[PATCH 4.19 20/42] net/mlx5e: Adjust to max number of channles when re-attaching

Greg Kroah-Hartman
2018-11-21T19:07:06Z

From: Yuval Avnery <yuvalav@mellanox.com>

[ Upstream commit a1f240f1801721f76bee734c50df2d9529da86e0 ]

When core driver enters deattach/attach flow after pci reset,
Number of logical CPUs may have changed.
As a result we need to update the cpu affiliated resource tables.
1. indirect rqt list
2. eq table

Reproduction (PowerPC):
echo 1000 > /sys/kernel/debug/powerpc/eeh_max_freezes
ppc64_cpu --smt=on
# Restart driver
modprobe -r ... ; modprobe ...
# Link up
ifconfig ...
# Only physical CPUs
ppc64_cpu --smt=off
# Inject PCI errors so PCI will reset - calling the pci error handler
echo 0x8000000000000000 > /sys/kernel/debug/powerpc/<PCI BUS>/err_injct_inboundA

Call trace when trying to add non-existing rqs to an indirect rqt:
mlx5e_redirect_rqt+0x84/0x260 [mlx5_core] (unreliable)
mlx5e_redirect_rqts+0x188/0x190 [mlx5_core]
mlx5e_activate_priv_channels+0x488/0x570 [mlx5_core]
mlx5e_open_locked+0xbc/0x140 [mlx5_core]
mlx5e_open+0x50/0x130 [mlx5_core]
mlx5e_nic_enable+0x174/0x1b0 [mlx5_core]
mlx5e_attach_netdev+0x154/0x290 [mlx5_core]
mlx5e_attach+0x88/0xd0 [mlx5_core]
mlx5_attach_device+0x168/0x1e0 [mlx5_core]
mlx5_load_one+0x1140/0x1210 [mlx5_core]
mlx5_pci_resume+0x6c/0xf0 [mlx5_core]

Create cq will fail when trying to use non-existing EQ.

Fixes: 89d44f0a6c73 ("net/mlx5_core: Add pci error handlers to mlx5_core driver")
Signed-off-by: Yuval Avnery <yuvalav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 27 +++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -1610,13 +1610,15 @@ static int mlx5e_alloc_cq_common(struct
int err;
u32 i;

+ err = mlx5_vector2eqn(mdev, param->eq_ix, &eqn_not_used, &irqn);
+ if (err)
+ return err;
+
err = mlx5_cqwq_create(mdev, &param->wq, param->cqc, &cq->wq,
&cq->wq_ctrl);
if (err)
return err;

- mlx5_vector2eqn(mdev, param->eq_ix, &eqn_not_used, &irqn);
-
mcq->cqe_sz = 64;
mcq->set_ci_db = cq->wq_ctrl.db.db;
mcq->arm_db = cq->wq_ctrl.db.db + 1;
@@ -1674,6 +1676,10 @@ static int mlx5e_create_cq(struct mlx5e_
int eqn;
int err;

+ err = mlx5_vector2eqn(mdev, param->eq_ix, &eqn, &irqn_not_used);
+ if (err)
+ return err;
+
inlen = MLX5_ST_SZ_BYTES(create_cq_in) +
sizeof(u64) * cq->wq_ctrl.buf.npages;
in = kvzalloc(inlen, GFP_KERNEL);
@@ -1687,8 +1693,6 @@ static int mlx5e_create_cq(struct mlx5e_
mlx5_fill_page_frag_array(&cq->wq_ctrl.buf,
(__be64 *)MLX5_ADDR_OF(create_cq_in, in, pas));

- mlx5_vector2eqn(mdev, param->eq_ix, &eqn, &irqn_not_used);
-
MLX5_SET(cqc, cqc, cq_period_mode, param->cq_period_mode);
MLX5_SET(cqc, cqc, c_eqn, eqn);
MLX5_SET(cqc, cqc, uar_page, mdev->priv.uar->index);
@@ -1908,6 +1912,10 @@ static int mlx5e_open_channel(struct mlx
int err;
int eqn;

+ err = mlx5_vector2eqn(priv->mdev, ix, &eqn, &irq);
+ if (err)
+ return err;
+
c = kvzalloc_node(sizeof(*c), GFP_KERNEL, cpu_to_node(cpu));
if (!c)
return -ENOMEM;
@@ -1924,7 +1932,6 @@ static int mlx5e_open_channel(struct mlx
c->xdp = !!params->xdp_prog;
c->stats = &priv->channel_stats[ix].ch;

- mlx5_vector2eqn(priv->mdev, ix, &eqn, &irq);
c->irq_desc = irq_to_desc(irq);

netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64);
@@ -4964,11 +4971,21 @@ int mlx5e_attach_netdev(struct mlx5e_pri
{
struct mlx5_core_dev *mdev = priv->mdev;
const struct mlx5e_profile *profile;
+ int max_nch;
int err;

profile = priv->profile;
clear_bit(MLX5E_STATE_DESTROYING, &priv->state);

+ /* max number of channels may have changed */
+ max_nch = mlx5e_get_max_num_channels(priv->mdev);
+ if (priv->channels.params.num_channels > max_nch) {
+ mlx5_core_warn(priv->mdev, "MLX5E: Reducing number of channels to %d\n", max_nch);
+ priv->channels.params.num_channels = max_nch;
+ mlx5e_build_default_indir_rqt(priv->channels.params.indirection_rqt,
+ MLX5E_INDIR_RQT_SIZE, max_nch);
+ }
+
err = profile->init_tx(priv);
if (err)
goto out;