firmware: arm_ffa: Reject higher major version as incompatible

[ Upstream commit efff6a7 ]

When the firmware compatibility was handled previously in the commit
8e3f9da ("firmware: arm_ffa: Handle compatibility with different firmware versions"),
we only addressed firmware versions that have higher minor versions
compared to the driver version which is should be considered compatible
unless the firmware returns NOT_SUPPORTED.

However, if the firmware reports higher major version than the driver
supported, we need to reject it. If the firmware can work in a compatible
mode with the driver requested version, it must return the same major
version as requested.

Tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Message-Id: <20250217-ffa_updates-v3-12-bd1d9de615e7@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 3da8088afd13a24ab1e2911c087966f107ba86bc)

Author: sudeep-holla

drivers/firmware/arm_ffa/driver.c

@@ -121,6 +121,14 @@ static int ffa_version_check(u32 *version)
 		return -EOPNOTSUPP;
 	}
 
+	if (FFA_MAJOR_VERSION(ver.a0) > FFA_MAJOR_VERSION(FFA_DRIVER_VERSION)) {
+		pr_err("Incompatible v%d.%d! Latest supported v%d.%d\n",
+		       FFA_MAJOR_VERSION(ver.a0), FFA_MINOR_VERSION(ver.a0),
+		       FFA_MAJOR_VERSION(FFA_DRIVER_VERSION),
+		       FFA_MINOR_VERSION(FFA_DRIVER_VERSION));
+		return -EINVAL;
+	}
+
 	if (ver.a0 < FFA_MIN_VERSION) {
 		pr_err("Incompatible v%d.%d! Earliest supported v%d.%d\n",
 		       FFA_MAJOR_VERSION(ver.a0), FFA_MINOR_VERSION(ver.a0),