powerpc/pseries: Expose PLPKS config values, support additional fields

The plpks driver uses the H_PKS_GET_CONFIG hcall to retrieve configuration
and status information about the PKS from the hypervisor.

Update _plpks_get_config() to handle some additional fields. Add getter
functions to allow the PKS configuration information to be accessed from
other files. Validate that the values we're getting comply with the spec.

While we're here, move the config struct in _plpks_get_config() off the
stack - it's getting large and we also need to make sure it doesn't cross
a page boundary.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
[ajd: split patch, extend to support additional v3 API fields, minor fixes]
Co-developed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230210080401.345462-17-ajd@linux.ibm.com

1 files changed, 58 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h
index 6466aadd7145..7c5f51a9af7c 100644
--- a/arch/powerpc/include/asm/plpks.h
+++ b/arch/powerpc/include/asm/plpks.h
@@ -96,6 +96,64 @@ int plpks_read_fw_var(struct plpks_var *var);
  */
 int plpks_read_bootloader_var(struct plpks_var *var);
 
+/**
+ * Returns if PKS is available on this LPAR.
+ */
+bool plpks_is_available(void);
+
+/**
+ * Returns version of the Platform KeyStore.
+ */
+u8 plpks_get_version(void);
+
+/**
+ * Returns hypervisor storage overhead per object, not including the size of
+ * the object or label. Only valid for config version >= 2
+ */
+u16 plpks_get_objoverhead(void);
+
+/**
+ * Returns maximum password size. Must be >= 32 bytes
+ */
+u16 plpks_get_maxpwsize(void);
+
+/**
+ * Returns maximum object size supported by Platform KeyStore.
+ */
+u16 plpks_get_maxobjectsize(void);
+
+/**
+ * Returns maximum object label size supported by Platform KeyStore.
+ */
+u16 plpks_get_maxobjectlabelsize(void);
+
+/**
+ * Returns total size of the configured Platform KeyStore.
+ */
+u32 plpks_get_totalsize(void);
+
+/**
+ * Returns used space from the total size of the Platform KeyStore.
+ */
+u32 plpks_get_usedspace(void);
+
+/**
+ * Returns bitmask of policies supported by the hypervisor.
+ */
+u32 plpks_get_supportedpolicies(void);
+
+/**
+ * Returns maximum byte size of a single object supported by the hypervisor.
+ * Only valid for config version >= 3
+ */
+u32 plpks_get_maxlargeobjectsize(void);
+
+/**
+ * Returns bitmask of signature algorithms supported for signed updates.
+ * Only valid for config version >= 3
+ */
+u64 plpks_get_signedupdatealgorithms(void);
+
 #endif // CONFIG_PSERIES_PLPKS
 
 #endif // _ASM_POWERPC_PLPKS_H