[PATCH 7/7] amdgpu: allow overriding of the GPU's list of supported BAR sizes

[Darren Salt]

Some cards don't advertise a BAR size which covers all of the VRAM.

Mine, a Sapphire RX 5600 XT Pulse, advertises only 256MB, 512MB and 1GB.
Despite this, it works fine with the full 6GB visible via an 8GB BAR.
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 5 +++--
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c    | 8 ++++----
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index c844e2a8500a..a64a9ac92ac1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -201,7 +201,7 @@ static const bool __maybe_unused no_system_mem_limit;
 
 extern int amdgpu_tmz;
 extern int amdgpu_reset_method;
-extern bool amdgpu_resize_bar;
+extern int amdgpu_resize_bar;
 extern int amdgpu_max_bar_size;
 
 #ifdef CONFIG_DRM_AMDGPU_SI
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index b6c5ee490cbf..0f04686ed6c0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -1114,6 +1114,7 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 	u16 cmd;
 	int r;
 	bool nospc = false;
+	const bool force = amdgpu_resize_bar == 2;
 
 	if (!amdgpu_resize_bar)
 		return 0;
@@ -1175,10 +1176,10 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 		/* Skip this size if it isn't advertised.
 		 * This avoids pci_resize_resources returning -EINVAL for that reason.
 		 */
-		if (!(available_sizes & BIT(rbar_size)))
+		if (!force && !(available_sizes & BIT(rbar_size)))
 			continue;
 
-		r = pci_resize_resource(adev->pdev, 0, rbar_size);
+		r = pci_resize_resource(adev->pdev, 0, rbar_size, force);
 		if (r == 0) {
 			dev_dbg(adev->dev, "Succeeded in resizing to %lluMB.",
 			        pci_rebar_size_to_bytes(rbar_size) >> 20);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 0542843c7d63..468ca3725890 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -161,7 +161,7 @@ int amdgpu_force_asic_type = -1;
 int amdgpu_tmz;
 int amdgpu_reset_method = -1; /* auto */
 int amdgpu_num_kcq = -1;
-bool amdgpu_resize_bar = true;
+int amdgpu_resize_bar = 1;
 int amdgpu_max_bar_size = -1;
 
 struct amdgpu_mgpu_info mgpu_info = {
@@ -810,12 +810,12 @@ MODULE_PARM_DESC(num_kcq, "number of kernel compute queue user want to setup (8
 module_param_named(num_kcq, amdgpu_num_kcq, int, 0444);
 
 /**
- * DOC: resize_bar (bool)
+ * DOC: resize_bar (int)
  * Control whether FB BAR should be resized.
  * Enabled by default.
  */
-module_param_named(resize_bar, amdgpu_resize_bar, bool, 0444);
-MODULE_PARM_DESC(resize_bar, "Controls whether the FB BAR should be resized (default = true).");
+module_param_named(resize_bar, amdgpu_resize_bar, int, 0444);
+MODULE_PARM_DESC(resize_bar, "Controls whether the FB BAR should be resized (0 = off, 1 = on (default), 2 = override the GPU's supported sizes).");
 
 /**
  * DOC: max_bar_size (int)
-- 
2.20.1