[PATCH v2 13/21] ipmi: kcs_bmc: Decouple the IPMI chardev from the core

Andrew Jeffery
2021-03-19T06:30:17Z

Now that we have untangled the data-structures, split the userspace
interface out into its own module. Userspace interfaces and drivers are
registered to the KCS BMC core to support arbitrary binding of either.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
drivers/char/ipmi/Kconfig | 13 +++++
drivers/char/ipmi/Makefile | 3 +-
drivers/char/ipmi/kcs_bmc.c | 78 ++++++++++++++++++++++++++-
drivers/char/ipmi/kcs_bmc.h | 4 --
drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 33 +++++++++---
drivers/char/ipmi/kcs_bmc_client.h | 14 +++++
6 files changed, 132 insertions(+), 13 deletions(-)

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 07847d9a459a..bc5f81899b62 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -124,6 +124,19 @@ config NPCM7XX_KCS_IPMI_BMC
This support is also available as a module. If so, the module
will be called kcs_bmc_npcm7xx.

+config IPMI_KCS_BMC_CDEV_IPMI
+ depends on IPMI_KCS_BMC
+ tristate "IPMI character device interface for BMC KCS devices"
+ help
+ Provides a BMC-side character device implementing IPMI
+ semantics for KCS IPMI devices.
+
+ Say YES if you wish to expose KCS devices on the BMC for IPMI
+ purposes.
+
+ This support is also available as a module. The module will be
+ called kcs_bmc_cdev_ipmi.
+
config ASPEED_BT_IPMI_BMC
depends on ARCH_ASPEED || COMPILE_TEST
depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index a302bc865370..fcfa676afddb 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -22,7 +22,8 @@ obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
-obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o kcs_bmc_cdev_ipmi.o
+obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o
+obj-$(CONFIG_IPMI_KCS_BMC_CDEV_IPMI) += kcs_bmc_cdev_ipmi.o
obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index 266ebec71d6f..694db6ee2a92 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -5,7 +5,9 @@
*/

#include <linux/device.h>
+#include <linux/list.h>
#include <linux/module.h>
+#include <linux/mutex.h>

#include "kcs_bmc.h"

@@ -13,6 +15,11 @@
#include "kcs_bmc_device.h"
#include "kcs_bmc_client.h"

+/* Record probed devices and cdevs */
+static DEFINE_MUTEX(kcs_bmc_lock);
+static LIST_HEAD(kcs_bmc_devices);
+static LIST_HEAD(kcs_bmc_cdevs);
+
/* Consumer data access */

u8 kcs_bmc_read_data(struct kcs_bmc_device *kcs_bmc)
@@ -100,16 +107,83 @@ EXPORT_SYMBOL(kcs_bmc_disable_device);

int kcs_bmc_add_device(struct kcs_bmc_device *kcs_bmc)
{
- return kcs_bmc_ipmi_attach_cdev(kcs_bmc);
+ struct kcs_bmc_cdev *cdev;
+ int rc;
+
+ spin_lock_init(&kcs_bmc->lock);
+ kcs_bmc->client = NULL;
+
+ mutex_lock(&kcs_bmc_lock);
+ list_add(&kcs_bmc->entry, &kcs_bmc_devices);
+ list_for_each_entry(cdev, &kcs_bmc_cdevs, entry) {
+ rc = cdev->ops->add_device(kcs_bmc);
+ if (rc)
+ dev_err(kcs_bmc->dev, "Failed to add chardev for KCS channel %d: %d",
+ kcs_bmc->channel, rc);
+ }
+ mutex_unlock(&kcs_bmc_lock);
+
+ return 0;
}
EXPORT_SYMBOL(kcs_bmc_add_device);

int kcs_bmc_remove_device(struct kcs_bmc_device *kcs_bmc)
{
- return kcs_bmc_ipmi_detach_cdev(kcs_bmc);
+ struct kcs_bmc_cdev *cdev;
+ int rc;
+
+ mutex_lock(&kcs_bmc_lock);
+ list_del(&kcs_bmc->entry);
+ list_for_each_entry(cdev, &kcs_bmc_cdevs, entry) {
+ rc = cdev->ops->remove_device(kcs_bmc);
+ if (rc)
+ dev_err(kcs_bmc->dev, "Failed to remove chardev for KCS channel %d: %d",
+ kcs_bmc->channel, rc);
+ }
+ mutex_unlock(&kcs_bmc_lock);
+
+ return 0;
}
EXPORT_SYMBOL(kcs_bmc_remove_device);

+int kcs_bmc_register_cdev(struct kcs_bmc_cdev *cdev)
+{
+ struct kcs_bmc_device *kcs_bmc;
+ int rc;
+
+ mutex_lock(&kcs_bmc_lock);
+ list_add(&cdev->entry, &kcs_bmc_cdevs);
+ list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
+ rc = cdev->ops->add_device(kcs_bmc);
+ if (rc)
+ dev_err(kcs_bmc->dev, "Failed to add chardev for KCS channel %d: %d",
+ kcs_bmc->channel, rc);
+ }
+ mutex_unlock(&kcs_bmc_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(kcs_bmc_register_cdev);
+
+int kcs_bmc_unregister_cdev(struct kcs_bmc_cdev *cdev)
+{
+ struct kcs_bmc_device *kcs_bmc;
+ int rc;
+
+ mutex_lock(&kcs_bmc_lock);
+ list_del(&cdev->entry);
+ list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
+ rc = cdev->ops->remove_device(kcs_bmc);
+ if (rc)
+ dev_err(kcs_bmc->dev, "Failed to add chardev for KCS channel %d: %d",
+ kcs_bmc->channel, rc);
+ }
+ mutex_unlock(&kcs_bmc_lock);
+
+ return rc;
+}
+EXPORT_SYMBOL(kcs_bmc_unregister_cdev);
+
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index 3f266740c759..5deb9a0b8e60 100644
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -42,8 +42,4 @@ struct kcs_bmc_device {
spinlock_t lock;
struct kcs_bmc_client *client;
};
-
-/* Temporary exports while refactoring */
-int kcs_bmc_ipmi_attach_cdev(struct kcs_bmc_device *kcs_bmc);
-int kcs_bmc_ipmi_detach_cdev(struct kcs_bmc_device *kcs_bmc);
#endif /* __KCS_BMC_H__ */
diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
index 58c42e76483d..df83d67851ac 100644
--- a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
@@ -469,8 +469,7 @@ static const struct file_operations kcs_bmc_ipmi_fops = {
static DEFINE_SPINLOCK(kcs_bmc_ipmi_instances_lock);
static LIST_HEAD(kcs_bmc_ipmi_instances);

-int kcs_bmc_ipmi_attach_cdev(struct kcs_bmc_device *kcs_bmc);
-int kcs_bmc_ipmi_attach_cdev(struct kcs_bmc_device *kcs_bmc)
+static int kcs_bmc_ipmi_attach_cdev(struct kcs_bmc_device *kcs_bmc)
{
struct kcs_bmc_ipmi *priv;
int rc;
@@ -512,10 +511,8 @@ int kcs_bmc_ipmi_attach_cdev(struct kcs_bmc_device *kcs_bmc)

return 0;
}
-EXPORT_SYMBOL(kcs_bmc_ipmi_attach_cdev);

-int kcs_bmc_ipmi_detach_cdev(struct kcs_bmc_device *kcs_bmc);
-int kcs_bmc_ipmi_detach_cdev(struct kcs_bmc_device *kcs_bmc)
+static int kcs_bmc_ipmi_detach_cdev(struct kcs_bmc_device *kcs_bmc)
{
struct kcs_bmc_ipmi *priv = NULL, *pos;

@@ -541,7 +538,31 @@ int kcs_bmc_ipmi_detach_cdev(struct kcs_bmc_device *kcs_bmc)

return 0;
}
-EXPORT_SYMBOL(kcs_bmc_ipmi_detach_cdev);
+
+static const struct kcs_bmc_cdev_ops kcs_bmc_ipmi_cdev_ops = {
+ .add_device = kcs_bmc_ipmi_attach_cdev,
+ .remove_device = kcs_bmc_ipmi_detach_cdev,
+};
+
+static struct kcs_bmc_cdev kcs_bmc_ipmi_cdev = {
+ .ops = &kcs_bmc_ipmi_cdev_ops,
+};
+
+static int kcs_bmc_ipmi_init(void)
+{
+ return kcs_bmc_register_cdev(&kcs_bmc_ipmi_cdev);
+}
+module_init(kcs_bmc_ipmi_init);
+
+static void kcs_bmc_ipmi_exit(void)
+{
+ int rc;
+
+ rc = kcs_bmc_unregister_cdev(&kcs_bmc_ipmi_cdev);
+ if (rc)
+ pr_warn("Failed to remove KCS BMC client: %d", rc);
+}
+module_exit(kcs_bmc_ipmi_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
diff --git a/drivers/char/ipmi/kcs_bmc_client.h b/drivers/char/ipmi/kcs_bmc_client.h
index 2dd710f4b4aa..d0a7404ff584 100644
--- a/drivers/char/ipmi/kcs_bmc_client.h
+++ b/drivers/char/ipmi/kcs_bmc_client.h
@@ -10,6 +10,17 @@

#include "kcs_bmc.h"

+struct kcs_bmc_cdev_ops {
+ int (*add_device)(struct kcs_bmc_device *kcs_bmc);
+ int (*remove_device)(struct kcs_bmc_device *kcs_bmc);
+};
+
+struct kcs_bmc_cdev {
+ struct list_head entry;
+
+ const struct kcs_bmc_cdev_ops *ops;
+};
+
struct kcs_bmc_client_ops {
int (*event)(struct kcs_bmc_client *client);
};
@@ -20,6 +31,9 @@ struct kcs_bmc_client {
struct kcs_bmc_device *dev;
};

+int kcs_bmc_register_cdev(struct kcs_bmc_cdev *cdev);
+int kcs_bmc_unregister_cdev(struct kcs_bmc_cdev *cdev);
+
int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);
void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);

--
2.27.0