[PATCH v2 03/22] PCI: endpoint: Introduce configfs entry for configuring EP functions

From: Kishon Vijay Abraham I
Date: Fri Feb 17 2017 - 04:52:00 EST


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@xxxxxx>
---
drivers/pci/endpoint/Kconfig | 14 +-
drivers/pci/endpoint/Makefile | 1 +
drivers/pci/endpoint/pci-ep-cfs.c | 427 +++++++++++++++++++++++++++++++++++++
3 files changed, 440 insertions(+), 2 deletions(-)
create mode 100644 drivers/pci/endpoint/pci-ep-cfs.c

diff --git a/drivers/pci/endpoint/Kconfig b/drivers/pci/endpoint/Kconfig
index 7eb1c79..8470f0b 100644
--- a/drivers/pci/endpoint/Kconfig
+++ b/drivers/pci/endpoint/Kconfig
@@ -6,7 +6,6 @@ menu "PCI Endpoint"

config PCI_ENDPOINT
bool "PCI Endpoint Support"
- select CONFIGFS_FS
help
Enable this configuration option to support configurable PCI
endpoint. This should be enabled if the platform has a PCI
@@ -14,8 +13,19 @@ config PCI_ENDPOINT

Enabling this option will build the endpoint library, which
includes endpoint controller library and endpoint function
- library.
+ library. This will also enable the configfs entry required to
+ configure the endpoint function and used to bind the
+ function with a endpoint controller.

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..dd9163c 100644
--- a/drivers/pci/endpoint/Makefile
+++ b/drivers/pci/endpoint/Makefile
@@ -4,3 +4,4 @@

obj-$(CONFIG_PCI_ENDPOINT) += pci-epc-core.o pci-epf-core.o\
pci-epc-mem.o
+obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS) += pci-ep-cfs.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..ed0f8c2
--- /dev/null
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -0,0 +1,427 @@
+/**
+ * configfs to configure the PCI endpoint
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@xxxxxx>
+ *
+ * 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/configfs.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
+struct pci_epf_info {
+ struct config_group group;
+ struct list_head list;
+ struct pci_epf *epf;
+};
+
+struct pci_ep_info {
+ struct config_group group;
+ struct config_group pci_epf_group;
+ /* mutex to protect pci_epf list */
+ struct mutex lock;
+ struct list_head pci_epf;
+ const char *epc_name;
+ struct pci_epc *epc;
+};
+
+static inline struct pci_epf_info *to_pci_epf_info(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct pci_epf_info, group);
+}
+
+static inline struct pci_ep_info *to_pci_ep_info(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct pci_ep_info, 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_info(item)->epf; \
+ if (!epf->header) { \
+ WARN_ON_ONCE("epf device not bound to function driver\n"); \
+ return 0; \
+ } \
+ 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_info(item)->epf; \
+ if (!epf->header) { \
+ WARN_ON_ONCE("epf device not bound to function driver\n"); \
+ return 0; \
+ } \
+ 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_info(item)->epf; \
+ if (!epf->header) { \
+ WARN_ON_ONCE("epf device not bound to function driver\n"); \
+ return 0; \
+ } \
+ 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_info(item)->epf; \
+ if (!epf->header) { \
+ WARN_ON_ONCE("epf device not bound to function driver\n"); \
+ return 0; \
+ } \
+ 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_info(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_info(item)->epf->msi_interrupts);
+}
+
+static ssize_t pci_epf_function_show(struct config_item *item,
+ char *page)
+{
+ return sprintf(page, "%s\n",
+ to_pci_epf_info(item)->epf->name);
+}
+
+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);
+CONFIGFS_ATTR_RO(pci_epf_, function);
+
+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,
+ &pci_epf_attr_function,
+ NULL,
+};
+
+static void pci_epf_release(struct config_item *item)
+{
+ struct pci_epf_info *epf_info = to_pci_epf_info(item);
+
+ pci_epf_destroy(epf_info->epf);
+ kfree(epf_info);
+}
+
+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_info *epf_info;
+ struct pci_ep_info *ep_info;
+ struct pci_epf *epf;
+
+ epf_info = kzalloc(sizeof(*epf_info), GFP_KERNEL);
+ if (!epf_info)
+ return ERR_PTR(-ENOMEM);
+
+ config_group_init_type_name(&epf_info->group, name, &pci_epf_type);
+
+ epf = pci_epf_create(name);
+ if (IS_ERR(epf)) {
+ pr_err("failed to create endpoint function device\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ epf_info->epf = epf;
+ ep_info = container_of(group, struct pci_ep_info, pci_epf_group);
+
+ mutex_lock(&ep_info->lock);
+ list_add_tail(&epf_info->list, &ep_info->pci_epf);
+ mutex_unlock(&ep_info->lock);
+
+ return &epf_info->group;
+}
+
+static void pci_epf_drop(struct config_group *group, struct config_item *item)
+{
+ struct pci_ep_info *ep_info;
+ struct pci_epf_info *epf_info = to_pci_epf_info(item);
+
+ ep_info = container_of(group, struct pci_ep_info, pci_epf_group);
+
+ pci_epf_unbind(epf_info->epf);
+ pci_epc_remove_epf(ep_info->epc, epf_info->epf);
+
+ mutex_lock(&ep_info->lock);
+ list_del(&epf_info->list);
+ mutex_unlock(&ep_info->lock);
+
+ config_item_put(item);
+}
+
+static struct configfs_group_operations pci_epfs_ops = {
+ .make_group = &pci_epf_make,
+ .drop_item = &pci_epf_drop,
+};
+
+static struct config_item_type pci_epfs_type = {
+ .ct_group_ops = &pci_epfs_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static ssize_t pci_ep_epc_store(struct config_item *item, const char *page,
+ size_t len)
+{
+ int ret;
+ u8 func_no = 0;
+ char *epc_name;
+ struct pci_epc *epc;
+ struct pci_epf *epf;
+ struct pci_epf_info *epf_info;
+ struct pci_ep_info *ep_info = to_pci_ep_info(item);
+
+ epc_name = kstrdup(page, GFP_KERNEL);
+ if (!epc_name)
+ return -ENOMEM;
+ if (epc_name[len - 1] == '\n')
+ epc_name[len - 1] = '\0';
+
+ if (ep_info->epc) {
+ ret = -EBUSY;
+ goto err;
+ }
+
+ epc = pci_epc_get(epc_name);
+ if (IS_ERR(epc)) {
+ ret = PTR_ERR(epc);
+ goto err;
+ }
+
+ ep_info->epc = epc;
+ ep_info->epc_name = epc_name;
+
+ list_for_each_entry(epf_info, &ep_info->pci_epf, list) {
+ epf = epf_info->epf;
+ epf->func_no = func_no;
+ epf->epc = epc;
+ pci_epc_add_epf(epc, epf);
+ pci_epf_bind(epf);
+ func_no++;
+ }
+
+ return len;
+
+err:
+ kfree(epc_name);
+ return ret;
+}
+
+static ssize_t pci_ep_epc_show(struct config_item *item, char *page)
+{
+ return sprintf(page, "%s\n",
+ to_pci_ep_info(item)->epc_name);
+}
+
+CONFIGFS_ATTR(pci_ep_, epc);
+
+static struct configfs_attribute *pci_ep_attrs[] = {
+ &pci_ep_attr_epc,
+ NULL,
+};
+
+static void pci_ep_attr_release(struct config_item *item)
+{
+ struct pci_ep_info *ep_info = to_pci_ep_info(item);
+
+ pci_epc_put(ep_info->epc);
+ kfree(ep_info->epc_name);
+ kfree(ep_info);
+}
+
+static struct configfs_item_operations pci_ep_device_ops = {
+ .release = pci_ep_attr_release,
+};
+
+static struct config_item_type pci_ep_device_type = {
+ .ct_item_ops = &pci_ep_device_ops,
+ .ct_attrs = pci_ep_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_group *pci_ep_make(struct config_group *group,
+ const char *name)
+{
+ struct pci_ep_info *ep_info;
+
+ ep_info = kzalloc(sizeof(*ep_info), GFP_KERNEL);
+ if (!ep_info)
+ return ERR_PTR(-ENOMEM);
+
+ config_group_init_type_name(&ep_info->group, name, &pci_ep_device_type);
+ config_group_init_type_name(&ep_info->pci_epf_group,
+ "epf", &pci_epfs_type);
+ configfs_add_default_group(&ep_info->pci_epf_group, &ep_info->group);
+
+ mutex_init(&ep_info->lock);
+ INIT_LIST_HEAD(&ep_info->pci_epf);
+
+ return &ep_info->group;
+}
+
+static void pci_ep_drop(struct config_group *group, struct config_item *item)
+{
+ config_item_put(item);
+}
+
+static struct configfs_group_operations pci_ep_ops = {
+ .make_group = &pci_ep_make,
+ .drop_item = &pci_ep_drop,
+};
+
+static struct config_item_type pci_ep_type = {
+ .ct_group_ops = &pci_ep_ops,
+ .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;
+
+ config_group_init(&pci_ep_cfs_subsys.su_group);
+
+ ret = configfs_register_subsystem(&pci_ep_cfs_subsys);
+ if (ret)
+ pr_err("Error %d while registering subsystem %s\n",
+ ret, pci_ep_cfs_subsys.su_group.cg_item.ci_namebuf);
+
+ return ret;
+}
+module_init(pci_ep_cfs_init);
+
+static void __exit pci_ep_cfs_exit(void)
+{
+ 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@xxxxxx>");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5