From: Sudeep Holla <sudeep.holla@arm.com>
Date: Thu, 16 Oct 2025 09:41:11 +0000 (+0100)
Subject: firmware: arm_ffa: Tie FF-A version checks to specific features
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f183b1dda4fc0348c4016f6289588d5853ab7936;p=thirdparty%2Fkernel%2Flinux.git

firmware: arm_ffa: Tie FF-A version checks to specific features

The FF-A driver currently performs loose comparisons when checking the
supported FF-A feature, which can inadvertently treat future or
intermediate revisions as compatible.

Replace generic `version {>,<} FFA_VERSION_1_*` pattern checks with
feature-specific macros that clearly express which functionality
depends on FF-A versioning.

This improves readability and future maintainability by tying each
feature (e.g. GET_COUNT_ONLY, size/UUID/exec state in responses) to
explicit version requirements instead of relying on generic version
comparisons. This improves robustness and clarity as the FF-A
specification evolves.

No functional change, only improves code readability.

Message-Id: <20251016094111.946236-1-sudeep.holla@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 7209a630f6d16..351780ac8d725 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -246,6 +246,11 @@ static int ffa_features(u32 func_feat_id, u32 input_props,
 }
 
 #define PARTITION_INFO_GET_RETURN_COUNT_ONLY	BIT(0)
+#define FFA_SUPPORTS_GET_COUNT_ONLY(version)	((version) > FFA_VERSION_1_0)
+#define FFA_PART_INFO_HAS_SIZE_IN_RESP(version)	((version) > FFA_VERSION_1_0)
+#define FFA_PART_INFO_HAS_UUID_IN_RESP(version)	((version) > FFA_VERSION_1_0)
+#define FFA_PART_INFO_HAS_EXEC_STATE_IN_RESP(version)	\
+	((version) > FFA_VERSION_1_0)
 
 /* buffer must be sizeof(struct ffa_partition_info) * num_partitions */
 static int
@@ -255,7 +260,7 @@ __ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
 	int idx, count, flags = 0, sz, buf_sz;
 	ffa_value_t partition_info;
 
-	if (drv_info->version > FFA_VERSION_1_0 &&
+	if (FFA_SUPPORTS_GET_COUNT_ONLY(drv_info->version) &&
 	    (!buffer || !num_partitions)) /* Just get the count for now */
 		flags = PARTITION_INFO_GET_RETURN_COUNT_ONLY;
 
@@ -273,12 +278,11 @@ __ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
 
 	count = partition_info.a2;
 
-	if (drv_info->version > FFA_VERSION_1_0) {
+	if (FFA_PART_INFO_HAS_SIZE_IN_RESP(drv_info->version)) {
 		buf_sz = sz = partition_info.a3;
 		if (sz > sizeof(*buffer))
 			buf_sz = sizeof(*buffer);
 	} else {
-		/* FFA_VERSION_1_0 lacks size in the response */
 		buf_sz = sz = 8;
 	}
 
@@ -1706,7 +1710,7 @@ static int ffa_setup_partitions(void)
 	struct ffa_device *ffa_dev;
 	struct ffa_partition_info *pbuf, *tpbuf;
 
-	if (drv_info->version == FFA_VERSION_1_0) {
+	if (!FFA_PART_INFO_HAS_UUID_IN_RESP(drv_info->version)) {
 		ret = bus_register_notifier(&ffa_bus_type, &ffa_bus_nb);
 		if (ret)
 			pr_err("Failed to register FF-A bus notifiers\n");
@@ -1733,7 +1737,7 @@ static int ffa_setup_partitions(void)
 			continue;
 		}
 
-		if (drv_info->version > FFA_VERSION_1_0 &&
+		if (FFA_PART_INFO_HAS_EXEC_STATE_IN_RESP(drv_info->version) &&
 		    !(tpbuf->properties & FFA_PARTITION_AARCH64_EXEC))
 			ffa_mode_32bit_set(ffa_dev);