diff --git a/drivers/net/tile/tilepro.c b/drivers/net/tile/tilepro.c
index f9012992d21e5ccf973d7ab5df2bd15251de7ded..0825db6d883fb71cc8452c1617c89184300fccab 100644
--- a/drivers/net/tile/tilepro.c
+++ b/drivers/net/tile/tilepro.c
@@ -1,5 +1,5 @@
/*
- * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -44,10 +44,6 @@
#include <linux/tcp.h>
-/* There is no singlethread_cpu, so schedule work on the current cpu. */
-#define singlethread_cpu -1
-
-
/*
* First, "tile_net_init_module()" initializes all four "devices" which
* can be used by linux.
@@ -73,15 +69,16 @@
* return, knowing we will be called again later. Otherwise, we
* reenable the ingress interrupt, and call "napi_complete()".
*
+ * HACK: Since disabling the ingress interrupt is not reliable, we
+ * ignore the interrupt if the global "active" flag is false.
+ *
*
* NOTE: The use of "native_driver" ensures that EPP exists, and that
- * "epp_sendv" is legal, and that "LIPP" is being used.
+ * we are using "LIPP" and "LEPP".
*
* NOTE: Failing to free completions for an arbitrarily long time
* (which is defined to be illegal) does in fact cause bizarre
* problems. The "egress_timer" helps prevent this from happening.
- *
- * NOTE: The egress code can be interrupted by the interrupt handler.
*/
@@ -142,6 +139,7 @@
MODULE_AUTHOR("Tilera");
MODULE_LICENSE("GPL");
+
/*
* Queue of incoming packets for a specific cpu and device.
*
@@ -177,7 +175,7 @@ struct tile_net_cpu {
struct tile_netio_queue queue;
/* Statistics. */
struct tile_net_stats_t stats;
- /* ISSUE: Is this needed? */
+ /* True iff NAPI is enabled. */
bool napi_enabled;
/* True if this tile has succcessfully registered with the IPP. */
bool registered;
@@ -200,20 +198,20 @@ struct tile_net_cpu {
struct tile_net_priv {
/* Our network device. */
struct net_device *dev;
- /* The actual egress queue. */
- lepp_queue_t *epp_queue;
- /* Protects "epp_queue->cmd_tail" and "epp_queue->comp_tail" */
- spinlock_t cmd_lock;
- /* Protects "epp_queue->comp_head". */
- spinlock_t comp_lock;
+ /* Pages making up the egress queue. */
+ struct page *eq_pages;
+ /* Address of the actual egress queue. */
+ lepp_queue_t *eq;
+ /* Protects "eq". */
+ spinlock_t eq_lock;
/* The hypervisor handle for this interface. */
int hv_devhdl;
/* The intr bit mask that IDs this device. */
u32 intr_id;
/* True iff "tile_net_open_aux()" has succeeded. */
- int partly_opened;
- /* True iff "tile_net_open_inner()" has succeeded. */
- int fully_opened;
+ bool partly_opened;
+ /* True iff the device is "active". */
+ bool active;
/* Effective network cpus. */
struct cpumask network_cpus_map;
/* Number of network cpus. */
@@ -228,6 +226,10 @@ struct tile_net_priv {
struct tile_net_cpu *cpu[NR_CPUS];
};
+/* Log2 of the number of small pages needed for the egress queue. */
+#define EQ_ORDER get_order(sizeof(lepp_queue_t))
+/* Size of the egress queue's pages. */
+#define EQ_SIZE (1 << (PAGE_SHIFT + EQ_ORDER))
/*
* The actual devices (xgbe0, xgbe1, gbe0, gbe1).
@@ -284,7 +286,11 @@ static void net_printk(char *fmt, ...)
*/
static void dump_packet(unsigned char *data, unsigned long length, char *s)
{
+ int my_cpu = smp_processor_id();
+
unsigned long i;
+ char buf[128];
+
static unsigned int count;
pr_info("dump_packet(data %p, length 0x%lx s %s count 0x%x)\n",
@@ -294,10 +300,12 @@ static void dump_packet(unsigned char *data, unsigned long length, char *s)
for (i = 0; i < length; i++) {
if ((i & 0xf) == 0)
- sprintf(buf, "%8.8lx:", i);
+ sprintf(buf, "[%02d] %8.8lx:", my_cpu, i);
sprintf(buf + strlen(buf), " %2.2x", data[i]);
- if ((i & 0xf) == 0xf || i == length - 1)
- pr_info("%s\n", buf);
+ if ((i & 0xf) == 0xf || i == length - 1) {
+ strcat(buf, "\n");
+ pr_info("%s", buf);
+ }
}
}
#endif
@@ -351,60 +359,109 @@ static void tile_net_provide_linux_buffer(struct tile_net_cpu *info,
/*
* Provide a linux buffer for LIPP.
+ *
+ * Note that the ACTUAL allocation for each buffer is a "struct sk_buff",
+ * plus a chunk of memory that includes not only the requested bytes, but
+ * also NET_SKB_PAD bytes of initial padding, and a "struct skb_shared_info".
+ *
+ * Note that "struct skb_shared_info" is 88 bytes with 64K pages and
+ * 268 bytes with 4K pages (since the frags[] array needs 18 entries).
+ *
+ * Without jumbo packets, the maximum packet size will be 1536 bytes,
+ * and we use 2 bytes (NET_IP_ALIGN) of padding. ISSUE: If we told
+ * the hardware to clip at 1518 bytes instead of 1536 bytes, then we
+ * could save an entire cache line, but in practice, we don't need it.
+ *
+ * Since CPAs are 38 bits, and we can only encode the high 31 bits in
+ * a "linux_buffer_t", the low 7 bits must be zero, and thus, we must
+ * align the actual "va" mod 128.
+ *
+ * We assume that the underlying "head" will be aligned mod 64. Note
+ * that in practice, we have seen "head" NOT aligned mod 128 even when
+ * using 2048 byte allocations, which is surprising.
+ *
+ * If "head" WAS always aligned mod 128, we could change LIPP to
+ * assume that the low SIX bits are zero, and the 7th bit is one, that
+ * is, align the actual "va" mod 128 plus 64, which would be "free".
+ *
+ * For now, the actual "head" pointer points at NET_SKB_PAD bytes of
+ * padding, plus 28 or 92 bytes of extra padding, plus the sk_buff
+ * pointer, plus the NET_IP_ALIGN padding, plus 126 or 1536 bytes for
+ * the actual packet, plus 62 bytes of empty padding, plus some
+ * padding and the "struct skb_shared_info".
+ *
+ * With 64K pages, a large buffer thus needs 32+92+4+2+1536+62+88
+ * bytes, or 1816 bytes, which fits comfortably into 2048 bytes.
+ *
+ * With 64K pages, a small buffer thus needs 32+92+4+2+126+88
+ * bytes, or 344 bytes, which means we are wasting 64+ bytes, and
+ * could presumably increase the size of small buffers.
+ *
+ * With 4K pages, a large buffer thus needs 32+92+4+2+1536+62+268
+ * bytes, or 1996 bytes, which fits comfortably into 2048 bytes.
+ *
+ * With 4K pages, a small buffer thus needs 32+92+4+2+126+268
+ * bytes, or 524 bytes, which is annoyingly wasteful.
+ *
+ * Maybe we should increase LIPP_SMALL_PACKET_SIZE to 192?
+ *
+ * ISSUE: Maybe we should increase "NET_SKB_PAD" to 64?
*/
static bool tile_net_provide_needed_buffer(struct tile_net_cpu *info,
bool small)
{
- /* ISSUE: What should we use here? */
+#if TILE_NET_MTU <= 1536
+ /* Without "jumbo", 2 + 1536 should be sufficient. */
+ unsigned int large_size = NET_IP_ALIGN + 1536;
+#else
+ /* ISSUE: This has not been tested. */
unsigned int large_size = NET_IP_ALIGN + TILE_NET_MTU + 100;
+#endif
- /* Round up to ensure to avoid "false sharing" with last cache line. */
- unsigned int buffer_size =
+ /* Avoid "false sharing" with last cache line. */
+ /* ISSUE: This is already done by "dev_alloc_skb()". */
+ unsigned int len =
(((small ? LIPP_SMALL_PACKET_SIZE : large_size) +
CHIP_L2_LINE_SIZE() - 1) & -CHIP_L2_LINE_SIZE());
- /*
- * ISSUE: Since CPAs are 38 bits, and we can only encode the
- * high 31 bits in a "linux_buffer_t", the low 7 bits must be
- * zero, and thus, we must align the actual "va" mod 128.
- */
- const unsigned long align = 128;
+ unsigned int padding = 128 - NET_SKB_PAD;
+ unsigned int align;
struct sk_buff *skb;
void *va;
struct sk_buff **skb_ptr;
- /* Note that "dev_alloc_skb()" adds NET_SKB_PAD more bytes, */
- /* and also "reserves" that many bytes. */
- /* ISSUE: Can we "share" the NET_SKB_PAD bytes with "skb_ptr"? */
- int len = sizeof(*skb_ptr) + align + buffer_size;
-
- while (1) {
-
- /* Allocate (or fail). */
- skb = dev_alloc_skb(len);
- if (skb == NULL)
- return false;
-
- /* Make room for a back-pointer to 'skb'. */
- skb_reserve(skb, sizeof(*skb_ptr));
+ /* Request 96 extra bytes for alignment purposes. */
+ skb = dev_alloc_skb(len + padding);
+ if (skb == NULL)
+ return false;
- /* Make sure we are aligned. */
- skb_reserve(skb, -(long)skb->data & (align - 1));
+ /* Skip 32 or 96 bytes to align "data" mod 128. */
+ align = -(long)skb->data & (128 - 1);
+ BUG_ON(align > padding);
+ skb_reserve(skb, align);
- /* This address is given to IPP. */
- va = skb->data;
+ /* This address is given to IPP. */
+ va = skb->data;
- if (small)
- break;
+ /* Buffers must not span a huge page. */
+ BUG_ON(((((long)va & ~HPAGE_MASK) + len) & HPAGE_MASK) != 0);
- /* ISSUE: This has never been observed! */
- /* Large buffers must not span a huge page. */
- if (((((long)va & ~HPAGE_MASK) + 1535) & HPAGE_MASK) == 0)
- break;
- pr_err("Leaking unaligned linux buffer at %p.\n", va);
+#ifdef TILE_NET_PARANOIA
+#if CHIP_HAS_CBOX_HOME_MAP()
+ if (hash_default) {
+ HV_PTE pte = *virt_to_pte(current->mm, (unsigned long)va);
+ if (hv_pte_get_mode(pte) != HV_PTE_MODE_CACHE_HASH_L3)
+ panic("Non-HFH ingress buffer! VA=%p Mode=%d PTE=%llx",
+ va, hv_pte_get_mode(pte), hv_pte_val(pte));
}
+#endif
+#endif
+
+ /* Invalidate the packet buffer. */
+ if (!hash_default)
+ __inv_buffer(va, len);
/* Skip two bytes to satisfy LIPP assumptions. */
/* Note that this aligns IP on a 16 byte boundary. */
@@ -415,23 +472,9 @@ static bool tile_net_provide_needed_buffer(struct tile_net_cpu *info,
skb_ptr = va - sizeof(*skb_ptr);
*skb_ptr = skb;
- /* Invalidate the packet buffer. */
- if (!hash_default)
- __inv_buffer(skb->data, buffer_size);
-
/* Make sure "skb_ptr" has been flushed. */
__insn_mf();
-#ifdef TILE_NET_PARANOIA
-#if CHIP_HAS_CBOX_HOME_MAP()
- if (hash_default) {
- HV_PTE pte = *virt_to_pte(current->mm, (unsigned long)va);
- if (hv_pte_get_mode(pte) != HV_PTE_MODE_CACHE_HASH_L3)
- panic("Non-coherent ingress buffer!");
- }
-#endif
-#endif
-
/* Provide the new buffer. */
tile_net_provide_linux_buffer(info, va, small);
@@ -469,47 +512,63 @@ oops:
* Grab some LEPP completions, and store them in "comps", of size
* "comps_size", and return the number of completions which were
* stored, so the caller can free them.
- *
- * If "pending" is not NULL, it will be set to true if there might
- * still be some pending completions caused by this tile, else false.
*/
-static unsigned int tile_net_lepp_grab_comps(struct net_device *dev,
+static unsigned int tile_net_lepp_grab_comps(lepp_queue_t *eq,
struct sk_buff *comps[],
unsigned int comps_size,
- bool *pending)
+ unsigned int min_size)
{
- struct tile_net_priv *priv = netdev_priv(dev);
-
- lepp_queue_t *eq = priv->epp_queue;
-
unsigned int n = 0;
- unsigned int comp_head;
- unsigned int comp_busy;
- unsigned int comp_tail;
-
- spin_lock(&priv->comp_lock);
-
- comp_head = eq->comp_head;
- comp_busy = eq->comp_busy;
- comp_tail = eq->comp_tail;
+ unsigned int comp_head = eq->comp_head;
+ unsigned int comp_busy = eq->comp_busy;
while (comp_head != comp_busy && n < comps_size) {
comps[n++] = eq->comps[comp_head];
LEPP_QINC(comp_head);
}
- if (pending != NULL)
- *pending = (comp_head != comp_tail);
+ if (n < min_size)
+ return 0;
eq->comp_head = comp_head;
- spin_unlock(&priv->comp_lock);
-
return n;
}
+/*
+ * Free some comps, and return true iff there are still some pending.
+ */
+static bool tile_net_lepp_free_comps(struct net_device *dev, bool all)
+{
+ struct tile_net_priv *priv = netdev_priv(dev);
+
+ lepp_queue_t *eq = priv->eq;
+
+ struct sk_buff *olds[64];
+ unsigned int wanted = 64;
+ unsigned int i, n;
+ bool pending;
+
+ spin_lock(&priv->eq_lock);
+
+ if (all)
+ eq->comp_busy = eq->comp_tail;
+
+ n = tile_net_lepp_grab_comps(eq, olds, wanted, 0);
+
+ pending = (eq->comp_head != eq->comp_tail);
+
+ spin_unlock(&priv->eq_lock);
+
+ for (i = 0; i < n; i++)
+ kfree_skb(olds[i]);
+
+ return pending;
+}
+
+
/*
* Make sure the egress timer is scheduled.
*
@@ -544,21 +603,11 @@ static void tile_net_handle_egress_timer(unsigned long arg)
struct tile_net_cpu *info = (struct tile_net_cpu *)arg;
struct net_device *dev = info->napi.dev;
- struct sk_buff *olds[32];
- unsigned int wanted = 32;
- unsigned int i, nolds = 0;
- bool pending;
-
/* The timer is no longer scheduled. */
info->egress_timer_scheduled = false;
- nolds = tile_net_lepp_grab_comps(dev, olds, wanted, &pending);
-
- for (i = 0; i < nolds; i++)
- kfree_skb(olds[i]);
-
- /* Reschedule timer if needed. */
- if (pending)
+ /* Free comps, and reschedule timer if more are pending. */
+ if (tile_net_lepp_free_comps(dev, false))
tile_net_schedule_egress_timer(info);
}
@@ -636,8 +685,39 @@ static bool is_dup_ack(char *s1, char *s2, unsigned int len)
+static void tile_net_discard_aux(struct tile_net_cpu *info, int index)
+{
+ struct tile_netio_queue *queue = &info->queue;
+ netio_queue_impl_t *qsp = queue->__system_part;
+ netio_queue_user_impl_t *qup = &queue->__user_part;
+
+ int index2_aux = index + sizeof(netio_pkt_t);
+ int index2 =
+ ((index2_aux ==
+ qsp->__packet_receive_queue.__last_packet_plus_one) ?
+ 0 : index2_aux);
+
+ netio_pkt_t *pkt = (netio_pkt_t *)((unsigned long) &qsp[1] + index);
+
+ /* Extract the "linux_buffer_t". */
+ unsigned int buffer = pkt->__packet.word;
+
+ /* Convert "linux_buffer_t" to "va". */
+ void *va = __va((phys_addr_t)(buffer >> 1) << 7);
+
+ /* Acquire the associated "skb". */
+ struct sk_buff **skb_ptr = va - sizeof(*skb_ptr);
+ struct sk_buff *skb = *skb_ptr;
+
+ kfree_skb(skb);
+
+ /* Consume this packet. */
+ qup->__packet_receive_read = index2;
+}
+
+
/*
- * Like "tile_net_handle_packets()", but just discard packets.
+ * Like "tile_net_poll()", but just discard packets.
*/
static void tile_net_discard_packets(struct net_device *dev)
{
@@ -650,32 +730,8 @@ static void tile_net_discard_packets(struct net_device *dev)
while (qup->__packet_receive_read !=
qsp->__packet_receive_queue.__packet_write) {
-
int index = qup->__packet_receive_read;
-
- int index2_aux = index + sizeof(netio_pkt_t);
- int index2 =
- ((index2_aux ==
- qsp->__packet_receive_queue.__last_packet_plus_one) ?
- 0 : index2_aux);
-
- netio_pkt_t *pkt = (netio_pkt_t *)
- ((unsigned long) &qsp[1] + index);
-
- /* Extract the "linux_buffer_t". */
- unsigned int buffer = pkt->__packet.word;
-
- /* Convert "linux_buffer_t" to "va". */
- void *va = __va((phys_addr_t)(buffer >> 1) << 7);
-
- /* Acquire the associated "skb". */
- struct sk_buff **skb_ptr = va - sizeof(*skb_ptr);
- struct sk_buff *skb = *skb_ptr;
-
- kfree_skb(skb);
-
- /* Consume this packet. */
- qup->__packet_receive_read = index2;
+ tile_net_discard_aux(info, index);
}
}
@@ -704,7 +760,8 @@ static bool tile_net_poll_aux(struct tile_net_cpu *info, int index)
netio_pkt_metadata_t *metadata = NETIO_PKT_METADATA(pkt);
- /* Extract the packet size. */
+ /* Extract the packet size. FIXME: Shouldn't the second line */
+ /* get subtracted? Mostly moot, since it should be "zero". */
unsigned long len =
(NETIO_PKT_CUSTOM_LENGTH(pkt) +
NET_IP_ALIGN - NETIO_PACKET_PADDING);
@@ -722,15 +779,6 @@ static bool tile_net_poll_aux(struct tile_net_cpu *info, int index)
/* Compare to "NETIO_PKT_CUSTOM_DATA(pkt)". */
unsigned char *buf = va + NET_IP_ALIGN;
-#ifdef IGNORE_DUP_ACKS
-
- static int other;
- static int final;
- static int keep;
- static int skip;
-
-#endif
-
/* Invalidate the packet buffer. */
if (!hash_default)
__inv_buffer(buf, len);
@@ -745,16 +793,8 @@ static bool tile_net_poll_aux(struct tile_net_cpu *info, int index)
#ifdef TILE_NET_VERIFY_INGRESS
if (!NETIO_PKT_L4_CSUM_CORRECT_M(metadata, pkt) &&
NETIO_PKT_L4_CSUM_CALCULATED_M(metadata, pkt)) {
- /*
- * FIXME: This complains about UDP packets
- * with a "zero" checksum (bug 6624).
- */
-#ifdef TILE_NET_PANIC_ON_BAD
- dump_packet(buf, len, "rx");
- panic("Bad L4 checksum.");
-#else
+ /* Bug 6624: Includes UDP packets with a "zero" checksum. */
pr_warning("Bad L4 checksum on %d byte packet.\n", len);
-#endif
}
if (!NETIO_PKT_L3_CSUM_CORRECT_M(metadata, pkt) &&
NETIO_PKT_L3_CSUM_CALCULATED_M(metadata, pkt)) {
@@ -769,90 +809,29 @@ static bool tile_net_poll_aux(struct tile_net_cpu *info, int index)
}
break;
case NETIO_PKT_STATUS_BAD:
-#ifdef TILE_NET_PANIC_ON_BAD
- dump_packet(buf, len, "rx");
- panic("Unexpected BAD packet.");
-#else
- pr_warning("Unexpected BAD %d byte packet.\n", len);
-#endif
+ pr_warning("Unexpected BAD %ld byte packet.\n", len);
}
#endif
filter = 0;
+ /* ISSUE: Filter TCP packets with "bad" checksums? */
+
if (!(dev->flags & IFF_UP)) {
/* Filter packets received before we're up. */
filter = 1;
+ } else if (NETIO_PKT_STATUS_M(metadata, pkt) == NETIO_PKT_STATUS_BAD) {
+ /* Filter "truncated" packets. */
+ filter = 1;
} else if (!(dev->flags & IFF_PROMISC)) {
- /*
- * FIXME: Implement HW multicast filter.
- */
- if (is_unicast_ether_addr(buf)) {
+ /* FIXME: Implement HW multicast filter. */
+ if (!is_multicast_ether_addr(buf)) {
/* Filter packets not for our address. */
const u8 *mine = dev->dev_addr;
filter = compare_ether_addr(mine, buf);
}
}
-#ifdef IGNORE_DUP_ACKS
-
- if (len != 66) {
- /* FIXME: Must check "is_tcp_ack(buf, len)" somehow. */
-
- other++;
-
- } else if (index2 ==
- qsp->__packet_receive_queue.__packet_write) {
-
- final++;
-
- } else {
-
- netio_pkt_t *pkt2 = (netio_pkt_t *)
- ((unsigned long) &qsp[1] + index2);
-
- netio_pkt_metadata_t *metadata2 =
- NETIO_PKT_METADATA(pkt2);
-
- /* Extract the packet size. */
- unsigned long len2 =
- (NETIO_PKT_CUSTOM_LENGTH(pkt2) +
- NET_IP_ALIGN - NETIO_PACKET_PADDING);
-
- if (len2 == 66 &&
- NETIO_PKT_FLOW_HASH_M(metadata, pkt) ==
- NETIO_PKT_FLOW_HASH_M(metadata2, pkt2)) {
-
- /* Extract the "linux_buffer_t". */
- unsigned int buffer2 = pkt2->__packet.word;
-
- /* Convert "linux_buffer_t" to "va". */
- void *va2 =
- __va((phys_addr_t)(buffer2 >> 1) << 7);
-
- /* Extract the packet data pointer. */
- /* Compare to "NETIO_PKT_CUSTOM_DATA(pkt)". */
- unsigned char *buf2 = va2 + NET_IP_ALIGN;
-
- /* Invalidate the packet buffer. */
- if (!hash_default)
- __inv_buffer(buf2, len2);
-
- if (is_dup_ack(buf, buf2, len)) {
- skip++;
- filter = 1;
- } else {
- keep++;
- }
- }
- }
-
- if (net_ratelimit())
- pr_info("Other %d Final %d Keep %d Skip %d.\n",
- other, final, keep, skip);
-
-#endif
-
if (filter) {
/* ISSUE: Update "drop" statistics? */
@@ -877,10 +856,7 @@ static bool tile_net_poll_aux(struct tile_net_cpu *info, int index)
/* NOTE: This call also sets "skb->dev = dev". */
skb->protocol = eth_type_trans(skb, dev);
- /* ISSUE: Discard corrupt packets? */
- /* ISSUE: Discard packets with bad checksums? */
-
- /* Avoid recomputing TCP/UDP checksums. */
+ /* Avoid recomputing "good" TCP/UDP checksums. */
if (NETIO_PKT_L4_CSUM_CORRECT_M(metadata, pkt))
skb->ip_summed = CHECKSUM_UNNECESSARY;
@@ -912,9 +888,14 @@ static bool tile_net_poll_aux(struct tile_net_cpu *info, int index)
/*
* Handle some packets for the given device on the current CPU.
*
- * ISSUE: The "rotting packet" race condition occurs if a packet
- * arrives after the queue appears to be empty, and before the
- * hypervisor interrupt is re-enabled.
+ * If "tile_net_stop()" is called on some other tile while this
+ * function is running, we will return, hopefully before that
+ * other tile asks us to call "napi_disable()".
+ *
+ * The "rotting packet" race condition occurs if a packet arrives
+ * during the extremely narrow window between the queue appearing to
+ * be empty, and the ingress interrupt being re-enabled. This happens
+ * a LOT under heavy network load.
*/
static int tile_net_poll(struct napi_struct *napi, int budget)
{
@@ -928,7 +909,7 @@ static int tile_net_poll(struct napi_struct *napi, int budget)
unsigned int work = 0;
- while (1) {
+ while (priv->active) {
int index = qup->__packet_receive_read;
if (index == qsp->__packet_receive_queue.__packet_write)
break;
@@ -941,19 +922,24 @@ static int tile_net_poll(struct napi_struct *napi, int budget)
napi_complete(&info->napi);
- /* Re-enable hypervisor interrupts. */
+ if (!priv->active)
+ goto done;
+
+ /* Re-enable the ingress interrupt. */
enable_percpu_irq(priv->intr_id);
- /* HACK: Avoid the "rotting packet" problem. */
+ /* HACK: Avoid the "rotting packet" problem (see above). */
if (qup->__packet_receive_read !=
- qsp->__packet_receive_queue.__packet_write)
- napi_schedule(&info->napi);
-
- /* ISSUE: Handle completions? */
+ qsp->__packet_receive_queue.__packet_write) {
+ /* ISSUE: Sometimes this returns zero, presumably */
+ /* because an interrupt was handled for this tile. */
+ (void)napi_reschedule(&info->napi);
+ }
done:
- tile_net_provide_needed_buffers(info);
+ if (priv->active)
+ tile_net_provide_needed_buffers(info);
return work;
}
@@ -961,6 +947,12 @@ done:
/*
* Handle an ingress interrupt for the given device on the current cpu.
+ *
+ * ISSUE: Sometimes this gets called after "disable_percpu_irq()" has
+ * been called! This is probably due to "pending hypervisor downcalls".
+ *
+ * ISSUE: Is there any race condition between the "napi_schedule()" here
+ * and the "napi_complete()" call above?
*/
static irqreturn_t tile_net_handle_ingress_interrupt(int irq, void *dev_ptr)
{
@@ -969,9 +961,15 @@ static irqreturn_t tile_net_handle_ingress_interrupt(int irq, void *dev_ptr)
int my_cpu = smp_processor_id();
struct tile_net_cpu *info = priv->cpu[my_cpu];
- /* Disable hypervisor interrupt. */
+ /* Disable the ingress interrupt. */
disable_percpu_irq(priv->intr_id);
+ /* Ignore unwanted interrupts. */
+ if (!priv->active)
+ return IRQ_HANDLED;
+
+ /* ISSUE: Sometimes "info->napi_enabled" is false here. */
+
napi_schedule(&info->napi);
return IRQ_HANDLED;
@@ -1005,8 +1003,7 @@ static int tile_net_open_aux(struct net_device *dev)
*/
{
int epp_home = hv_lotar_to_cpu(epp_lotar);
- struct page *page = virt_to_page(priv->epp_queue);
- homecache_change_page_home(page, 0, epp_home);
+ homecache_change_page_home(priv->eq_pages, EQ_ORDER, epp_home);
}
/*
@@ -1015,9 +1012,9 @@ static int tile_net_open_aux(struct net_device *dev)
{
netio_ipp_address_t ea = {
.va = 0,
- .pa = __pa(priv->epp_queue),
+ .pa = __pa(priv->eq),
.pte = hv_pte(0),
- .size = PAGE_SIZE,
+ .size = EQ_SIZE,
};
ea.pte = hv_pte_set_lotar(ea.pte, epp_lotar);
ea.pte = hv_pte_set_mode(ea.pte, HV_PTE_MODE_CACHE_TILE_L3);
@@ -1043,7 +1040,7 @@ static int tile_net_open_aux(struct net_device *dev)
/*
- * Register with hypervisor on each CPU.
+ * Register with hypervisor on the current CPU.
*
* Strangely, this function does important things even if it "fails",
* which is especially common if the link is not up yet. Hopefully
@@ -1092,7 +1089,8 @@ static void tile_net_register(void *dev_ptr)
priv->cpu[my_cpu] = info;
/*
- * Register ourselves with the IPP.
+ * Register ourselves with LIPP. This does a lot of stuff,
+ * including invoking the LIPP registration code.
*/
ret = hv_dev_pwrite(priv->hv_devhdl, 0,
(HV_VirtAddr)&config,
@@ -1101,8 +1099,11 @@ static void tile_net_register(void *dev_ptr)
PDEBUG("hv_dev_pwrite(NETIO_IPP_INPUT_REGISTER_OFF) returned %d\n",
ret);
if (ret < 0) {
- printk(KERN_DEBUG "hv_dev_pwrite NETIO_IPP_INPUT_REGISTER_OFF"
- " failure %d\n", ret);
+ if (ret != NETIO_LINK_DOWN) {
+ printk(KERN_DEBUG "hv_dev_pwrite "
+ "NETIO_IPP_INPUT_REGISTER_OFF failure %d\n",
+ ret);
+ }
info->link_down = (ret == NETIO_LINK_DOWN);
return;
}
@@ -1145,15 +1146,47 @@ static void tile_net_register(void *dev_ptr)
NETIO_IPP_GET_FASTIO_OFF);
PDEBUG("hv_dev_pread(NETIO_IPP_GET_FASTIO_OFF) returned %d\n", ret);
- netif_napi_add(dev, &info->napi, tile_net_poll, 64);
-
/* Now we are registered. */
info->registered = true;
}
/*
- * Unregister with hypervisor on each CPU.
+ * Deregister with hypervisor on the current CPU.
+ *
+ * This simply discards all our credits, so no more packets will be
+ * delivered to this tile. There may still be packets in our queue.
+ *
+ * Also, disable the ingress interrupt.
+ */
+static void tile_net_deregister(void *dev_ptr)
+{
+ struct net_device *dev = (struct net_device *)dev_ptr;
+ struct tile_net_priv *priv = netdev_priv(dev);
+ int my_cpu = smp_processor_id();
+ struct tile_net_cpu *info = priv->cpu[my_cpu];
+
+ /* Disable the ingress interrupt. */
+ disable_percpu_irq(priv->intr_id);
+
+ /* Do nothing else if not registered. */
+ if (info == NULL || !info->registered)
+ return;
+
+ {
+ struct tile_netio_queue *queue = &info->queue;
+ netio_queue_user_impl_t *qup = &queue->__user_part;
+
+ /* Discard all our credits. */
+ __netio_fastio_return_credits(qup->__fastio_index, -1);
+ }
+}
+
+
+/*
+ * Unregister with hypervisor on the current CPU.
+ *
+ * Also, disable the ingress interrupt.
*/
static void tile_net_unregister(void *dev_ptr)
{
@@ -1162,35 +1195,23 @@ static void tile_net_unregister(void *dev_ptr)
int my_cpu = smp_processor_id();
struct tile_net_cpu *info = priv->cpu[my_cpu];
- int ret = 0;
+ int ret;
int dummy = 0;
- /* Do nothing if never registered. */
- if (info == NULL)
- return;
+ /* Disable the ingress interrupt. */
+ disable_percpu_irq(priv->intr_id);
- /* Do nothing if already unregistered. */
- if (!info->registered)
+ /* Do nothing else if not registered. */
+ if (info == NULL || !info->registered)
return;
- /*
- * Unregister ourselves with LIPP.
- */
+ /* Unregister ourselves with LIPP/LEPP. */
ret = hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy,
sizeof(dummy), NETIO_IPP_INPUT_UNREGISTER_OFF);
- PDEBUG("hv_dev_pwrite(NETIO_IPP_INPUT_UNREGISTER_OFF) returned %d\n",
- ret);
- if (ret < 0) {
- /* FIXME: Just panic? */
- pr_err("hv_dev_pwrite NETIO_IPP_INPUT_UNREGISTER_OFF"
- " failure %d\n", ret);
- }
+ if (ret < 0)
+ panic("Failed to unregister with LIPP/LEPP!\n");
- /*
- * Discard all packets still in our NetIO queue. Hopefully,
- * once the unregister call is complete, there will be no
- * packets still in flight on the IDN.
- */
+ /* Discard all packets still in our NetIO queue. */
tile_net_discard_packets(dev);
/* Reset state. */
@@ -1200,11 +1221,6 @@ static void tile_net_unregister(void *dev_ptr)
/* Cancel egress timer. */
del_timer(&info->egress_timer);
info->egress_timer_scheduled = false;
-
- netif_napi_del(&info->napi);
-
- /* Now we are unregistered. */
- info->registered = false;
}
@@ -1212,18 +1228,28 @@ static void tile_net_unregister(void *dev_ptr)
* Helper function for "tile_net_stop()".
*
* Also used to handle registration failure in "tile_net_open_inner()",
- * when "fully_opened" is known to be false, and the various extra
- * steps in "tile_net_stop()" are not necessary. ISSUE: It might be
- * simpler if we could just call "tile_net_stop()" anyway.
+ * when the various extra steps in "tile_net_stop()" are not necessary.
*/
static void tile_net_stop_aux(struct net_device *dev)
{
struct tile_net_priv *priv = netdev_priv(dev);
+ int i;
int dummy = 0;
- /* Unregister all tiles, so LIPP will stop delivering packets. */
+ /*
+ * Unregister all tiles, so LIPP will stop delivering packets.
+ * Also, delete all the "napi" objects (sequentially, to protect
+ * "dev->napi_list").
+ */
on_each_cpu(tile_net_unregister, (void *)dev, 1);
+ for_each_online_cpu(i) {
+ struct tile_net_cpu *info = priv->cpu[i];
+ if (info != NULL && info->registered) {
+ netif_napi_del(&info->napi);
+ info->registered = false;
+ }
+ }
/* Stop LIPP/LEPP. */
if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy,
@@ -1235,18 +1261,15 @@ static void tile_net_stop_aux(struct net_device *dev)
/*
- * Disable ingress interrupts for the given device on the current cpu.
+ * Disable NAPI for the given device on the current cpu.
*/
-static void tile_net_disable_intr(void *dev_ptr)
+static void tile_net_stop_disable(void *dev_ptr)
{
struct net_device *dev = (struct net_device *)dev_ptr;
struct tile_net_priv *priv = netdev_priv(dev);
int my_cpu = smp_processor_id();
struct tile_net_cpu *info = priv->cpu[my_cpu];
- /* Disable hypervisor interrupt. */
- disable_percpu_irq(priv->intr_id);
-
/* Disable NAPI if needed. */
if (info != NULL && info->napi_enabled) {
napi_disable(&info->napi);
@@ -1256,21 +1279,24 @@ static void tile_net_disable_intr(void *dev_ptr)
/*
- * Enable ingress interrupts for the given device on the current cpu.
+ * Enable NAPI and the ingress interrupt for the given device
+ * on the current cpu.
+ *
+ * ISSUE: Only do this for "network cpus"?
*/
-static void tile_net_enable_intr(void *dev_ptr)
+static void tile_net_open_enable(void *dev_ptr)
{
struct net_device *dev = (struct net_device *)dev_ptr;
struct tile_net_priv *priv = netdev_priv(dev);
int my_cpu = smp_processor_id();
struct tile_net_cpu *info = priv->cpu[my_cpu];
- /* Enable hypervisor interrupt. */
- enable_percpu_irq(priv->intr_id);
-
/* Enable NAPI. */
napi_enable(&info->napi);
info->napi_enabled = true;
+
+ /* Enable the ingress interrupt. */
+ enable_percpu_irq(priv->intr_id);
}
@@ -1288,8 +1314,9 @@ static int tile_net_open_inner(struct net_device *dev)
int my_cpu = smp_processor_id();
struct tile_net_cpu *info;
struct tile_netio_queue *queue;
- unsigned int irq;
+ int result = 0;
int i;
+ int dummy = 0;
/*
* First try to register just on the local CPU, and handle any
@@ -1307,42 +1334,52 @@ static int tile_net_open_inner(struct net_device *dev)
/*
* Now register everywhere else. If any registration fails,
* even for "link down" (which might not be possible), we
- * clean up using "tile_net_stop_aux()".
+ * clean up using "tile_net_stop_aux()". Also, add all the
+ * "napi" objects (sequentially, to protect "dev->napi_list").
+ * ISSUE: Only use "netif_napi_add()" for "network cpus"?
*/
smp_call_function(tile_net_register, (void *)dev, 1);
for_each_online_cpu(i) {
- if (!priv->cpu[i]->registered) {
- tile_net_stop_aux(dev);
- return -EAGAIN;
- }
+ struct tile_net_cpu *info = priv->cpu[i];
+ if (info->registered)
+ netif_napi_add(dev, &info->napi, tile_net_poll, 64);
+ else
+ result = -EAGAIN;
+ }
+ if (result != 0) {
+ tile_net_stop_aux(dev);
+ return result;
}
queue = &info->queue;
- /*
- * Set the device intr bit mask.
- * The tile_net_register above sets per tile __intr_id.
- */
- priv->intr_id = queue->__system_part->__intr_id;
- BUG_ON(!priv->intr_id);
-
- /*
- * Register the device interrupt handler.
- * The __ffs() function returns the index into the interrupt handler
- * table from the interrupt bit mask which should have one bit
- * and one bit only set.
- */
- irq = __ffs(priv->intr_id);
- tile_irq_activate(irq, TILE_IRQ_PERCPU);
- BUG_ON(request_irq(irq, tile_net_handle_ingress_interrupt,
- 0, dev->name, (void *)dev) != 0);
+ if (priv->intr_id == 0) {
+ unsigned int irq;
- /* ISSUE: How could "priv->fully_opened" ever be "true" here? */
-
- if (!priv->fully_opened) {
+ /*
+ * Acquire the irq allocated by the hypervisor. Every
+ * queue gets the same irq. The "__intr_id" field is
+ * "1 << irq", so we use "__ffs()" to extract "irq".
+ */
+ priv->intr_id = queue->__system_part->__intr_id;
+ BUG_ON(priv->intr_id == 0);
+ irq = __ffs(priv->intr_id);
- int dummy = 0;
+ /*
+ * Register the ingress interrupt handler for this
+ * device, permanently.
+ *
+ * We used to call "free_irq()" in "tile_net_stop()",
+ * and then re-register the handler here every time,
+ * but that caused DNP errors in "handle_IRQ_event()"
+ * because "desc->action" was NULL. See bug 9143.
+ */
+ tile_irq_activate(irq, TILE_IRQ_PERCPU);
+ BUG_ON(request_irq(irq, tile_net_handle_ingress_interrupt,
+ 0, dev->name, (void *)dev) != 0);
+ }
+ {
/* Allocate initial buffers. */
int max_buffers =
@@ -1359,18 +1396,21 @@ static int tile_net_open_inner(struct net_device *dev)
if (info->num_needed_small_buffers != 0 ||
info->num_needed_large_buffers != 0)
panic("Insufficient memory for buffer stack!");
+ }
- /* Start LIPP/LEPP and activate "ingress" at the shim. */
- if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy,
- sizeof(dummy), NETIO_IPP_INPUT_INIT_OFF) < 0)
- panic("Failed to activate the LIPP Shim!\n");
+ /* We are about to be active. */
+ priv->active = true;
- priv->fully_opened = 1;
- }
+ /* Make sure "active" is visible to all tiles. */
+ mb();
- /* On each tile, enable the hypervisor to trigger interrupts. */
- /* ISSUE: Do this before starting LIPP/LEPP? */
- on_each_cpu(tile_net_enable_intr, (void *)dev, 1);
+ /* On each tile, enable NAPI and the ingress interrupt. */
+ on_each_cpu(tile_net_open_enable, (void *)dev, 1);
+
+ /* Start LIPP/LEPP and activate "ingress" at the shim. */
+ if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy,
+ sizeof(dummy), NETIO_IPP_INPUT_INIT_OFF) < 0)
+ panic("Failed to activate the LIPP Shim!\n");
/* Start our transmit queue. */
netif_start_queue(dev);
@@ -1396,9 +1436,9 @@ static void tile_net_open_retry(struct work_struct *w)
* ourselves to try again later; otherwise, tell Linux we now have
* a working link. ISSUE: What if the return value is negative?
*/
- if (tile_net_open_inner(priv->dev))
- schedule_delayed_work_on(singlethread_cpu, &priv->retry_work,
- TILE_NET_RETRY_INTERVAL);
+ if (tile_net_open_inner(priv->dev) != 0)
+ schedule_delayed_work(&priv->retry_work,
+ TILE_NET_RETRY_INTERVAL);
else
netif_carrier_on(priv->dev);
}
@@ -1412,8 +1452,8 @@ static void tile_net_open_retry(struct work_struct *w)
* The open entry point is called when a network interface is made
* active by the system (IFF_UP). At this point all resources needed
* for transmit and receive operations are allocated, the interrupt
- * handler is registered with the OS, the watchdog timer is started,
- * and the stack is notified that the interface is ready.
+ * handler is registered with the OS (if needed), the watchdog timer
+ * is started, and the stack is notified that the interface is ready.
*
* If the actual link is not available yet, then we tell Linux that
* we have no carrier, and we keep checking until the link comes up.
@@ -1468,6 +1508,10 @@ static int tile_net_open(struct net_device *dev)
#endif
priv->partly_opened = 1;
+
+ } else {
+ /* FIXME: Is this possible? */
+ /* printk("Already partly opened.\n"); */
}
/*
@@ -1487,57 +1531,17 @@ static int tile_net_open(struct net_device *dev)
* and then remember to try again later.
*/
netif_carrier_off(dev);
- schedule_delayed_work_on(singlethread_cpu, &priv->retry_work,
- TILE_NET_RETRY_INTERVAL);
+ schedule_delayed_work(&priv->retry_work, TILE_NET_RETRY_INTERVAL);
return 0;
}
-/*
- * Disables a network interface.
- *
- * Returns 0, this is not allowed to fail.
- *
- * The close entry point is called when an interface is de-activated
- * by the OS. The hardware is still under the drivers control, but
- * needs to be disabled. A global MAC reset is issued to stop the
- * hardware, and all transmit and receive resources are freed.
- *
- * ISSUE: Can this can be called while "tile_net_poll()" is running?
- */
-static int tile_net_stop(struct net_device *dev)
+static int tile_net_drain_lipp_buffers(struct tile_net_priv *priv)
{
- struct tile_net_priv *priv = netdev_priv(dev);
-
- bool pending = true;
-
- PDEBUG("tile_net_stop()\n");
-
- /* ISSUE: Only needed if not yet fully open. */
- cancel_delayed_work_sync(&priv->retry_work);
-
- /* Can't transmit any more. */
- netif_stop_queue(dev);
-
- /*
- * Disable hypervisor interrupts on each tile.
- */
- on_each_cpu(tile_net_disable_intr, (void *)dev, 1);
-
- /*
- * Unregister the interrupt handler.
- * The __ffs() function returns the index into the interrupt handler
- * table from the interrupt bit mask which should have one bit
- * and one bit only set.
- */
- if (priv->intr_id)
- free_irq(__ffs(priv->intr_id), dev);
-
- /*
- * Drain all the LIPP buffers.
- */
+ int n = 0;
+ /* Drain all the LIPP buffers. */
while (true) {
int buffer;
@@ -1560,43 +1564,105 @@ static int tile_net_stop(struct net_device *dev)
kfree_skb(skb);
}
+
+ n++;
}
- /* Stop LIPP/LEPP. */
- tile_net_stop_aux(dev);
+ return n;
+}
- priv->fully_opened = 0;
+/*
+ * Disables a network interface.
+ *
+ * Returns 0, this is not allowed to fail.
+ *
+ * The close entry point is called when an interface is de-activated
+ * by the OS. The hardware is still under the drivers control, but
+ * needs to be disabled. A global MAC reset is issued to stop the
+ * hardware, and all transmit and receive resources are freed.
+ *
+ * ISSUE: How closely does "netif_running(dev)" mirror "priv->active"?
+ *
+ * Before we are called by "__dev_close()", "netif_running()" will
+ * have been cleared, so no NEW calls to "tile_net_poll()" will be
+ * made by "netpoll_poll_dev()".
+ *
+ * Often, this can cause some tiles to still have packets in their
+ * queues, so we must call "tile_net_discard_packets()" later.
+ *
+ * Note that some other tile may still be INSIDE "tile_net_poll()",
+ * and in fact, many will be, if there is heavy network load.
+ *
+ * Calling "on_each_cpu(tile_net_stop_disable, (void *)dev, 1)" when
+ * any tile is still "napi_schedule()"'d will induce a horrible crash
+ * when "msleep()" is called. This includes tiles which are inside
+ * "tile_net_poll()" which have not yet called "napi_complete()".
+ *
+ * So, we must first try to wait long enough for other tiles to finish
+ * with any current "tile_net_poll()" call, and, hopefully, to clear
+ * the "scheduled" flag. ISSUE: It is unclear what happens to tiles
+ * which have called "napi_schedule()" but which had not yet tried to
+ * call "tile_net_poll()", or which exhausted their budget inside
+ * "tile_net_poll()" just before this function was called.
+ */
+static int tile_net_stop(struct net_device *dev)
+{
+ struct tile_net_priv *priv = netdev_priv(dev);
+
+ PDEBUG("tile_net_stop()\n");
+ /* Start discarding packets. */
+ priv->active = false;
+
+ /* Make sure "active" is visible to all tiles. */
+ mb();
/*
- * XXX: ISSUE: It appears that, in practice anyway, by the
- * time we get here, there are no pending completions.
+ * On each tile, make sure no NEW packets get delivered, and
+ * disable the ingress interrupt.
+ *
+ * Note that the ingress interrupt can fire AFTER this,
+ * presumably due to packets which were recently delivered,
+ * but it will have no effect.
*/
- while (pending) {
+ on_each_cpu(tile_net_deregister, (void *)dev, 1);
- struct sk_buff *olds[32];
- unsigned int wanted = 32;
- unsigned int i, nolds = 0;
+ /* Optimistically drain LIPP buffers. */
+ (void)tile_net_drain_lipp_buffers(priv);
- nolds = tile_net_lepp_grab_comps(dev, olds,
- wanted, &pending);
+ /* ISSUE: Only needed if not yet fully open. */
+ cancel_delayed_work_sync(&priv->retry_work);
- /* ISSUE: We have never actually seen this debug spew. */
- if (nolds != 0)
- pr_info("During tile_net_stop(), grabbed %d comps.\n",
- nolds);
+ /* Can't transmit any more. */
+ netif_stop_queue(dev);
- for (i = 0; i < nolds; i++)
- kfree_skb(olds[i]);
- }
+ /* Disable NAPI on each tile. */
+ on_each_cpu(tile_net_stop_disable, (void *)dev, 1);
+
+ /*
+ * Drain any remaining LIPP buffers. NOTE: This "printk()"
+ * has never been observed, but in theory it could happen.
+ */
+ if (tile_net_drain_lipp_buffers(priv) != 0)
+ printk("Had to drain some extra LIPP buffers!\n");
+ /* Stop LIPP/LEPP. */
+ tile_net_stop_aux(dev);
+
+ /*
+ * ISSUE: It appears that, in practice anyway, by the time we
+ * get here, there are no pending completions, but just in case,
+ * we free (all of) them anyway.
+ */
+ while (tile_net_lepp_free_comps(dev, true))
+ /* loop */;
/* Wipe the EPP queue. */
- memset(priv->epp_queue, 0, sizeof(lepp_queue_t));
+ memset(priv->eq, 0, sizeof(lepp_queue_t));
/* Evict the EPP queue. */
- finv_buffer(priv->epp_queue, PAGE_SIZE);
+ finv_buffer(priv->eq, EQ_SIZE);
return 0;
}
@@ -1742,17 +1808,15 @@ static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev)
unsigned long irqflags;
- lepp_queue_t *eq = priv->epp_queue;
+ lepp_queue_t *eq = priv->eq;
- struct sk_buff *olds[4];
- unsigned int wanted = 4;
+ struct sk_buff *olds[8];
+ unsigned int wanted = 8;
unsigned int i, nolds = 0;
unsigned int cmd_head, cmd_tail, cmd_next;
unsigned int comp_tail;
- unsigned int free_slots;
-
/* Paranoia. */
BUG_ON(skb->protocol != htons(ETH_P_IP));
@@ -1780,34 +1844,32 @@ static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev)
/* Enqueue the command. */
- spin_lock_irqsave(&priv->cmd_lock, irqflags);
+ spin_lock_irqsave(&priv->eq_lock, irqflags);
/*
* Handle completions if needed to make room.
* HACK: Spin until there is sufficient room.
*/
- free_slots = lepp_num_free_comp_slots(eq);
- if (free_slots < 1) {
-spin:
- nolds += tile_net_lepp_grab_comps(dev, olds + nolds,
- wanted - nolds, NULL);
- if (lepp_num_free_comp_slots(eq) < 1)
- goto spin;
+ if (lepp_num_free_comp_slots(eq) == 0) {
+ nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 0);
+ if (nolds == 0) {
+busy:
+ spin_unlock_irqrestore(&priv->eq_lock, irqflags);
+ return NETDEV_TX_BUSY;
+ }
}
cmd_head = eq->cmd_head;
cmd_tail = eq->cmd_tail;
- /* NOTE: The "gotos" below are untested. */
-
/* Prepare to advance, detecting full queue. */
cmd_next = cmd_tail + cmd_size;
if (cmd_tail < cmd_head && cmd_next >= cmd_head)
- goto spin;
+ goto busy;
if (cmd_next > LEPP_CMD_LIMIT) {
cmd_next = 0;
if (cmd_next == cmd_head)
- goto spin;
+ goto busy;
}
/* Copy the command. */
@@ -1823,14 +1885,18 @@ spin:
eq->comp_tail = comp_tail;
/* Flush before allowing LEPP to handle the command. */
+ /* ISSUE: Is this the optimal location for the flush? */
__insn_mf();
eq->cmd_tail = cmd_tail;
- spin_unlock_irqrestore(&priv->cmd_lock, irqflags);
-
+ /* NOTE: Using "4" here is more efficient than "0" or "2", */
+ /* and, strangely, more efficient than pre-checking the number */
+ /* of available completions, and comparing it to 4. */
if (nolds == 0)
- nolds = tile_net_lepp_grab_comps(dev, olds, wanted, NULL);
+ nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 4);
+
+ spin_unlock_irqrestore(&priv->eq_lock, irqflags);
/* Handle completions. */
for (i = 0; i < nolds; i++)
@@ -1870,10 +1936,10 @@ static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
unsigned int num_frags;
- lepp_queue_t *eq = priv->epp_queue;
+ lepp_queue_t *eq = priv->eq;
- struct sk_buff *olds[4];
- unsigned int wanted = 4;
+ struct sk_buff *olds[8];
+ unsigned int wanted = 8;
unsigned int i, nolds = 0;
unsigned int cmd_size = sizeof(lepp_cmd_t);
@@ -1883,8 +1949,6 @@ static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
lepp_cmd_t cmds[LEPP_MAX_FRAGS];
- unsigned int free_slots;
-
/*
* This is paranoia, since we think that if the link doesn't come
@@ -1905,7 +1969,8 @@ static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
if (hash_default) {
HV_PTE pte = *virt_to_pte(current->mm, (unsigned long)data);
if (hv_pte_get_mode(pte) != HV_PTE_MODE_CACHE_HASH_L3)
- panic("Non-coherent egress buffer!");
+ panic("Non-HFH egress buffer! VA=%p Mode=%d PTE=%llx",
+ data, hv_pte_get_mode(pte), hv_pte_val(pte));
}
#endif
#endif
@@ -1958,37 +2023,35 @@ static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
/* Enqueue the commands. */
- spin_lock_irqsave(&priv->cmd_lock, irqflags);
+ spin_lock_irqsave(&priv->eq_lock, irqflags);
/*
* Handle completions if needed to make room.
* HACK: Spin until there is sufficient room.
*/
- free_slots = lepp_num_free_comp_slots(eq);
- if (free_slots < 1) {
-spin:
- nolds += tile_net_lepp_grab_comps(dev, olds + nolds,
- wanted - nolds, NULL);
- if (lepp_num_free_comp_slots(eq) < 1)
- goto spin;
+ if (lepp_num_free_comp_slots(eq) == 0) {
+ nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 0);
+ if (nolds == 0) {
+busy:
+ spin_unlock_irqrestore(&priv->eq_lock, irqflags);
+ return NETDEV_TX_BUSY;
+ }
}
cmd_head = eq->cmd_head;
cmd_tail = eq->cmd_tail;
- /* NOTE: The "gotos" below are untested. */
-
/* Copy the commands, or fail. */
for (i = 0; i < num_frags; i++) {
/* Prepare to advance, detecting full queue. */
cmd_next = cmd_tail + cmd_size;
if (cmd_tail < cmd_head && cmd_next >= cmd_head)
- goto spin;
+ goto busy;
if (cmd_next > LEPP_CMD_LIMIT) {
cmd_next = 0;
if (cmd_next == cmd_head)
- goto spin;
+ goto busy;
}
/* Copy the command. */
@@ -2005,14 +2068,18 @@ spin:
eq->comp_tail = comp_tail;
/* Flush before allowing LEPP to handle the command. */
+ /* ISSUE: Is this the optimal location for the flush? */
__insn_mf();
eq->cmd_tail = cmd_tail;
- spin_unlock_irqrestore(&priv->cmd_lock, irqflags);
-
+ /* NOTE: Using "4" here is more efficient than "0" or "2", */
+ /* and, strangely, more efficient than pre-checking the number */
+ /* of available completions, and comparing it to 4. */
if (nolds == 0)
- nolds = tile_net_lepp_grab_comps(dev, olds, wanted, NULL);
+ nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 4);
+
+ spin_unlock_irqrestore(&priv->eq_lock, irqflags);
/* Handle completions. */
for (i = 0; i < nolds; i++)
@@ -2261,7 +2328,6 @@ static struct net_device *tile_net_dev_init(const char *name)
int ret;
struct net_device *dev;
struct tile_net_priv *priv;
- struct page *page;
/*
* Allocate the device structure. This allocates "priv", calls
@@ -2285,23 +2351,21 @@ static struct net_device *tile_net_dev_init(const char *name)
INIT_DELAYED_WORK(&priv->retry_work, tile_net_open_retry);
- spin_lock_init(&priv->cmd_lock);
- spin_lock_init(&priv->comp_lock);
+ spin_lock_init(&priv->eq_lock);
- /* Allocate "epp_queue". */
- BUG_ON(get_order(sizeof(lepp_queue_t)) != 0);
- page = alloc_pages(GFP_KERNEL | __GFP_ZERO, 0);
- if (!page) {
+ /* Allocate "eq". */
+ priv->eq_pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, EQ_ORDER);
+ if (!priv->eq_pages) {
free_netdev(dev);
return NULL;
}
- priv->epp_queue = page_address(page);
+ priv->eq = page_address(priv->eq_pages);
/* Register the network device. */
ret = register_netdev(dev);
if (ret) {
pr_err("register_netdev %s failed %d\n", dev->name, ret);
- free_page((unsigned long)priv->epp_queue);
+ __free_pages(priv->eq_pages, EQ_ORDER);
free_netdev(dev);
return NULL;
}
@@ -2310,7 +2374,7 @@ static struct net_device *tile_net_dev_init(const char *name)
ret = tile_net_get_mac(dev);
if (ret < 0) {
unregister_netdev(dev);
- free_page((unsigned long)priv->epp_queue);
+ __free_pages(priv->eq_pages, EQ_ORDER);
free_netdev(dev);
return NULL;
}
@@ -2321,6 +2385,9 @@ static struct net_device *tile_net_dev_init(const char *name)
/*
* Module cleanup.
+ *
+ * FIXME: If compiled as a module, this module cannot be "unloaded",
+ * because the "ingress interrupt handler" is registered permanently.
*/
static void tile_net_cleanup(void)
{
@@ -2331,8 +2398,8 @@ static void tile_net_cleanup(void)
struct net_device *dev = tile_net_devs[i];
struct tile_net_priv *priv = netdev_priv(dev);
unregister_netdev(dev);
- finv_buffer(priv->epp_queue, PAGE_SIZE);
- free_page((unsigned long)priv->epp_queue);
+ finv_buffer(priv->eq, EQ_SIZE);
+ __free_pages(priv->eq_pages, EQ_ORDER);
free_netdev(dev);
}
}
@@ -2355,7 +2422,12 @@ static int tile_net_init_module(void)
}
+module_init(tile_net_init_module);
+module_exit(tile_net_cleanup);
+
+
#ifndef MODULE
+
/*
* The "network_cpus" boot argument specifies the cpus that are dedicated
* to handle ingress packets.
@@ -2391,8 +2463,5 @@ static int __init network_cpus_setup(char *str)
return 0;
}
__setup("network_cpus=", network_cpus_setup);
-#endif
-
-module_init(tile_net_init_module);
-module_exit(tile_net_cleanup);
+#endif