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| author | Huang Ying <ying.huang@intel.com> | 2023-12-08 06:06:36 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-26 02:27:44 +0300 |
| commit | 970c0899a4ac35b642ca10e43b6ae26073f9bcdd (patch) | |
| tree | a46f27acd9b6bea86e9c7c12890dfde5d2ac5c0f /drivers/cxl | |
| parent | 23f974910862e9b959a4a35b019bcd8c7e295eb4 (diff) | |
| download | linux-970c0899a4ac35b642ca10e43b6ae26073f9bcdd.tar.xz | |
cxl/port: Fix decoder initialization when nr_targets > interleave_ways
commit d6488fee66472b468ed88d265b14aa3f04dc3bdf upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/cxl')
| -rw-r--r-- | drivers/cxl/core/port.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index bd4142431980..1f1483a9e525 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -1403,7 +1403,7 @@ 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) { |