diff options
Diffstat (limited to 'drivers/net/ethernet/stmicro/stmmac/chain_mode.c')
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/chain_mode.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c new file mode 100644 index 000000000..d2cdc02d9 --- /dev/null +++ b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0-only +/******************************************************************************* + Specialised functions for managing Chained mode + + Copyright(C) 2011 STMicroelectronics Ltd + + It defines all the functions used to handle the normal/enhanced + descriptors in case of the DMA is configured to work in chained or + in ring mode. + + + Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> +*******************************************************************************/ + +#include "stmmac.h" + +static int jumbo_frm(void *p, struct sk_buff *skb, int csum) +{ + struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)p; + unsigned int nopaged_len = skb_headlen(skb); + struct stmmac_priv *priv = tx_q->priv_data; + unsigned int entry = tx_q->cur_tx; + unsigned int bmax, des2; + unsigned int i = 1, len; + struct dma_desc *desc; + + desc = tx_q->dma_tx + entry; + + if (priv->plat->enh_desc) + bmax = BUF_SIZE_8KiB; + else + bmax = BUF_SIZE_2KiB; + + len = nopaged_len - bmax; + + des2 = dma_map_single(priv->device, skb->data, + bmax, DMA_TO_DEVICE); + desc->des2 = cpu_to_le32(des2); + if (dma_mapping_error(priv->device, des2)) + return -1; + tx_q->tx_skbuff_dma[entry].buf = des2; + tx_q->tx_skbuff_dma[entry].len = bmax; + /* do not close the descriptor and do not set own bit */ + stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum, STMMAC_CHAIN_MODE, + 0, false, skb->len); + + while (len != 0) { + tx_q->tx_skbuff[entry] = NULL; + entry = STMMAC_GET_ENTRY(entry, priv->dma_tx_size); + desc = tx_q->dma_tx + entry; + + if (len > bmax) { + des2 = dma_map_single(priv->device, + (skb->data + bmax * i), + bmax, DMA_TO_DEVICE); + desc->des2 = cpu_to_le32(des2); + if (dma_mapping_error(priv->device, des2)) + return -1; + tx_q->tx_skbuff_dma[entry].buf = des2; + tx_q->tx_skbuff_dma[entry].len = bmax; + stmmac_prepare_tx_desc(priv, desc, 0, bmax, csum, + STMMAC_CHAIN_MODE, 1, false, skb->len); + len -= bmax; + i++; + } else { + des2 = dma_map_single(priv->device, + (skb->data + bmax * i), len, + DMA_TO_DEVICE); + desc->des2 = cpu_to_le32(des2); + if (dma_mapping_error(priv->device, des2)) + return -1; + tx_q->tx_skbuff_dma[entry].buf = des2; + tx_q->tx_skbuff_dma[entry].len = len; + /* last descriptor can be set now */ + stmmac_prepare_tx_desc(priv, desc, 0, len, csum, + STMMAC_CHAIN_MODE, 1, true, skb->len); + len = 0; + } + } + + tx_q->cur_tx = entry; + + return entry; +} + +static unsigned int is_jumbo_frm(int len, int enh_desc) +{ + unsigned int ret = 0; + + if ((enh_desc && (len > BUF_SIZE_8KiB)) || + (!enh_desc && (len > BUF_SIZE_2KiB))) { + ret = 1; + } + + return ret; +} + +static void init_dma_chain(void *des, dma_addr_t phy_addr, + unsigned int size, unsigned int extend_desc) +{ + /* + * In chained mode the des3 points to the next element in the ring. + * The latest element has to point to the head. + */ + int i; + dma_addr_t dma_phy = phy_addr; + + if (extend_desc) { + struct dma_extended_desc *p = (struct dma_extended_desc *)des; + for (i = 0; i < (size - 1); i++) { + dma_phy += sizeof(struct dma_extended_desc); + p->basic.des3 = cpu_to_le32((unsigned int)dma_phy); + p++; + } + p->basic.des3 = cpu_to_le32((unsigned int)phy_addr); + + } else { + struct dma_desc *p = (struct dma_desc *)des; + for (i = 0; i < (size - 1); i++) { + dma_phy += sizeof(struct dma_desc); + p->des3 = cpu_to_le32((unsigned int)dma_phy); + p++; + } + p->des3 = cpu_to_le32((unsigned int)phy_addr); + } +} + +static void refill_desc3(void *priv_ptr, struct dma_desc *p) +{ + struct stmmac_rx_queue *rx_q = (struct stmmac_rx_queue *)priv_ptr; + struct stmmac_priv *priv = rx_q->priv_data; + + if (priv->hwts_rx_en && !priv->extend_desc) + /* NOTE: Device will overwrite des3 with timestamp value if + * 1588-2002 time stamping is enabled, hence reinitialize it + * to keep explicit chaining in the descriptor. + */ + p->des3 = cpu_to_le32((unsigned int)(rx_q->dma_rx_phy + + (((rx_q->dirty_rx) + 1) % + priv->dma_rx_size) * + sizeof(struct dma_desc))); +} + +static void clean_desc3(void *priv_ptr, struct dma_desc *p) +{ + struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr; + struct stmmac_priv *priv = tx_q->priv_data; + unsigned int entry = tx_q->dirty_tx; + + if (tx_q->tx_skbuff_dma[entry].last_segment && !priv->extend_desc && + priv->hwts_tx_en) + /* NOTE: Device will overwrite des3 with timestamp value if + * 1588-2002 time stamping is enabled, hence reinitialize it + * to keep explicit chaining in the descriptor. + */ + p->des3 = cpu_to_le32((unsigned int)((tx_q->dma_tx_phy + + ((tx_q->dirty_tx + 1) % + priv->dma_tx_size)) + * sizeof(struct dma_desc))); +} + +const struct stmmac_mode_ops chain_mode_ops = { + .init = init_dma_chain, + .is_jumbo_frm = is_jumbo_frm, + .jumbo_frm = jumbo_frm, + .refill_desc3 = refill_desc3, + .clean_desc3 = clean_desc3, +}; |