Currently, enabling SG_DEBUG in the kernel will cause nouveau to hit a
BUG() on startup:
kernel BUG at include/linux/scatterlist.h:187!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 7 PID: 930 Comm: (udev-worker) Not tainted 6.9.0-rc3Lyude-Test+ #30
Hardware name: MSI MS-7A39/A320M GAMING PRO (MS-7A39), BIOS 1.I0 01/22/2019
RIP: 0010:sg_init_one+0x85/0xa0
Code: 69 88 32 01 83 e1 03 f6 c3 03 75 20 a8 01 75 1e 48 09 cb 41 89 54
24 08 49 89 1c 24 41 89 6c 24 0c 5b 5d 41 5c e9 7b b9 88 00 <0f> 0b 0f 0b
0f 0b 48 8b 05 5e 46 9a 01 eb b2 66 66 2e 0f 1f 84 00
RSP: 0018:ffffa776017bf6a0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffa77600d87000 RCX: 000000000000002b
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffa77680d87000
RBP: 000000000000e000 R08: 0000000000000000 R09: 0000000000000000
R10: ffff98f4c46aa508 R11: 0000000000000000 R12: ffff98f4c46aa508
R13: ffff98f4c46aa008 R14: ffffa77600d4a000 R15: ffffa77600d4a018
FS: 00007feeb5aae980(0000) GS:ffff98f5c4dc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f22cb9a4520 CR3: 00000001043ba000 CR4: 00000000003506f0
Call Trace:
<TASK>
? die+0x36/0x90
? do_trap+0xdd/0x100
? sg_init_one+0x85/0xa0
? do_error_trap+0x65/0x80
? sg_init_one+0x85/0xa0
? exc_invalid_op+0x50/0x70
? sg_init_one+0x85/0xa0
? asm_exc_invalid_op+0x1a/0x20
? sg_init_one+0x85/0xa0
nvkm_firmware_ctor+0x14a/0x250 [nouveau]
nvkm_falcon_fw_ctor+0x42/0x70 [nouveau]
ga102_gsp_booter_ctor+0xb4/0x1a0 [nouveau]
r535_gsp_oneinit+0xb3/0x15f0 [nouveau]
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? nvkm_udevice_new+0x95/0x140 [nouveau]
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? ktime_get+0x47/0xb0
? srso_return_thunk+0x5/0x5f
nvkm_subdev_oneinit_+0x4f/0x120 [nouveau]
nvkm_subdev_init_+0x39/0x140 [nouveau]
? srso_return_thunk+0x5/0x5f
nvkm_subdev_init+0x44/0x90 [nouveau]
nvkm_device_init+0x166/0x2e0 [nouveau]
nvkm_udevice_init+0x47/0x70 [nouveau]
nvkm_object_init+0x41/0x1c0 [nouveau]
nvkm_ioctl_new+0x16a/0x290 [nouveau]
? __pfx_nvkm_client_child_new+0x10/0x10 [nouveau]
? __pfx_nvkm_udevice_new+0x10/0x10 [nouveau]
nvkm_ioctl+0x126/0x290 [nouveau]
nvif_object_ctor+0x112/0x190 [nouveau]
nvif_device_ctor+0x23/0x60 [nouveau]
nouveau_cli_init+0x164/0x640 [nouveau]
nouveau_drm_device_init+0x97/0x9e0 [nouveau]
? srso_return_thunk+0x5/0x5f
? pci_update_current_state+0x72/0xb0
? srso_return_thunk+0x5/0x5f
nouveau_drm_probe+0x12c/0x280 [nouveau]
? srso_return_thunk+0x5/0x5f
local_pci_probe+0x45/0xa0
pci_device_probe+0xc7/0x270
really_probe+0xe6/0x3a0
__driver_probe_device+0x87/0x160
driver_probe_device+0x1f/0xc0
__driver_attach+0xec/0x1f0
? __pfx___driver_attach+0x10/0x10
bus_for_each_dev+0x88/0xd0
bus_add_driver+0x116/0x220
driver_register+0x59/0x100
? __pfx_nouveau_drm_init+0x10/0x10 [nouveau]
do_one_initcall+0x5b/0x320
do_init_module+0x60/0x250
init_module_from_file+0x86/0xc0
idempotent_init_module+0x120/0x2b0
__x64_sys_finit_module+0x5e/0xb0
do_syscall_64+0x83/0x160
? srso_return_thunk+0x5/0x5f
entry_SYSCALL_64_after_hwframe+0x71/0x79
RIP: 0033:0x7feeb5cc20cd
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89
f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0
ff ff 73 01 c3 48 8b 0d 1b cd 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffcf220b2c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 000055fdd2916aa0 RCX: 00007feeb5cc20cd
RDX: 0000000000000000 RSI: 000055fdd29161e0 RDI: 0000000000000035
RBP: 00007ffcf220b380 R08: 00007feeb5d8fb20 R09: 00007ffcf220b310
R10: 000055fdd2909dc0 R11: 0000000000000246 R12: 000055fdd29161e0
R13: 0000000000020000 R14: 000055fdd29203e0 R15: 000055fdd2909d80
</TASK>
We hit this when trying to initialize firmware of type
NVKM_FIRMWARE_IMG_DMA because we allocate our memory with
dma_alloc_coherent, and DMA allocations can't be turned back into memory
pages - which a scatterlist needs in order to map them.
So, fix this by allocating the memory with vmalloc instead().
V2:
* Fixup explanation as the prior one was bogus
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nvkm/core/firmware.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nvkm/core/firmware.c b/drivers/gpu/drm/nouveau/nvkm/core/firmware.c
index adc60b25f8e6c..141b0a513bf52 100644
--- a/drivers/gpu/drm/nouveau/nvkm/core/firmware.c
+++ b/drivers/gpu/drm/nouveau/nvkm/core/firmware.c
@@ -205,7 +205,9 @@ nvkm_firmware_dtor(struct nvkm_firmware *fw)
break;
case NVKM_FIRMWARE_IMG_DMA:
nvkm_memory_unref(&memory);
- dma_free_coherent(fw->device->dev, sg_dma_len(&fw->mem.sgl), fw->img, fw->phys);
+ dma_unmap_single(fw->device->dev, fw->phys, sg_dma_len(&fw->mem.sgl),
+ DMA_TO_DEVICE);
+ kfree(fw->img);
break;
case NVKM_FIRMWARE_IMG_SGT:
nvkm_memory_unref(&memory);
@@ -235,14 +237,17 @@ nvkm_firmware_ctor(const struct nvkm_firmware_func *func, const char *name,
fw->img = kmemdup(src, fw->len, GFP_KERNEL);
break;
case NVKM_FIRMWARE_IMG_DMA: {
- dma_addr_t addr;
-
len = ALIGN(fw->len, PAGE_SIZE);
- fw->img = dma_alloc_coherent(fw->device->dev, len, &addr, GFP_KERNEL);
- if (fw->img) {
- memcpy(fw->img, src, fw->len);
- fw->phys = addr;
+ fw->img = kmalloc(len, GFP_KERNEL);
+ if (!fw->img)
+ return -ENOMEM;
+
+ memcpy(fw->img, src, fw->len);
+ fw->phys = dma_map_single(fw->device->dev, fw->img, len, DMA_TO_DEVICE);
+ if (dma_mapping_error(fw->device->dev, fw->phys)) {
+ kfree(fw->img);
+ return -EFAULT;
}
sg_init_one(&fw->mem.sgl, fw->img, len);
--
2.44.0
