[PATCH 3/4] powerpc/pseries: initialize fwsecurityfs with plpks arch-specific structure

Nayna Jain
2022-11-06T21:09:11Z

PowerVM PLPKS variables are exposed via fwsecurityfs.

Initialize fwsecurityfs arch-specific structure with plpks configuration.

Eg:

[root@ltcfleet35-lp1 config]# pwd
/sys/firmware/security/plpks/config
[root@ltcfleet35-lp1 config]# ls -ltrh
total 0
-r--r--r-- 1 root root 1 Sep 28 15:01 version
-r--r--r-- 1 root root 4 Sep 28 15:01 used_space
-r--r--r-- 1 root root 4 Sep 28 15:01 total_size
-r--r--r-- 1 root root 2 Sep 28 15:01 max_object_size
-r--r--r-- 1 root root 2 Sep 28 15:01 max_object_label_size

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
---
arch/powerpc/platforms/pseries/Kconfig | 10 ++
arch/powerpc/platforms/pseries/Makefile | 1 +
.../platforms/pseries/fwsecurityfs_arch.c | 116 ++++++++++++++++++
include/linux/fwsecurityfs.h | 4 +
4 files changed, 131 insertions(+)
create mode 100644 arch/powerpc/platforms/pseries/fwsecurityfs_arch.c

diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index a3b4d99567cb..5fb45e601982 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -162,6 +162,16 @@ config PSERIES_PLPKS

If unsure, select N.

+config PSERIES_FWSECURITYFS_ARCH
+ select FWSECURITYFS
+ bool "Support fwsecurityfs for pseries"
+ help
+ Enable fwsecurityfs arch specific code. This would initialize
+ the firmware security filesystem with initial platform specific
+ structure.
+
+ If you are unsure how to use it, say N.
+
config PAPR_SCM
depends on PPC_PSERIES && MEMORY_HOTPLUG && LIBNVDIMM
tristate "Support for the PAPR Storage Class Memory interface"
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index 92310202bdd7..2903cff26258 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_PPC_SPLPAR) += vphn.o
obj-$(CONFIG_PPC_SVM) += svm.o
obj-$(CONFIG_FA_DUMP) += rtas-fadump.o
obj-$(CONFIG_PSERIES_PLPKS) += plpks.o
+obj-$(CONFIG_PSERIES_FWSECURITYFS_ARCH) += fwsecurityfs_arch.o

obj-$(CONFIG_SUSPEND) += suspend.o
obj-$(CONFIG_PPC_VAS) += vas.o vas-sysfs.o
diff --git a/arch/powerpc/platforms/pseries/fwsecurityfs_arch.c b/arch/powerpc/platforms/pseries/fwsecurityfs_arch.c
new file mode 100644
index 000000000000..b43bd3cf7889
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/fwsecurityfs_arch.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Initialize fwsecurityfs with POWER LPAR Platform KeyStore (PLPKS)
+ * Copyright (C) 2022 IBM Corporation
+ * Author: Nayna Jain <nayna@linux.ibm.com>
+ *
+ */
+
+#include <linux/fwsecurityfs.h>
+#include "plpks.h"
+
+static struct dentry *plpks_dir;
+
+static ssize_t plpks_config_file_read(struct file *file, char __user *userbuf,
+ size_t count, loff_t *ppos)
+{
+ u8 out[4];
+ u32 outlen;
+ size_t size;
+ char *name;
+ u32 data;
+
+ name = file_dentry(file)->d_iname;
+
+ if (strcmp(name, "max_object_size") == 0) {
+ outlen = sizeof(u16);
+ data = plpks_get_maxobjectsize();
+ } else if (strcmp(name, "max_object_label_size") == 0) {
+ outlen = sizeof(u16);
+ data = plpks_get_maxobjectlabelsize();
+ } else if (strcmp(name, "total_size") == 0) {
+ outlen = sizeof(u32);
+ data = plpks_get_totalsize();
+ } else if (strcmp(name, "used_space") == 0) {
+ outlen = sizeof(u32);
+ data = plpks_get_usedspace();
+ } else if (strcmp(name, "version") == 0) {
+ outlen = sizeof(u8);
+ data = plpks_get_version();
+ } else {
+ return -EINVAL;
+ }
+
+ memcpy(out, &data, outlen);
+
+ size = simple_read_from_buffer(userbuf, count, ppos, out, outlen);
+
+ return size;
+}
+
+static const struct file_operations plpks_config_file_operations = {
+ .open = simple_open,
+ .read = plpks_config_file_read,
+ .llseek = no_llseek,
+};
+
+static int create_plpks_dir(void)
+{
+ struct dentry *config_dir;
+ struct dentry *fdentry;
+
+ if (!IS_ENABLED(CONFIG_PSERIES_PLPKS) || !plpks_is_available()) {
+ pr_warn("Platform KeyStore is not available on this LPAR\n");
+ return 0;
+ }
+
+ plpks_dir = fwsecurityfs_create_dir("plpks", S_IFDIR | 0755, NULL,
+ NULL);
+ if (IS_ERR(plpks_dir)) {
+ pr_err("Unable to create PLPKS dir: %ld\n", PTR_ERR(plpks_dir));
+ return PTR_ERR(plpks_dir);
+ }
+
+ config_dir = fwsecurityfs_create_dir("config", S_IFDIR | 0755, plpks_dir, NULL);
+ if (IS_ERR(config_dir)) {
+ pr_err("Unable to create config dir: %ld\n", PTR_ERR(config_dir));
+ return PTR_ERR(config_dir);
+ }
+
+ fdentry = fwsecurityfs_create_file("max_object_size", S_IFREG | 0444,
+ sizeof(u16), config_dir, NULL, NULL,
+ &plpks_config_file_operations);
+ if (IS_ERR(fdentry))
+ pr_err("Could not create max object size %ld\n", PTR_ERR(fdentry));
+
+ fdentry = fwsecurityfs_create_file("max_object_label_size", S_IFREG | 0444,
+ sizeof(u16), config_dir, NULL, NULL,
+ &plpks_config_file_operations);
+ if (IS_ERR(fdentry))
+ pr_err("Could not create max object label size %ld\n", PTR_ERR(fdentry));
+
+ fdentry = fwsecurityfs_create_file("total_size", S_IFREG | 0444,
+ sizeof(u32), config_dir, NULL, NULL,
+ &plpks_config_file_operations);
+ if (IS_ERR(fdentry))
+ pr_err("Could not create total size %ld\n", PTR_ERR(fdentry));
+
+ fdentry = fwsecurityfs_create_file("used_space", S_IFREG | 0444,
+ sizeof(u32), config_dir, NULL, NULL,
+ &plpks_config_file_operations);
+ if (IS_ERR(fdentry))
+ pr_err("Could not create used space %ld\n", PTR_ERR(fdentry));
+
+ fdentry = fwsecurityfs_create_file("version", S_IFREG | 0444,
+ sizeof(u8), config_dir, NULL, NULL,
+ &plpks_config_file_operations);
+ if (IS_ERR(fdentry))
+ pr_err("Could not create version %ld\n", PTR_ERR(fdentry));
+
+ return 0;
+}
+
+int arch_fwsecurityfs_init(void)
+{
+ return create_plpks_dir();
+}
diff --git a/include/linux/fwsecurityfs.h b/include/linux/fwsecurityfs.h
index ed8f328f3133..38fcb3cb374e 100644
--- a/include/linux/fwsecurityfs.h
+++ b/include/linux/fwsecurityfs.h
@@ -21,9 +21,13 @@ struct dentry *fwsecurityfs_create_dir(const char *name, umode_t mode,
const struct inode_operations *iops);
int fwsecurityfs_remove_dir(struct dentry *dentry);

+#ifdef CONFIG_PSERIES_FWSECURITYFS_ARCH
+int arch_fwsecurityfs_init(void);
+#else
static int arch_fwsecurityfs_init(void)
{
return 0;
}
+#endif

#endif /* _FWSECURITYFS_H_ */
--
2.31.1