[PATCH mpam/v6.10-rc1 RFC 1/4] arm_mpam: Correct MBA granularity calculation

Zeng Heng zengheng4 at huawei.com
Sun Jul 21 21:01:18 PDT 2024


Correct MBA granularity calculation function. As said in the comments,
"bwa_wd is the number of bits implemented in the 0.xxx fixed point
fraction".

Fixes: 867471fefd5c ("SPLIT untested: arm_mpam: resctrl: Add support for MB resource")
Signed-off-by: Zeng Heng <zengheng4 at huawei.com>
---
 drivers/platform/arm64/mpam/mpam_resctrl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/arm64/mpam/mpam_resctrl.c b/drivers/platform/arm64/mpam/mpam_resctrl.c
index 2fa732a42d4f..a217f2e1f350 100644
--- a/drivers/platform/arm64/mpam/mpam_resctrl.c
+++ b/drivers/platform/arm64/mpam/mpam_resctrl.c
@@ -523,7 +523,7 @@ static u32 get_mba_granularity(struct mpam_props *cprops)
 		 * bwa_wd is the number of bits implemented in the 0.xxx
 		 * fixed point fraction. 1 bit is 50%, 2 is 25% etc.
 		 */
-		return MAX_MBA_BW / (cprops->bwa_wd + 1);
+		return MAX_MBA_BW / (1 << cprops->bwa_wd);
 	}
 
 	return 0;
-- 
2.25.1




More information about the linux-arm-kernel mailing list