linux-zen-desktop/drivers/net/ethernet/stmicro/stmmac/ring_mode.c

147 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*******************************************************************************
Specialised functions for managing Ring 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(struct stmmac_tx_queue *tx_q, struct sk_buff *skb,
int csum)
{
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, len, des2;
struct dma_desc *desc;
if (priv->extend_desc)
desc = (struct dma_desc *)(tx_q->dma_etx + entry);
else
desc = tx_q->dma_tx + entry;
if (priv->plat->enh_desc)
bmax = BUF_SIZE_8KiB;
else
bmax = BUF_SIZE_2KiB;
len = nopaged_len - bmax;
if (nopaged_len > BUF_SIZE_8KiB) {
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;
tx_q->tx_skbuff_dma[entry].is_jumbo = true;
desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum,
STMMAC_RING_MODE, 0, false, skb->len);
tx_q->tx_skbuff[entry] = NULL;
entry = STMMAC_GET_ENTRY(entry, priv->dma_conf.dma_tx_size);
if (priv->extend_desc)
desc = (struct dma_desc *)(tx_q->dma_etx + entry);
else
desc = tx_q->dma_tx + entry;
des2 = dma_map_single(priv->device, skb->data + bmax, 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;
tx_q->tx_skbuff_dma[entry].is_jumbo = true;
desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
stmmac_prepare_tx_desc(priv, desc, 0, len, csum,
STMMAC_RING_MODE, 1, !skb_is_nonlinear(skb),
skb->len);
} else {
des2 = dma_map_single(priv->device, skb->data,
nopaged_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 = nopaged_len;
tx_q->tx_skbuff_dma[entry].is_jumbo = true;
desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
stmmac_prepare_tx_desc(priv, desc, 1, nopaged_len, csum,
STMMAC_RING_MODE, 0, !skb_is_nonlinear(skb),
skb->len);
}
tx_q->cur_tx = entry;
return entry;
}
static unsigned int is_jumbo_frm(int len, int enh_desc)
{
unsigned int ret = 0;
if (len >= BUF_SIZE_4KiB)
ret = 1;
return ret;
}
static void refill_desc3(struct stmmac_rx_queue *rx_q, struct dma_desc *p)
{
struct stmmac_priv *priv = rx_q->priv_data;
/* Fill DES3 in case of RING mode */
if (priv->dma_conf.dma_buf_sz == BUF_SIZE_16KiB)
p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
}
/* In ring mode we need to fill the desc3 because it is used as buffer */
static void init_desc3(struct dma_desc *p)
{
p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
}
static void clean_desc3(struct stmmac_tx_queue *tx_q, struct dma_desc *p)
{
struct stmmac_priv *priv = tx_q->priv_data;
unsigned int entry = tx_q->dirty_tx;
/* des3 is only used for jumbo frames tx or time stamping */
if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo ||
(tx_q->tx_skbuff_dma[entry].last_segment &&
!priv->extend_desc && priv->hwts_tx_en)))
p->des3 = 0;
}
static int set_16kib_bfsize(int mtu)
{
int ret = 0;
if (unlikely(mtu > BUF_SIZE_8KiB))
ret = BUF_SIZE_16KiB;
return ret;
}
const struct stmmac_mode_ops ring_mode_ops = {
.is_jumbo_frm = is_jumbo_frm,
.jumbo_frm = jumbo_frm,
.refill_desc3 = refill_desc3,
.init_desc3 = init_desc3,
.clean_desc3 = clean_desc3,
.set_16kib_bfsize = set_16kib_bfsize,
};