drm/radeon: fix render backend setup for SI and CIK

Only the render backends of the first shader engine were enabled. The others
were erroneously disabled. Enabling the other render backends improves
performance a lot.

Unigine Sanctuary on Bonaire:
  Before: 15 fps
  After:  90 fps

Judging from the fan noise, the GPU was also underclocked when the other
render backends were disabled, resulting in horrible performance. The fan is
a lot noisy under load now.

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index b43a3a3..138a776 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -3057,7 +3057,7 @@
  * Returns the disabled RB bitmask.
  */
 static u32 cik_get_rb_disabled(struct radeon_device *rdev,
-			      u32 max_rb_num, u32 se_num,
+			      u32 max_rb_num_per_se,
 			      u32 sh_per_se)
 {
 	u32 data, mask;
@@ -3071,7 +3071,7 @@
 
 	data >>= BACKEND_DISABLE_SHIFT;
 
-	mask = cik_create_bitmask(max_rb_num / se_num / sh_per_se);
+	mask = cik_create_bitmask(max_rb_num_per_se / sh_per_se);
 
 	return data & mask;
 }
@@ -3088,7 +3088,7 @@
  */
 static void cik_setup_rb(struct radeon_device *rdev,
 			 u32 se_num, u32 sh_per_se,
-			 u32 max_rb_num)
+			 u32 max_rb_num_per_se)
 {
 	int i, j;
 	u32 data, mask;
@@ -3098,7 +3098,7 @@
 	for (i = 0; i < se_num; i++) {
 		for (j = 0; j < sh_per_se; j++) {
 			cik_select_se_sh(rdev, i, j);
-			data = cik_get_rb_disabled(rdev, max_rb_num, se_num, sh_per_se);
+			data = cik_get_rb_disabled(rdev, max_rb_num_per_se, sh_per_se);
 			if (rdev->family == CHIP_HAWAII)
 				disabled_rbs |= data << ((i * sh_per_se + j) * HAWAII_RB_BITMAP_WIDTH_PER_SH);
 			else
@@ -3108,7 +3108,7 @@
 	cik_select_se_sh(rdev, 0xffffffff, 0xffffffff);
 
 	mask = 1;
-	for (i = 0; i < max_rb_num; i++) {
+	for (i = 0; i < max_rb_num_per_se * se_num; i++) {
 		if (!(disabled_rbs & mask))
 			enabled_rbs |= mask;
 		mask <<= 1;