[PATCH] drm/xe: Allow to drop vram resizing

[Lucas De Marchi]

The default behavior if the LMEMBAR doesn't match the maximum possible
size is to try to resize it. However the user might want to keep, even
for testing the behavior with small BAR, whatever size was set via
sysfs. Change the module parameter to int and check for negative value.

Cc: Michał Winiarski <michal.winiarski at intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/xe/xe_module.c | 4 ++--
 drivers/gpu/drm/xe/xe_vram.c   | 5 ++++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
index 475acdba2b550..7309c0c9bc0d0 100644
--- a/drivers/gpu/drm/xe/xe_module.c
+++ b/drivers/gpu/drm/xe/xe_module.c
@@ -41,8 +41,8 @@ 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_param_named(vram_bar_size, xe_modparam.force_vram_bar_size, uint, 0600);
-MODULE_PARM_DESC(vram_bar_size, "Set the vram bar size(in MiB)");
+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_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..5=enable with verbosity min..max)");
diff --git a/drivers/gpu/drm/xe/xe_vram.c b/drivers/gpu/drm/xe/xe_vram.c
index b1f81dca610dc..e421a74fb87c6 100644
--- a/drivers/gpu/drm/xe/xe_vram.c
+++ b/drivers/gpu/drm/xe/xe_vram.c
@@ -49,7 +49,7 @@ _resize_bar(struct xe_device *xe, int resno, resource_size_t size)
  */
 static void resize_vram_bar(struct xe_device *xe)
 {
-	u64 force_vram_bar_size = xe_modparam.force_vram_bar_size;
+	int force_vram_bar_size = xe_modparam.force_vram_bar_size;
 	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
 	struct pci_bus *root = pdev->bus;
 	resource_size_t current_size;
@@ -66,6 +66,9 @@ static void resize_vram_bar(struct xe_device *xe)
 	if (!bar_size_mask)
 		return;
 
+	if (force_vram_bar_size < 0)
+		return;
+
 	/* set to a specific size? */
 	if (force_vram_bar_size) {
 		u32 bar_size_bit;