[PATCH v3 12/19] firmware: arm_ffa: Reject higher major version as incompatible

[Sudeep Holla]

When the firmware compatibility was handled previously in the commit
8e3f9da608f1 ("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@xxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
 drivers/firmware/arm_ffa/driver.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index d8421a32a92fed6d56770cba282ea55b2571b155..ad2f6b410e4431bb133fa0f05dd3eec802f5ee07 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -150,6 +150,14 @@ 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),

-- 
2.34.1