[PATCH v3 3/4] platform/x86/amd/pmf: Use struct for cookie header

From: Armin Wolf
Date: Mon Mar 04 2024 - 15:51:01 EST


The cookie header consists of a sign field and a length field.
Combine both in a single struct to make accesses simpler.

Compile-tested only.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
---
drivers/platform/x86/amd/pmf/pmf.h | 6 +++++-
drivers/platform/x86/amd/pmf/tee-if.c | 9 ++++-----
2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h
index bcf777a5659a..0c90805dc85b 100644
--- a/drivers/platform/x86/amd/pmf/pmf.h
+++ b/drivers/platform/x86/amd/pmf/pmf.h
@@ -17,7 +17,11 @@
#define POLICY_BUF_MAX_SZ 0x4b000
#define POLICY_SIGN_COOKIE 0x31535024
#define POLICY_COOKIE_OFFSET 0x10
-#define POLICY_COOKIE_LEN 0x14
+
+struct cookie_header {
+ u32 sign;
+ u32 length;
+} __packed;

/* APMF Functions */
#define APMF_FUNC_VERIFY_INTERFACE 0
diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c
index 58ec2c9606e1..71ea7eefc211 100644
--- a/drivers/platform/x86/amd/pmf/tee-if.c
+++ b/drivers/platform/x86/amd/pmf/tee-if.c
@@ -246,17 +246,16 @@ static void amd_pmf_invoke_cmd(struct work_struct *work)

static int amd_pmf_start_policy_engine(struct amd_pmf_dev *dev)
{
- u32 cookie, length;
+ struct cookie_header *header;
int res;

- cookie = *(u32 *)(dev->policy_buf + POLICY_COOKIE_OFFSET);
- length = *(u32 *)(dev->policy_buf + POLICY_COOKIE_LEN);
+ header = (struct cookie_header *)(dev->policy_buf + POLICY_COOKIE_OFFSET);

- if (cookie != POLICY_SIGN_COOKIE || !length)
+ if (header->sign != POLICY_SIGN_COOKIE || !header->length)
return -EINVAL;

/* Update the actual length */
- dev->policy_sz = length + 512;
+ dev->policy_sz = header->length + 512;
res = amd_pmf_invoke_cmd_init(dev);
if (res == TA_PMF_TYPE_SUCCESS) {
/* Now its safe to announce that smart pc is enabled */
--
2.39.2