[PATCH v3 03/23] PCI: endpoint: Introduce configfs entry for configuring EP functions

Kishon Vijay Abraham I
2017-03-09T07:59:11Z

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: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/pci/endpoint/Kconfig | 9 +
drivers/pci/endpoint/Makefile | 1 +
drivers/pci/endpoint/pci-ep-cfs.c | 509 +++++++++++++++++++++++++++++++++++++
include/linux/pci-ep-cfs.h | 41 +++
4 files changed, 560 insertions(+)
create mode 100644 drivers/pci/endpoint/pci-ep-cfs.c
create mode 100644 include/linux/pci-ep-cfs.h

diff --git a/drivers/pci/endpoint/Kconfig b/drivers/pci/endpoint/Kconfig
index a5442ac..c86bca9 100644
--- a/drivers/pci/endpoint/Kconfig
+++ b/drivers/pci/endpoint/Kconfig
@@ -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
diff --git a/drivers/pci/endpoint/Makefile b/drivers/pci/endpoint/Makefile
index dc1bc16..7219d51 100644
--- a/drivers/pci/endpoint/Makefile
+++ b/drivers/pci/endpoint/Makefile
@@ -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
diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
new file mode 100644
index 0000000..424fdd6
--- /dev/null
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -0,0 +1,509 @@
+/**
+ * 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");
diff --git a/include/linux/pci-ep-cfs.h b/include/linux/pci-ep-cfs.h
new file mode 100644
index 0000000..263b89e
--- /dev/null
+++ b/include/linux/pci-ep-cfs.h
@@ -0,0 +1,41 @@
+/**
+ * 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 */
--
1.7.9.5