684901a6df
For the higher mtu sizes requiring the buffer size greater than 8192, the buffers are sent or received using multiple dma descriptors/ same descriptor with option of multi buffer handling. It was observed during tests that the driver was missing on data packets during the normal ping operations if the data buffers being used catered to jumbo frame handling. The memory barrriers are added in between preparation of dma descriptors in the jumbo frame handling path to ensure all instructions before enabling the dma are complete. Signed-off-by: Deepak Sikri <deepak.sikri@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
128 lines
3.6 KiB
C
128 lines
3.6 KiB
C
/*******************************************************************************
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Specialised functions for managing Ring mode
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Copyright(C) 2011 STMicroelectronics Ltd
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It defines all the functions used to handle the normal/enhanced
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descriptors in case of the DMA is configured to work in chained or
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in ring mode.
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This program is free software; you can redistribute it and/or modify it
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under the terms and conditions of the GNU General Public License,
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version 2, as published by the Free Software Foundation.
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This program is distributed in the hope it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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The full GNU General Public License is included in this distribution in
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the file called "COPYING".
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Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
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*******************************************************************************/
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#include "stmmac.h"
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static unsigned int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
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{
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struct stmmac_priv *priv = (struct stmmac_priv *) p;
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unsigned int txsize = priv->dma_tx_size;
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unsigned int entry = priv->cur_tx % txsize;
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struct dma_desc *desc = priv->dma_tx + entry;
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unsigned int nopaged_len = skb_headlen(skb);
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unsigned int bmax, len;
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if (priv->plat->enh_desc)
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bmax = BUF_SIZE_8KiB;
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else
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bmax = BUF_SIZE_2KiB;
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len = nopaged_len - bmax;
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if (nopaged_len > BUF_SIZE_8KiB) {
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desc->des2 = dma_map_single(priv->device, skb->data,
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bmax, DMA_TO_DEVICE);
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desc->des3 = desc->des2 + BUF_SIZE_4KiB;
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priv->hw->desc->prepare_tx_desc(desc, 1, bmax,
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csum);
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wmb();
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entry = (++priv->cur_tx) % txsize;
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desc = priv->dma_tx + entry;
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desc->des2 = dma_map_single(priv->device, skb->data + bmax,
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len, DMA_TO_DEVICE);
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desc->des3 = desc->des2 + BUF_SIZE_4KiB;
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priv->hw->desc->prepare_tx_desc(desc, 0, len, csum);
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wmb();
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priv->hw->desc->set_tx_owner(desc);
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priv->tx_skbuff[entry] = NULL;
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} else {
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desc->des2 = dma_map_single(priv->device, skb->data,
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nopaged_len, DMA_TO_DEVICE);
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desc->des3 = desc->des2 + BUF_SIZE_4KiB;
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priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum);
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}
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return entry;
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}
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static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc)
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{
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unsigned int ret = 0;
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if (len >= BUF_SIZE_4KiB)
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ret = 1;
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return ret;
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}
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static void stmmac_refill_desc3(int bfsize, struct dma_desc *p)
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{
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/* Fill DES3 in case of RING mode */
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if (bfsize >= BUF_SIZE_8KiB)
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p->des3 = p->des2 + BUF_SIZE_8KiB;
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}
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/* In ring mode we need to fill the desc3 because it is used
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* as buffer */
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static void stmmac_init_desc3(int des3_as_data_buf, struct dma_desc *p)
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{
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if (unlikely(des3_as_data_buf))
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p->des3 = p->des2 + BUF_SIZE_8KiB;
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}
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static void stmmac_init_dma_chain(struct dma_desc *des, dma_addr_t phy_addr,
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unsigned int size)
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{
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}
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static void stmmac_clean_desc3(struct dma_desc *p)
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{
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if (unlikely(p->des3))
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p->des3 = 0;
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}
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static int stmmac_set_16kib_bfsize(int mtu)
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{
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int ret = 0;
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if (unlikely(mtu >= BUF_SIZE_8KiB))
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ret = BUF_SIZE_16KiB;
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return ret;
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}
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const struct stmmac_ring_mode_ops ring_mode_ops = {
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.is_jumbo_frm = stmmac_is_jumbo_frm,
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.jumbo_frm = stmmac_jumbo_frm,
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.refill_desc3 = stmmac_refill_desc3,
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.init_desc3 = stmmac_init_desc3,
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.init_dma_chain = stmmac_init_dma_chain,
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.clean_desc3 = stmmac_clean_desc3,
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.set_16kib_bfsize = stmmac_set_16kib_bfsize,
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};
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