--- /dev/null
+/*******************************************************************************
+ 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 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);
+ if (dma_mapping_error(priv->device, desc->des2))
+ return -1;
+ priv->tx_skbuff_dma[entry].buf = desc->des2;
+ priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, STMMAC_CHAIN_MODE);
+
+ while (len != 0) {
+ priv->tx_skbuff[entry] = NULL;
+ 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);
+ if (dma_mapping_error(priv->device, desc->des2))
+ return -1;
+ priv->tx_skbuff_dma[entry].buf = desc->des2;
+ priv->hw->desc->prepare_tx_desc(desc, 0, bmax, csum,
+ STMMAC_CHAIN_MODE);
+ priv->hw->desc->set_tx_owner(desc);
+ len -= bmax;
+ i++;
+ } else {
+ desc->des2 = dma_map_single(priv->device,
+ (skb->data + bmax * i), len,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(priv->device, desc->des2))
+ return -1;
+ priv->tx_skbuff_dma[entry].buf = desc->des2;
+ priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
+ STMMAC_CHAIN_MODE);
+ priv->hw->desc->set_tx_owner(desc);
+ 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(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 = (unsigned int)dma_phy;
+ p++;
+ }
+ p->basic.des3 = (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 = (unsigned int)dma_phy;
+ p++;
+ }
+ p->des3 = (unsigned int)phy_addr;
+ }
+}
+
+static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p)
+{
+ struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+
+ 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 = (unsigned int)(priv->dma_rx_phy +
+ (((priv->dirty_rx) + 1) %
+ priv->dma_rx_size) *
+ sizeof(struct dma_desc));
+}
+
+static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
+{
+ struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+
+ if (priv->hw->desc->get_tx_ls(p) && !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 = (unsigned int)(priv->dma_tx_phy +
+ (((priv->dirty_tx + 1) %
+ priv->dma_tx_size) *
+ sizeof(struct dma_desc)));
+}
+
+const struct stmmac_mode_ops chain_mode_ops = {
+ .init = stmmac_init_dma_chain,
+ .is_jumbo_frm = stmmac_is_jumbo_frm,
+ .jumbo_frm = stmmac_jumbo_frm,
+ .refill_desc3 = stmmac_refill_desc3,
+ .clean_desc3 = stmmac_clean_desc3,
+};
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