stmmac: add CHAINED descriptor mode support (V4)
This patch enhances the STMMAC driver to support CHAINED mode of
descriptor.
STMMAC supports DMA descriptor to operate both in dual buffer(RING)
and linked-list(CHAINED) mode. In RING mode (default) each descriptor
points to two data buffer pointers whereas in CHAINED mode they point
to only one data buffer pointer.
In CHAINED mode each descriptor will have pointer to next descriptor in
the list, hence creating the explicit chaining in the descriptor itself,
whereas such explicit chaining is not possible in RING mode.
First version of this work has been done by Rayagond.
Then the patch has been reworked avoiding ifdef inside the C code.
A new header file has been added to define all the functions needed for
managing enhanced and normal descriptors.
In fact, these have to be specialized according to the ring/chain usage.
Two new C files have been also added to implement the helper routines
needed to manage: jumbo frames, chain and ring setup (i.e. desc3).
Signed-off-by: Rayagond Kokatanur <rayagond@vayavyalabs.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index bf895cb..5eccd99 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2,7 +2,7 @@
This is the driver for the ST MAC 10/100/1000 on-chip Ethernet controllers.
ST Ethernet IPs are built around a Synopsys IP Core.
- Copyright (C) 2007-2009 STMicroelectronics Ltd
+ Copyright(C) 2007-2011 STMicroelectronics Ltd
This program is free software; you can redistribute it and/or modify it
under the terms and conditions of the GNU General Public License,
@@ -41,17 +41,16 @@
#include <linux/if_ether.h>
#include <linux/crc32.h>
#include <linux/mii.h>
-#include <linux/phy.h>
#include <linux/if.h>
#include <linux/if_vlan.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/prefetch.h>
-#include "stmmac.h"
#ifdef CONFIG_STMMAC_DEBUG_FS
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#endif
+#include "stmmac.h"
#define STMMAC_RESOURCE_NAME "stmmaceth"
@@ -388,11 +387,28 @@
}
}
+static int stmmac_set_bfsize(int mtu, int bufsize)
+{
+ int ret = bufsize;
+
+ if (mtu >= BUF_SIZE_4KiB)
+ ret = BUF_SIZE_8KiB;
+ else if (mtu >= BUF_SIZE_2KiB)
+ ret = BUF_SIZE_4KiB;
+ else if (mtu >= DMA_BUFFER_SIZE)
+ ret = BUF_SIZE_2KiB;
+ else
+ ret = DMA_BUFFER_SIZE;
+
+ return ret;
+}
+
/**
* init_dma_desc_rings - init the RX/TX descriptor rings
* @dev: net device structure
* Description: this function initializes the DMA RX/TX descriptors
- * and allocates the socket buffers.
+ * and allocates the socket buffers. It suppors the chained and ring
+ * modes.
*/
static void init_dma_desc_rings(struct net_device *dev)
{
@@ -401,31 +417,24 @@
struct sk_buff *skb;
unsigned int txsize = priv->dma_tx_size;
unsigned int rxsize = priv->dma_rx_size;
- unsigned int bfsize = priv->dma_buf_sz;
- int buff2_needed = 0, dis_ic = 0;
+ unsigned int bfsize;
+ int dis_ic = 0;
+ int des3_as_data_buf = 0;
- /* Set the Buffer size according to the MTU;
- * indeed, in case of jumbo we need to bump-up the buffer sizes.
- */
- if (unlikely(dev->mtu >= BUF_SIZE_8KiB))
- bfsize = BUF_SIZE_16KiB;
- else if (unlikely(dev->mtu >= BUF_SIZE_4KiB))
- bfsize = BUF_SIZE_8KiB;
- else if (unlikely(dev->mtu >= BUF_SIZE_2KiB))
- bfsize = BUF_SIZE_4KiB;
- else if (unlikely(dev->mtu >= DMA_BUFFER_SIZE))
- bfsize = BUF_SIZE_2KiB;
+ /* Set the max buffer size according to the DESC mode
+ * and the MTU. Note that RING mode allows 16KiB bsize. */
+ bfsize = priv->hw->ring->set_16kib_bfsize(dev->mtu);
+
+ if (bfsize == BUF_SIZE_16KiB)
+ des3_as_data_buf = 1;
else
- bfsize = DMA_BUFFER_SIZE;
+ bfsize = stmmac_set_bfsize(dev->mtu, priv->dma_buf_sz);
#ifdef CONFIG_STMMAC_TIMER
/* Disable interrupts on completion for the reception if timer is on */
if (likely(priv->tm->enable))
dis_ic = 1;
#endif
- /* If the MTU exceeds 8k so use the second buffer in the chain */
- if (bfsize >= BUF_SIZE_8KiB)
- buff2_needed = 1;
DBG(probe, INFO, "stmmac: txsize %d, rxsize %d, bfsize %d\n",
txsize, rxsize, bfsize);
@@ -453,7 +462,7 @@
return;
}
- DBG(probe, INFO, "stmmac (%s) DMA desc rings: virt addr (Rx %p, "
+ DBG(probe, INFO, "stmmac (%s) DMA desc: virt addr (Rx %p, "
"Tx %p)\n\tDMA phy addr (Rx 0x%08x, Tx 0x%08x)\n",
dev->name, priv->dma_rx, priv->dma_tx,
(unsigned int)priv->dma_rx_phy, (unsigned int)priv->dma_tx_phy);
@@ -475,8 +484,9 @@
bfsize, DMA_FROM_DEVICE);
p->des2 = priv->rx_skbuff_dma[i];
- if (unlikely(buff2_needed))
- p->des3 = p->des2 + BUF_SIZE_8KiB;
+
+ priv->hw->ring->init_desc3(des3_as_data_buf, p);
+
DBG(probe, INFO, "[%p]\t[%p]\t[%x]\n", priv->rx_skbuff[i],
priv->rx_skbuff[i]->data, priv->rx_skbuff_dma[i]);
}
@@ -490,6 +500,12 @@
priv->tx_skbuff[i] = NULL;
priv->dma_tx[i].des2 = 0;
}
+
+ /* In case of Chained mode this sets the des3 to the next
+ * element in the chain */
+ priv->hw->ring->init_dma_chain(priv->dma_rx, priv->dma_rx_phy, rxsize);
+ priv->hw->ring->init_dma_chain(priv->dma_tx, priv->dma_tx_phy, txsize);
+
priv->dirty_tx = 0;
priv->cur_tx = 0;
@@ -620,8 +636,7 @@
dma_unmap_single(priv->device, p->des2,
priv->hw->desc->get_tx_len(p),
DMA_TO_DEVICE);
- if (unlikely(p->des3))
- p->des3 = 0;
+ priv->hw->ring->clean_desc3(p);
if (likely(skb != NULL)) {
/*
@@ -728,7 +743,6 @@
*/
static void stmmac_tx_err(struct stmmac_priv *priv)
{
-
netif_stop_queue(priv->dev);
priv->hw->dma->stop_tx(priv->ioaddr);
@@ -1028,47 +1042,6 @@
return 0;
}
-static unsigned int stmmac_handle_jumbo_frames(struct sk_buff *skb,
- struct net_device *dev,
- int csum_insertion)
-{
- struct stmmac_priv *priv = netdev_priv(dev);
- unsigned int nopaged_len = skb_headlen(skb);
- unsigned int txsize = priv->dma_tx_size;
- unsigned int entry = priv->cur_tx % txsize;
- struct dma_desc *desc = priv->dma_tx + entry;
-
- if (nopaged_len > BUF_SIZE_8KiB) {
-
- int buf2_size = nopaged_len - BUF_SIZE_8KiB;
-
- desc->des2 = dma_map_single(priv->device, skb->data,
- BUF_SIZE_8KiB, DMA_TO_DEVICE);
- desc->des3 = desc->des2 + BUF_SIZE_4KiB;
- priv->hw->desc->prepare_tx_desc(desc, 1, BUF_SIZE_8KiB,
- csum_insertion);
-
- entry = (++priv->cur_tx) % txsize;
- desc = priv->dma_tx + entry;
-
- desc->des2 = dma_map_single(priv->device,
- skb->data + BUF_SIZE_8KiB,
- buf2_size, DMA_TO_DEVICE);
- desc->des3 = desc->des2 + BUF_SIZE_4KiB;
- priv->hw->desc->prepare_tx_desc(desc, 0, buf2_size,
- csum_insertion);
- 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);
- desc->des3 = desc->des2 + BUF_SIZE_4KiB;
- priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len,
- csum_insertion);
- }
- return entry;
-}
-
/**
* stmmac_xmit:
* @skb : the socket buffer
@@ -1083,6 +1056,7 @@
int i, csum_insertion = 0;
int nfrags = skb_shinfo(skb)->nr_frags;
struct dma_desc *desc, *first;
+ unsigned int nopaged_len = skb_headlen(skb);
if (unlikely(stmmac_tx_avail(priv) < nfrags + 1)) {
if (!netif_queue_stopped(dev)) {
@@ -1103,7 +1077,7 @@
pr_info("stmmac xmit:\n"
"\tskb addr %p - len: %d - nopaged_len: %d\n"
"\tn_frags: %d - ip_summed: %d - %s gso\n",
- skb, skb->len, skb_headlen(skb), nfrags, skb->ip_summed,
+ skb, skb->len, nopaged_len, nfrags, skb->ip_summed,
!skb_is_gso(skb) ? "isn't" : "is");
#endif
@@ -1116,14 +1090,14 @@
if ((nfrags > 0) || (skb->len > ETH_FRAME_LEN))
pr_debug("stmmac xmit: skb len: %d, nopaged_len: %d,\n"
"\t\tn_frags: %d, ip_summed: %d\n",
- skb->len, skb_headlen(skb), nfrags, skb->ip_summed);
+ skb->len, nopaged_len, nfrags, skb->ip_summed);
#endif
priv->tx_skbuff[entry] = skb;
- if (unlikely(skb->len >= BUF_SIZE_4KiB)) {
- entry = stmmac_handle_jumbo_frames(skb, dev, csum_insertion);
+
+ if (priv->hw->ring->is_jumbo_frm(skb->len, priv->plat->enh_desc)) {
+ entry = priv->hw->ring->jumbo_frm(priv, skb, csum_insertion);
desc = priv->dma_tx + entry;
} else {
- unsigned int nopaged_len = skb_headlen(skb);
desc->des2 = dma_map_single(priv->device, skb->data,
nopaged_len, DMA_TO_DEVICE);
priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len,
@@ -1214,11 +1188,10 @@
DMA_FROM_DEVICE);
(p + entry)->des2 = priv->rx_skbuff_dma[entry];
- if (unlikely(priv->plat->has_gmac)) {
- if (bfsize >= BUF_SIZE_8KiB)
- (p + entry)->des3 =
- (p + entry)->des2 + BUF_SIZE_8KiB;
- }
+
+ if (unlikely(priv->plat->has_gmac))
+ priv->hw->ring->refill_desc3(bfsize, p + entry);
+
RX_DBG(KERN_INFO "\trefill entry #%d\n", entry);
}
wmb();
@@ -1795,6 +1768,7 @@
device->desc = &ndesc_ops;
priv->hw = device;
+ priv->hw->ring = &ring_mode_ops;
if (device_can_wakeup(priv->device)) {
priv->wolopts = WAKE_MAGIC; /* Magic Frame as default */