linux_dsm_epyc7002/drivers/net/ethernet/stmicro/stmmac/chain_mode.c
Giuseppe CAVALLARO 4a7d666a72 stmmac: reorganize chain/ring modes removing Koptions
Previously we had two Koptions to decide if the stmmac
had to use either a ring or a chain to manage its descriptors.
This patch removes the Kernel configuration options and it allow us
to use the chain mode by passing a module option.
Ring mode continues to be the default.

Also with this patch, it will be easier to validate the driver built and
guarantee that all the two modes always compile fine.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-26 12:53:36 -04:00

116 lines
3.3 KiB
C

/*******************************************************************************
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.
This program is free software; you can redistribute it and/or modify it
under the terms and conditions of the GNU General Public License,
version 2, as published by the Free Software Foundation.
This program is distributed in the hope it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
The full GNU General Public License is included in this distribution in
the file called "COPYING".
Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
*******************************************************************************/
#include "stmmac.h"
static unsigned int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
{
struct stmmac_priv *priv = (struct stmmac_priv *) p;
unsigned int txsize = priv->dma_tx_size;
unsigned int entry = priv->cur_tx % txsize;
struct dma_desc *desc = priv->dma_tx + entry;
unsigned int nopaged_len = skb_headlen(skb);
unsigned int bmax;
unsigned int i = 1, len;
if (priv->plat->enh_desc)
bmax = BUF_SIZE_8KiB;
else
bmax = BUF_SIZE_2KiB;
len = nopaged_len - bmax;
desc->des2 = dma_map_single(priv->device, skb->data,
bmax, DMA_TO_DEVICE);
priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, STMMAC_CHAIN_MODE);
while (len != 0) {
entry = (++priv->cur_tx) % txsize;
desc = priv->dma_tx + entry;
if (len > bmax) {
desc->des2 = dma_map_single(priv->device,
(skb->data + bmax * i),
bmax, DMA_TO_DEVICE);
priv->hw->desc->prepare_tx_desc(desc, 0, bmax, csum,
STMMAC_CHAIN_MODE);
priv->hw->desc->set_tx_owner(desc);
priv->tx_skbuff[entry] = NULL;
len -= bmax;
i++;
} else {
desc->des2 = dma_map_single(priv->device,
(skb->data + bmax * i), len,
DMA_TO_DEVICE);
priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
STMMAC_CHAIN_MODE);
priv->hw->desc->set_tx_owner(desc);
priv->tx_skbuff[entry] = NULL;
len = 0;
}
}
return entry;
}
static unsigned int stmmac_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 stmmac_init_dma_chain(struct dma_desc *des, dma_addr_t phy_addr,
unsigned int size)
{
/*
* In chained mode the des3 points to the next element in the ring.
* The latest element has to point to the head.
*/
int i;
struct dma_desc *p = des;
dma_addr_t dma_phy = phy_addr;
for (i = 0; i < (size - 1); i++) {
dma_phy += sizeof(struct dma_desc);
p->des3 = (unsigned int)dma_phy;
p++;
}
p->des3 = (unsigned int)phy_addr;
}
const struct stmmac_chain_mode_ops chain_mode_ops = {
.is_jumbo_frm = stmmac_is_jumbo_frm,
.jumbo_frm = stmmac_jumbo_frm,
.init_dma_chain = stmmac_init_dma_chain,
};