[PATCH v7 0/7] cxl: Add CXL type2 accelerator support for cxl_test

[PATCH v7 0/7] cxl: Add CXL type2 accelerator support for cxl_test

[Dave Jiang]

v7
- Fixed sachiko raised issues

Based against v7.2-rc1 and sits on top of the the immutable branch [1]
for type 2.

See individual patches for changes from previous version.
Fixed up sashiko reported issues.

Series adds a 'type2_test' module parameter where it setup a mock type2
hierarchy with a mock type2 accelerator device directly under a root
port that has an auto region setup.

It also includes a CXL fix that was encountered when running tests with
the new code.

[
  {
    "memdevs":[
      {
        "memdev":"mem0",
        "ram_size":536870912,
        "ram_qos_class":42,
        "host":"cxl_type2_accel.0",
        "poison_injectable":false
      }
    ]
  },
  {
    "regions":[
      {
        "region":"region0",
        "resource":70300293136384,
        "size":536870912,
        "type":"ram",
        "interleave_ways":1,
        "interleave_granularity":4096,
        "decode_state":"commit"
      }
    ]
  }
]

    "root decoders":[
      {
        "decoder":"decoder0.0",
        "resource":70300293136384,
        "size":1073741824,
        "interleave_ways":1,
        "accelmem_capable":true,
        "qos_class":42,
        "nr_targets":1
      },

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git/log/?h=for-7.3/cxl-type2-support

Dave Jiang (7):
  cxl/test: Add test for module parameters
  cxl/test: Add type2 support for mock CFMWS0
  cxl/test: Refactor platform device enumerations
  cxl/test: Add hierarchy enumeration support for type2 device
  cxl/test: Propagate -ENOMEM on platform_device_alloc() failures
  cxl/test: Fixup hdm init for auto region to support type2
  cxl/test: Add cxl_test accelerator driver

 tools/testing/cxl/test/Kbuild      |   2 +
 tools/testing/cxl/test/accel.c     |  66 +++
 tools/testing/cxl/test/cxl.c       | 850 ++++++++++++++++++++++-------
 tools/testing/cxl/test/hmem_test.c |   3 +-
 tools/testing/cxl/test/mock.h      |   2 +
 5 files changed, 720 insertions(+), 203 deletions(-)
 create mode 100644 tools/testing/cxl/test/accel.c


base-commit: 96ddf1af34f5f9e29891a5bfb7a18dd0a5bab9d6
-- 
2.54.0

[PATCH v7 1/7] cxl/test: Add test for module parameters

[Dave Jiang]

Add a test for module paraters during module init to make sure that
only one is activated.

Suggested-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 tools/testing/cxl/test/cxl.c       | 20 ++++++++++++++++++++
 tools/testing/cxl/test/hmem_test.c |  3 ++-
 tools/testing/cxl/test/mock.h      |  2 ++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index ef92dd35e030..198a128181b9 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -1827,11 +1827,31 @@ static struct attribute *cxl_acpi_attrs[] = {
 };
 ATTRIBUTE_GROUPS(cxl_acpi);
 
+static bool __init have_multiple_modparms(void)
+{
+	int count = 0;
+
+	if (interleave_arithmetic)
+		count++;
+	if (extended_linear_cache)
+		count++;
+	if (fail_autoassemble)
+		count++;
+	if (hmem_test)
+		count++;
+
+	return count > 1;
+}
+
 static __init int cxl_test_init(void)
 {
 	int rc, i;
 	struct range mappable;
 
+	/* Enforce a single module param active at a time */
+	if (have_multiple_modparms())
+		return -EINVAL;
+
 	if (!IS_ALIGNED(mock_auto_region_size, PMD_SIZE)) {
 		pr_err_once("mock_auto_region_size %d must be PMD-aligned\n",
 			    mock_auto_region_size);
diff --git a/tools/testing/cxl/test/hmem_test.c b/tools/testing/cxl/test/hmem_test.c
index 3a1a089e1721..0fa00f7e16db 100644
--- a/tools/testing/cxl/test/hmem_test.c
+++ b/tools/testing/cxl/test/hmem_test.c
@@ -3,8 +3,9 @@
 #include <linux/moduleparam.h>
 #include <linux/workqueue.h>
 #include "../../../drivers/dax/bus.h"
+#include "mock.h"
 
-static bool hmem_test;
+bool hmem_test;
 
 static void hmem_test_work(struct work_struct *work)
 {
diff --git a/tools/testing/cxl/test/mock.h b/tools/testing/cxl/test/mock.h
index 4f57dc80ae7d..846d7c5d6eaa 100644
--- a/tools/testing/cxl/test/mock.h
+++ b/tools/testing/cxl/test/mock.h
@@ -5,6 +5,8 @@
 #include <linux/dax.h>
 #include <cxl.h>
 
+extern bool hmem_test;
+
 struct cxl_mock_ops {
 	struct list_head list;
 	bool (*is_mock_adev)(struct acpi_device *dev);
-- 
2.54.0

Re: [PATCH v7 1/7] cxl/test: Add test for module parameters

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Pre-existing Use-After-Free due to static `struct platform_device` inside a loadable module.
--

commit 6c236a64c339f0b27ff963a194f46fc253545d89
Author: Dave Jiang <dave.jiang@intel.com>

cxl/test: Add test for module parameters

Add a test for module paraters during module init to make sure that
only one is activated.

> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> index ef92dd35e030c..198a128181b93 100644
> --- a/tools/testing/cxl/test/cxl.c
> +++ b/tools/testing/cxl/test/cxl.c

[ ... ]

> diff --git a/tools/testing/cxl/test/hmem_test.c b/tools/testing/cxl/test/hmem_test.c
> index 3a1a089e1721b..0fa00f7e16db5 100644
> --- a/tools/testing/cxl/test/hmem_test.c
> +++ b/tools/testing/cxl/test/hmem_test.c
> @@ -3,8 +3,9 @@
>  #include <linux/moduleparam.h>
>  #include <linux/workqueue.h>
>  #include "../../../drivers/dax/bus.h"
> +#include "mock.h"
>  
> -static bool hmem_test;
> +bool hmem_test;

[Severity: High]
This is a pre-existing issue, but could this module encounter a use-after-free
on unload due to how platform_device is managed in this file?

Looking at hmem_test_exit() and the hmem_test_device definition:

static struct hmem_platform_device hmem_test_device = {
    ...
};

void hmem_test_exit(void)
{
    if (hmem_test)
        platform_device_unregister(&hmem_test_device.pdev);
}

If the dax_hmem driver has queued work on dax_hmem_wq (which holds a reference
to the device via get_device()), platform_device_unregister() doesn't appear
to synchronously wait for those references to drop or for the work to complete
because dax_hmem_platform_driver lacks a remove() callback to cancel the work.

Since hmem_test_device is statically allocated in the module's data section,
once the module memory is freed on unload, would the kernel access unmapped
memory when the delayed work executes, or when the final reference drops and
invokes the unmapped hmem_test_release() function?

>  
>  static void hmem_test_work(struct work_struct *work)
>  {

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260629221104.3891733-1-dave.jiang@intel.com?part=1

Re: [PATCH v7 1/7] cxl/test: Add test for module parameters

[Alison Schofield]

On Mon, Jun 29, 2026 at 03:10:58PM -0700, Dave Jiang wrote:
> Add a test for module paraters during module init to make sure that
> only one is activated.
> 
> Suggested-by: Alison Schofield <alison.schofield@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  tools/testing/cxl/test/cxl.c       | 20 ++++++++++++++++++++
>  tools/testing/cxl/test/hmem_test.c |  3 ++-
>  tools/testing/cxl/test/mock.h      |  2 ++
>  3 files changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> index ef92dd35e030..198a128181b9 100644
> --- a/tools/testing/cxl/test/cxl.c
> +++ b/tools/testing/cxl/test/cxl.c
> @@ -1827,11 +1827,31 @@ static struct attribute *cxl_acpi_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(cxl_acpi);
>  
> +static bool __init have_multiple_modparms(void)
> +{
> +	int count = 0;
> +
> +	if (interleave_arithmetic)
> +		count++;
> +	if (extended_linear_cache)
> +		count++;
> +	if (fail_autoassemble)
> +		count++;
> +	if (hmem_test)
> +		count++;
> +
> +	return count > 1;
> +}

fail_autoassemble is a modifier of hmem_test, not a standalone mode.
Needs to be dropped from above func for cxl-dax-hmem.sh to run.

Tested with this diff:
 --- a/tools/testing/cxl/test/cxl.c
  +++ b/tools/testing/cxl/test/cxl.c
  @@ -2081,8 +2081,6 @@ static bool __init have_multiple_modparms(void)
                count++;
        if (extended_linear_cache)
                count++;
  -     if (fail_autoassemble)
  -             count++;
        if (hmem_test)
                count++;
        if (type2_test)

Re: [PATCH v7 1/7] cxl/test: Add test for module parameters

[Dave Jiang]

On 6/30/26 10:21 AM, Alison Schofield wrote:
> On Mon, Jun 29, 2026 at 03:10:58PM -0700, Dave Jiang wrote:
>> Add a test for module paraters during module init to make sure that
>> only one is activated.
>>
>> Suggested-by: Alison Schofield <alison.schofield@intel.com>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>>  tools/testing/cxl/test/cxl.c       | 20 ++++++++++++++++++++
>>  tools/testing/cxl/test/hmem_test.c |  3 ++-
>>  tools/testing/cxl/test/mock.h      |  2 ++
>>  3 files changed, 24 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
>> index ef92dd35e030..198a128181b9 100644
>> --- a/tools/testing/cxl/test/cxl.c
>> +++ b/tools/testing/cxl/test/cxl.c
>> @@ -1827,11 +1827,31 @@ static struct attribute *cxl_acpi_attrs[] = {
>>  };
>>  ATTRIBUTE_GROUPS(cxl_acpi);
>>  
>> +static bool __init have_multiple_modparms(void)
>> +{
>> +	int count = 0;
>> +
>> +	if (interleave_arithmetic)
>> +		count++;
>> +	if (extended_linear_cache)
>> +		count++;
>> +	if (fail_autoassemble)
>> +		count++;
>> +	if (hmem_test)
>> +		count++;
>> +
>> +	return count > 1;
>> +}
> 
> fail_autoassemble is a modifier of hmem_test, not a standalone mode.
> Needs to be dropped from above func for cxl-dax-hmem.sh to run.
> 
> Tested with this diff:
>  --- a/tools/testing/cxl/test/cxl.c
>   +++ b/tools/testing/cxl/test/cxl.c
>   @@ -2081,8 +2081,6 @@ static bool __init have_multiple_modparms(void)
>                 count++;
>         if (extended_linear_cache)
>                 count++;
>   -     if (fail_autoassemble)
>   -             count++;
>         if (hmem_test)
>                 count++;
>         if (type2_test)
> 

ok will drop

[PATCH v7 2/7] cxl/test: Add type2 support for mock CFMWS0

[Dave Jiang]

Add a module parameter 'type2_test' for triggering type2 test support
in cxl_test. Setup the CFMWS0 configuration to be type2 when 'type2_test'
is set.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 tools/testing/cxl/test/cxl.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 198a128181b9..32964420e470 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -17,6 +17,7 @@
 static int interleave_arithmetic;
 static bool extended_linear_cache;
 static bool fail_autoassemble;
+static bool type2_test;
 
 #define FAKE_QTG_ID	42
 
@@ -384,6 +385,19 @@ static struct {
 	},
 };
 
+static struct acpi_cedt_cfmws type2_cfmws0 = {
+	.header = {
+		.type = ACPI_CEDT_TYPE_CFMWS,
+		.length = sizeof(mock_cedt.cfmws0),
+	},
+	.interleave_ways = 0,
+	.granularity = 4,
+	.restrictions = ACPI_CEDT_CFMWS_RESTRICT_DEVMEM |
+			ACPI_CEDT_CFMWS_RESTRICT_VOLATILE,
+	.qtg_id = FAKE_QTG_ID,
+	.window_size = SZ_256M * 4,
+};
+
 struct acpi_cedt_cfmws *mock_cfmws[] = {
 	[0] = &mock_cedt.cfmws0.cfmws,
 	[1] = &mock_cedt.cfmws1.cfmws,
@@ -476,6 +490,11 @@ static void cfmws_elc_update(struct acpi_cedt_cfmws *window, int index)
 	window->window_size = mock_auto_region_size * 2;
 }
 
+static void update_type2_cfmws(void)
+{
+	memcpy(&mock_cedt.cfmws0.cfmws, &type2_cfmws0, sizeof(type2_cfmws0));
+}
+
 static int populate_cedt(void)
 {
 	struct cxl_mock_res *res;
@@ -497,11 +516,15 @@ static int populate_cedt(void)
 		chbs->length = size;
 	}
 
+	if (type2_test)
+		update_type2_cfmws();
+
 	for (i = cfmws_start; i <= cfmws_end; i++) {
 		struct acpi_cedt_cfmws *window = mock_cfmws[i];
 		int align = SZ_256M;
 
-		cfmws_elc_update(window, i);
+		if (i == 0 && !type2_test)
+			cfmws_elc_update(window, i);
 		if (window->restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE)
 			align = max_t(int, SZ_256M, PMD_SIZE);
 		res = alloc_mock_res(window->window_size, align);
@@ -1839,6 +1862,8 @@ static bool __init have_multiple_modparms(void)
 		count++;
 	if (hmem_test)
 		count++;
+	if (type2_test)
+		count++;
 
 	return count > 1;
 }
@@ -2069,6 +2094,8 @@ module_param(extended_linear_cache, bool, 0444);
 MODULE_PARM_DESC(extended_linear_cache, "Enable extended linear cache support");
 module_param(fail_autoassemble, bool, 0444);
 MODULE_PARM_DESC(fail_autoassemble, "Simulate missing member of an auto-region");
+module_param(type2_test, bool, 0444);
+MODULE_PARM_DESC(type2_test, "Enable type 2 support testing");
 module_init(cxl_test_init);
 module_exit(cxl_test_exit);
 MODULE_LICENSE("GPL v2");
-- 
2.54.0

[PATCH v7 3/7] cxl/test: Refactor platform device enumerations

[Dave Jiang]

Split all the host bridges, rootports, upstream and downstream ports
enumerations to separate helper functions. This should make adding
type2 hierarchy easier later on.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 tools/testing/cxl/test/cxl.c | 312 ++++++++++++++++++++++++-----------
 1 file changed, 214 insertions(+), 98 deletions(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 32964420e470..8abe066080bc 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -1868,10 +1868,204 @@ static bool __init have_multiple_modparms(void)
 	return count > 1;
 }
 
+static void host_bridges_remove(void)
+{
+	int i;
+
+	for (i = ARRAY_SIZE(cxl_host_bridge) - 1; i >= 0; i--) {
+		struct platform_device *pdev = cxl_host_bridge[i];
+
+		if (!pdev)
+			continue;
+
+		sysfs_remove_link(&pdev->dev.kobj, "physical_node");
+		platform_device_unregister(cxl_host_bridge[i]);
+	}
+}
+
+static int host_bridges_populate(void)
+{
+	int rc = 0;
+
+	for (int i = 0; i < ARRAY_SIZE(cxl_host_bridge); i++) {
+		struct acpi_device *adev = &host_bridge[i];
+		struct platform_device *pdev;
+
+		pdev = platform_device_alloc("cxl_host_bridge", i);
+		if (!pdev) {
+			rc = -ENOMEM;
+			goto err_bridge;
+		}
+
+		mock_companion(adev, &pdev->dev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_host_bridge[i]);
+		if (rc)
+			goto err_bridge;
+
+		mock_pci_bus[i].bridge = &pdev->dev;
+		rc = sysfs_create_link(&pdev->dev.kobj, &pdev->dev.kobj,
+				       "physical_node");
+		if (rc)
+			goto err_bridge;
+	}
+
+	return 0;
+
+err_bridge:
+	host_bridges_remove();
+	return rc;
+}
+
+static void cxl_rootports_remove(void)
+{
+	for (int i = ARRAY_SIZE(cxl_root_port) - 1; i >= 0; i--) {
+		struct platform_device *pdev = cxl_root_port[i];
+
+		if (!pdev)
+			continue;
+
+		platform_device_unregister(pdev);
+	}
+}
+
+static int cxl_rootports_populate(void)
+{
+	int rc = 0;
+
+	for (int i = 0; i < ARRAY_SIZE(cxl_root_port); i++) {
+		struct platform_device *bridge =
+			cxl_host_bridge[i % ARRAY_SIZE(cxl_host_bridge)];
+		struct platform_device *pdev;
+
+		pdev = platform_device_alloc("cxl_root_port", i);
+		if (!pdev) {
+			rc = -ENOMEM;
+			goto err_port;
+		}
+
+		pdev->dev.parent = &bridge->dev;
+
+		rc = cxl_mock_platform_device_add(pdev, &cxl_root_port[i]);
+		if (rc)
+			goto err_port;
+	}
+
+	return 0;
+
+err_port:
+	cxl_rootports_remove();
+	return rc;
+}
+
+static void cxl_usps_remove(void)
+{
+	for (int i = ARRAY_SIZE(cxl_switch_uport) - 1; i >= 0; i--) {
+		struct platform_device *pdev = cxl_switch_uport[i];
+
+		if (!pdev)
+			continue;
+
+		platform_device_unregister(cxl_switch_uport[i]);
+	}
+}
+
+static int cxl_usps_populate(void)
+{
+	int rc = 0;
+
+	for (int i = 0; i < ARRAY_SIZE(cxl_switch_uport); i++) {
+		struct platform_device *root_port = cxl_root_port[i];
+		struct platform_device *pdev;
+
+		pdev = platform_device_alloc("cxl_switch_uport", i);
+		if (!pdev) {
+			rc = -ENOMEM;
+			goto err_uport;
+		}
+
+		pdev->dev.parent = &root_port->dev;
+
+		rc = cxl_mock_platform_device_add(pdev, &cxl_switch_uport[i]);
+		if (rc)
+			goto err_uport;
+	}
+
+	return 0;
+
+err_uport:
+	cxl_usps_remove();
+	return rc;
+}
+
+static void cxl_dsps_remove(void)
+{
+	for (int i = ARRAY_SIZE(cxl_switch_dport) - 1; i >= 0; i--) {
+		struct platform_device *pdev = cxl_switch_dport[i];
+
+		if (!pdev)
+			continue;
+
+		platform_device_unregister(cxl_switch_dport[i]);
+	}
+}
+
+
+static int cxl_dsps_populate(void)
+{
+	int rc = 0;
+
+	for (int i = 0; i < ARRAY_SIZE(cxl_switch_dport); i++) {
+		struct platform_device *uport =
+			cxl_switch_uport[i % ARRAY_SIZE(cxl_switch_uport)];
+		struct platform_device *pdev;
+
+		pdev = platform_device_alloc("cxl_switch_dport", i);
+		if (!pdev) {
+			rc = -ENOMEM;
+			goto err_dport;
+		}
+		pdev->dev.parent = &uport->dev;
+
+		rc = cxl_mock_platform_device_add(pdev, &cxl_switch_dport[i]);
+		if (rc)
+			goto err_dport;
+	}
+
+	return 0;
+
+err_dport:
+	cxl_dsps_remove();
+	return rc;
+}
+
+static void cxl_switches_remove(void)
+{
+	cxl_dsps_remove();
+	cxl_usps_remove();
+}
+
+static int cxl_switches_populate(void)
+{
+	int rc;
+
+	BUILD_BUG_ON(ARRAY_SIZE(cxl_switch_uport) != ARRAY_SIZE(cxl_root_port));
+	rc = cxl_usps_populate();
+	if (rc)
+		return rc;
+
+	rc = cxl_dsps_populate();
+	if (rc) {
+		cxl_usps_remove();
+		return rc;
+	}
+
+	return 0;
+}
+
 static __init int cxl_test_init(void)
 {
-	int rc, i;
 	struct range mappable;
+	int rc;
 
 	/* Enforce a single module param active at a time */
 	if (have_multiple_modparms())
@@ -1917,74 +2111,21 @@ static __init int cxl_test_init(void)
 	if (rc)
 		goto err_populate;
 
-	for (i = 0; i < ARRAY_SIZE(cxl_host_bridge); i++) {
-		struct acpi_device *adev = &host_bridge[i];
-		struct platform_device *pdev;
+	rc = host_bridges_populate();
+	if (rc)
+		goto err_populate;
 
-		pdev = platform_device_alloc("cxl_host_bridge", i);
-		if (!pdev)
-			goto err_bridge;
+	rc = cxl_rootports_populate();
+	if (rc)
+		goto err_host_bridges;
 
-		mock_companion(adev, &pdev->dev);
-		rc = cxl_mock_platform_device_add(pdev, &cxl_host_bridge[i]);
-		if (rc)
-			goto err_bridge;
-
-		mock_pci_bus[i].bridge = &pdev->dev;
-		rc = sysfs_create_link(&pdev->dev.kobj, &pdev->dev.kobj,
-				       "physical_node");
-		if (rc)
-			goto err_bridge;
-	}
-
-	for (i = 0; i < ARRAY_SIZE(cxl_root_port); i++) {
-		struct platform_device *bridge =
-			cxl_host_bridge[i % ARRAY_SIZE(cxl_host_bridge)];
-		struct platform_device *pdev;
-
-		pdev = platform_device_alloc("cxl_root_port", i);
-		if (!pdev)
-			goto err_port;
-		pdev->dev.parent = &bridge->dev;
-
-		rc = cxl_mock_platform_device_add(pdev, &cxl_root_port[i]);
-		if (rc)
-			goto err_port;
-	}
-
-	BUILD_BUG_ON(ARRAY_SIZE(cxl_switch_uport) != ARRAY_SIZE(cxl_root_port));
-	for (i = 0; i < ARRAY_SIZE(cxl_switch_uport); i++) {
-		struct platform_device *root_port = cxl_root_port[i];
-		struct platform_device *pdev;
-
-		pdev = platform_device_alloc("cxl_switch_uport", i);
-		if (!pdev)
-			goto err_uport;
-		pdev->dev.parent = &root_port->dev;
-
-		rc = cxl_mock_platform_device_add(pdev, &cxl_switch_uport[i]);
-		if (rc)
-			goto err_uport;
-	}
-
-	for (i = 0; i < ARRAY_SIZE(cxl_switch_dport); i++) {
-		struct platform_device *uport =
-			cxl_switch_uport[i % ARRAY_SIZE(cxl_switch_uport)];
-		struct platform_device *pdev;
-
-		pdev = platform_device_alloc("cxl_switch_dport", i);
-		if (!pdev)
-			goto err_dport;
-		pdev->dev.parent = &uport->dev;
-
-		rc = cxl_mock_platform_device_add(pdev, &cxl_switch_dport[i]);
-		if (rc)
-			goto err_dport;
-	}
+	rc = cxl_switches_populate();
+	if (rc)
+		goto err_root_ports;
 
 	rc = cxl_single_topo_init();
 	if (rc)
-		goto err_dport;
+		goto err_switches;
 
 	rc = cxl_rch_topo_init();
 	if (rc)
@@ -2020,24 +2161,12 @@ static __init int cxl_test_init(void)
 	cxl_rch_topo_exit();
 err_single:
 	cxl_single_topo_exit();
-err_dport:
-	for (i = ARRAY_SIZE(cxl_switch_dport) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_switch_dport[i]);
-err_uport:
-	for (i = ARRAY_SIZE(cxl_switch_uport) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_switch_uport[i]);
-err_port:
-	for (i = ARRAY_SIZE(cxl_root_port) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_root_port[i]);
-err_bridge:
-	for (i = ARRAY_SIZE(cxl_host_bridge) - 1; i >= 0; i--) {
-		struct platform_device *pdev = cxl_host_bridge[i];
-
-		if (!pdev)
-			continue;
-		sysfs_remove_link(&pdev->dev.kobj, "physical_node");
-		platform_device_unregister(cxl_host_bridge[i]);
-	}
+err_switches:
+	cxl_switches_remove();
+err_root_ports:
+	cxl_rootports_remove();
+err_host_bridges:
+	host_bridges_remove();
 err_populate:
 	depopulate_all_mock_resources();
 err_gen_pool_add:
@@ -2060,27 +2189,14 @@ static void free_decoder_registry(void)
 
 static __exit void cxl_test_exit(void)
 {
-	int i;
-
 	hmem_test_exit();
 	cxl_mem_exit();
 	platform_device_unregister(cxl_acpi);
 	cxl_rch_topo_exit();
 	cxl_single_topo_exit();
-	for (i = ARRAY_SIZE(cxl_switch_dport) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_switch_dport[i]);
-	for (i = ARRAY_SIZE(cxl_switch_uport) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_switch_uport[i]);
-	for (i = ARRAY_SIZE(cxl_root_port) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_root_port[i]);
-	for (i = ARRAY_SIZE(cxl_host_bridge) - 1; i >= 0; i--) {
-		struct platform_device *pdev = cxl_host_bridge[i];
-
-		if (!pdev)
-			continue;
-		sysfs_remove_link(&pdev->dev.kobj, "physical_node");
-		platform_device_unregister(cxl_host_bridge[i]);
-	}
+	cxl_switches_remove();
+	cxl_rootports_remove();
+	host_bridges_remove();
 	depopulate_all_mock_resources();
 	gen_pool_destroy(cxl_mock_pool);
 	unregister_cxl_mock_ops(&cxl_mock_ops);
-- 
2.54.0

[PATCH v7 4/7] cxl/test: Add hierarchy enumeration support for type2 device

[Dave Jiang]

Add enumeration of type2 device hierarchy in cxl-test. The type2 device
is setup to be directly attached to a root port instead of rp -> switch
-> device that type3 hierarchy is setup..

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v7:
- Replace platform_device_put() with platform_device_unregister(). (sashiko)
---
 tools/testing/cxl/test/cxl.c | 238 ++++++++++++++++++++++++++++-------
 1 file changed, 192 insertions(+), 46 deletions(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 8abe066080bc..801d42ac1bad 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -28,6 +28,7 @@ static bool type2_test;
 #define NR_CXL_SWITCH_PORTS 2
 #define NR_CXL_PORT_DECODERS 8
 #define NR_BRIDGES (NR_CXL_HOST_BRIDGES + NR_CXL_SINGLE_HOST + NR_CXL_RCH)
+#define NR_CXL_TYPE2_ACCEL 1
 
 #define MOCK_AUTO_REGION_SIZE_DEFAULT SZ_512M
 static int mock_auto_region_size = MOCK_AUTO_REGION_SIZE_DEFAULT;
@@ -1747,19 +1748,93 @@ static void cxl_single_topo_exit(void)
 	}
 }
 
+static void cxl_type3_mem_exit(void)
+{
+	struct platform_device *pdev;
+	int i;
+
+	for (i = ARRAY_SIZE(cxl_rcd) - 1; i >= 0; i--) {
+		pdev = cxl_rcd[i];
+		if (!pdev)
+			continue;
+		platform_device_unregister(cxl_rcd[i]);
+	}
+
+	for (i = ARRAY_SIZE(cxl_mem_single) - 1; i >= 0; i--) {
+		pdev = cxl_mem_single[i];
+		if (!pdev)
+			continue;
+		platform_device_unregister(cxl_mem_single[i]);
+	}
+
+	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--) {
+		pdev = cxl_mem[i];
+		if (!pdev)
+			continue;
+		platform_device_unregister(pdev);
+	}
+}
+
+static void cxl_type2_mem_exit(void)
+{
+	for (int i = NR_CXL_TYPE2_ACCEL - 1; i >= 0; i--) {
+		struct platform_device *pdev = cxl_mem[i];
+
+		if (!pdev)
+			continue;
+		platform_device_unregister(pdev);
+	}
+}
+
 static void cxl_mem_exit(void)
 {
-	int i;
-
-	for (i = ARRAY_SIZE(cxl_rcd) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_rcd[i]);
-	for (i = ARRAY_SIZE(cxl_mem_single) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_mem_single[i]);
-	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--)
-		platform_device_unregister(cxl_mem[i]);
+	if (type2_test) {
+		cxl_type2_mem_exit();
+		return;
+	}
+
+	cxl_type3_mem_exit();
+}
+
+static int cxl_type2_mem_init(void)
+{
+	int i, rc;
+
+	for (i = 0; i < NR_CXL_TYPE2_ACCEL; i++) {
+		struct platform_device *dport = cxl_root_port[i];
+		struct platform_device *pdev;
+
+		pdev = platform_device_alloc("cxl_type2_accel", i);
+		if (!pdev) {
+			rc = -ENOMEM;
+			goto err_mem;
+		}
+		pdev->dev.parent = &dport->dev;
+		set_dev_node(&pdev->dev, i % 2);
+
+		rc = platform_device_add(pdev);
+		if (rc) {
+			rc = -ENOMEM;
+			platform_device_put(pdev);
+			goto err_mem;
+		}
+		cxl_mem[i] = pdev;
+	}
+
+	return 0;
+
+err_mem:
+	for (i = NR_CXL_TYPE2_ACCEL - 1; i >= 0; i--) {
+		struct platform_device *pdev = cxl_mem[i];
+
+		if (!pdev)
+			continue;
+		platform_device_unregister(pdev);
+	}
+	return rc;
 }
 
-static int cxl_mem_init(void)
+static int cxl_type3_mem_init(void)
 {
 	int i, rc;
 
@@ -1768,8 +1843,10 @@ static int cxl_mem_init(void)
 		struct platform_device *pdev;
 
 		pdev = platform_device_alloc("cxl_mem", i);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_mem;
+		}
 		pdev->dev.parent = &dport->dev;
 		set_dev_node(&pdev->dev, i % 2);
 
@@ -1783,8 +1860,10 @@ static int cxl_mem_init(void)
 		struct platform_device *pdev;
 
 		pdev = platform_device_alloc("cxl_mem", NR_MEM_MULTI + i);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_single;
+		}
 		pdev->dev.parent = &dport->dev;
 		set_dev_node(&pdev->dev, i % 2);
 
@@ -1799,8 +1878,10 @@ static int cxl_mem_init(void)
 		struct platform_device *pdev;
 
 		pdev = platform_device_alloc("cxl_rcd", idx);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_rcd;
+		}
 		pdev->dev.parent = &rch->dev;
 		set_dev_node(&pdev->dev, i % 2);
 
@@ -1823,6 +1904,13 @@ static int cxl_mem_init(void)
 	return rc;
 }
 
+static int cxl_mem_init(void)
+{
+	if (type2_test)
+		return cxl_type2_mem_init();
+	return cxl_type3_mem_init();
+}
+
 static ssize_t
 decoder_reset_preserve_registry_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
@@ -2062,6 +2150,92 @@ static int cxl_switches_populate(void)
 	return 0;
 }
 
+static void cxl_type2_topo_exit(void)
+{
+	cxl_rootports_remove();
+	host_bridges_remove();
+}
+
+static int cxl_type2_topo_init(void)
+{
+	int rc;
+
+	rc = host_bridges_populate();
+	if (rc)
+		return rc;
+
+	rc = cxl_rootports_populate();
+	if (rc) {
+		host_bridges_remove();
+		return rc;
+	}
+
+	return 0;
+}
+
+static void cxl_type3_topo_exit(void)
+{
+	cxl_rch_topo_exit();
+	cxl_single_topo_exit();
+	cxl_switches_remove();
+	cxl_rootports_remove();
+	host_bridges_remove();
+}
+
+static int cxl_type3_topo_init(void)
+{
+	int rc;
+
+	rc = host_bridges_populate();
+	if (rc)
+		return rc;
+
+	rc = cxl_rootports_populate();
+	if (rc)
+		goto err_host_bridges;
+
+	rc = cxl_switches_populate();
+	if (rc)
+		goto err_root_ports;
+
+	rc = cxl_single_topo_init();
+	if (rc)
+		goto err_switches;
+
+	rc = cxl_rch_topo_init();
+	if (rc)
+		goto err_single;
+
+	return 0;
+
+err_single:
+	cxl_single_topo_exit();
+err_switches:
+	cxl_switches_remove();
+err_root_ports:
+	cxl_rootports_remove();
+err_host_bridges:
+	host_bridges_remove();
+	return rc;
+}
+
+static void cxl_topo_exit(void)
+{
+	if (type2_test) {
+		cxl_type2_topo_exit();
+		return;
+	}
+
+	cxl_type3_topo_exit();
+}
+
+static int cxl_topo_init(void)
+{
+	if (type2_test)
+		return cxl_type2_topo_init();
+	return cxl_type3_topo_init();
+}
+
 static __init int cxl_test_init(void)
 {
 	struct range mappable;
@@ -2111,29 +2285,13 @@ static __init int cxl_test_init(void)
 	if (rc)
 		goto err_populate;
 
-	rc = host_bridges_populate();
+	rc = cxl_topo_init();
 	if (rc)
 		goto err_populate;
 
-	rc = cxl_rootports_populate();
-	if (rc)
-		goto err_host_bridges;
-
-	rc = cxl_switches_populate();
-	if (rc)
-		goto err_root_ports;
-
-	rc = cxl_single_topo_init();
-	if (rc)
-		goto err_switches;
-
-	rc = cxl_rch_topo_init();
-	if (rc)
-		goto err_single;
-
 	cxl_acpi = platform_device_alloc("cxl_acpi", 0);
 	if (!cxl_acpi)
-		goto err_rch;
+		goto err_topo;
 
 	mock_companion(&acpi0017_mock, &cxl_acpi->dev);
 	acpi0017_mock.dev.bus = &platform_bus_type;
@@ -2141,7 +2299,7 @@ static __init int cxl_test_init(void)
 
 	rc = cxl_mock_platform_device_add(cxl_acpi, NULL);
 	if (rc)
-		goto err_rch;
+		goto err_topo;
 
 	rc = cxl_mem_init();
 	if (rc)
@@ -2157,16 +2315,8 @@ static __init int cxl_test_init(void)
 	cxl_mem_exit();
 err_root:
 	platform_device_unregister(cxl_acpi);
-err_rch:
-	cxl_rch_topo_exit();
-err_single:
-	cxl_single_topo_exit();
-err_switches:
-	cxl_switches_remove();
-err_root_ports:
-	cxl_rootports_remove();
-err_host_bridges:
-	host_bridges_remove();
+err_topo:
+	cxl_topo_exit();
 err_populate:
 	depopulate_all_mock_resources();
 err_gen_pool_add:
@@ -2192,11 +2342,7 @@ static __exit void cxl_test_exit(void)
 	hmem_test_exit();
 	cxl_mem_exit();
 	platform_device_unregister(cxl_acpi);
-	cxl_rch_topo_exit();
-	cxl_single_topo_exit();
-	cxl_switches_remove();
-	cxl_rootports_remove();
-	host_bridges_remove();
+	cxl_topo_exit();
 	depopulate_all_mock_resources();
 	gen_pool_destroy(cxl_mock_pool);
 	unregister_cxl_mock_ops(&cxl_mock_ops);
-- 
2.54.0

Re: [PATCH v7 4/7] cxl/test: Add hierarchy enumeration support for type2 device

[Li Ming]

On 6/30/2026 6:11 AM, Dave Jiang wrote:
> Add enumeration of type2 device hierarchy in cxl-test. The type2 device
> is setup to be directly attached to a root port instead of rp -> switch
> -> device that type3 hierarchy is setup..
>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
> v7:
> - Replace platform_device_put() with platform_device_unregister(). (sashiko)
> ---
>  tools/testing/cxl/test/cxl.c | 238 ++++++++++++++++++++++++++++-------
>  1 file changed, 192 insertions(+), 46 deletions(-)
>
> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> index 8abe066080bc..801d42ac1bad 100644
> --- a/tools/testing/cxl/test/cxl.c
> +++ b/tools/testing/cxl/test/cxl.c
> @@ -28,6 +28,7 @@ static bool type2_test;
>  #define NR_CXL_SWITCH_PORTS 2
>  #define NR_CXL_PORT_DECODERS 8
>  #define NR_BRIDGES (NR_CXL_HOST_BRIDGES + NR_CXL_SINGLE_HOST + NR_CXL_RCH)
> +#define NR_CXL_TYPE2_ACCEL 1
>  
>  #define MOCK_AUTO_REGION_SIZE_DEFAULT SZ_512M
>  static int mock_auto_region_size = MOCK_AUTO_REGION_SIZE_DEFAULT;
> @@ -1747,19 +1748,93 @@ static void cxl_single_topo_exit(void)
>  	}
>  }
>  
> +static void cxl_type3_mem_exit(void)
> +{
> +	struct platform_device *pdev;
> +	int i;
> +
> +	for (i = ARRAY_SIZE(cxl_rcd) - 1; i >= 0; i--) {
> +		pdev = cxl_rcd[i];
> +		if (!pdev)
> +			continue;
> +		platform_device_unregister(cxl_rcd[i]);
> +	}
> +
> +	for (i = ARRAY_SIZE(cxl_mem_single) - 1; i >= 0; i--) {
> +		pdev = cxl_mem_single[i];
> +		if (!pdev)
> +			continue;
> +		platform_device_unregister(cxl_mem_single[i]);
> +	}
> +
> +	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--) {
> +		pdev = cxl_mem[i];
> +		if (!pdev)
> +			continue;
> +		platform_device_unregister(pdev);
> +	}
> +}
> +
> +static void cxl_type2_mem_exit(void)
> +{
> +	for (int i = NR_CXL_TYPE2_ACCEL - 1; i >= 0; i--) {
> +		struct platform_device *pdev = cxl_mem[i];
> +
> +		if (!pdev)
> +			continue;
> +		platform_device_unregister(pdev);
> +	}
> +}
> +
>  static void cxl_mem_exit(void)
>  {
> -	int i;
> -
> -	for (i = ARRAY_SIZE(cxl_rcd) - 1; i >= 0; i--)
> -		platform_device_unregister(cxl_rcd[i]);
> -	for (i = ARRAY_SIZE(cxl_mem_single) - 1; i >= 0; i--)
> -		platform_device_unregister(cxl_mem_single[i]);
> -	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--)
> -		platform_device_unregister(cxl_mem[i]);
> +	if (type2_test) {
> +		cxl_type2_mem_exit();
> +		return;
> +	}
> +
> +	cxl_type3_mem_exit();
> +}
> +
> +static int cxl_type2_mem_init(void)
> +{
> +	int i, rc;
> +
> +	for (i = 0; i < NR_CXL_TYPE2_ACCEL; i++) {
> +		struct platform_device *dport = cxl_root_port[i];
> +		struct platform_device *pdev;
> +
> +		pdev = platform_device_alloc("cxl_type2_accel", i);
> +		if (!pdev) {
> +			rc = -ENOMEM;
> +			goto err_mem;
> +		}
> +		pdev->dev.parent = &dport->dev;
> +		set_dev_node(&pdev->dev, i % 2);
> +
> +		rc = platform_device_add(pdev);
> +		if (rc) {
> +			rc = -ENOMEM;
> +			platform_device_put(pdev);
> +			goto err_mem;
> +		}
> +		cxl_mem[i] = pdev;

Hi Dave,

Sorry for the delayed review.

I think that we should use cxl_mock_platform_device_add() helper here when adding the device, otherwise it may hit the issue resolved by the patch[1].

If we confirm that we need to use the helper here, I can send out a fixup patch for this, or you can make the change directly.


Ming

[1]: https://lore.kernel.org/all/20260520121457.234404-1-ming.li@zohomail.com/

Re: [PATCH v7 4/7] cxl/test: Add hierarchy enumeration support for type2 device

[Dave Jiang]

On 7/1/26 12:31 AM, Li Ming wrote:
> On 6/30/2026 6:11 AM, Dave Jiang wrote:
>> Add enumeration of type2 device hierarchy in cxl-test. The type2 device
>> is setup to be directly attached to a root port instead of rp -> switch
>> -> device that type3 hierarchy is setup..
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>> v7:
>> - Replace platform_device_put() with platform_device_unregister(). (sashiko)
>> ---
>>  tools/testing/cxl/test/cxl.c | 238 ++++++++++++++++++++++++++++-------
>>  1 file changed, 192 insertions(+), 46 deletions(-)
>>
>> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
>> index 8abe066080bc..801d42ac1bad 100644
>> --- a/tools/testing/cxl/test/cxl.c
>> +++ b/tools/testing/cxl/test/cxl.c
>> @@ -28,6 +28,7 @@ static bool type2_test;
>>  #define NR_CXL_SWITCH_PORTS 2
>>  #define NR_CXL_PORT_DECODERS 8
>>  #define NR_BRIDGES (NR_CXL_HOST_BRIDGES + NR_CXL_SINGLE_HOST + NR_CXL_RCH)
>> +#define NR_CXL_TYPE2_ACCEL 1
>>  
>>  #define MOCK_AUTO_REGION_SIZE_DEFAULT SZ_512M
>>  static int mock_auto_region_size = MOCK_AUTO_REGION_SIZE_DEFAULT;
>> @@ -1747,19 +1748,93 @@ static void cxl_single_topo_exit(void)
>>  	}
>>  }
>>  
>> +static void cxl_type3_mem_exit(void)
>> +{
>> +	struct platform_device *pdev;
>> +	int i;
>> +
>> +	for (i = ARRAY_SIZE(cxl_rcd) - 1; i >= 0; i--) {
>> +		pdev = cxl_rcd[i];
>> +		if (!pdev)
>> +			continue;
>> +		platform_device_unregister(cxl_rcd[i]);
>> +	}
>> +
>> +	for (i = ARRAY_SIZE(cxl_mem_single) - 1; i >= 0; i--) {
>> +		pdev = cxl_mem_single[i];
>> +		if (!pdev)
>> +			continue;
>> +		platform_device_unregister(cxl_mem_single[i]);
>> +	}
>> +
>> +	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--) {
>> +		pdev = cxl_mem[i];
>> +		if (!pdev)
>> +			continue;
>> +		platform_device_unregister(pdev);
>> +	}
>> +}
>> +
>> +static void cxl_type2_mem_exit(void)
>> +{
>> +	for (int i = NR_CXL_TYPE2_ACCEL - 1; i >= 0; i--) {
>> +		struct platform_device *pdev = cxl_mem[i];
>> +
>> +		if (!pdev)
>> +			continue;
>> +		platform_device_unregister(pdev);
>> +	}
>> +}
>> +
>>  static void cxl_mem_exit(void)
>>  {
>> -	int i;
>> -
>> -	for (i = ARRAY_SIZE(cxl_rcd) - 1; i >= 0; i--)
>> -		platform_device_unregister(cxl_rcd[i]);
>> -	for (i = ARRAY_SIZE(cxl_mem_single) - 1; i >= 0; i--)
>> -		platform_device_unregister(cxl_mem_single[i]);
>> -	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--)
>> -		platform_device_unregister(cxl_mem[i]);
>> +	if (type2_test) {
>> +		cxl_type2_mem_exit();
>> +		return;
>> +	}
>> +
>> +	cxl_type3_mem_exit();
>> +}
>> +
>> +static int cxl_type2_mem_init(void)
>> +{
>> +	int i, rc;
>> +
>> +	for (i = 0; i < NR_CXL_TYPE2_ACCEL; i++) {
>> +		struct platform_device *dport = cxl_root_port[i];
>> +		struct platform_device *pdev;
>> +
>> +		pdev = platform_device_alloc("cxl_type2_accel", i);
>> +		if (!pdev) {
>> +			rc = -ENOMEM;
>> +			goto err_mem;
>> +		}
>> +		pdev->dev.parent = &dport->dev;
>> +		set_dev_node(&pdev->dev, i % 2);
>> +
>> +		rc = platform_device_add(pdev);
>> +		if (rc) {
>> +			rc = -ENOMEM;
>> +			platform_device_put(pdev);
>> +			goto err_mem;
>> +		}
>> +		cxl_mem[i] = pdev;
> 
> Hi Dave,
> 
> Sorry for the delayed review.
> 
> I think that we should use cxl_mock_platform_device_add() helper here when adding the device, otherwise it may hit the issue resolved by the patch[1].
> 
> If we confirm that we need to use the helper here, I can send out a fixup patch for this, or you can make the change directly.

Please send a fixup patch. Thanks!

> 
> 
> Ming
> 
> [1]: https://lore.kernel.org/all/20260520121457.234404-1-ming.li@zohomail.com/
> 
> 

[PATCH v7 5/7] cxl/test: Propagate -ENOMEM on platform_device_alloc() failures

[Dave Jiang]

Set rc = -ENOMEM at every platform_device_alloc() failure site in
cxl_rch_topo_init(), cxl_single_topo_init() and cxl_test_init() so the
failure is propagated and the module load aborts cleanly.

The cxl_acpi allocation site originates in the commit below, while the
host-bridge/root-port/uport/dport allocation sites fixed here were added
later in the single-host and RCH topology configs.

Fixes: 67dcdd4d3b83 ("tools/testing/cxl: Introduce a mocked-up CXL port hierarchy")
Fixes: e41c8452b9b2 ("tools/testing/cxl: Add a single-port host-bridge regression config")
Fixes: c9435dbee119 ("tools/testing/cxl: Add an RCH topology")
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 tools/testing/cxl/test/cxl.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 801d42ac1bad..7aafdc03230d 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -1587,8 +1587,10 @@ static __init int cxl_rch_topo_init(void)
 		struct platform_device *pdev;
 
 		pdev = platform_device_alloc("cxl_host_bridge", idx);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_bridge;
+		}
 
 		mock_companion(adev, &pdev->dev);
 		rc = cxl_mock_platform_device_add(pdev, &cxl_rch[i]);
@@ -1642,8 +1644,10 @@ static __init int cxl_single_topo_init(void)
 
 		pdev = platform_device_alloc("cxl_host_bridge",
 					     NR_CXL_HOST_BRIDGES + i);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_bridge;
+		}
 
 		mock_companion(adev, &pdev->dev);
 		rc = cxl_mock_platform_device_add(pdev, &cxl_hb_single[i]);
@@ -1664,8 +1668,10 @@ static __init int cxl_single_topo_init(void)
 
 		pdev = platform_device_alloc("cxl_root_port",
 					     NR_MULTI_ROOT + i);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_port;
+		}
 		pdev->dev.parent = &bridge->dev;
 
 		rc = cxl_mock_platform_device_add(pdev, &cxl_root_single[i]);
@@ -1679,8 +1685,10 @@ static __init int cxl_single_topo_init(void)
 
 		pdev = platform_device_alloc("cxl_switch_uport",
 					     NR_MULTI_ROOT + i);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_uport;
+		}
 		pdev->dev.parent = &root_port->dev;
 
 		rc = cxl_mock_platform_device_add(pdev, &cxl_swu_single[i]);
@@ -1695,8 +1703,10 @@ static __init int cxl_single_topo_init(void)
 
 		pdev = platform_device_alloc("cxl_switch_dport",
 					     i + NR_MEM_MULTI);
-		if (!pdev)
+		if (!pdev) {
+			rc = -ENOMEM;
 			goto err_dport;
+		}
 		pdev->dev.parent = &uport->dev;
 
 		rc = cxl_mock_platform_device_add(pdev, &cxl_swd_single[i]);
@@ -2290,8 +2300,10 @@ static __init int cxl_test_init(void)
 		goto err_populate;
 
 	cxl_acpi = platform_device_alloc("cxl_acpi", 0);
-	if (!cxl_acpi)
+	if (!cxl_acpi) {
+		rc = -ENOMEM;
 		goto err_topo;
+	}
 
 	mock_companion(&acpi0017_mock, &cxl_acpi->dev);
 	acpi0017_mock.dev.bus = &platform_bus_type;
-- 
2.54.0

[PATCH v7 6/7] cxl/test: Fixup hdm init for auto region to support type2

[Dave Jiang]

Add support to setup initialization of decoders in order to support
type2 auto region.

Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v7:
- Drop unused pdev param for mock_init_hdm_type2_cxled(). (sashiko)
- Use cxl_port_update_decoder_targets() instead. (sashiko)
---
 tools/testing/cxl/test/cxl.c | 263 ++++++++++++++++++++++++++---------
 1 file changed, 194 insertions(+), 69 deletions(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 7aafdc03230d..a91ac72c6843 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -1084,74 +1084,26 @@ static int first_decoder(struct device *dev, const void *data)
 	return 0;
 }
 
-/*
- * Initialize a decoder during HDM enumeration.
- *
- * If a saved registry entry exists:
- *   - enabled decoders are restored from the saved programming
- *   - disabled decoders are initialized in a clean disabled state
- *
- * If no registry entry exists the decoder follows the normal mock
- * initialization path, including the special auto-region setup for
- * the first endpoints under host-bridge0.
- *
- * Returns true if decoder state was restored from the registry. In
- * that case the saved decode configuration (including target mapping)
- * has already been applied and the map_targets() is skipped.
- */
-static bool mock_init_hdm_decoder(struct cxl_decoder *cxld)
+enum cxld_init_type {
+	MOCK_DECODER_INIT_DEFAULT,
+	MOCK_DECODER_INIT_SAVED,
+	MOCK_DECODER_INIT_TYPE3_AUTO,
+	MOCK_DECODER_INIT_TYPE2_AUTO,
+};
+
+static enum cxld_init_type get_decoder_init_type(struct cxl_decoder *cxld,
+						 struct platform_device *pdev,
+						 bool hb0,
+						 struct cxl_test_decoder **td)
 {
-	struct acpi_cedt_cfmws *window = mock_cfmws[0];
-	struct platform_device *pdev = NULL;
-	struct cxl_endpoint_decoder *cxled;
-	struct cxl_switch_decoder *cxlsd;
-	struct cxl_port *port, *iter;
-	struct cxl_test_decoder *td;
-	struct cxl_memdev *cxlmd;
-	struct cxl_dport *dport;
-	struct device *dev;
-	bool hb0 = false;
-	u64 base;
-	int i;
+	struct cxl_test_decoder *found_td = cxld_registry_find(cxld);
 
-	if (is_endpoint_decoder(&cxld->dev)) {
-		cxled = to_cxl_endpoint_decoder(&cxld->dev);
-		cxlmd = cxled_to_memdev(cxled);
-		WARN_ON(!dev_is_platform(cxlmd->dev.parent));
-		pdev = to_platform_device(cxlmd->dev.parent);
-
-		/* check is endpoint is attach to host-bridge0 */
-		port = cxled_to_port(cxled);
-		do {
-			if (port->uport_dev == &cxl_host_bridge[0]->dev) {
-				hb0 = true;
-				break;
-			}
-			if (is_cxl_port(port->dev.parent))
-				port = to_cxl_port(port->dev.parent);
-			else
-				port = NULL;
-		} while (port);
-		port = cxled_to_port(cxled);
-	} else {
-		port = to_cxl_port(cxld->dev.parent);
+	if (found_td) {
+		*td = found_td;
+		return MOCK_DECODER_INIT_SAVED;
 	}
 
-	td = cxld_registry_find(cxld);
-	if (td) {
-		bool enabled;
-
-		if (is_switch_decoder(&cxld->dev))
-			enabled = td->cxlsd.cxld.flags & CXL_DECODER_F_ENABLE;
-		else
-			enabled = td->cxled.cxld.flags & CXL_DECODER_F_ENABLE;
-
-		if (enabled)
-			return !cxld_registry_restore(cxld, td);
-
-		init_disabled_mock_decoder(cxld);
-		return false;
-	}
+	*td = NULL;
 
 	/*
 	 * The first decoder on the first 2 devices on the first switch
@@ -1162,15 +1114,119 @@ static bool mock_init_hdm_decoder(struct cxl_decoder *cxld)
 	 * See 'cxl list -BMPu -m cxl_mem.0,cxl_mem.4'
 	 */
 	if (!is_endpoint_decoder(&cxld->dev) || !hb0 || pdev->id % 4 ||
-	    pdev->id > 4 || cxld->id > 0) {
-		default_mock_decoder(cxld);
-		return false;
-	}
+	    pdev->id > 4 || cxld->id > 0)
+		return MOCK_DECODER_INIT_DEFAULT;
+
+	return type2_test ? MOCK_DECODER_INIT_TYPE2_AUTO :
+			    MOCK_DECODER_INIT_TYPE3_AUTO;
+}
+
+static bool mock_decoder_handle_saved(struct cxl_decoder *cxld, struct cxl_test_decoder *td)
+{
+	bool enabled;
+
+	if (is_switch_decoder(&cxld->dev))
+		enabled = td->cxlsd.cxld.flags & CXL_DECODER_F_ENABLE;
+	else
+		enabled = td->cxled.cxld.flags & CXL_DECODER_F_ENABLE;
+
+	if (enabled)
+		return !cxld_registry_restore(cxld, td);
+
+	init_disabled_mock_decoder(cxld);
+	return false;
+}
+
+static void mock_init_hdm_type2_cxled(struct cxl_endpoint_decoder *cxled,
+				      struct cxl_port *port)
+{
+	struct acpi_cedt_cfmws *window = mock_cfmws[0];
+	struct cxl_decoder *cxld = &cxled->cxld;
+	struct cxl_switch_decoder *cxlsd;
+	struct cxl_dport *dport;
+	struct cxl_port *root_port;
+	struct device *dev;
+	u64 base;
+
+	base = window->base_hpa;
+	cxld->hpa_range = (struct range) {
+		.start = base,
+		.end = base + mock_auto_region_size - 1,
+	};
+
+	cxld->interleave_ways = 1;
+	eig_to_granularity(window->granularity, &cxld->interleave_granularity);
+	cxld->target_type = CXL_DECODER_DEVMEM;
+	cxld->flags = CXL_DECODER_F_ENABLE;
+	cxled->state = CXL_DECODER_STATE_AUTO;
+	port->commit_end = cxld->id;
+	devm_cxl_dpa_reserve(cxled, 0,
+			     mock_auto_region_size / cxld->interleave_ways, 0);
+	cxld->commit = mock_decoder_commit;
+	cxld->reset = mock_decoder_reset;
+
+	WARN_ON_ONCE(!cxld_registry_new(cxld));
+	/*
+	 * Now that endpoint decoder is set up, walk up the hierarchy
+	 * and setup the root port decoder targeting @cxlmd.
+	 */
+	dport = port->parent_dport;
+	root_port = dport->port;
+	dev = device_find_child(&root_port->dev, NULL, first_decoder);
+	/*
+	 * Ancestor ports are guaranteed to be enumerated before
+	 * @port, and all ports have at least one decoder.
+	 */
+	if (WARN_ON(!dev))
+		return;
+
+	cxlsd = to_cxl_switch_decoder(dev);
+	cxld = &cxlsd->cxld;
+	cxld->target_type = CXL_DECODER_DEVMEM;
+	cxld->flags = CXL_DECODER_F_ENABLE;
+	root_port->commit_end = 0;
+	cxld->interleave_ways = 1;
+	cxld->interleave_granularity = 4096;
+	cxld->target_map[0] = dport->port_id;
+	cxld->hpa_range = (struct range) {
+		.start = base,
+		.end = base + mock_auto_region_size - 1,
+	};
+	cxld->commit = mock_decoder_commit;
+	cxld->reset = mock_decoder_reset;
+
+	/*
+	 * Only target_map[] is programmed above, mimicking
+	 * firmware. On real hardware target[] is populated as
+	 * dports enumerate, via update_decoder_targets(). The
+	 * mock's dports are already bound by now, so fire that
+	 * resolution explicitly here rather than stamping
+	 * target[] directly.
+	 */
+	cxl_port_update_decoder_targets(root_port, dport);
+
+	cxld_registry_update(cxld);
+	put_device(dev);
+}
+
+static void mock_init_hdm_type3_cxled(struct cxl_endpoint_decoder *cxled,
+				      struct cxl_port *port,
+				      struct platform_device *pdev,
+				      bool hb0)
+{
+	struct acpi_cedt_cfmws *window = mock_cfmws[0];
+	struct cxl_decoder *cxld = &cxled->cxld;
+	struct cxl_switch_decoder *cxlsd;
+	struct cxl_dport *dport;
+	struct cxl_port *iter;
+	struct device *dev;
+	u64 base;
+	int i;
 
 	/* Simulate missing cxl_mem.4 configuration */
 	if (hb0 && pdev->id == 4 && cxld->id == 0 && fail_autoassemble) {
 		default_mock_decoder(cxld);
-		return false;
+		return;
 	}
 
 	base = window->base_hpa;
@@ -1252,7 +1308,76 @@ static bool mock_init_hdm_decoder(struct cxl_decoder *cxld)
 		cxld_registry_update(cxld);
 		put_device(dev);
 	}
+}
 
+/*
+ * Initialize a decoder during HDM enumeration.
+ *
+ * If a saved registry entry exists:
+ *   - enabled decoders are restored from the saved programming
+ *   - disabled decoders are initialized in a clean disabled state
+ *
+ * If no registry entry exists the decoder follows the normal mock
+ * initialization path, including the special auto-region setup for
+ * the first endpoints under host-bridge0.
+ *
+ * Returns true if decoder state was restored from the registry. In
+ * that case the saved decode configuration (including target mapping)
+ * has already been applied and the map_targets() is skipped.
+ */
+static bool mock_init_hdm_decoder(struct cxl_decoder *cxld)
+{
+	struct cxl_endpoint_decoder *cxled = NULL;
+	struct platform_device *pdev = NULL;
+	struct cxl_test_decoder *td;
+	struct cxl_memdev *cxlmd;
+	struct cxl_port *port;
+	bool hb0 = false;
+
+	if (is_endpoint_decoder(&cxld->dev)) {
+		cxled = to_cxl_endpoint_decoder(&cxld->dev);
+		cxlmd = cxled_to_memdev(cxled);
+		WARN_ON(!dev_is_platform(cxlmd->dev.parent));
+		pdev = to_platform_device(cxlmd->dev.parent);
+
+		/* check is endpoint is attach to host-bridge0 */
+		port = cxled_to_port(cxled);
+		do {
+			if (port->uport_dev == &cxl_host_bridge[0]->dev) {
+				hb0 = true;
+				break;
+			}
+			if (is_cxl_port(port->dev.parent))
+				port = to_cxl_port(port->dev.parent);
+			else
+				port = NULL;
+		} while (port);
+		port = cxled_to_port(cxled);
+	} else {
+		port = to_cxl_port(cxld->dev.parent);
+	}
+
+	switch (get_decoder_init_type(cxld, pdev, hb0, &td)) {
+	case MOCK_DECODER_INIT_SAVED:
+		if (WARN_ON(!td))
+			return false;
+		return mock_decoder_handle_saved(cxld, td);
+	case MOCK_DECODER_INIT_DEFAULT:
+		/*
+		 * The default path picks up all the decoders that are not
+		 * endpoint.
+		 */
+		default_mock_decoder(cxld);
+		return false;
+	case MOCK_DECODER_INIT_TYPE3_AUTO:
+		mock_init_hdm_type3_cxled(cxled, port, pdev, hb0);
+		return false;
+	case MOCK_DECODER_INIT_TYPE2_AUTO:
+		mock_init_hdm_type2_cxled(cxled, port);
+		return false;
+	default:
+		return false;
+	}
 	return false;
 }
 
-- 
2.54.0

[PATCH v7 7/7] cxl/test: Add cxl_test accelerator driver

[Dave Jiang]

Add a type2 accelerator mock driver for the platform device that
simulates a CXL type2 device. The driver exercises the same
minimal API calls that a real CXL type2 driver would utilize.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v6:
- drop extra init member in platform_device_id init. (Uwe)
---
 tools/testing/cxl/test/Kbuild  |  2 ++
 tools/testing/cxl/test/accel.c | 66 ++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 tools/testing/cxl/test/accel.c

diff --git a/tools/testing/cxl/test/Kbuild b/tools/testing/cxl/test/Kbuild
index c168e3c998a7..9a24ddc28488 100644
--- a/tools/testing/cxl/test/Kbuild
+++ b/tools/testing/cxl/test/Kbuild
@@ -5,10 +5,12 @@ obj-m += cxl_test.o
 obj-m += cxl_mock.o
 obj-m += cxl_mock_mem.o
 obj-m += cxl_translate.o
+obj-m += cxl_mock_accel.o
 
 cxl_test-y := cxl.o
 cxl_test-y += hmem_test.o
 cxl_mock-y := mock.o
 cxl_mock_mem-y := mem.o
+cxl_mock_accel-y := accel.o
 
 KBUILD_CFLAGS := $(filter-out -Wmissing-prototypes -Wmissing-declarations, $(KBUILD_CFLAGS))
diff --git a/tools/testing/cxl/test/accel.c b/tools/testing/cxl/test/accel.c
new file mode 100644
index 000000000000..8e6f4687ca02
--- /dev/null
+++ b/tools/testing/cxl/test/accel.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright(c) 2026 Intel Corporation. All rights reserved.
+
+#include <linux/platform_device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/sizes.h>
+#include <cxl/mailbox.h>
+#include <cxlmem.h>
+
+struct mock_cxl_accel {
+	struct cxl_dev_state cxlds;
+	struct cxl_memdev *cxlmd;
+};
+
+static int cxl_mock_accel_probe(struct platform_device *pdev)
+{
+	struct mock_cxl_accel *cxl_accel;
+	struct device *dev = &pdev->dev;
+	struct cxl_dev_state *cxlds;
+	struct cxl_memdev *cxlmd;
+	struct range mock_range;
+	int rc;
+
+	cxl_accel = devm_cxl_dev_state_create(&pdev->dev, CXL_DEVTYPE_DEVMEM,
+					      pdev->id + 1, 0,
+					      struct mock_cxl_accel, cxlds,
+					      false);
+	if (!cxl_accel)
+		return -ENOMEM;
+
+	cxlds = &cxl_accel->cxlds;
+	cxlds->media_ready = true;
+	rc = cxl_set_capacity(cxlds, SZ_512M);
+	if (rc)
+		return rc;
+
+	cxlmd = devm_cxl_probe_mem(cxlds, &mock_range);
+	if (IS_ERR(cxlmd))
+		return PTR_ERR(cxlmd);
+	cxl_accel->cxlmd = cxlmd;
+
+	dev_dbg(dev, "Probed mock accelerator with range %pra\n", &mock_range);
+
+	return 0;
+}
+
+static const struct platform_device_id cxl_mock_accel_ids[] = {
+	{ .name = "cxl_type2_accel" },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, cxl_mock_accel_ids);
+
+static struct platform_driver cxl_mock_accel_driver = {
+	.probe = cxl_mock_accel_probe,
+	.id_table = cxl_mock_accel_ids,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+
+module_platform_driver(cxl_mock_accel_driver);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("cxl_test: accelerator device mock module");
+MODULE_IMPORT_NS("CXL");
-- 
2.54.0

Re: [PATCH v7 7/7] cxl/test: Add cxl_test accelerator driver

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The function `cxl_set_capacity` is called but is neither declared nor defined anywhere in the kernel source.
--

commit e5897ac16ebf5251d0c169fc17ca2e8cde0dd51b
Author: Dave Jiang <dave.jiang@intel.com>

cxl/test: Add cxl_test accelerator driver

Add a type2 accelerator mock driver for the platform device that simulates
a CXL type2 device. The driver exercises the same minimal API calls that
a real CXL type2 driver would utilize.

> diff --git a/tools/testing/cxl/test/accel.c b/tools/testing/cxl/test/accel.c
> new file mode 100644
> index 0000000000000..8e6f4687ca02a
> --- /dev/null
> +++ b/tools/testing/cxl/test/accel.c
> @@ -0,0 +1,66 @@

[ ... ]

> +static int cxl_mock_accel_probe(struct platform_device *pdev)
> +{
> +	struct mock_cxl_accel *cxl_accel;
> +	struct device *dev = &pdev->dev;
> +	struct cxl_dev_state *cxlds;
> +	struct cxl_memdev *cxlmd;
> +	struct range mock_range;
> +	int rc;
> +
> +	cxl_accel = devm_cxl_dev_state_create(&pdev->dev, CXL_DEVTYPE_DEVMEM,
> +					      pdev->id + 1, 0,
> +					      struct mock_cxl_accel, cxlds,
> +					      false);
> +	if (!cxl_accel)
> +		return -ENOMEM;
> +
> +	cxlds = &cxl_accel->cxlds;
> +	cxlds->media_ready = true;
> +	rc = cxl_set_capacity(cxlds, SZ_512M);

[Severity: Low]
Is cxl_set_capacity() defined in a different patch in this series?

It appears this function is neither declared nor defined in the tree. Calling
an undeclared function here causes an implicit declaration error and a linker
failure, breaking the build when compiling the CXL mock test module.

> +	if (rc)
> +		return rc;
> +
> +	cxlmd = devm_cxl_probe_mem(cxlds, &mock_range);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260629221104.3891733-1-dave.jiang@intel.com?part=7

Re: [PATCH v7 0/7] cxl: Add CXL type2 accelerator support for cxl_test

[Alison Schofield]

On Mon, Jun 29, 2026 at 03:10:57PM -0700, Dave Jiang wrote:


> Dave Jiang (7):
>   cxl/test: Add test for module parameters

With the fixup asked for in Patch 1, for the series you can add:

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


>   cxl/test: Add type2 support for mock CFMWS0
>   cxl/test: Refactor platform device enumerations
>   cxl/test: Add hierarchy enumeration support for type2 device
>   cxl/test: Propagate -ENOMEM on platform_device_alloc() failures
>   cxl/test: Fixup hdm init for auto region to support type2
>   cxl/test: Add cxl_test accelerator driver
> 
>  tools/testing/cxl/test/Kbuild      |   2 +
>  tools/testing/cxl/test/accel.c     |  66 +++
>  tools/testing/cxl/test/cxl.c       | 850 ++++++++++++++++++++++-------
>  tools/testing/cxl/test/hmem_test.c |   3 +-
>  tools/testing/cxl/test/mock.h      |   2 +
>  5 files changed, 720 insertions(+), 203 deletions(-)
>  create mode 100644 tools/testing/cxl/test/accel.c
> 
> 
> base-commit: 96ddf1af34f5f9e29891a5bfb7a18dd0a5bab9d6
> -- 
> 2.54.0
> 

Re: [PATCH v7 0/7] cxl: Add CXL type2 accelerator support for cxl_test

[Dave Jiang]

On 6/29/26 3:10 PM, Dave Jiang wrote:
> v7
> - Fixed sachiko raised issues
> 
> Based against v7.2-rc1 and sits on top of the the immutable branch [1]
> for type 2.
> 
> See individual patches for changes from previous version.
> Fixed up sashiko reported issues.
> 
> Series adds a 'type2_test' module parameter where it setup a mock type2
> hierarchy with a mock type2 accelerator device directly under a root
> port that has an auto region setup.
> 
> It also includes a CXL fix that was encountered when running tests with
> the new code.
> 
> [
>   {
>     "memdevs":[
>       {
>         "memdev":"mem0",
>         "ram_size":536870912,
>         "ram_qos_class":42,
>         "host":"cxl_type2_accel.0",
>         "poison_injectable":false
>       }
>     ]
>   },
>   {
>     "regions":[
>       {
>         "region":"region0",
>         "resource":70300293136384,
>         "size":536870912,
>         "type":"ram",
>         "interleave_ways":1,
>         "interleave_granularity":4096,
>         "decode_state":"commit"
>       }
>     ]
>   }
> ]
> 
>     "root decoders":[
>       {
>         "decoder":"decoder0.0",
>         "resource":70300293136384,
>         "size":1073741824,
>         "interleave_ways":1,
>         "accelmem_capable":true,
>         "qos_class":42,
>         "nr_targets":1
>       },
> 
> [1]: https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git/log/?h=for-7.3/cxl-type2-support
> 
> Dave Jiang (7):
>   cxl/test: Add test for module parameters
>   cxl/test: Add type2 support for mock CFMWS0
>   cxl/test: Refactor platform device enumerations
>   cxl/test: Add hierarchy enumeration support for type2 device
>   cxl/test: Propagate -ENOMEM on platform_device_alloc() failures
>   cxl/test: Fixup hdm init for auto region to support type2
>   cxl/test: Add cxl_test accelerator driver
> 
>  tools/testing/cxl/test/Kbuild      |   2 +
>  tools/testing/cxl/test/accel.c     |  66 +++
>  tools/testing/cxl/test/cxl.c       | 850 ++++++++++++++++++++++-------
>  tools/testing/cxl/test/hmem_test.c |   3 +-
>  tools/testing/cxl/test/mock.h      |   2 +
>  5 files changed, 720 insertions(+), 203 deletions(-)
>  create mode 100644 tools/testing/cxl/test/accel.c
> 
> 
> base-commit: 96ddf1af34f5f9e29891a5bfb7a18dd0a5bab9d6

Applied to cxl/next with change from Alison
1c6b4ceafc3b cxl/test: Add cxl_test accelerator driver
b3df5a5a38c3 cxl/test: Fixup hdm init for auto region to support type2
98ba41c3236b cxl/test: Propagate -ENOMEM on platform_device_alloc() failures
6b2e585142e6 cxl/test: Add hierarchy enumeration support for type2 device
a6d37152d284 cxl/test: Refactor platform device enumerations
fc8fc576d909 cxl/test: Add type2 support for mock CFMWS0
afae0fa7c6b1 cxl/test: Add test for module parameters