[PATCH v3] drm/xe: Normalize default param values

[Lucas De Marchi]

Document xe module params with the default values following a similar
strategy for all of them:

	1) Define a DEFAULT_* macro with the default value. When the
	   value can't be directly stringified, also define a *_STR
	   variant
	2) Use __stringify() or the _STR variant to make sure the
	   default value shows up in the param description

This allows us to show the correct default according to the
configuration. max_vfs for example was wrongly documented for
CONFIG_DRM_XE_DEBUG and svm_notifier_size didn't have its default
documented.

Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
Changes in v3:
- First 2 patches merged
- Rework the last one according to review feedback (John Harrison):
  - Add missing DEFAULT_VRAM_BAR_SIZE
  - Define DEFAULT_MAX_VFS_STR based on DEFAULT_MAX_VFS if possible
  - Bring back ifdef for CONFIG_PCI_IOV
- Link to v2: https://lore.kernel.org/r/20250613-guc-log-level-v2-0-cb84a63e49fe@intel.com

Changes in v2:
- Rework the second patch so the default is kept in a single place and
  the module description doesn't need to be repeated according to the
  configuration, suggested by Michal Wajdeczko.
- Add a new patch to normalize all module param descriptions
- Link to v1: https://lore.kernel.org/r/20250612-guc-log-level-v1-0-51f124a3be6d@intel.com
---
 drivers/gpu/drm/xe/xe_module.c | 44 ++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
index 192908fa074cb..064093bf1adca 100644
--- a/drivers/gpu/drm/xe/xe_module.c
+++ b/drivers/gpu/drm/xe/xe_module.c
@@ -19,34 +19,47 @@
 #include "xe_sched_job.h"
 
 #if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
-#define DEFAULT_GUC_LOG_LEVEL	3
+#define DEFAULT_GUC_LOG_LEVEL		3
+#define DEFAULT_MAX_VFS			~0
+#define DEFAULT_MAX_VFS_STR		"unlimited"
 #else
-#define DEFAULT_GUC_LOG_LEVEL	1
+#define DEFAULT_GUC_LOG_LEVEL		1
+#define DEFAULT_MAX_VFS			0
+#define DEFAULT_MAX_VFS_STR		__stringify(DEFAULT_MAX_VFS)
 #endif
 
+#define DEFAULT_PROBE_DISPLAY		true
+#define DEFAULT_VRAM_BAR_SIZE		0
+#define DEFAULT_FORCE_PROBE		CONFIG_DRM_XE_FORCE_PROBE
+#define DEFAULT_WEDGED_MODE		1
+#define DEFAULT_SVM_NOTIFIER_SIZE	512
+
 struct xe_modparam xe_modparam = {
-	.probe_display = true,
-	.guc_log_level = DEFAULT_GUC_LOG_LEVEL,
-	.force_probe = CONFIG_DRM_XE_FORCE_PROBE,
+	.probe_display =	DEFAULT_PROBE_DISPLAY,
+	.guc_log_level =	DEFAULT_GUC_LOG_LEVEL,
+	.force_probe =		DEFAULT_FORCE_PROBE,
 #ifdef CONFIG_PCI_IOV
-	.max_vfs = IS_ENABLED(CONFIG_DRM_XE_DEBUG) ? ~0 : 0,
+	.max_vfs =		DEFAULT_MAX_VFS,
 #endif
-	.wedged_mode = 1,
-	.svm_notifier_size = 512,
+	.wedged_mode =		DEFAULT_WEDGED_MODE,
+	.svm_notifier_size =	DEFAULT_SVM_NOTIFIER_SIZE,
 	/* the rest are 0 by default */
 };
 
 module_param_named(svm_notifier_size, xe_modparam.svm_notifier_size, uint, 0600);
-MODULE_PARM_DESC(svm_notifier_size, "Set the svm notifier size(in MiB), must be power of 2");
+MODULE_PARM_DESC(svm_notifier_size, "Set the svm notifier size in MiB, must be power of 2 "
+		 "[default=" __stringify(DEFAULT_SVM_NOTIFIER_SIZE) "]");
 
 module_param_named_unsafe(force_execlist, xe_modparam.force_execlist, bool, 0444);
 MODULE_PARM_DESC(force_execlist, "Force Execlist submission");
 
 module_param_named(probe_display, xe_modparam.probe_display, bool, 0444);
-MODULE_PARM_DESC(probe_display, "Probe display HW, otherwise it's left untouched (default: true)");
+MODULE_PARM_DESC(probe_display, "Probe display HW, otherwise it's left untouched "
+		 "[default=" __stringify(DEFAULT_PROBE_DISPLAY) "])");
 
 module_param_named(vram_bar_size, xe_modparam.force_vram_bar_size, int, 0600);
-MODULE_PARM_DESC(vram_bar_size, "Set the vram bar size (in MiB) - <0=disable-resize, 0=max-needed-size[default], >0=force-size");
+MODULE_PARM_DESC(vram_bar_size, "Set the vram bar size in MiB (<0=disable-resize, 0=max-needed-size, >0=force-size "
+		 "[default=" __stringify(DEFAULT_VRAM_BAR_SIZE) "])");
 
 module_param_named(guc_log_level, xe_modparam.guc_log_level, int, 0600);
 MODULE_PARM_DESC(guc_log_level, "GuC firmware logging level (0=disable, 1=normal, 2..5=verbose-levels "
@@ -66,18 +79,21 @@ MODULE_PARM_DESC(gsc_firmware_path,
 
 module_param_named_unsafe(force_probe, xe_modparam.force_probe, charp, 0400);
 MODULE_PARM_DESC(force_probe,
-		 "Force probe options for specified devices. See CONFIG_DRM_XE_FORCE_PROBE for details.");
+		 "Force probe options for specified devices. See CONFIG_DRM_XE_FORCE_PROBE for details "
+		 "[default=" DEFAULT_FORCE_PROBE "])");
 
 #ifdef CONFIG_PCI_IOV
 module_param_named(max_vfs, xe_modparam.max_vfs, uint, 0400);
 MODULE_PARM_DESC(max_vfs,
 		 "Limit number of Virtual Functions (VFs) that could be managed. "
-		 "(0 = no VFs [default]; N = allow up to N VFs)");
+		 "(0=no VFs; N=allow up to N VFs "
+		 "[default=" DEFAULT_MAX_VFS_STR "])");
 #endif
 
 module_param_named_unsafe(wedged_mode, xe_modparam.wedged_mode, int, 0600);
 MODULE_PARM_DESC(wedged_mode,
-		 "Module's default policy for the wedged mode - 0=never, 1=upon-critical-errors[default], 2=upon-any-hang");
+		 "Module's default policy for the wedged mode (0=never, 1=upon-critical-errors, 2=upon-any-hang "
+		 "[default=" __stringify(DEFAULT_WEDGED_MODE) "])");
 
 static int xe_check_nomodeset(void)
 {