drm/amdgpu: Use pci_rebar_get_max_size()

Use pci_rebar_get_max_size() to simplify amdgpu_device_resize_fb_bar().

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patch.msgid.link/20251113180053.27944-11-ilpo.jarvinen@linux.intel.com

Author: ij-intel

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -1673,9 +1673,9 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 	int rbar_size = pci_rebar_bytes_to_size(adev->gmc.real_vram_size);
 	struct pci_bus *root;
 	struct resource *res;
+	int max_size, r;
 	unsigned int i;
 	u16 cmd;
-	int r;
 
 	if (!IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
 		return 0;
@@ -1721,8 +1721,10 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 		return 0;
 
 	/* Limit the BAR size to what is available */
-	rbar_size = min(fls(pci_rebar_get_possible_sizes(adev->pdev, 0)) - 1,
-			rbar_size);
+	max_size = pci_rebar_get_max_size(adev->pdev, 0);
+	if (max_size < 0)
+		return 0;
+	rbar_size = min(max_size, rbar_size);
 
 	/* Disable memory decoding while we change the BAR addresses and size */
 	pci_read_config_word(adev->pdev, PCI_COMMAND, &cmd);