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authorHuang Ying <ying.huang@intel.com>2023-12-08 11:06:36 +0800
committerDan Williams <dan.j.williams@intel.com>2024-01-04 13:59:50 -0800
commitd6488fee66472b468ed88d265b14aa3f04dc3bdf (patch)
treeb8b74ad3e07dacc83814d010c17b8eaa36f0c1b4
parentceb6a6f023fd3e8b07761ed900352ef574010bcb (diff)
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cxl/port: Fix decoder initialization when nr_targets > interleave_ways
The decoder_populate_targets() helper walks all of the targets in a port and makes sure they can be looked up in @target_map. Where @target_map is a lookup table from target position to target id (corresponding to a cxl_dport instance). However @target_map is only responsible for conveying the active dport instances as indicated by interleave_ways. When nr_targets > interleave_ways it results in decoder_populate_targets() walking off the end of the valid entries in @target_map. Given target_map is initialized to 0 it results in the dport lookup failing if position 0 is not mapped to a dport with an id of 0: cxl_port port3: Failed to populate active decoder targets cxl_port port3: Failed to add decoder cxl_port port3: Failed to add decoder3.0 cxl_bus_probe: cxl_port port3: probe: -6 This bug also highlights that when the decoder's ->targets[] array is written in cxl_port_setup_targets() it is missing a hold of the targets_lock to synchronize against sysfs readers of the target list. A fix for that is saved for a later patch. Fixes: a5c258021689 ("cxl/bus: Populate the target list at decoder create") Cc: <stable@vger.kernel.org> Signed-off-by: Huang, Ying <ying.huang@intel.com> [djbw: rewrite the changelog, find the Fixes: tag] Co-developed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/cxl/core/port.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index b7c93bb18f6e..57495cdc181f 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1644,7 +1644,7 @@ static int decoder_populate_targets(struct cxl_switch_decoder *cxlsd,
return -EINVAL;
write_seqlock(&cxlsd->target_lock);
- for (i = 0; i < cxlsd->nr_targets; i++) {
+ for (i = 0; i < cxlsd->cxld.interleave_ways; i++) {
struct cxl_dport *dport = find_dport(port, target_map[i]);
if (!dport) {