When building amdgpu for 32-bit x86 (CONFIG_X86_32), modpost fails
with:
ERROR: modpost: drivers/gpu/drm/amd/amdgpu/amdgpu.ko: symbol
'__udivdi3' undefined!
The UTM QoS helpers dchub_v2_get_sop_total_available_bandwidth_KBps()
and dchub_v2_is_qos_bandwidth_supported_by_sop() divide a 64-bit
bandwidth product by 100 using the native '/' operator. On 32-bit
targets GCC lowers this to a __udivdi3() libgcc call, which the
kernel does not link into modules.
Replace the raw divisions with div_u64(), the kernel's standard
64-bit division helper.
Fixes: 7f7d7ea1fa51 ("drm/amd/display: Add new sources for DCN6")
Reported-by: k2ci <[email protected]>
Signed-off-by: Linlin Yang <[email protected]>
---
.../bounding_boxes/utm_qos_model_dchub_v2.h | 23 +++++++++++--------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git
a/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/inc/bounding_boxes/utm_qos_model_dchub_v2.h
b/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/inc/bounding_boxes/utm_qos_model_dchub_v2.h
index ebca5ddda284..39df427a9ee7 100644
---
a/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/inc/bounding_boxes/utm_qos_model_dchub_v2.h
+++
b/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/inc/bounding_boxes/utm_qos_model_dchub_v2.h
@@ -3,6 +3,7 @@
// Copyright 2025 Advanced Micro Devices, Inc.
#ifndef UTM_QOS_MODEL_DCHUB_V2_H
#define UTM_QOS_MODEL_DCHUB_V2_H
+#include <linux/math64.h>
#include "utm_qos_model_types.h"
struct utm_qos_model_dchub_memory_path_latency_v2 {
@@ -63,22 +64,22 @@ static inline void
dchub_v2_get_sop_total_available_bandwidth_KBps(
uint64_t dram_available_bandwidth_KBps_urgent;
uint64_t fabric_available_bandwidth_KBps_urgent;
- dram_available_bandwidth_KBps_nominal = (uint64_t) sop->uclk_khz
+ dram_available_bandwidth_KBps_nominal = div_u64((uint64_t)sop->uclk_khz
* socbb->dram_channel_count
* socbb->dram_channel_width_bytes
* socbb->dram_transactions_per_clock
- * socbb->dram_derate_percent_nominal / 100;
- dram_available_bandwidth_KBps_urgent = (uint64_t) sop->uclk_khz
+ * socbb->dram_derate_percent_nominal, 100);
+ dram_available_bandwidth_KBps_urgent = div_u64((uint64_t)sop->uclk_khz
* socbb->dram_channel_count
* socbb->dram_channel_width_bytes
* socbb->dram_transactions_per_clock
- * socbb->dram_derate_percent_urgent / 100;
- fabric_available_bandwidth_KBps_nominal = (uint64_t) sop->fclk_khz
+ * socbb->dram_derate_percent_urgent, 100);
+ fabric_available_bandwidth_KBps_nominal =
div_u64((uint64_t)sop->fclk_khz
* socbb->fabric_datapath_to_dcn_data_return_bytes
- * socbb->fabric_derate_percent_nominal / 100;
- fabric_available_bandwidth_KBps_urgent = (uint64_t) sop->fclk_khz
+ * socbb->fabric_derate_percent_nominal, 100);
+ fabric_available_bandwidth_KBps_urgent = div_u64((uint64_t)sop->fclk_khz
* socbb->fabric_datapath_to_dcn_data_return_bytes
- * socbb->fabric_derate_percent_urgent / 100;
+ * socbb->fabric_derate_percent_urgent, 100);
total_available_bandwidth->nominal_bandwidth_KBps =
dram_available_bandwidth_KBps_nominal <
fabric_available_bandwidth_KBps_nominal ?
@@ -112,9 +113,11 @@ static inline bool
dchub_v2_is_qos_bandwidth_supported_by_sop(
nominal_available_bandwidth_KBps =
available_bandwidth.nominal_bandwidth_KBps;
urgent_available_bandwidth_KBps =
available_bandwidth.urgent_bandwidth_KBps;
- if ((nominal_available_bandwidth_KBps * nominal_utm_budget_percent /
100) < qos_bandwidth->nominal_bandwidth_KBps)
+ if (div_u64(nominal_available_bandwidth_KBps *
nominal_utm_budget_percent, 100) <
+ qos_bandwidth->nominal_bandwidth_KBps)
return false;
- else if ((urgent_available_bandwidth_KBps * urgent_utm_budget_percent /
100) < qos_bandwidth->urgent_bandwidth_KBps)
+ else if (div_u64(urgent_available_bandwidth_KBps *
urgent_utm_budget_percent, 100) <
+ qos_bandwidth->urgent_bandwidth_KBps)
return false;
else
return true;
--
2.25.1
