[PATCH 2/2] drm/amdgpu/gmc9: fix 64 bit division in partition code

[Alex Deucher]

Rework logic or use do_div() to avoid problems on 32 bit.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c |  5 ++++-
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c   | 11 ++++++-----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index d5958e8e3c16..76dadf181d4c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -818,11 +818,14 @@ static void amdgpu_ttm_gart_bind_gfx9_mqd(struct amdgpu_device *adev,
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
 	uint64_t total_pages = ttm->num_pages;
 	int num_xcc = max(1U, adev->gfx.num_xcc_per_xcp);
-	uint64_t page_idx, pages_per_xcc = total_pages / num_xcc;
+	uint64_t page_idx, pages_per_xcc;
 	int i;
 	uint64_t ctrl_flags = (flags & ~AMDGPU_PTE_MTYPE_VG10_MASK) |
 			AMDGPU_PTE_MTYPE_VG10(AMDGPU_MTYPE_NC);
 
+	pages_per_xcc = total_pages;
+	do_div(pages_per_xcc, num_xcc);
+
 	for (i = 0, page_idx = 0; i < num_xcc; i++, page_idx += pages_per_xcc) {
 		/* MQD page: use default flags */
 		amdgpu_gart_bind(adev,
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index 938c8dba9057..d559e7bc0f09 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -1919,9 +1919,10 @@ gmc_v9_0_init_acpi_mem_ranges(struct amdgpu_device *adev,
 	adev->gmc.num_mem_partitions = num_ranges;
 
 	/* If there is only partition, don't use entire size */
-	if (adev->gmc.num_mem_partitions == 1)
-		mem_ranges[0].size =
-			(mem_ranges[0].size * (mem_groups - 1) / mem_groups);
+	if (adev->gmc.num_mem_partitions == 1) {
+		mem_ranges[0].size = mem_ranges[0].size * (mem_groups - 1);
+		do_div(mem_ranges[0].size, mem_groups);
+	}
 }
 
 static void
@@ -1953,8 +1954,8 @@ gmc_v9_0_init_sw_mem_ranges(struct amdgpu_device *adev,
 		break;
 	}
 
-	size = (adev->gmc.real_vram_size >> AMDGPU_GPU_PAGE_SHIFT) /
-	       adev->gmc.num_mem_partitions;
+	size = adev->gmc.real_vram_size >> AMDGPU_GPU_PAGE_SHIFT;
+	size /= adev->gmc.num_mem_partitions;
 
 	for (i = 0; i < adev->gmc.num_mem_partitions; ++i) {
 		mem_ranges[i].range.fpfn = start_addr;
-- 
2.40.1