mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
e3ad57c967
This patch is to rework the ring management now optimized. The indexes into the ring buffer are always incremented, and the entry is accessed via doing a modulo to find the "real" position in the ring. It is inefficient, modulo is an expensive operation. The formula [(entry + 1) & (size - 1)] is now adopted on a ring that is power-of-2 in size. Then, the number of elements cannot be set by command line but it is fixed. Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
144 lines
4.0 KiB
C
144 lines
4.0 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 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 entry = priv->cur_tx;
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struct dma_desc *desc;
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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->extend_desc)
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desc = (struct dma_desc *)(priv->dma_etx + entry);
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else
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desc = priv->dma_tx + entry;
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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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if (dma_mapping_error(priv->device, desc->des2))
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return -1;
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priv->tx_skbuff_dma[entry].buf = desc->des2;
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desc->des3 = desc->des2 + BUF_SIZE_4KiB;
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priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum,
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STMMAC_RING_MODE);
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wmb();
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priv->tx_skbuff[entry] = NULL;
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entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE);
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if (priv->extend_desc)
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desc = (struct dma_desc *)(priv->dma_etx + entry);
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else
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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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if (dma_mapping_error(priv->device, desc->des2))
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return -1;
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priv->tx_skbuff_dma[entry].buf = desc->des2;
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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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STMMAC_RING_MODE);
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wmb();
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priv->hw->desc->set_tx_owner(desc);
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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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if (dma_mapping_error(priv->device, desc->des2))
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return -1;
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priv->tx_skbuff_dma[entry].buf = desc->des2;
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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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STMMAC_RING_MODE);
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}
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priv->cur_tx = entry;
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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(void *priv_ptr, struct dma_desc *p)
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{
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struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
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/* Fill DES3 in case of RING mode */
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if (priv->dma_buf_sz >= 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 as buffer */
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static void stmmac_init_desc3(struct dma_desc *p)
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{
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p->des3 = p->des2 + BUF_SIZE_8KiB;
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}
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static void stmmac_clean_desc3(void *priv_ptr, 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_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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.clean_desc3 = stmmac_clean_desc3,
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.set_16kib_bfsize = stmmac_set_16kib_bfsize,
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};
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