From 18f385b8104c362d384bbddb42baf5010ca81e48 Mon Sep 17 00:00:00 2001
From: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Date: Tue, 4 Oct 2022 07:33:39 -0700
Subject: drm/amdgpu: Fix VRAM BO swap issue
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Git-commit: 312b4dc11d4f74bfe03ea25ffe04c1f2fdd13cb9
Patch-mainline: v6.1-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849

DRM buddy manager allocates the contiguous memory requests in
a single block or multiple blocks. So for the ttm move operation
(incase of low vram memory) we should consider all the blocks to
compute the total memory size which compared with the struct
ttm_resource num_pages in order to verify that the blocks are
contiguous for the eviction process.

v2: Added a Fixes tag
v3: Rewrite the code to save a bit of calculations and
    variables (Christian)

Fixes: c9cad937c0c5 ("drm/amdgpu: add drm buddy support to amdgpu")
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 2e97099808ca..eca2682ab5c7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -424,8 +424,9 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
 static bool amdgpu_mem_visible(struct amdgpu_device *adev,
 			       struct ttm_resource *mem)
 {
-	uint64_t mem_size = (u64)mem->num_pages << PAGE_SHIFT;
+	u64 mem_size = (u64)mem->num_pages << PAGE_SHIFT;
 	struct amdgpu_res_cursor cursor;
+	u64 end;
 
 	if (mem->mem_type == TTM_PL_SYSTEM ||
 	    mem->mem_type == TTM_PL_TT)
@@ -434,12 +435,18 @@ static bool amdgpu_mem_visible(struct amdgpu_device *adev,
 		return false;
 
 	amdgpu_res_first(mem, 0, mem_size, &cursor);
+	end = cursor.start + cursor.size;
+	while (cursor.remaining) {
+		amdgpu_res_next(&cursor, cursor.size);
 
-	/* ttm_resource_ioremap only supports contiguous memory */
-	if (cursor.size != mem_size)
-		return false;
+		/* ttm_resource_ioremap only supports contiguous memory */
+		if (end != cursor.start)
+			return false;
+
+		end = cursor.start + cursor.size;
+	}
 
-	return cursor.start + cursor.size <= adev->gmc.visible_vram_size;
+	return end <= adev->gmc.visible_vram_size;
 }
 
 /*
-- 
2.38.1