drm/xe/tests/pci: Ensure all platforms have a valid GT/tile count

Add a simple kunit test to ensure each platform's GT per tile count is
non-zero and does not exceed the global XE_MAX_GT_PER_TILE definition.

We need to move 'struct xe_subplatform_desc' from the .c file to the
types header to ensure it is accessible from the kunit test.

v2:
 - Rebase on latest xe_pci test rework from Michal and convert to
   a parameterized test that runs on each PCI ID supported by the
   driver.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Ravi Kumar Vodapalli <ravi.kumar.vodapalli@intel.com>
Link: https://lore.kernel.org/r/20250701201320.2514369-13-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>

3 files changed, 44 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/tests/xe_pci.c b/drivers/gpu/drm/xe/tests/xe_pci.c
index baccb657bd05..9c715e59f030 100644
--- a/drivers/gpu/drm/xe/tests/xe_pci.c
+++ b/drivers/gpu/drm/xe/tests/xe_pci.c
@@ -21,6 +21,18 @@ static void xe_ip_kunit_desc(const struct xe_ip *param, char *desc)
 KUNIT_ARRAY_PARAM(graphics_ip, graphics_ips, xe_ip_kunit_desc);
 KUNIT_ARRAY_PARAM(media_ip, media_ips, xe_ip_kunit_desc);
 
+static void xe_pci_id_kunit_desc(const struct pci_device_id *param, char *desc)
+{
+	const struct xe_device_desc *dev_desc =
+		(const struct xe_device_desc *)param->driver_data;
+
+	if (dev_desc)
+		snprintf(desc, KUNIT_PARAM_DESC_SIZE, "0x%X (%s)",
+			 param->device, dev_desc->platform_name);
+}
+
+KUNIT_ARRAY_PARAM(pci_id, pciidlist, xe_pci_id_kunit_desc);
+
 /**
  * xe_pci_graphics_ip_gen_param - Generate graphics struct xe_ip parameters
  * @prev: the pointer to the previous parameter to iterate from or NULL
@@ -55,6 +67,25 @@ const void *xe_pci_media_ip_gen_param(const void *prev, char *desc)
 }
 EXPORT_SYMBOL_IF_KUNIT(xe_pci_media_ip_gen_param);
 
+/**
+ * xe_pci_id_gen_param - Generate struct pci_device_id parameters
+ * @prev: the pointer to the previous parameter to iterate from or NULL
+ * @desc: output buffer with minimum size of KUNIT_PARAM_DESC_SIZE
+ *
+ * This function prepares struct pci_device_id parameter.
+ *
+ * To be used only as a parameter generator function in &KUNIT_CASE_PARAM.
+ *
+ * Return: pointer to the next parameter or NULL if no more parameters
+ */
+const void *xe_pci_id_gen_param(const void *prev, char *desc)
+{
+	const struct pci_device_id *pci = pci_id_gen_params(prev, desc);
+
+	return pci->driver_data ? pci : NULL;
+}
+EXPORT_SYMBOL_IF_KUNIT(xe_pci_id_gen_param);
+
 static void fake_read_gmdid(struct xe_device *xe, enum xe_gmdid_type type,
 			    u32 *ver, u32 *revid)
 {
diff --git a/drivers/gpu/drm/xe/tests/xe_pci_test.c b/drivers/gpu/drm/xe/tests/xe_pci_test.c
index 95fed41f7ff2..37b344df2dc3 100644
--- a/drivers/gpu/drm/xe/tests/xe_pci_test.c
+++ b/drivers/gpu/drm/xe/tests/xe_pci_test.c
@@ -44,9 +44,21 @@ static void check_media_ip(struct kunit *test)
 	KUNIT_ASSERT_EQ(test, mask, 0);
 }
 
+static void check_platform_gt_count(struct kunit *test)
+{
+	const struct pci_device_id *pci = test->param_value;
+	const struct xe_device_desc *desc =
+		(const struct xe_device_desc *)pci->driver_data;
+	int max_gt = desc->max_gt_per_tile;
+
+	KUNIT_ASSERT_GT(test, max_gt, 0);
+	KUNIT_ASSERT_LE(test, max_gt, XE_MAX_GT_PER_TILE);
+}
+
 static struct kunit_case xe_pci_tests[] = {
 	KUNIT_CASE_PARAM(check_graphics_ip, xe_pci_graphics_ip_gen_param),
 	KUNIT_CASE_PARAM(check_media_ip, xe_pci_media_ip_gen_param),
+	KUNIT_CASE_PARAM(check_platform_gt_count, xe_pci_id_gen_param),
 	{}
 };
 
diff --git a/drivers/gpu/drm/xe/tests/xe_pci_test.h b/drivers/gpu/drm/xe/tests/xe_pci_test.h
index 3a1df7a5e291..ce4d2b86b778 100644
--- a/drivers/gpu/drm/xe/tests/xe_pci_test.h
+++ b/drivers/gpu/drm/xe/tests/xe_pci_test.h
@@ -27,6 +27,7 @@ int xe_pci_fake_device_init(struct xe_device *xe);
 
 const void *xe_pci_graphics_ip_gen_param(const void *prev, char *desc);
 const void *xe_pci_media_ip_gen_param(const void *prev, char *desc);
+const void *xe_pci_id_gen_param(const void *prev, char *desc);
 const void *xe_pci_live_device_gen_param(const void *prev, char *desc);
 
 #endif