Subject: inux-next: build failure after merge of the drm-msm tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 19 May 2020 15:09:55 +1000

Hi all,

After merging the drm-msm tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

ERROR: modpost: "__aeabi_ldivmod" [drivers/gpu/drm/msm/msm.ko] undefined!
ERROR: modpost: "__aeabi_uldivmod" [drivers/gpu/drm/msm/msm.ko] undefined!

Caused by commit

  04d9044f6c57 ("drm/msm/dpu: add support for clk and bw scaling for display")

I applied the following patch for today (this is mechanical, there may
be a better way):

From: Stephen Rothwell <[email-masked]>
Date: Tue, 19 May 2020 14:12:39 +1000
Subject: [PATCH] drm/msm/dpu: fix up u64/u32 division for 32 bit architectures

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c | 23 ++++++++++++++-----
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c     | 15 ++++++++----
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
index 9697abcbec3f..85c2a4190840 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
@@ -10,6 +10,7 @@
 #include <linux/sort.h>
 #include <linux/clk.h>
 #include <linux/bitmap.h>
+#include <asm/div64.h>
 
 #include "dpu_kms.h"
 #include "dpu_trace.h"
@@ -53,8 +54,11 @@ static u64 _dpu_core_perf_calc_bw(struct dpu_kms *kms,
 	}
 
 	bw_factor = kms->catalog->perf.bw_inefficiency_factor;
-	if (bw_factor)
-		crtc_plane_bw = mult_frac(crtc_plane_bw, bw_factor, 100);
+	if (bw_factor) {
+		u64 quot = crtc_plane_bw;
+		u32 rem = do_div(quot, 100);
+		crtc_plane_bw = (quot * bw_factor) + ((rem * bw_factor) / 100);
+	}
 
 	return crtc_plane_bw;
 }
@@ -89,8 +93,11 @@ static u64 _dpu_core_perf_calc_clk(struct dpu_kms *kms,
 	}
 
 	clk_factor = kms->catalog->perf.clk_inefficiency_factor;
-	if (clk_factor)
-		crtc_clk = mult_frac(crtc_clk, clk_factor, 100);
+	if (clk_factor) {
+		u64 quot = crtc_clk;
+		u32 rem = do_div(quot, 100);
+		crtc_clk = (quot * clk_factor) + ((rem * clk_factor) / 100);
+	}
 
 	return crtc_clk;
 }
@@ -234,8 +241,12 @@ static int _dpu_core_perf_crtc_update_bus(struct dpu_kms *kms,
 		}
 	}
 
-	avg_bw = kms->num_paths ?
-			perf.bw_ctl / kms->num_paths : 0;
+	if (kms->num_paths) {
+		avg_bw = perf.bw_ctl;
+		do_div(avg_bw, kms->num_paths);
+	} else {
+		avg_bw = 0;
+	}
 
 	for (i = 0; i < kms->num_paths; i++)
 		icc_set_bw(kms->path[i],
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index c2a6e3dacd68..ad95f32eac13 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -9,6 +9,7 @@
 
 #include <linux/debugfs.h>
 #include <linux/dma-buf.h>
+#include <asm/div64.h>
 
 #include <drm/drm_atomic_uapi.h>
 #include <drm/drm_damage_helper.h>
@@ -174,7 +175,11 @@ static void _dpu_plane_calc_bw(struct drm_plane *plane,
 	plane_prefill_bw =
 		src_width * hw_latency_lines * fps * fmt->bpp * scale_factor;
 
-	plane_prefill_bw = mult_frac(plane_prefill_bw, mode->vtotal, (vbp+vpw));
+	{
+		u64 quot = plane_prefill_bw;
+		u32 rem = do_div(plane_prefill_bw, vbp + vpw);
+		plane_prefill_bw = quot * mode->vtotal + rem * mode->vtotal / (vbp + vpw);
+	}
 
 	pstate->plane_fetch_bw = max(plane_bw, plane_prefill_bw);
 }
@@ -204,9 +209,11 @@ static void _dpu_plane_calc_clk(struct drm_plane *plane)
 	pstate->plane_clk =
 		dst_width * mode->vtotal * fps;
 
-	if (src_height > dst_height)
-		pstate->plane_clk = mult_frac(pstate->plane_clk,
-					src_height, dst_height);
+	if (src_height > dst_height) {
+		u64 quot = pstate->plane_clk;
+		u32 rem = do_div(quot, dst_height);
+		pstate->plane_clk = quot * src_height + rem * src_height / dst_height;
+	}
 }
 
 /**
-- 
2.26.2

-- 
Cheers,
Stephen Rothwell