From bfc02cc199dc6259c2f4e2af8f77c88fe8ba4cc5 Mon Sep 17 00:00:00 2001 From: Camelia Groza Date: Tue, 5 Mar 2019 11:55:54 +0200 Subject: [PATCH] sdk_dpaa: ls1043a errata: impose S/G frame realignment Scatter/Gather frames are not support on LS1043A beacuse they trigger the A010022 errata. Even though we do not advertise S/G support to the stack, we need to make sure that if S/G frames do reach the driver somehow, they trigger the errata workaround. Signed-off-by: Camelia Groza --- drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h | 7 ++++--- .../net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 23 +++++----------------- 2 files changed, 9 insertions(+), 21 deletions(-) --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h @@ -653,9 +653,10 @@ static inline void _dpa_bp_free_pf(void /* LS1043A SoC has a HW issue regarding FMan DMA transactions; The issue * manifests itself at high traffic rates when frames cross 4K memory - * boundaries or when they are not aligned to 16 bytes; For the moment, we - * use a SW workaround that realigns frames to 256 bytes. Scatter/Gather - * frames aren't supported on egress. + * boundaries, when they are not aligned to 16 bytes or when they have + * Scatter/Gather fragments; For the moment, we use a SW workaround that + * realigns frames to 256 bytes. Scatter/Gather frames aren't supported + * on egress. */ #ifndef CONFIG_PPC --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c @@ -772,18 +772,19 @@ EXPORT_SYMBOL(skb_to_contig_fd); #ifndef CONFIG_PPC /* Verify the conditions that trigger the A010022 errata: data unaligned to - * 16 bytes and 4K memory address crossings. + * 16 bytes, 4K memory address crossings and S/G fragments. */ static bool a010022_check_skb(struct sk_buff *skb, struct dpa_priv_s *priv) { - int nr_frags, i = 0; - skb_frag_t *frag; - /* Check if the headroom is aligned */ if (((uintptr_t)skb->data - priv->tx_headroom) % priv->buf_layout[TX].data_align != 0) return true; + /* Check for paged data in the skb. We do not support S/G fragments */ + if (skb_is_nonlinear(skb)) + return true; + /* Check if the headroom crosses a boundary */ if (HAS_DMA_ISSUE(skb->head, skb_headroom(skb))) return true; @@ -796,20 +797,6 @@ static bool a010022_check_skb(struct sk_ if (HAS_DMA_ISSUE(skb->head, skb_end_offset(skb))) return true; - nr_frags = skb_shinfo(skb)->nr_frags; - - while (i < nr_frags) { - frag = &skb_shinfo(skb)->frags[i]; - - /* Check if a paged fragment crosses a boundary from its - * offset to its end. - */ - if (HAS_DMA_ISSUE(frag->page_offset, frag->size)) - return true; - - i++; - } - return false; }