Rayagond Kokatanur cf32deec16 stmmac: add tx_skbuff_dma to save descriptors used by PTP
This patch adds a new pointer variable called "tx_skbuff_dma" to private
data structure. This variable will holds the physical address of packet
to be transmitted & same will be used to free/unmap the memory once the
corresponding packet is transmitted by device.

Prior to this patch the descriptor buffer pointer(ie des2) itself was
being used for freeing/unmapping the buffer memory. But in case PTP v1
with normal descriptor the field(des2) will be overwritten by device
with timestamp value, hence driver will loose the buffer pointer to be
freed/unmapped.

Signed-off-by: Rayagond Kokatanur <rayagond@vayavyalabs.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-26 12:53:37 -04:00

125 lines
3.6 KiB
C

/*******************************************************************************
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.
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, len;
if (priv->plat->enh_desc)
bmax = BUF_SIZE_8KiB;
else
bmax = BUF_SIZE_2KiB;
len = nopaged_len - bmax;
if (nopaged_len > BUF_SIZE_8KiB) {
desc->des2 = dma_map_single(priv->device, skb->data,
bmax, DMA_TO_DEVICE);
priv->tx_skbuff_dma[entry] = desc->des2;
desc->des3 = desc->des2 + BUF_SIZE_4KiB;
priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum,
STMMAC_RING_MODE);
wmb();
entry = (++priv->cur_tx) % txsize;
desc = priv->dma_tx + entry;
desc->des2 = dma_map_single(priv->device, skb->data + bmax,
len, DMA_TO_DEVICE);
priv->tx_skbuff_dma[entry] = desc->des2;
desc->des3 = desc->des2 + BUF_SIZE_4KiB;
priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
STMMAC_RING_MODE);
wmb();
priv->hw->desc->set_tx_owner(desc);
priv->tx_skbuff[entry] = NULL;
} else {
desc->des2 = dma_map_single(priv->device, skb->data,
nopaged_len, DMA_TO_DEVICE);
priv->tx_skbuff_dma[entry] = desc->des2;
desc->des3 = desc->des2 + BUF_SIZE_4KiB;
priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum,
STMMAC_RING_MODE);
}
return entry;
}
static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc)
{
unsigned int ret = 0;
if (len >= BUF_SIZE_4KiB)
ret = 1;
return ret;
}
static void stmmac_refill_desc3(int bfsize, struct dma_desc *p)
{
/* Fill DES3 in case of RING mode */
if (bfsize >= BUF_SIZE_8KiB)
p->des3 = p->des2 + BUF_SIZE_8KiB;
}
/* In ring mode we need to fill the desc3 because it is used as buffer */
static void stmmac_init_desc3(struct dma_desc *p)
{
p->des3 = p->des2 + BUF_SIZE_8KiB;
}
static void stmmac_clean_desc3(struct dma_desc *p)
{
if (unlikely(p->des3))
p->des3 = 0;
}
static int stmmac_set_16kib_bfsize(int mtu)
{
int ret = 0;
if (unlikely(mtu >= BUF_SIZE_8KiB))
ret = BUF_SIZE_16KiB;
return ret;
}
const struct stmmac_ring_mode_ops ring_mode_ops = {
.is_jumbo_frm = stmmac_is_jumbo_frm,
.jumbo_frm = stmmac_jumbo_frm,
.refill_desc3 = stmmac_refill_desc3,
.init_desc3 = stmmac_init_desc3,
.clean_desc3 = stmmac_clean_desc3,
.set_16kib_bfsize = stmmac_set_16kib_bfsize,
};