[PATCH] cxl: Test decoder flags as bitmasks

[Alison Schofield <alison.schofield@intel.com>]

The CXL decoder flags are defined as bitmasks, not bit indices.
Using test_bit() to check them interprets the mask value as a bit
index, which is the wrong test.

For CXL_DECODER_F_NORMALIZED_ADDRESSING the test reads beyond the
flags word, making the flag sometimes appear set and blocking creation
of CXL region debugfs attributes that support poison operations.

For CXL_DECODER_F_LOCK the test reads beyond the defined bits, causing
the test to always return false and allowing resets that should have
been blocked.

Replace test_bit() with a bitmask check.

Found with cxl-test.

Fixes: 208f432406b7 ("cxl: Disable HPA/SPA translation handlers for Normalized Addressing")
Fixes: 2230c4bdc412 ("cxl: Add handling of locked CXL decoder")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---

Obsoletes prior patch that only fixed up one test:
cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING as a bitmask
https://lore.kernel.org/linux-cxl/20260206013135.1012375-1-alison.schofield@intel.com/


 drivers/cxl/core/hdm.c    | 2 +-
 drivers/cxl/core/region.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index e3f0c39e6812..c222e98ae736 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -904,7 +904,7 @@ static void cxl_decoder_reset(struct cxl_decoder *cxld)
 	if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
 		return;
 
-	if (test_bit(CXL_DECODER_F_LOCK, &cxld->flags))
+	if (cxld->flags & CXL_DECODER_F_LOCK)
 		return;
 
 	if (port->commit_end == id)
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 08fa3deef70a..befa2a7b81c2 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1100,12 +1100,12 @@ static int cxl_rr_assign_decoder(struct cxl_port *port, struct cxl_region *cxlr,
 static void cxl_region_setup_flags(struct cxl_region *cxlr,
 				   struct cxl_decoder *cxld)
 {
-	if (test_bit(CXL_DECODER_F_LOCK, &cxld->flags)) {
+	if (cxld->flags & CXL_DECODER_F_LOCK) {
 		set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
 		clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
 	}
 
-	if (test_bit(CXL_DECODER_F_NORMALIZED_ADDRESSING, &cxld->flags))
+	if (cxld->flags & CXL_DECODER_F_NORMALIZED_ADDRESSING)
 		set_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags);
 }
 

base-commit: 9845cf73f7db6094c0d8419d6adb848028f4a921
-- 
2.37.3