This is a note to let you know that I've just added the patch titled
perf/arm-cmn: Ensure dtm_idx is big enough
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-arm-cmn-ensure-dtm_idx-is-big-enough.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cb8e8bfcf0438ab06ee1ca9c5bcd07ac7a4a4dd3
Author: Robin Murphy <robin.murphy@xxxxxxx>
Date: Mon Sep 2 18:51:59 2024 +0100
perf/arm-cmn: Ensure dtm_idx is big enough
[ Upstream commit 359414b33e00bae91e4eabf3e4ef8e76024c7673 ]
While CMN_MAX_DIMENSION was bumped to 12 for CMN-650, that only supports
up to a 10x10 mesh, so bumping dtm_idx to 256 bits at the time worked
out OK in practice. However CMN-700 did finally support up to 144 XPs,
and thus needs a worst-case 288 bits of dtm_idx for an aggregated XP
event on a maxed-out config. Oops.
Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
Link: https://lore.kernel.org/r/e771b358526a0d7fc06efee2c3a2fdc0c9f51d44.1725296395.git.robin.murphy@xxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index f33fd110081c3..058ea798b669b 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -35,6 +35,9 @@
#define CMN_MAX_XPS (CMN_MAX_DIMENSION * CMN_MAX_DIMENSION)
#define CMN_MAX_DTMS (CMN_MAX_XPS + (CMN_MAX_DIMENSION - 1) * 4)
+/* Currently XPs are the node type we can have most of; others top out at 128 */
+#define CMN_MAX_NODES_PER_EVENT CMN_MAX_XPS
+
/* The CFG node has various info besides the discovery tree */
#define CMN_CFGM_PERIPH_ID_01 0x0008
#define CMN_CFGM_PID0_PART_0 GENMASK_ULL(7, 0)
@@ -565,7 +568,7 @@ static void arm_cmn_debugfs_init(struct arm_cmn *cmn, int id) {}
struct arm_cmn_hw_event {
struct arm_cmn_node *dn;
- u64 dtm_idx[4];
+ u64 dtm_idx[DIV_ROUND_UP(CMN_MAX_NODES_PER_EVENT * 2, 64)];
s8 dtc_idx[CMN_MAX_DTCS];
u8 num_dns;
u8 dtm_offset;
