BACKPORT: FROMLIST: drm/xe/bo: fix alignment with non-4K kernel page sizes

MingcongBai · MingcongBai · commit 32b75e31dacd · 2025-10-27T14:22:12.000+08:00
The bo/ttm interfaces with kernel memory mapping from dedicated GPU memory. It is not correct to assume that SZ_4K would suffice for page alignment as there are a few hardware platforms that commonly uses non-4K pages - for instance, currently, Loongson 3A5000/6000 devices (of the LoongArch architecture) commonly uses 16K kernel pages. Per my testing Intel Xe/Arc families of GPUs works on at least Loongson 3A6000 platforms so long as "Above 4G Decoding" and "Resizable BAR" were enabled in the EFI firmware settings. I tested this patch series on my Loongson XA61200 (3A6000) motherboard with an Intel Arc A750 GPU. Without this fix, the kernel will hang at a kernel BUG(): [ 7.425445] ------------[ cut here ]------------ [ 7.430032] kernel BUG at drivers/gpu/drm/drm_gem.c:181! [ 7.435330] Oops - BUG[#1]: [ 7.438099] CPU: 0 UID: 0 PID: 102 Comm: kworker/0:4 Tainted: G E 6.13.3-aosc-main-00336-g60829239b300-dirty #3 [ 7.449511] Tainted: [E]=UNSIGNED_MODULE [ 7.453402] Hardware name: Loongson Loongson-3A6000-HV-7A2000-1w-V0.1-EVB/Loongson-3A6000-HV-7A2000-1w-EVB-V1.21, BIOS Loongson-UDK2018-V4.0.05756-prestab [ 7.467144] Workqueue: events work_for_cpu_fn [ 7.471472] pc 9000000001045fa4 ra ffff8000025331dc tp 90000001010c8000 sp 90000001010cb960 [ 7.479770] a0 900000012a3e8000 a1 900000010028c000 a2 000000000005d000 a3 0000000000000000 [ 7.488069] a4 0000000000000000 a5 0000000000000000 a6 0000000000000000 a7 0000000000000001 [ 7.496367] t0 0000000000001000 t1 9000000001045000 t2 0000000000000000 t3 0000000000000000 [ 7.504665] t4 0000000000000000 t5 0000000000000000 t6 0000000000000000 t7 0000000000000000 [ 7.504667] t8 0000000000000000 u0 90000000029ea7d8 s9 900000012a3e9360 s0 900000010028c000 [ 7.504668] s1 ffff800002744000 s2 0000000000000000 s3 0000000000000000 s4 0000000000000001 [ 7.504669] s5 900000012a3e8000 s6 0000000000000001 s7 0000000000022022 s8 0000000000000000 [ 7.537855] ra: ffff8000025331dc ___xe_bo_create_locked+0x158/0x3b0 [xe] [ 7.544893] ERA: 9000000001045fa4 drm_gem_private_object_init+0xcc/0xd0 [ 7.551639] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) [ 7.557785] PRMD: 00000004 (PPLV0 +PIE -PWE) [ 7.562111] EUEN: 00000000 (-FPE -SXE -ASXE -BTE) [ 7.566870] ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) [ 7.571628] ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) [ 7.577163] PRID: 0014d000 (Loongson-64bit, Loongson-3A6000-HV) [ 7.583128] Modules linked in: xe(E+) drm_gpuvm(E) drm_exec(E) drm_buddy(E) gpu_sched(E) drm_suballoc_helper(E) drm_display_helper(E) loongson(E) r8169(E) cec(E) rc_core(E) realtek(E) i2c_algo_bit(E) tpm_tis_spi(E) led_class(E) hid_generic(E) drm_ttm_helper(E) ttm(E) drm_client_lib(E) drm_kms_helper(E) sunrpc(E) la_ow_syscall(E) i2c_dev(E) [ 7.613049] Process kworker/0:4 (pid: 102, threadinfo=00000000bc26ebd1, task=0000000055480707) [ 7.621606] Stack : 0000000000000000 3030303a6963702b 000000000005d000 0000000000000000 [ 7.629563] 0000000000000001 0000000000000000 0000000000000000 8e1bfae42b2f7877 [ 7.637519] 000000000005d000 900000012a3e8000 900000012a3e9360 0000000000000000 [ 7.645475] ffffffffffffffff 0000000000000000 0000000000022022 0000000000000000 [ 7.653431] 0000000000000001 ffff800002533660 0000000000022022 9000000000234470 [ 7.661386] 90000001010cba28 0000000000001000 0000000000000000 000000000005c300 [ 7.669342] 900000012a3e8000 0000000000000000 0000000000000001 900000012a3e8000 [ 7.677298] ffffffffffffffff 0000000000022022 900000012a3e9498 ffff800002533a14 [ 7.685254] 0000000000022022 0000000000000000 900000000209c000 90000000010589e0 [ 7.693209] 90000001010cbab8 ffff8000027c78c0 fffffffffffff000 900000012a3e8000 [ 7.701165] ... [ 7.703588] Call Trace: [ 7.703590] [<9000000001045fa4>] drm_gem_private_object_init+0xcc/0xd0 [ 7.712496] [<ffff8000025331d8>] ___xe_bo_create_locked+0x154/0x3b0 [xe] [ 7.719268] [<ffff80000253365c>] __xe_bo_create_locked+0x228/0x304 [xe] [ 7.725951] [<ffff800002533a10>] xe_bo_create_pin_map_at_aligned+0x70/0x1b0 [xe] [ 7.733410] [<ffff800002533c7c>] xe_managed_bo_create_pin_map+0x34/0xcc [xe] [ 7.740522] [<ffff800002533d58>] xe_managed_bo_create_from_data+0x44/0xb0 [xe] [ 7.747807] [<ffff80000258d19c>] xe_uc_fw_init+0x3ec/0x904 [xe] [ 7.753814] [<ffff80000254a478>] xe_guc_init+0x30/0x3dc [xe] [ 7.759553] [<ffff80000258bc04>] xe_uc_init+0x20/0xf0 [xe] [ 7.765121] [<ffff800002542abc>] xe_gt_init_hwconfig+0x5c/0xd0 [xe] [ 7.771461] [<ffff800002537204>] xe_device_probe+0x240/0x588 [xe] [ 7.777627] [<ffff800002575448>] xe_pci_probe+0x6c0/0xa6c [xe] [ 7.783540] [<9000000000e9828c>] local_pci_probe+0x4c/0xb4 [ 7.788989] [<90000000002aa578>] work_for_cpu_fn+0x20/0x40 [ 7.794436] [<90000000002aeb50>] process_one_work+0x1a4/0x458 [ 7.800143] [<90000000002af5a0>] worker_thread+0x304/0x3fc [ 7.805591] [<90000000002bacac>] kthread+0x114/0x138 [ 7.810520] [<9000000000241f64>] ret_from_kernel_thread+0x8/0xa4 [ 7.816489] [ 7.817961] Code: 4c000020 29c3e2f9 53ff93ff <002a0001> 0015002c 03400000 02ff8063 29c04077 001500f7 [ 7.827651] [ 7.829140] ---[ end trace 0000000000000000 ]--- Revise all instances of `SZ_4K' with `PAGE_SIZE' and revise the call to `drm_gem_private_object_init()' in `*___xe_bo_create_locked()' (last call before BUG()) to use `size_t aligned_size' calculated from `PAGE_SIZE' to fix the above error. Cc: <stable@vger.kernel.org> Fixes: 4e03b58 ("drm/xe/uapi: Reject bo creation of unaligned size") Fixes: dd08ebf ("drm/xe: Introduce a new DRM driver for Intel GPUs") Tested-by: Mingcong Bai <jeffbai@aosc.io> Tested-by: Haien Liang <27873200@qq.com> Tested-by: Shirong Liu <lsr1024@qq.com> Tested-by: Haofeng Wu <s2600cw2@126.com> Link: FanFansfan@22c55ab Co-developed-by: Shang Yatsen <429839446@qq.com> Signed-off-by: Shang Yatsen <429839446@qq.com> Signed-off-by: Mingcong Bai <jeffbai@aosc.io> [Mingcong Bai: Resolved a minor merge conflict post-6.16 in drivers/gpu/drm/xe/xe_bo.c] Link: https://lore.kernel.org/all/20250613-upstream-xe-non-4k-v2-v2-1-934f82249f8a@aosc.io/ Signed-off-by: Mingcong Bai <jeffbai@aosc.io>
diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
@@ -2129,9 +2129,9 @@ struct xe_bo *xe_bo_init_locked(struct xe_device *xe, struct xe_bo *bo,
 		flags |= XE_BO_FLAG_INTERNAL_64K;
 		alignment = align >> PAGE_SHIFT;
 	} else {
-		aligned_size = ALIGN(size, SZ_4K);
+		aligned_size = ALIGN(size, PAGE_SIZE);
 		flags &= ~XE_BO_FLAG_INTERNAL_64K;
-		alignment = SZ_4K >> PAGE_SHIFT;
+		alignment = PAGE_SIZE >> PAGE_SHIFT;
 	}
 
 	if (type == ttm_bo_type_device && aligned_size != size)
@@ -2155,7 +2155,7 @@ struct xe_bo *xe_bo_init_locked(struct xe_device *xe, struct xe_bo *bo,
 #endif
 	INIT_LIST_HEAD(&bo->vram_userfault_link);
 
-	drm_gem_private_object_init(&xe->drm, &bo->ttm.base, size);
+	drm_gem_private_object_init(&xe->drm, &bo->ttm.base, aligned_size);
 
 	if (resv) {
 		ctx.allow_res_evict = !(flags & XE_BO_FLAG_NO_RESV_EVICT);
