* [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK as a bitmask
@ 2026-02-23 19:13 Alison Schofield
2026-02-23 19:13 ` [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING " Alison Schofield
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Alison Schofield @ 2026-02-23 19:13 UTC (permalink / raw)
To: Davidlohr Bueso, Jonathan Cameron, Dave Jiang, Alison Schofield,
Vishal Verma, Ira Weiny, Dan Williams
Cc: linux-cxl
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_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.
Fixes: 2230c4bdc412 ("cxl: Add handling of locked CXL decoder")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
Changes in v2:
Split patches to align w Fixes Tags for backport ease
Rebased on 7.0-rc1
drivers/cxl/core/hdm.c | 2 +-
drivers/cxl/core/region.c | 2 +-
2 files changed, 2 insertions(+), 2 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 fec37af1dfbf..780ec947ecf2 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1100,7 +1100,7 @@ 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);
}
base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
--
2.37.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING as a bitmask
2026-02-23 19:13 [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK as a bitmask Alison Schofield
@ 2026-02-23 19:13 ` Alison Schofield
2026-02-23 21:27 ` Gregory Price
2026-02-23 23:06 ` Dave Jiang
2026-02-23 21:27 ` [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK " Gregory Price
2026-02-23 23:05 ` Dave Jiang
2 siblings, 2 replies; 6+ messages in thread
From: Alison Schofield @ 2026-02-23 19:13 UTC (permalink / raw)
To: Davidlohr Bueso, Jonathan Cameron, Dave Jiang, Alison Schofield,
Vishal Verma, Ira Weiny, Dan Williams
Cc: linux-cxl
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.
Replace test_bit() with a bitmask check.
Found with cxl-test.
Fixes: 208f432406b7 ("cxl: Disable HPA/SPA translation handlers for Normalized Addressing")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
Changes in v2:
Split patches to align w Fixes Tags for backport ease
Rebased on 7.0-rc1
drivers/cxl/core/region.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 780ec947ecf2..42874948b589 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1105,7 +1105,7 @@ static void cxl_region_setup_flags(struct cxl_region *cxlr,
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);
}
--
2.37.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK as a bitmask
2026-02-23 19:13 [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK as a bitmask Alison Schofield
2026-02-23 19:13 ` [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING " Alison Schofield
@ 2026-02-23 21:27 ` Gregory Price
2026-02-23 23:05 ` Dave Jiang
2 siblings, 0 replies; 6+ messages in thread
From: Gregory Price @ 2026-02-23 21:27 UTC (permalink / raw)
To: Alison Schofield
Cc: Davidlohr Bueso, Jonathan Cameron, Dave Jiang, Vishal Verma,
Ira Weiny, Dan Williams, linux-cxl
On Mon, Feb 23, 2026 at 11:13:39AM -0800, Alison Schofield wrote:
> 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_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.
>
> Fixes: 2230c4bdc412 ("cxl: Add handling of locked CXL decoder")
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> ---
Op, missed the v4 and responded to v1
Reviewed-by: Gregory Price <gourry@gourry.net>
Tested-by: Gregory Price <gourry@gourry.net>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING as a bitmask
2026-02-23 19:13 ` [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING " Alison Schofield
@ 2026-02-23 21:27 ` Gregory Price
2026-02-23 23:06 ` Dave Jiang
1 sibling, 0 replies; 6+ messages in thread
From: Gregory Price @ 2026-02-23 21:27 UTC (permalink / raw)
To: Alison Schofield
Cc: Davidlohr Bueso, Jonathan Cameron, Dave Jiang, Vishal Verma,
Ira Weiny, Dan Williams, linux-cxl
On Mon, Feb 23, 2026 at 11:13:40AM -0800, Alison Schofield wrote:
> 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.
>
> Replace test_bit() with a bitmask check.
>
> Found with cxl-test.
>
> Fixes: 208f432406b7 ("cxl: Disable HPA/SPA translation handlers for Normalized Addressing")
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Tested-by: Gregory Price <gourry@gourry.net>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK as a bitmask
2026-02-23 19:13 [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK as a bitmask Alison Schofield
2026-02-23 19:13 ` [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING " Alison Schofield
2026-02-23 21:27 ` [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK " Gregory Price
@ 2026-02-23 23:05 ` Dave Jiang
2 siblings, 0 replies; 6+ messages in thread
From: Dave Jiang @ 2026-02-23 23:05 UTC (permalink / raw)
To: Alison Schofield, Davidlohr Bueso, Jonathan Cameron, Vishal Verma,
Ira Weiny, Dan Williams
Cc: linux-cxl
On 2/23/26 12:13 PM, Alison Schofield wrote:
> 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_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.
>
> Fixes: 2230c4bdc412 ("cxl: Add handling of locked CXL decoder")
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Applied to cxl/fixes
8c0025ee29f03d74d34b77127192b9db8457564c
> ---
>
> Changes in v2:
> Split patches to align w Fixes Tags for backport ease
> Rebased on 7.0-rc1
>
> drivers/cxl/core/hdm.c | 2 +-
> drivers/cxl/core/region.c | 2 +-
> 2 files changed, 2 insertions(+), 2 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 fec37af1dfbf..780ec947ecf2 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1100,7 +1100,7 @@ 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);
> }
>
> base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING as a bitmask
2026-02-23 19:13 ` [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING " Alison Schofield
2026-02-23 21:27 ` Gregory Price
@ 2026-02-23 23:06 ` Dave Jiang
1 sibling, 0 replies; 6+ messages in thread
From: Dave Jiang @ 2026-02-23 23:06 UTC (permalink / raw)
To: Alison Schofield, Davidlohr Bueso, Jonathan Cameron, Vishal Verma,
Ira Weiny, Dan Williams
Cc: linux-cxl
On 2/23/26 12:13 PM, Alison Schofield wrote:
> 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.
>
> Replace test_bit() with a bitmask check.
>
> Found with cxl-test.
>
> Fixes: 208f432406b7 ("cxl: Disable HPA/SPA translation handlers for Normalized Addressing")
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Applied to cxl/fixes
ebd11be59f7421e4b1ea19eaa8102d17ade3d6c6
> ---
>
> Changes in v2:
> Split patches to align w Fixes Tags for backport ease
> Rebased on 7.0-rc1
>
> drivers/cxl/core/region.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 780ec947ecf2..42874948b589 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1105,7 +1105,7 @@ static void cxl_region_setup_flags(struct cxl_region *cxlr,
> 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);
> }
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-02-23 23:06 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2026-02-23 19:13 [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK as a bitmask Alison Schofield
2026-02-23 19:13 ` [PATCH v2 2/2] cxl/region: Test CXL_DECODER_F_NORMALIZED_ADDRESSING " Alison Schofield
2026-02-23 21:27 ` Gregory Price
2026-02-23 23:06 ` Dave Jiang
2026-02-23 21:27 ` [PATCH v2 1/2] cxl: Test CXL_DECODER_F_LOCK " Gregory Price
2026-02-23 23:05 ` Dave Jiang
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