The dpaa-eth driver is written for PowerPC and Arm SoCs which have 1-24 CPUs. It depends on CONFIG_NR_CPUS having a reasonably small value in Kconfig. Otherwise, there are 2 functions which allocate on-stack arrays of NR_CPUS elements, and these can quickly explode in size, leading to warnings such as:
drivers/net/ethernet/freescale/dpaa/dpaa_eth.c:3280:12: warning: stack frame size (16664) exceeds limit (2048) in 'dpaa_eth_probe' [-Wframe-larger-than] The problem is twofold: - Reducing the array size to the boot-time num_possible_cpus() (rather than the compile-time NR_CPUS) creates a variable-length array, which should be avoided in the Linux kernel. - Using NR_CPUS as an array size makes the driver blow up in stack consumption with generic, as opposed to hand-crafted, .config files. A simple solution is to use dynamic allocation for num_possible_cpus() elements (aka a small number determined at runtime). Link: https://lore.kernel.org/all/202406261920.l5pzm1rj-...@intel.com/ Signed-off-by: Vladimir Oltean <vladimir.olt...@nxp.com> --- .../net/ethernet/freescale/dpaa/dpaa_eth.c | 20 ++++++++++++++----- .../ethernet/freescale/dpaa/dpaa_ethtool.c | 10 +++++++++- 2 files changed, 24 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c index ddeb0a5f2317..c856b556929d 100644 --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c @@ -931,14 +931,18 @@ static inline void dpaa_setup_egress(const struct dpaa_priv *priv, } } -static void dpaa_fq_setup(struct dpaa_priv *priv, - const struct dpaa_fq_cbs *fq_cbs, - struct fman_port *tx_port) +static int dpaa_fq_setup(struct dpaa_priv *priv, + const struct dpaa_fq_cbs *fq_cbs, + struct fman_port *tx_port) { int egress_cnt = 0, conf_cnt = 0, num_portals = 0, portal_cnt = 0, cpu; const cpumask_t *affine_cpus = qman_affine_cpus(); - u16 channels[NR_CPUS]; struct dpaa_fq *fq; + u16 *channels; + + channels = kcalloc(num_possible_cpus(), sizeof(u16), GFP_KERNEL); + if (!channels) + return -ENOMEM; for_each_cpu_and(cpu, affine_cpus, cpu_online_mask) channels[num_portals++] = qman_affine_channel(cpu); @@ -997,6 +1001,10 @@ static void dpaa_fq_setup(struct dpaa_priv *priv, break; } } + + kfree(channels); + + return 0; } static inline int dpaa_tx_fq_to_id(const struct dpaa_priv *priv, @@ -3416,7 +3424,9 @@ static int dpaa_eth_probe(struct platform_device *pdev) */ dpaa_eth_add_channel(priv->channel, &pdev->dev); - dpaa_fq_setup(priv, &dpaa_fq_cbs, priv->mac_dev->port[TX]); + err = dpaa_fq_setup(priv, &dpaa_fq_cbs, priv->mac_dev->port[TX]); + if (err) + goto free_dpaa_bps; /* Create a congestion group for this netdev, with * dynamically-allocated CGR ID. diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_ethtool.c b/drivers/net/ethernet/freescale/dpaa/dpaa_ethtool.c index 5bd0b36d1feb..3f8cd4a7d845 100644 --- a/drivers/net/ethernet/freescale/dpaa/dpaa_ethtool.c +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_ethtool.c @@ -457,12 +457,16 @@ static int dpaa_set_coalesce(struct net_device *dev, struct netlink_ext_ack *extack) { const cpumask_t *cpus = qman_affine_cpus(); - bool needs_revert[NR_CPUS] = {false}; struct qman_portal *portal; u32 period, prev_period; u8 thresh, prev_thresh; + bool *needs_revert; int cpu, res; + needs_revert = kcalloc(num_possible_cpus(), sizeof(bool), GFP_KERNEL); + if (!needs_revert) + return -ENOMEM; + period = c->rx_coalesce_usecs; thresh = c->rx_max_coalesced_frames; @@ -485,6 +489,8 @@ static int dpaa_set_coalesce(struct net_device *dev, needs_revert[cpu] = true; } + kfree(needs_revert); + return 0; revert_values: @@ -498,6 +504,8 @@ static int dpaa_set_coalesce(struct net_device *dev, qman_dqrr_set_ithresh(portal, prev_thresh); } + kfree(needs_revert); + return res; } -- 2.34.1
