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// 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, 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) %
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) % 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,
};