[PATCH v5 08/25] powerpc/secvar: Handle max object size in the consumer

Andrew Donnellan
2023-01-31T06:41:38Z

From: Russell Currey <ruscur@russell.cc>

Currently the max object size is handled in the core secvar code with an
entirely OPAL-specific implementation, so create a new max_size() op and
move the existing implementation into the powernv platform. Should be
no functional change.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>

---

v3: Change uint64_t type to u64 (mpe)

v4: Return immediately if node is NULL (gjoyce)
---
arch/powerpc/include/asm/secvar.h | 1 +
arch/powerpc/kernel/secvar-sysfs.c | 17 +++------------
arch/powerpc/platforms/powernv/opal-secvar.c | 22 ++++++++++++++++++++
3 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h
index 1a2c696a48ad..bf396215903d 100644
--- a/arch/powerpc/include/asm/secvar.h
+++ b/arch/powerpc/include/asm/secvar.h
@@ -18,6 +18,7 @@ struct secvar_operations {
int (*get_next)(const char *key, u64 *key_len, u64 keybufsize);
int (*set)(const char *key, u64 key_len, u8 *data, u64 data_size);
ssize_t (*format)(char *buf, size_t bufsize);
+ int (*max_size)(u64 *max_size);
};

#ifdef CONFIG_PPC_SECURE_BOOT
diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c
index e4661559c855..0966806f28c7 100644
--- a/arch/powerpc/kernel/secvar-sysfs.c
+++ b/arch/powerpc/kernel/secvar-sysfs.c
@@ -132,27 +132,16 @@ static struct kobj_type secvar_ktype = {
static int update_kobj_size(void)
{

- struct device_node *node;
u64 varsize;
- int rc = 0;
+ int rc = secvar_ops->max_size(&varsize);

- node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend");
- if (!of_device_is_available(node)) {
- rc = -ENODEV;
- goto out;
- }
-
- rc = of_property_read_u64(node, "max-var-size", &varsize);
if (rc)
- goto out;
+ return rc;

data_attr.size = varsize;
update_attr.size = varsize;

-out:
- of_node_put(node);
-
- return rc;
+ return 0;
}

static int secvar_sysfs_load(void)
diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c b/arch/powerpc/platforms/powernv/opal-secvar.c
index e33bb703ecbc..a8436bf35e2f 100644
--- a/arch/powerpc/platforms/powernv/opal-secvar.c
+++ b/arch/powerpc/platforms/powernv/opal-secvar.c
@@ -122,11 +122,33 @@ static ssize_t opal_secvar_format(char *buf, size_t bufsize)
return rc;
}

+static int opal_secvar_max_size(u64 *max_size)
+{
+ int rc;
+ struct device_node *node;
+
+ node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend");
+ if (!node)
+ return -ENODEV;
+
+ if (!of_device_is_available(node)) {
+ rc = -ENODEV;
+ goto out;
+ }
+
+ rc = of_property_read_u64(node, "max-var-size", max_size);
+
+out:
+ of_node_put(node);
+ return rc;
+}
+
static const struct secvar_operations opal_secvar_ops = {
.get = opal_get_variable,
.get_next = opal_get_next_variable,
.set = opal_set_variable,
.format = opal_secvar_format,
+ .max_size = opal_secvar_max_size,
};

static int opal_secvar_probe(struct platform_device *pdev)
--
2.39.1