[PATCH] drm/msm/mdp5: fix 64-bit division in bandwidth calculation

[Dmitry Baryshkov]

Fix undefined symbols errors arising from 64-bit division on 32-bit
arm targets. Add 64-bit version of mult_frac and use it for calculating
bandwidth.

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

Fixes: 7e0230fd096c ("drm/msm/mdp5: provide dynamic bandwidth management")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c  |  2 +-
 drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c   |  5 ++++-
 drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c |  2 +-
 include/linux/math.h                       | 13 +++++++++++++
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
index a9332078aa13..52724d0a6fea 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
@@ -755,7 +755,7 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc,
 	hw_cfg = mdp5_cfg_get_hw_config(mdp5_kms->cfg);
 
 	if (hw_cfg->perf.ab_inefficiency)
-		crtc_bw = mult_frac(crtc_bw, hw_cfg->perf.ab_inefficiency, 100);
+		crtc_bw = mult_frac_ull(crtc_bw, hw_cfg->perf.ab_inefficiency, 100);
 	mdp5_cstate->new_crtc_bw = crtc_bw;
 
 	/*
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
index 3e1b28d3e41b..85b7093a1218 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
@@ -301,6 +301,7 @@ static const struct mdp_kms_funcs kms_funcs = {
 void mdp5_kms_set_bandwidth(struct mdp5_kms *mdp5_kms)
 {
 	int i;
+	u64 bw;
 	u32 full_bw = 0;
 	struct drm_crtc *tmp_crtc;
 
@@ -311,7 +312,9 @@ void mdp5_kms_set_bandwidth(struct mdp5_kms *mdp5_kms)
 		if (!tmp_crtc->enabled)
 			continue;
 
-		full_bw += Bps_to_icc(to_mdp5_crtc_state(tmp_crtc->state)->new_crtc_bw / mdp5_kms->num_paths);
+		bw = to_mdp5_crtc_state(tmp_crtc->state)->new_crtc_bw;
+		do_div(bw, mdp5_kms->num_paths * 1000); /* Bps_to_icc */
+		full_bw += bw;
 	}
 
 	DBG("SET BW to %d\n", full_bw);
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
index 85275665558b..2ede34177a90 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
@@ -191,7 +191,7 @@ static void mdp5_plane_calc_bw(struct drm_plane_state *state, struct drm_crtc_st
 		prefill_div = vbp + vpw + vfp;
 #endif
 
-	pstate->plane_bw = max(plane_bw, mult_frac(plane_bw, hw_latency_lines, prefill_div));
+	pstate->plane_bw = max(plane_bw, mult_frac_ull(plane_bw, hw_latency_lines, prefill_div));
 }
 
 static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state,
diff --git a/include/linux/math.h b/include/linux/math.h
index 53674a327e39..1327385905df 100644
--- a/include/linux/math.h
+++ b/include/linux/math.h
@@ -118,6 +118,19 @@
 }							\
 )
 
+#define mult_frac_ull(x, numer, denom)(			\
+{							\
+	typeof(x) quot = (x);				\
+	typeof(x) rem;					\
+	do_div(quot, (denom));				\
+	rem = (x) - quot * (denom);			\
+	rem = (rem * (numer));				\
+	do_div(rem, (denom));				\
+	(quot * (numer)) + rem;				\
+}							\
+)
+
+
 #define sector_div(a, b) do_div(a, b)
 
 /**
-- 
2.30.2