This is a note to let you know that I've just added the patch titled
cxl/region: Fix x1 root-decoder granularity calculations
to the 6.6-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:
cxl-region-fix-x1-root-decoder-granularity-calculations.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 98a04c7aced2b43b3ac4befe216c4eecc7257d4b Mon Sep 17 00:00:00 2001
From: Jim Harris <jim.harris@xxxxxxxxxxx>
Date: Thu, 26 Oct 2023 10:09:06 -0700
Subject: cxl/region: Fix x1 root-decoder granularity calculations
From: Jim Harris <jim.harris@xxxxxxxxxxx>
commit 98a04c7aced2b43b3ac4befe216c4eecc7257d4b upstream.
Root decoder granularity must match value from CFWMS, which may not
be the region's granularity for non-interleaved root decoders.
So when calculating granularities for host bridge decoders, use the
region's granularity instead of the root decoder's granularity to ensure
the correct granularities are set for the host bridge decoders and any
downstream switch decoders.
Test configuration is 1 host bridge * 2 switches * 2 endpoints per switch.
Region created with 2048 granularity using following command line:
cxl create-region -m -d decoder0.0 -w 4 mem0 mem2 mem1 mem3 \
-g 2048 -s 2048M
Use "cxl list -PDE | grep granularity" to get a view of the granularity
set at each level of the topology.
Before this patch:
"interleave_granularity":2048,
"interleave_granularity":2048,
"interleave_granularity":512,
"interleave_granularity":2048,
"interleave_granularity":2048,
"interleave_granularity":512,
"interleave_granularity":256,
After:
"interleave_granularity":2048,
"interleave_granularity":2048,
"interleave_granularity":4096,
"interleave_granularity":2048,
"interleave_granularity":2048,
"interleave_granularity":4096,
"interleave_granularity":2048,
Fixes: 27b3f8d13830 ("cxl/region: Program target lists")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jim Harris <jim.harris@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/169824893473.1403938.16110924262989774582.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
[djbw: fixup the prebuilt cxl_test region]
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cxl/core/region.c | 9 ++++++++-
tools/testing/cxl/test/cxl.c | 2 +-
2 files changed, 9 insertions(+), 2 deletions(-)
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1127,7 +1127,14 @@ static int cxl_port_setup_targets(struct
}
if (is_cxl_root(parent_port)) {
- parent_ig = cxlrd->cxlsd.cxld.interleave_granularity;
+ /*
+ * Root decoder IG is always set to value in CFMWS which
+ * may be different than this region's IG. We can use the
+ * region's IG here since interleave_granularity_store()
+ * does not allow interleaved host-bridges with
+ * root IG != region IG.
+ */
+ parent_ig = p->interleave_granularity;
parent_iw = cxlrd->cxlsd.cxld.interleave_ways;
/*
* For purposes of address bit routing, use power-of-2 math for
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -831,7 +831,7 @@ static void mock_init_hdm_decoder(struct
cxld->interleave_ways = 2;
else
cxld->interleave_ways = 1;
- cxld->interleave_granularity = 256;
+ cxld->interleave_granularity = 4096;
cxld->hpa_range = (struct range) {
.start = base,
.end = base + size - 1,
Patches currently in stable-queue which might be from jim.harris@xxxxxxxxxxx are
queue-6.6/cxl-region-do-not-try-to-cleanup-after-cxl_region_setup_targets-fails.patch
queue-6.6/cxl-region-fix-x1-root-decoder-granularity-calculations.patch
