cxl: Deprecate driver

The cxl driver is no longer actively maintained and we intend to remove it
in a future kernel release.

cxl has received minimal maintenance for several years, and is not
supported on the Power10 processor. We aren't aware of any users who are
likely to be using recent kernels.

Change its MAINTAINERS status to obsolete, update the sysfs ABI
documentation accordingly, add a warning message on device probe, change
the Kconfig options to label it as deprecated, and don't build it by
default.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20241210054055.144813-2-ajd@linux.ibm.com

diff --git a/Documentation/ABI/testing/sysfs-class-cxl b/Documentation/ABI/obsolete/sysfs-class-cxl
similarity index 99%
rename from Documentation/ABI/testing/sysfs-class-cxl
rename to Documentation/ABI/obsolete/sysfs-class-cxl
index cfc48a87706ba2fae0e7b2d1149354830fc0b74f..8cba1b626985ea41c234832bee14e1dd507dbbf9 100644 (file)
--- a/Documentation/ABI/testing/sysfs-class-cxl
+++ b/Documentation/ABI/obsolete/sysfs-class-cxl
@@ -1,3 +1,6 @@
+The cxl driver is no longer maintained, and will be removed from the kernel in
+the near future.
+
 Please note that attributes that are shared between devices are stored in
 the directory pointed to by the symlink device/.
 For example, the real path of the attribute /sys/class/cxl/afu0.0s/irqs_max is

diff --git a/MAINTAINERS b/MAINTAINERS
index 17daa9ee9384509c1ef3f2a3825a4594eab88741..1737a8ff4f2b15707a5710d8b7d245c68e8115bd 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6228,8 +6228,8 @@ CXL (IBM Coherent Accelerator Processor Interface CAPI) DRIVER
 M:     Frederic Barrat <fbarrat@linux.ibm.com>
 M:     Andrew Donnellan <ajd@linux.ibm.com>
 L:     linuxppc-dev@lists.ozlabs.org
-S:     Supported
-F:     Documentation/ABI/testing/sysfs-class-cxl
+S:     Obsolete
+F:     Documentation/ABI/obsolete/sysfs-class-cxl
 F:     Documentation/arch/powerpc/cxl.rst
 F:     arch/powerpc/platforms/powernv/pci-cxl.c
 F:     drivers/misc/cxl/

diff --git a/drivers/misc/cxl/Kconfig b/drivers/misc/cxl/Kconfig
index 5efc4151bf585cd53ee6fbc9bb6b55a97329456c..15307f5e4307feebf4c5af71b0fd3c63d0e5cac7 100644 (file)
--- a/drivers/misc/cxl/Kconfig
+++ b/drivers/misc/cxl/Kconfig
@@ -9,11 +9,13 @@ config CXL_BASE
        select PPC_64S_HASH_MMU
 
 config CXL
-       tristate "Support for IBM Coherent Accelerators (CXL)"
+       tristate "Support for IBM Coherent Accelerators (CXL) (DEPRECATED)"
        depends on PPC_POWERNV && PCI_MSI && EEH
        select CXL_BASE
-       default m
        help
+         The cxl driver is deprecated and will be removed in a future
+         kernel release.
+
          Select this option to enable driver support for IBM Coherent
          Accelerators (CXL).  CXL is otherwise known as Coherent Accelerator
          Processor Interface (CAPI).  CAPI allows accelerators in FPGAs to be

diff --git a/drivers/misc/cxl/of.c b/drivers/misc/cxl/of.c
index cf6bd8a43056e7d92ed9a4efed0fd0106b8c3c0c..e26ee85279faa3c6fc63f428af6b021f54e30fa7 100644 (file)
--- a/drivers/misc/cxl/of.c
+++ b/drivers/misc/cxl/of.c
@@ -295,6 +295,8 @@ int cxl_of_probe(struct platform_device *pdev)
        int ret;
        int slice = 0, slice_ok = 0;
 
+       dev_err_once(&pdev->dev, "DEPRECATION: cxl is deprecated and will be removed in a future kernel release\n");
+
        pr_devel("in %s\n", __func__);
 
        np = pdev->dev.of_node;

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 3d52f9b92d0de8f659980627d5a497ab858172a9..92bf7c5c7b35434cbdeb8ae6287a95feccf9b815 100644 (file)
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1726,6 +1726,8 @@ static int cxl_probe(struct pci_dev *dev, const struct pci_device_id *id)
        int slice;
        int rc;
 
+       dev_err_once(&dev->dev, "DEPRECATED: cxl is deprecated and will be removed in a future kernel release\n");
+
        if (cxl_pci_is_vphb_device(dev)) {
                dev_dbg(&dev->dev, "cxl_init_adapter: Ignoring cxl vphb device\n");
                return -ENODEV;