arm_mpam: Update architecture version check for MPAM MSC

In addition to updating the CPU MPAM version check, the MPAM MSC version
check also need to be updated. mpam_msc_check_aidr() is added to check
the MSC AIDR register, ensuring that both the major and minor version
numbers fall within the supported range of the MPAM architecture version.

Signed-off-by: Zeng Heng <zengheng4@huawei.com>
[ morse: changed mpam_msc_check_aidr() to accept versions like v1.2 ]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 41b14344b16f2d361e67c261a7243c40b7773ed9..83ddbddb278249bd7011d3fd254b1e3872e53d60 100644 (file)
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -218,6 +218,24 @@ static inline void _mpam_write_monsel_reg(struct mpam_msc *msc, u16 reg, u32 val
 
 #define mpam_write_monsel_reg(msc, reg, val)   _mpam_write_monsel_reg(msc, MSMON_##reg, val)
 
+static bool mpam_msc_check_aidr(struct mpam_msc *msc)
+{
+       u32 aidr = __mpam_read_reg(msc, MPAMF_AIDR);
+       u32 major = FIELD_GET(MPAMF_AIDR_ARCH_MAJOR_REV, aidr);
+       u32 minor = FIELD_GET(MPAMF_AIDR_ARCH_MINOR_REV, aidr);
+
+       /*
+        * v0.0 and >v2.x aren't supported, but anything else should be backward
+        * compatible to v0.1 or v1.0.
+        */
+       if (!major && !minor)
+               return false;
+       if (major > 1)
+               return false;
+
+       return true;
+}
+
 static u64 mpam_msc_read_idr(struct mpam_msc *msc)
 {
        u64 idr_high = 0, idr_low;
@@ -945,9 +963,8 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
 
        lockdep_assert_held(&msc->probe_lock);
 
-       idr = __mpam_read_reg(msc, MPAMF_AIDR);
-       if ((idr & MPAMF_AIDR_ARCH_MAJOR_REV) != MPAM_ARCHITECTURE_V1) {
-               dev_err_once(dev, "MSC does not match MPAM architecture v1.x\n");
+       if (!mpam_msc_check_aidr(msc)) {
+               dev_err_once(dev, "MSC does not match architecture v1.x\n");
                return -EIO;
        }