Bug#972794: linux-image-4.19.0-12-amd64: amdgpu-dkms 19.50-20.40 fails to build with error: implicit declaration of function ‘pci _platform_rom’ ;

["Dr. Nagy Elemér Kár oly" <eknagy@omikk.bme.hu>]

Dear All,

For amdgpu 20.10, patching amd/amdgpu/amdgpu_bios.c in /usr/src/amdgpu-5.4.7.53-1048554/ with the attached patch (posted 
by Mikel Rychliski at https://lore.kernel.org/amd-gfx/20200319021623.5426-1-
mikel@mikelr.com/#Z30drivers:gpu:drm:amd:amdgpu:amdgpu_bios.c) fixes the issue.

Best wishes:
Elemér K. Nagy

--- a/amd/amdgpu/amdgpu_bios.c
+++ b/amd/amdgpu/amdgpu_bios.c
@@ -192,30 +192,35 @@ static bool amdgpu_read_bios_from_rom(struct amdgpu_device *adev)
 
 static bool amdgpu_read_platform_bios(struct amdgpu_device *adev)
 {
-	uint8_t __iomem *bios;
-	size_t size;
+	phys_addr_t rom = adev->pdev->rom;
+	size_t romlen = adev->pdev->romlen;
+	void __iomem *bios;
 
 	adev->bios = NULL;
 
-	bios = pci_platform_rom(adev->pdev, &size);
-	if (!bios) {
+	if (!rom || romlen == 0)
 		return false;
-	}
 
-	adev->bios = kzalloc(size, GFP_KERNEL);
-	if (adev->bios == NULL)
+	adev->bios = kzalloc(romlen, GFP_KERNEL);
+	if (!adev->bios)
 		return false;
 
-	memcpy_fromio(adev->bios, bios, size);
+	bios = ioremap(rom, romlen);
+	if (!bios)
+		goto free_bios;
 
-	if (!check_atom_bios(adev->bios, size)) {
-		kfree(adev->bios);
-		return false;
-	}
+	memcpy_fromio(adev->bios, bios, romlen);
+	iounmap(bios);
 
-	adev->bios_size = size;
+	if (!check_atom_bios(adev->bios, romlen))
+		goto free_bios;
+
+	adev->bios_size = romlen;
 
 	return true;
+free_bios:
+	kfree(adev->bios);
+	return false;
 }
 
 #ifdef CONFIG_ACPI