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-rw-r--r--target/linux/leon/patches-2.6.36/024-greth_resolve_smp_and_other_issues.patch399
1 files changed, 0 insertions, 399 deletions
diff --git a/target/linux/leon/patches-2.6.36/024-greth_resolve_smp_and_other_issues.patch b/target/linux/leon/patches-2.6.36/024-greth_resolve_smp_and_other_issues.patch
deleted file mode 100644
index c2293cae0..000000000
--- a/target/linux/leon/patches-2.6.36/024-greth_resolve_smp_and_other_issues.patch
+++ /dev/null
@@ -1,399 +0,0 @@
-From 4439d933884ee3c7e320b8d33bd2e268dd5b6fa5 Mon Sep 17 00:00:00 2001
-From: Daniel Hellstrom <daniel@gaisler.com>
-Date: Wed, 1 Dec 2010 11:40:19 +0100
-Subject: [PATCH] GRETH: resolve SMP issues and other problems
-
-Fixes the following:
-1. POLL should not enable IRQ when work is not completed
-2. No locking between TX descriptor cleaning and XMIT descriptor handling
-3. No locking between RX POLL and XMIT modifying control register
-4. Since TX cleaning (called from POLL) is running in parallel with XMIT
- unnecessary locking is needed.
-5. IRQ handler looks at RX frame status solely, this is wrong when IRQ is
- temporarily disabled (in POLL), and when IRQ is shared.
-6. IRQ handler clears IRQ status, which is unnecessary
-7. TX queue was stopped in preventing cause when not MAX_SKB_FRAGS+1 descriptors
- were available after a SKB been scheduled by XMIT. Instead the TX queue is
- stopped first when not enough descriptors are available upon entering XMIT.
-
-It was hard to split up this patch in smaller pieces since all are tied
-together somehow.
-
-Note the RX flag used in the interrupt handler does not signal that interrtupt
-was asserted, but that a frame was received. Same goes for TX. Also, IRQ is not
-asserted when the RX flag is set before enabling IRQ enable until a new frame is
-received. So extra care must be taken to avoid enabling IRQ and all descriptors
-are already used, hence dead lock will upon us. See new POLL implementation that
-enableds IRQ then look at the RX flag to determine if one or more IRQs may have
-been missed. TX/RX flags are cleared before handling previously enabled
-descriptors, this ensures that the RX/TX flags are valid when determining if IRQ
-should be turned on again.
-
-By moving TX cleaning from POLL to XMIT in the standard case, removes some
-locking trouble. Enabling TX cleaning from poll only when not enough TX
-descriptors are available is safe because the TX queue is at the same time
-stopped, thus XMIT will not be called. The TX queue is woken up again when
-enough descriptrs are available.
-
-TX Frames are always enabled with IRQ, however the TX IRQ Enable flag will not
-be enabled until XMIT must wait for free descriptors.
-
-Locking RX and XMIT parts of the driver from each other is needed because the
-RX/TX enable bits share the same register.
-
-Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
----
- drivers/net/greth.c | 158 ++++++++++++++++++++++++++++++---------------------
- 1 files changed, 93 insertions(+), 65 deletions(-)
-
---- a/drivers/net/greth.c
-+++ b/drivers/net/greth.c
-@@ -1,7 +1,7 @@
- /*
- * Aeroflex Gaisler GRETH 10/100/1G Ethernet MAC.
- *
-- * 2005-2009 (c) Aeroflex Gaisler AB
-+ * 2005-2010 (c) Aeroflex Gaisler AB
- *
- * This driver supports GRETH 10/100 and GRETH 10/100/1G Ethernet MACs
- * available in the GRLIB VHDL IP core library.
-@@ -401,12 +401,20 @@ greth_start_xmit(struct sk_buff *skb, st
- struct greth_private *greth = netdev_priv(dev);
- struct greth_bd *bdp;
- int err = NETDEV_TX_OK;
-- u32 status, dma_addr;
-+ u32 status, dma_addr, ctrl;
-+ unsigned long flags;
-
-- bdp = greth->tx_bd_base + greth->tx_next;
-+ /* Clean TX Ring */
-+ greth_clean_tx(greth->netdev);
-
- if (unlikely(greth->tx_free <= 0)) {
-+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
-+ ctrl = GRETH_REGLOAD(greth->regs->control);
-+ /* Enable TX IRQ only if not already in poll() routine */
-+ if ( ctrl & GRETH_RXI )
-+ GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI);
- netif_stop_queue(dev);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
- return NETDEV_TX_BUSY;
- }
-
-@@ -419,13 +427,14 @@ greth_start_xmit(struct sk_buff *skb, st
- goto out;
- }
-
-+ bdp = greth->tx_bd_base + greth->tx_next;
- dma_addr = greth_read_bd(&bdp->addr);
-
- memcpy((unsigned char *) phys_to_virt(dma_addr), skb->data, skb->len);
-
- dma_sync_single_for_device(greth->dev, dma_addr, skb->len, DMA_TO_DEVICE);
-
-- status = GRETH_BD_EN | (skb->len & GRETH_BD_LEN);
-+ status = GRETH_BD_EN | GRETH_BD_IE | (skb->len & GRETH_BD_LEN);
-
- /* Wrap around descriptor ring */
- if (greth->tx_next == GRETH_TXBD_NUM_MASK) {
-@@ -435,22 +444,11 @@ greth_start_xmit(struct sk_buff *skb, st
- greth->tx_next = NEXT_TX(greth->tx_next);
- greth->tx_free--;
-
-- /* No more descriptors */
-- if (unlikely(greth->tx_free == 0)) {
--
-- /* Free transmitted descriptors */
-- greth_clean_tx(dev);
--
-- /* If nothing was cleaned, stop queue & wait for irq */
-- if (unlikely(greth->tx_free == 0)) {
-- status |= GRETH_BD_IE;
-- netif_stop_queue(dev);
-- }
-- }
--
- /* Write descriptor control word and enable transmission */
- greth_write_bd(&bdp->stat, status);
-+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
- greth_enable_tx(greth);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
-
- out:
- dev_kfree_skb(skb);
-@@ -463,13 +461,24 @@ greth_start_xmit_gbit(struct sk_buff *sk
- {
- struct greth_private *greth = netdev_priv(dev);
- struct greth_bd *bdp;
-- u32 status = 0, dma_addr;
-+ u32 status = 0, dma_addr, ctrl;
- int curr_tx, nr_frags, i, err = NETDEV_TX_OK;
-+ unsigned long flags;
-
- nr_frags = skb_shinfo(skb)->nr_frags;
-
-+ /* Clean TX Ring */
-+ greth_clean_tx_gbit(dev);
-+
- if (greth->tx_free < nr_frags + 1) {
-+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
-+ ctrl = GRETH_REGLOAD(greth->regs->control);
-+ /* Enable TX IRQ only if not already in poll() routine */
-+ if ( ctrl & GRETH_RXI ) {
-+ GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI);
-+ }
- netif_stop_queue(dev);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
- err = NETDEV_TX_BUSY;
- goto out;
- }
-@@ -522,14 +531,8 @@ greth_start_xmit_gbit(struct sk_buff *sk
- /* More fragments left */
- if (i < nr_frags - 1)
- status |= GRETH_TXBD_MORE;
--
-- /* ... last fragment, check if out of descriptors */
-- else if (greth->tx_free - nr_frags - 1 < (MAX_SKB_FRAGS + 1)) {
--
-- /* Enable interrupts and stop queue */
-- status |= GRETH_BD_IE;
-- netif_stop_queue(dev);
-- }
-+ else
-+ status |= GRETH_BD_IE; /* enable IRQ on last fragment */
-
- greth_write_bd(&bdp->stat, status);
-
-@@ -557,7 +560,9 @@ greth_start_xmit_gbit(struct sk_buff *sk
-
- wmb();
-
-+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
- greth_enable_tx(greth);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
-
- return NETDEV_TX_OK;
-
-@@ -579,12 +584,11 @@ out:
- return err;
- }
-
--
- static irqreturn_t greth_interrupt(int irq, void *dev_id)
- {
- struct net_device *dev = dev_id;
- struct greth_private *greth;
-- u32 status;
-+ u32 status, ctrl;
- irqreturn_t retval = IRQ_NONE;
-
- greth = netdev_priv(dev);
-@@ -594,13 +598,14 @@ static irqreturn_t greth_interrupt(int i
- /* Get the interrupt events that caused us to be here. */
- status = GRETH_REGLOAD(greth->regs->status);
-
-- /* Handle rx and tx interrupts through poll */
-- if (status & (GRETH_INT_RE | GRETH_INT_RX | GRETH_INT_TE | GRETH_INT_TX)) {
-+ /* Must see if interrupts are enabled also, INT_TX|INT_RX flags may be set regardless
-+ * of whether IRQ is enabled or not. Especially important when shared IRQ.
-+ */
-+ ctrl = GRETH_REGLOAD(greth->regs->control);
-
-- /* Clear interrupt status */
-- GRETH_REGSAVE(greth->regs->status,
-- status & (GRETH_INT_RE | GRETH_INT_RX |
-- GRETH_INT_TE | GRETH_INT_TX));
-+ /* Handle rx and tx interrupts through poll */
-+ if (((status & (GRETH_INT_RE | GRETH_INT_RX)) && (ctrl & GRETH_RXI)) ||
-+ ((status & (GRETH_INT_TE | GRETH_INT_TX)) && (ctrl & GRETH_TXI))) {
-
- retval = IRQ_HANDLED;
-
-@@ -625,6 +630,8 @@ static void greth_clean_tx(struct net_de
-
- while (1) {
- bdp = greth->tx_bd_base + greth->tx_last;
-+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX);
-+ mb();
- stat = greth_read_bd(&bdp->stat);
-
- if (unlikely(stat & GRETH_BD_EN))
-@@ -685,7 +692,10 @@ static void greth_clean_tx_gbit(struct n
-
- /* We only clean fully completed SKBs */
- bdp_last_frag = greth->tx_bd_base + SKIP_TX(greth->tx_last, nr_frags);
-- stat = bdp_last_frag->stat;
-+
-+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX);
-+ mb();
-+ stat = greth_read_bd(&bdp_last_frag->stat);
-
- if (stat & GRETH_BD_EN)
- break;
-@@ -717,23 +727,12 @@ static void greth_clean_tx_gbit(struct n
- greth->tx_free += nr_frags+1;
- dev_kfree_skb(skb);
- }
-- if (greth->tx_free > (MAX_SKB_FRAGS + 1)) {
-+
-+ if (netif_queue_stopped(dev) && (greth->tx_free > (MAX_SKB_FRAGS + 1))) {
- netif_wake_queue(dev);
- }
- }
-
--static int greth_pending_packets(struct greth_private *greth)
--{
-- struct greth_bd *bdp;
-- u32 status;
-- bdp = greth->rx_bd_base + greth->rx_cur;
-- status = greth_read_bd(&bdp->stat);
-- if (status & GRETH_BD_EN)
-- return 0;
-- else
-- return 1;
--}
--
- static int greth_rx(struct net_device *dev, int limit)
- {
- struct greth_private *greth;
-@@ -742,20 +741,24 @@ static int greth_rx(struct net_device *d
- int pkt_len;
- int bad, count;
- u32 status, dma_addr;
-+ unsigned long flags;
-
- greth = netdev_priv(dev);
-
- for (count = 0; count < limit; ++count) {
-
- bdp = greth->rx_bd_base + greth->rx_cur;
-+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX);
-+ mb();
- status = greth_read_bd(&bdp->stat);
-- dma_addr = greth_read_bd(&bdp->addr);
-- bad = 0;
-
- if (unlikely(status & GRETH_BD_EN)) {
- break;
- }
-
-+ dma_addr = greth_read_bd(&bdp->addr);
-+ bad = 0;
-+
- /* Check status for errors. */
- if (unlikely(status & GRETH_RXBD_STATUS)) {
- if (status & GRETH_RXBD_ERR_FT) {
-@@ -817,7 +820,9 @@ static int greth_rx(struct net_device *d
-
- dma_sync_single_for_device(greth->dev, dma_addr, MAX_FRAME_SIZE, DMA_FROM_DEVICE);
-
-+ spin_lock_irqsave(&greth->devlock, flags); /* save from XMIT */
- greth_enable_rx(greth);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
-
- greth->rx_cur = NEXT_RX(greth->rx_cur);
- }
-@@ -851,6 +856,7 @@ static int greth_rx_gbit(struct net_devi
- int pkt_len;
- int bad, count = 0;
- u32 status, dma_addr;
-+ unsigned long flags;
-
- greth = netdev_priv(dev);
-
-@@ -858,6 +864,8 @@ static int greth_rx_gbit(struct net_devi
-
- bdp = greth->rx_bd_base + greth->rx_cur;
- skb = greth->rx_skbuff[greth->rx_cur];
-+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX);
-+ mb();
- status = greth_read_bd(&bdp->stat);
- bad = 0;
-
-@@ -940,7 +948,9 @@ static int greth_rx_gbit(struct net_devi
-
- wmb();
- greth_write_bd(&bdp->stat, status);
-+ spin_lock_irqsave(&greth->devlock, flags);
- greth_enable_rx(greth);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
- greth->rx_cur = NEXT_RX(greth->rx_cur);
- }
-
-@@ -952,15 +962,19 @@ static int greth_poll(struct napi_struct
- {
- struct greth_private *greth;
- int work_done = 0;
-+ unsigned long flags;
-+ u32 mask, ctrl;
- greth = container_of(napi, struct greth_private, napi);
-
-- if (greth->gbit_mac) {
-- greth_clean_tx_gbit(greth->netdev);
-- } else {
-- greth_clean_tx(greth->netdev);
-+restart_txrx_poll:
-+ if ( netif_queue_stopped(greth->netdev) ) {
-+ if (greth->gbit_mac) {
-+ greth_clean_tx_gbit(greth->netdev);
-+ } else {
-+ greth_clean_tx(greth->netdev);
-+ }
- }
-
--restart_poll:
- if (greth->gbit_mac) {
- work_done += greth_rx_gbit(greth->netdev, budget - work_done);
- } else {
-@@ -969,15 +983,29 @@ restart_poll:
-
- if (work_done < budget) {
-
-- napi_complete(napi);
-+ spin_lock_irqsave(&greth->devlock, flags);
-
-- if (greth_pending_packets(greth)) {
-- napi_reschedule(napi);
-- goto restart_poll;
-+ ctrl = GRETH_REGLOAD(greth->regs->control);
-+ if (netif_queue_stopped(greth->netdev)) {
-+ GRETH_REGSAVE(greth->regs->control,
-+ ctrl | GRETH_TXI | GRETH_RXI);
-+ mask = GRETH_INT_RX | GRETH_INT_RE |
-+ GRETH_INT_TX | GRETH_INT_TE;
-+ } else {
-+ GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_RXI);
-+ mask = GRETH_INT_RX | GRETH_INT_RE;
-+ }
-+
-+ if (GRETH_REGLOAD(greth->regs->status) & mask) {
-+ GRETH_REGSAVE(greth->regs->control, ctrl);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
-+ goto restart_txrx_poll;
-+ } else {
-+ __napi_complete(napi);
-+ spin_unlock_irqrestore(&greth->devlock, flags);
- }
- }
-
-- greth_enable_irqs(greth);
- return work_done;
- }
-
-@@ -1172,11 +1200,11 @@ static const struct ethtool_ops greth_et
- };
-
- static struct net_device_ops greth_netdev_ops = {
-- .ndo_open = greth_open,
-- .ndo_stop = greth_close,
-- .ndo_start_xmit = greth_start_xmit,
-- .ndo_set_mac_address = greth_set_mac_add,
-- .ndo_validate_addr = eth_validate_addr,
-+ .ndo_open = greth_open,
-+ .ndo_stop = greth_close,
-+ .ndo_start_xmit = greth_start_xmit,
-+ .ndo_set_mac_address = greth_set_mac_add,
-+ .ndo_validate_addr = eth_validate_addr,
- };
-
- static inline int wait_for_mdio(struct greth_private *greth)
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-30 18:51:54 +0000