[PATCH AUTOSEL 4.14 28/35] net: hns: Fix WARNING when remove HNS driver with SMMU enabled

Sasha Levin
2019-04-24T14:48:29Z

From: Yonglong Liu <liuyonglong@huawei.com>

[ Upstream commit 8601a99d7c0256b7a7fdd1ab14cf6c1f1dfcadc6 ]

When enable SMMU, remove HNS driver will cause a WARNING:

[ 141.924177] WARNING: CPU: 36 PID: 2708 at drivers/iommu/dma-iommu.c:443 __iommu_dma_unmap+0xc0/0xc8
[ 141.954673] Modules linked in: hns_enet_drv(-)
[ 141.963615] CPU: 36 PID: 2708 Comm: rmmod Tainted: G W 5.0.0-rc1-28723-gb729c57de95c-dirty #32
[ 141.983593] Hardware name: Huawei D05/D05, BIOS Hisilicon D05 UEFI Nemo 1.8 RC0 08/31/2017
[ 142.000244] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 142.009886] pc : __iommu_dma_unmap+0xc0/0xc8
[ 142.018476] lr : __iommu_dma_unmap+0xc0/0xc8
[ 142.027066] sp : ffff000013533b90
[ 142.033728] x29: ffff000013533b90 x28: ffff8013e6983600
[ 142.044420] x27: 0000000000000000 x26: 0000000000000000
[ 142.055113] x25: 0000000056000000 x24: 0000000000000015
[ 142.065806] x23: 0000000000000028 x22: ffff8013e66eee68
[ 142.076499] x21: ffff8013db919800 x20: 0000ffffefbff000
[ 142.087192] x19: 0000000000001000 x18: 0000000000000007
[ 142.097885] x17: 000000000000000e x16: 0000000000000001
[ 142.108578] x15: 0000000000000019 x14: 363139343a70616d
[ 142.119270] x13: 6e75656761705f67 x12: 0000000000000000
[ 142.129963] x11: 00000000ffffffff x10: 0000000000000006
[ 142.140656] x9 : 1346c1aa88093500 x8 : ffff0000114de4e0
[ 142.151349] x7 : 6662666578303d72 x6 : ffff0000105ffec8
[ 142.162042] x5 : 0000000000000000 x4 : 0000000000000000
[ 142.172734] x3 : 00000000ffffffff x2 : ffff0000114de500
[ 142.183427] x1 : 0000000000000000 x0 : 0000000000000035
[ 142.194120] Call trace:
[ 142.199030] __iommu_dma_unmap+0xc0/0xc8
[ 142.206920] iommu_dma_unmap_page+0x20/0x28
[ 142.215335] __iommu_unmap_page+0x40/0x60
[ 142.223399] hnae_unmap_buffer+0x110/0x134
[ 142.231639] hnae_free_desc+0x6c/0x10c
[ 142.239177] hnae_fini_ring+0x14/0x34
[ 142.246540] hnae_fini_queue+0x2c/0x40
[ 142.254080] hnae_put_handle+0x38/0xcc
[ 142.261619] hns_nic_dev_remove+0x54/0xfc [hns_enet_drv]
[ 142.272312] platform_drv_remove+0x24/0x64
[ 142.280552] device_release_driver_internal+0x17c/0x20c
[ 142.291070] driver_detach+0x4c/0x90
[ 142.298259] bus_remove_driver+0x5c/0xd8
[ 142.306148] driver_unregister+0x2c/0x54
[ 142.314037] platform_driver_unregister+0x10/0x18
[ 142.323505] hns_nic_dev_driver_exit+0x14/0xf0c [hns_enet_drv]
[ 142.335248] __arm64_sys_delete_module+0x214/0x25c
[ 142.344891] el0_svc_common+0xb0/0x10c
[ 142.352430] el0_svc_handler+0x24/0x80
[ 142.359968] el0_svc+0x8/0x7c0
[ 142.366104] ---[ end trace 60ad1cd58e63c407 ]---

The tx ring buffer map when xmit and unmap when xmit done. So in
hnae_init_ring() did not map tx ring buffer, but in hnae_fini_ring()
have a unmap operation for tx ring buffer, which is already unmapped
when xmit done, than cause this WARNING.

The hnae_alloc_buffers() is called in hnae_init_ring(),
so the hnae_free_buffers() should be in hnae_fini_ring(), not in
hnae_free_desc().

In hnae_fini_ring(), adds a check is_rx_ring() as in hnae_init_ring().
When the ring buffer is tx ring, adds a piece of code to ensure that
the tx ring is unmap.

Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/hisilicon/hns/hnae.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/hisilicon/hns/hnae.c b/drivers/net/ethernet/hisilicon/hns/hnae.c
index 79d03f8ee7b1..c7fa97a7e1f4 100644
--- a/drivers/net/ethernet/hisilicon/hns/hnae.c
+++ b/drivers/net/ethernet/hisilicon/hns/hnae.c
@@ -150,7 +150,6 @@ static int hnae_alloc_buffers(struct hnae_ring *ring)
/* free desc along with its attached buffer */
static void hnae_free_desc(struct hnae_ring *ring)
{
- hnae_free_buffers(ring);
dma_unmap_single(ring_to_dev(ring), ring->desc_dma_addr,
ring->desc_num * sizeof(ring->desc[0]),
ring_to_dma_dir(ring));
@@ -183,6 +182,9 @@ static int hnae_alloc_desc(struct hnae_ring *ring)
/* fini ring, also free the buffer for the ring */
static void hnae_fini_ring(struct hnae_ring *ring)
{
+ if (is_rx_ring(ring))
+ hnae_free_buffers(ring);
+
hnae_free_desc(ring);
kfree(ring->desc_cb);
ring->desc_cb = NULL;
--
2.19.1