diff options
| author | Li Ming <ming.li@zohomail.com> | 2025-06-03 13:43:13 +0300 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2025-06-10 23:54:15 +0300 |
| commit | fdc9be90929081ed5a9658583aa5f3121d5e8365 (patch) | |
| tree | fe8c546225507296b19e18674825d700fd6c4272 | |
| parent | 87b42c114cdda76c8ad3002f2096699ad5146cb3 (diff) | |
| download | linux-fdc9be90929081ed5a9658583aa5f3121d5e8365.tar.xz | |
cxl/edac: Fix the min_scrub_cycle of a region miscalculation
When trying to update the scrub_cycle value of a cxl region, which means
updating the scrub_cycle value of each memdev under a cxl region. cxl
driver needs to guarantee the new scrub_cycle value is greater than the
min_scrub_cycle value of a memdev, otherwise the updating operation will
fail(Per Table 8-223 in CXL r3.2 section 8.2.10.9.11.1).
Current implementation logic of getting the min_scrub_cycle value of a
cxl region is that getting the min_scrub_cycle value of each memdevs
under the cxl region, then using the minimum min_scrub_cycle value as
the region's min_scrub_cycle. Checking if the new scrub_cycle value is
greater than this value. If yes, updating the new scrub_cycle value to
each memdevs. The issue is that the new scrub_cycle value is possibly
greater than the minimum min_scrub_cycle value of all memdevs but less
than the maximum min_scrub_cycle value of all memdevs if memdevs have
a different min_scrub_cycle value. The updating operation will always
fail on these memdevs which have a greater min_scrub_cycle than the new
scrub_cycle.
The correct implementation logic is to get the maximum value of these
memdevs' min_scrub_cycle, check if the new scrub_cycle value is greater
than the value. If yes, the new scrub_cycle value is fit for the region.
The change also impacts the result of
cxl_patrol_scrub_get_min_scrub_cycle(), the interface returned the
minimum min_scrub_cycle value among all memdevs under the region before
the change. The interface will return the maximum min_scrub_cycle value
among all memdevs under the region with the change.
Signed-off-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Shiju Jose <shiju.jose@huawei.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://patch.msgid.link/20250603104314.25569-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
| -rw-r--r-- | drivers/cxl/core/edac.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/cxl/core/edac.c b/drivers/cxl/core/edac.c index 2cbc664e5d62..0ef245d0bd9f 100644 --- a/drivers/cxl/core/edac.c +++ b/drivers/cxl/core/edac.c @@ -103,10 +103,10 @@ static int cxl_scrub_get_attrbs(struct cxl_patrol_scrub_context *cxl_ps_ctx, u8 *cap, u16 *cycle, u8 *flags, u8 *min_cycle) { struct cxl_mailbox *cxl_mbox; - u8 min_scrub_cycle = U8_MAX; struct cxl_region_params *p; struct cxl_memdev *cxlmd; struct cxl_region *cxlr; + u8 min_scrub_cycle = 0; int i, ret; if (!cxl_ps_ctx->cxlr) { @@ -133,8 +133,12 @@ static int cxl_scrub_get_attrbs(struct cxl_patrol_scrub_context *cxl_ps_ctx, if (ret) return ret; + /* + * The min_scrub_cycle of a region is the max of minimum scrub + * cycles supported by memdevs that back the region. + */ if (min_cycle) - min_scrub_cycle = min(*min_cycle, min_scrub_cycle); + min_scrub_cycle = max(*min_cycle, min_scrub_cycle); } if (min_cycle) |