drm/amdgpu: resize VRAM BAR for CPU access v6

Try to resize BAR0 to let CPU access all of VRAM.

v2: rebased, style cleanups, disable mem decode before resize,
    handle gmc_v9 as well, round size up to power of two.
v3: handle gmc_v6 as well, release and reassign all BARs in the driver.
v4: rename new function to amdgpu_device_resize_fb_bar,
    reenable mem decoding only if all resources are assigned.
v5: reorder resource release, return -ENODEV instead of BUG_ON().
v6: squash in rebase fix

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
index b0528ca..583d877 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
@@ -322,6 +322,8 @@ static void gmc_v7_0_mc_program(struct amdgpu_device *adev)
  */
 static int gmc_v7_0_mc_init(struct amdgpu_device *adev)
 {
+	int r;
+
 	adev->mc.vram_width = amdgpu_atombios_get_vram_width(adev);
 	if (!adev->mc.vram_width) {
 		u32 tmp;
@@ -367,13 +369,18 @@ static int gmc_v7_0_mc_init(struct amdgpu_device *adev)
 		}
 		adev->mc.vram_width = numchan * chansize;
 	}
-	/* Could aper size report 0 ? */
-	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
-	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
 	/* size in MB on si */
 	adev->mc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL * 1024ULL;
 	adev->mc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL * 1024ULL;
 
+	if (!(adev->flags & AMD_IS_APU)) {
+		r = amdgpu_device_resize_fb_bar(adev);
+		if (r)
+			return r;
+	}
+	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
+	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
+
 #ifdef CONFIG_X86_64
 	if (adev->flags & AMD_IS_APU) {
 		adev->mc.aper_base = ((u64)RREG32(mmMC_VM_FB_OFFSET)) << 22;