Diff line number Diff line 
/**

 * configfs to configure the PCI endpoint

 *

 * 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/module.h>

#include <linux/slab.h>



#include <linux/pci-epc.h>

#include <linux/pci-epf.h>

#include <linux/pci-ep-cfs.h>



static struct config_group *functions_group;

static struct config_group *controllers_group;



struct pci_epf_group {

	struct config_group group;

	struct pci_epf *epf;

};



struct pci_epc_group {

	struct config_group group;

	struct pci_epc *epc;

	bool start;

	unsigned long function_num_map;

};



static inline struct pci_epf_group *to_pci_epf_group(struct config_item *item)

{

	return container_of(to_config_group(item), struct pci_epf_group, group);

}



static inline struct pci_epc_group *to_pci_epc_group(struct config_item *item)

{

	return container_of(to_config_group(item), struct pci_epc_group, group);

}



static ssize_t pci_epc_start_store(struct config_item *item, const char *page,

				   size_t len)

{

	int ret;

	bool start;

	struct pci_epc *epc;

	struct pci_epc_group *epc_group = to_pci_epc_group(item);



	epc = epc_group->epc;



	ret = kstrtobool(page, &start);

	if (ret)

		return ret;



	if (!start) {

		pci_epc_stop(epc);

		return len;

	}



	ret = pci_epc_start(epc);

	if (ret) {

		dev_err(&epc->dev, "failed to start endpoint controller\n");

		return -EINVAL;

	}



	epc_group->start = start;



	return len;

}



static ssize_t pci_epc_start_show(struct config_item *item, char *page)

{

	return sprintf(page, "%d\n",

		       to_pci_epc_group(item)->start);

}



CONFIGFS_ATTR(pci_epc_, start);



static struct configfs_attribute *pci_epc_attrs[] = {

	&pci_epc_attr_start,

	NULL,

};



static int pci_epc_epf_link(struct config_item *epc_item,

			    struct config_item *epf_item)

{

	int ret;

	u32 func_no = 0;

	struct pci_epc *epc;

	struct pci_epf *epf;

	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);

	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);



	epc = epc_group->epc;

	epf = epf_group->epf;

	ret = pci_epc_add_epf(epc, epf);

	if (ret)

		goto err_add_epf;



	func_no = find_first_zero_bit(&epc_group->function_num_map,

				      sizeof(epc_group->function_num_map));

	set_bit(func_no, &epc_group->function_num_map);

	epf->func_no = func_no;



	ret = pci_epf_bind(epf);

	if (ret)

		goto err_epf_bind;



	return 0;



err_epf_bind:

	pci_epc_remove_epf(epc, epf);



err_add_epf:

	clear_bit(func_no, &epc_group->function_num_map);



	return ret;

}



static void pci_epc_epf_unlink(struct config_item *epc_item,

			       struct config_item *epf_item)

{

	struct pci_epc *epc;

	struct pci_epf *epf;

	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);

	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);



	WARN_ON_ONCE(epc_group->start);



	epc = epc_group->epc;

	epf = epf_group->epf;

	clear_bit(epf->func_no, &epc_group->function_num_map);

	pci_epf_unbind(epf);

	pci_epc_remove_epf(epc, epf);

}



static struct configfs_item_operations pci_epc_item_ops = {

	.allow_link	= pci_epc_epf_link,

	.drop_link	= pci_epc_epf_unlink,

};



static struct config_item_type pci_epc_type = {

	.ct_item_ops	= &pci_epc_item_ops,

	.ct_attrs	= pci_epc_attrs,

	.ct_owner	= THIS_MODULE,

};



struct config_group *pci_ep_cfs_add_epc_group(const char *name)

{

	int ret;

	struct pci_epc *epc;

	struct config_group *group;

	struct pci_epc_group *epc_group;



	epc_group = kzalloc(sizeof(*epc_group), GFP_KERNEL);

	if (!epc_group) {

		ret = -ENOMEM;

		goto err;

	}



	group = &epc_group->group;



	config_group_init_type_name(group, name, &pci_epc_type);

	ret = configfs_register_group(controllers_group, group);

	if (ret) {

		pr_err("failed to register configfs group for %s\n", name);

		goto err_register_group;

	}



	epc = pci_epc_get(name);

	if (IS_ERR(epc)) {

		ret = PTR_ERR(epc);

		goto err_epc_get;

	}



	epc_group->epc = epc;



	return group;



err_epc_get:

	configfs_unregister_group(group);



err_register_group:

	kfree(epc_group);



err:

	return ERR_PTR(ret);

}

EXPORT_SYMBOL(pci_ep_cfs_add_epc_group);



void pci_ep_cfs_remove_epc_group(struct config_group *group)

{

	struct pci_epc_group *epc_group;



	if (!group)

		return;



	epc_group = container_of(group, struct pci_epc_group, group);

	pci_epc_put(epc_group->epc);

	configfs_unregister_group(&epc_group->group);

	kfree(epc_group);

}

EXPORT_SYMBOL(pci_ep_cfs_remove_epc_group);



#define PCI_EPF_HEADER_R(_name)						       \

static ssize_t pci_epf_##_name##_show(struct config_item *item,	char *page)    \

{									       \

	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \

	if (WARN_ON_ONCE(!epf->header))					       \

		return -EINVAL;						       \

	return sprintf(page, "0x%04x\n", epf->header->_name);		       \

}



#define PCI_EPF_HEADER_W_u32(_name)					       \

static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \

				       const char *page, size_t len)	       \

{									       \

	u32 val;							       \

	int ret;							       \

	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \

	if (WARN_ON_ONCE(!epf->header))					       \

		return -EINVAL;						       \

	ret = kstrtou32(page, 0, &val);					       \

	if (ret)							       \

		return ret;						       \

	epf->header->_name = val;					       \

	return len;							       \

}



#define PCI_EPF_HEADER_W_u16(_name)					       \

static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \

				       const char *page, size_t len)	       \

{									       \

	u16 val;							       \

	int ret;							       \

	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \

	if (WARN_ON_ONCE(!epf->header))					       \

		return -EINVAL;						       \

	ret = kstrtou16(page, 0, &val);					       \

	if (ret)							       \

		return ret;						       \

	epf->header->_name = val;					       \

	return len;							       \

}



#define PCI_EPF_HEADER_W_u8(_name)					       \

static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \

				       const char *page, size_t len)	       \

{									       \

	u8 val;								       \

	int ret;							       \

	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \

	if (WARN_ON_ONCE(!epf->header))					       \

		return -EINVAL;						       \

	ret = kstrtou8(page, 0, &val);					       \

	if (ret)							       \

		return ret;						       \

	epf->header->_name = val;					       \

	return len;							       \

}



static ssize_t pci_epf_msi_interrupts_store(struct config_item *item,

					    const char *page, size_t len)

{

	u8 val;

	int ret;



	ret = kstrtou8(page, 0, &val);

	if (ret)

		return ret;



	to_pci_epf_group(item)->epf->msi_interrupts = val;



	return len;

}



static ssize_t pci_epf_msi_interrupts_show(struct config_item *item,

					   char *page)

{

	return sprintf(page, "%d\n",

		       to_pci_epf_group(item)->epf->msi_interrupts);

}



PCI_EPF_HEADER_R(vendorid)

PCI_EPF_HEADER_W_u16(vendorid)



PCI_EPF_HEADER_R(deviceid)

PCI_EPF_HEADER_W_u16(deviceid)



PCI_EPF_HEADER_R(revid)

PCI_EPF_HEADER_W_u8(revid)



PCI_EPF_HEADER_R(progif_code)

PCI_EPF_HEADER_W_u8(progif_code)



PCI_EPF_HEADER_R(subclass_code)

PCI_EPF_HEADER_W_u8(subclass_code)



PCI_EPF_HEADER_R(baseclass_code)

PCI_EPF_HEADER_W_u8(baseclass_code)



PCI_EPF_HEADER_R(cache_line_size)

PCI_EPF_HEADER_W_u8(cache_line_size)



PCI_EPF_HEADER_R(subsys_vendor_id)

PCI_EPF_HEADER_W_u16(subsys_vendor_id)



PCI_EPF_HEADER_R(subsys_id)

PCI_EPF_HEADER_W_u16(subsys_id)



PCI_EPF_HEADER_R(interrupt_pin)

PCI_EPF_HEADER_W_u8(interrupt_pin)



CONFIGFS_ATTR(pci_epf_, vendorid);

CONFIGFS_ATTR(pci_epf_, deviceid);

CONFIGFS_ATTR(pci_epf_, revid);

CONFIGFS_ATTR(pci_epf_, progif_code);

CONFIGFS_ATTR(pci_epf_, subclass_code);

CONFIGFS_ATTR(pci_epf_, baseclass_code);

CONFIGFS_ATTR(pci_epf_, cache_line_size);

CONFIGFS_ATTR(pci_epf_, subsys_vendor_id);

CONFIGFS_ATTR(pci_epf_, subsys_id);

CONFIGFS_ATTR(pci_epf_, interrupt_pin);

CONFIGFS_ATTR(pci_epf_, msi_interrupts);



static struct configfs_attribute *pci_epf_attrs[] = {

	&pci_epf_attr_vendorid,

	&pci_epf_attr_deviceid,

	&pci_epf_attr_revid,

	&pci_epf_attr_progif_code,

	&pci_epf_attr_subclass_code,

	&pci_epf_attr_baseclass_code,

	&pci_epf_attr_cache_line_size,

	&pci_epf_attr_subsys_vendor_id,

	&pci_epf_attr_subsys_id,

	&pci_epf_attr_interrupt_pin,

	&pci_epf_attr_msi_interrupts,

	NULL,

};



static void pci_epf_release(struct config_item *item)

{

	struct pci_epf_group *epf_group = to_pci_epf_group(item);



	pci_epf_destroy(epf_group->epf);

	kfree(epf_group);

}



static struct configfs_item_operations pci_epf_ops = {

	.release		= pci_epf_release,

};



static struct config_item_type pci_epf_type = {

	.ct_item_ops	= &pci_epf_ops,

	.ct_attrs	= pci_epf_attrs,

	.ct_owner	= THIS_MODULE,

};



static struct config_group *pci_epf_make(struct config_group *group,

					 const char *name)

{

	struct pci_epf_group *epf_group;

	struct pci_epf *epf;



	epf_group = kzalloc(sizeof(*epf_group), GFP_KERNEL);

	if (!epf_group)

		return ERR_PTR(-ENOMEM);



	config_group_init_type_name(&epf_group->group, name, &pci_epf_type);



	epf = pci_epf_create(group->cg_item.ci_name);

	if (IS_ERR(epf)) {

		pr_err("failed to create endpoint function device\n");

		return ERR_PTR(-EINVAL);

	}



	epf_group->epf = epf;



	return &epf_group->group;

}



static void pci_epf_drop(struct config_group *group, struct config_item *item)

{

	config_item_put(item);

}



static struct configfs_group_operations pci_epf_group_ops = {

	.make_group     = &pci_epf_make,

	.drop_item      = &pci_epf_drop,

};



static struct config_item_type pci_epf_group_type = {

	.ct_group_ops	= &pci_epf_group_ops,

	.ct_owner	= THIS_MODULE,

};



struct config_group *pci_ep_cfs_add_epf_group(const char *name)

{

	struct config_group *group;



	group = configfs_register_default_group(functions_group, name,

						&pci_epf_group_type);

	if (IS_ERR(group))

		pr_err("failed to register configfs group for %s function\n",

		       name);



	return group;

}

EXPORT_SYMBOL(pci_ep_cfs_add_epf_group);



void pci_ep_cfs_remove_epf_group(struct config_group *group)

{

	if (IS_ERR_OR_NULL(group))

		return;



	configfs_unregister_default_group(group);

}

EXPORT_SYMBOL(pci_ep_cfs_remove_epf_group);



static struct config_item_type pci_functions_type = {

	.ct_owner	= THIS_MODULE,

};



static struct config_item_type pci_controllers_type = {

	.ct_owner	= THIS_MODULE,

};



static struct config_item_type pci_ep_type = {

	.ct_owner	= THIS_MODULE,

};



static struct configfs_subsystem pci_ep_cfs_subsys = {

	.su_group = {

		.cg_item = {

			.ci_namebuf = "pci_ep",

			.ci_type = &pci_ep_type,

		},

	},

	.su_mutex = __MUTEX_INITIALIZER(pci_ep_cfs_subsys.su_mutex),

};



static int __init pci_ep_cfs_init(void)

{

	int ret;

	struct config_group *root = &pci_ep_cfs_subsys.su_group;



	config_group_init(root);



	ret = configfs_register_subsystem(&pci_ep_cfs_subsys);

	if (ret) {

		pr_err("Error %d while registering subsystem %s\n",

		       ret, root->cg_item.ci_namebuf);

		goto err;

	}



	functions_group = configfs_register_default_group(root, "functions",

							  &pci_functions_type);

	if (IS_ERR(functions_group)) {

		ret = PTR_ERR(functions_group);

		pr_err("Error %d while registering functions group\n",

		       ret);

		goto err_functions_group;

	}



	controllers_group =

		configfs_register_default_group(root, "controllers",

						&pci_controllers_type);

	if (IS_ERR(controllers_group)) {

		ret = PTR_ERR(controllers_group);

		pr_err("Error %d while registering controllers group\n",

		       ret);

		goto err_controllers_group;

	}



	return 0;



err_controllers_group:

	configfs_unregister_default_group(functions_group);



err_functions_group:

	configfs_unregister_subsystem(&pci_ep_cfs_subsys);



err:

	return ret;

}

module_init(pci_ep_cfs_init);



static void __exit pci_ep_cfs_exit(void)

{

	configfs_unregister_default_group(controllers_group);

	configfs_unregister_default_group(functions_group);

	configfs_unregister_subsystem(&pci_ep_cfs_subsys);

}

module_exit(pci_ep_cfs_exit);



MODULE_DESCRIPTION("PCI EP CONFIGFS");

MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");

MODULE_LICENSE("GPL v2");

include/linux/pci-ep-cfs.h

0 → 100644
+41 −0
Original line number Diff line number Diff line 
/**

 * PCI Endpoint ConfigFS header file

 *

 * 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.

 */



#ifndef __LINUX_PCI_EP_CFS_H

#define __LINUX_PCI_EP_CFS_H



#include <linux/configfs.h>



#ifdef CONFIG_PCI_ENDPOINT_CONFIGFS

struct config_group *pci_ep_cfs_add_epc_group(const char *name);

void pci_ep_cfs_remove_epc_group(struct config_group *group);

struct config_group *pci_ep_cfs_add_epf_group(const char *name);

void pci_ep_cfs_remove_epf_group(struct config_group *group);

#else

static inline struct config_group *pci_ep_cfs_add_epc_group(const char *name)

{

	return 0;

}



static inline void pci_ep_cfs_remove_epc_group(struct config_group *group)

{

}



static inline struct config_group *pci_ep_cfs_add_epf_group(const char *name)

{

	return 0;

}



static inline void pci_ep_cfs_remove_epf_group(struct config_group *group)

{

}

#endif

#endif /* __LINUX_PCI_EP_CFS_H */