From 9ff3eec958cf365857ae8a630237ece4f83bb337 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 3 Apr 2023 15:01:20 -0700 Subject: [PATCH] cxl/region: Move coherence tracking into cxl_region_attach() Each time the contents of a given HPA are potentially changed in a cache incoherent manner the CXL core sets CXL_REGION_F_INCOHERENT to invalidate CPU caches before the region is used. Successful invocation of attach_target() indicates that DPA has been newly assigned to a given HPA in the dynamic region creation flow. However, attach_target() is also reused in the autodiscovery flow where the region was activated by platform firmware. In that case there is no need to invalidate caches because that region is already in active use and nothing about the autodiscovery flow modifies the HPA-to-DPA relationship. In the autodiscovery case cxl_region_attach() exits early after determining the endpoint decoder is already correctly attached to the region. Fixes: a32320b71f08 ("cxl/region: Add region autodiscovery") Reviewed-by: Fan Ni Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/168002858817.50647.1217607907088920888.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- drivers/cxl/core/region.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 52bbf6268d5fb..b2fd67fcebfb5 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1674,6 +1674,7 @@ static int cxl_region_attach(struct cxl_region *cxlr, if (rc) goto err_decrement; p->state = CXL_CONFIG_ACTIVE; + set_bit(CXL_REGION_F_INCOHERENT, &cxlr->flags); } cxled->cxld.interleave_ways = p->interleave_ways; @@ -1775,8 +1776,6 @@ static int attach_target(struct cxl_region *cxlr, down_read(&cxl_dpa_rwsem); rc = cxl_region_attach(cxlr, cxled, pos); - if (rc == 0) - set_bit(CXL_REGION_F_INCOHERENT, &cxlr->flags); up_read(&cxl_dpa_rwsem); up_write(&cxl_region_rwsem); return rc; -- 2.30.2