[PATCH] cxl: Add dummy function for cxl_memdev_attach_region for !CONFIG_CXL_REGION

[PATCH] cxl: Add dummy function for cxl_memdev_attach_region for !CONFIG_CXL_REGION

[Dave Jiang]

Add a dummy function that returns -EOPNOTSUPP for cxl_memdev_attach_region
when CONFIG_CXL_REGION is not enabled. This allow sbuilding when
cxl/core/region.o isn't built.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 9b1e70e8f9ec ("cxl/region: Introduce devm_cxl_probe_mem()")
https://lore.kernel.org/oe-kbuild-all/202606100401.GOjzpKHo-lkp@intel.com/
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---

Fix is against last patch of Dan's [1] series for Introduce
devm_cxl_probe_mem() and fix region deletion.

[1]: https://lore.kernel.org/linux-cxl/48834616-6e75-4936-89be-9224a6dedefa@intel.com/T/#t
---
 drivers/cxl/cxlmem.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index d3bdd00f94b3..ed419d0c59f2 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -115,7 +115,14 @@ struct cxl_attach_region {
 	struct range hpa_range;
 };
 
+#ifdef CONFIG_CXL_REGION
 int cxl_memdev_attach_region(struct cxl_memdev *cxlmd);
+#else
+static inline int cxl_memdev_attach_region(struct cxl_memdev *cxlmd)
+{
+	return -EOPNOTSUPP;
+}
+#endif
 
 struct cxl_memdev *devm_cxl_add_classdev(struct cxl_dev_state *cxlds);
 struct cxl_memdev *__devm_cxl_add_memdev(struct cxl_dev_state *cxlds,

base-commit: 9b1e70e8f9ec4b5c6ce7fa774a0023bb6894c686
-- 
2.54.0

Re: [PATCH] cxl: Add dummy function for cxl_memdev_attach_region for !CONFIG_CXL_REGION

[Alison Schofield]

On Tue, Jun 09, 2026 at 05:13:24PM -0700, Dave Jiang wrote:
> Add a dummy function that returns -EOPNOTSUPP for cxl_memdev_attach_region
> when CONFIG_CXL_REGION is not enabled. This allow sbuilding when
> cxl/core/region.o isn't built.

Thought above could be more explicit about what it allows building.
Something like: 'This allows building cxl/core/memdev.o when ....'

With or without a commit log update: 

Reviewed-by: Alison Schofield <alison.schofield@intel.com>

Re: [PATCH] cxl: Add dummy function for cxl_memdev_attach_region for !CONFIG_CXL_REGION

[Dan Williams (nvidia)]

Dave Jiang wrote:
> Add a dummy function that returns -EOPNOTSUPP for cxl_memdev_attach_region
> when CONFIG_CXL_REGION is not enabled. This allow sbuilding when
> cxl/core/region.o isn't built.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Fixes: 9b1e70e8f9ec ("cxl/region: Introduce devm_cxl_probe_mem()")
> https://lore.kernel.org/oe-kbuild-all/202606100401.GOjzpKHo-lkp@intel.com/
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
> 
> Fix is against last patch of Dan's [1] series for Introduce
> devm_cxl_probe_mem() and fix region deletion.
> 
> [1]: https://lore.kernel.org/linux-cxl/48834616-6e75-4936-89be-9224a6dedefa@intel.com/T/#t

Looks good:

Reviewed-by: Dan Williams <djbw@kernel.org>

Re: [PATCH] cxl: Add dummy function for cxl_memdev_attach_region for !CONFIG_CXL_REGION

[Dave Jiang]

On 6/9/26 5:13 PM, Dave Jiang wrote:
> Add a dummy function that returns -EOPNOTSUPP for cxl_memdev_attach_region
> when CONFIG_CXL_REGION is not enabled. This allow sbuilding when
> cxl/core/region.o isn't built.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Fixes: 9b1e70e8f9ec ("cxl/region: Introduce devm_cxl_probe_mem()")
> https://lore.kernel.org/oe-kbuild-all/202606100401.GOjzpKHo-lkp@intel.com/
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Applied to cxl/next
383f69656359

> ---
> 
> Fix is against last patch of Dan's [1] series for Introduce
> devm_cxl_probe_mem() and fix region deletion.
> 
> [1]: https://lore.kernel.org/linux-cxl/48834616-6e75-4936-89be-9224a6dedefa@intel.com/T/#t
> ---
>  drivers/cxl/cxlmem.h | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index d3bdd00f94b3..ed419d0c59f2 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -115,7 +115,14 @@ struct cxl_attach_region {
>  	struct range hpa_range;
>  };
>  
> +#ifdef CONFIG_CXL_REGION
>  int cxl_memdev_attach_region(struct cxl_memdev *cxlmd);
> +#else
> +static inline int cxl_memdev_attach_region(struct cxl_memdev *cxlmd)
> +{
> +	return -EOPNOTSUPP;
> +}
> +#endif
>  
>  struct cxl_memdev *devm_cxl_add_classdev(struct cxl_dev_state *cxlds);
>  struct cxl_memdev *__devm_cxl_add_memdev(struct cxl_dev_state *cxlds,
> 
> base-commit: 9b1e70e8f9ec4b5c6ce7fa774a0023bb6894c686