Add memif - packet memory interface for intra-host communication

Change-Id: I94c06b07a39f07ceba87bf3e7fcfc70e43231e8a
Signed-off-by: Damjan Marion <damarion@cisco.com>
Co-Authored-By: Milan Lenco <Milan.Lenco@pantheon.tech>

1 files changed, 330 insertions, 0 deletions

diff --git a/src/plugins/memif/device.c b/src/plugins/memif/device.c
new file mode 100644
index 00000000000..446537a3792
--- /dev/null
+++ b/src/plugins/memif/device.c
@@ -0,0 +1,330 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+#define _GNU_SOURCE
+#include <stdint.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vnet/ethernet/ethernet.h>
+
+#include <memif/memif.h>
+
+#define foreach_memif_tx_func_error	       \
+_(NO_FREE_SLOTS, "no free tx slots")           \
+_(PENDING_MSGS, "pending msgs in tx ring")
+
+typedef enum
+{
+#define _(f,s) MEMIF_TX_ERROR_##f,
+  foreach_memif_tx_func_error
+#undef _
+    MEMIF_TX_N_ERROR,
+} memif_tx_func_error_t;
+
+static char *memif_tx_func_error_strings[] = {
+#define _(n,s) s,
+  foreach_memif_tx_func_error
+#undef _
+};
+
+
+static u8 *
+format_memif_device_name (u8 * s, va_list * args)
+{
+  u32 i = va_arg (*args, u32);
+
+  s = format (s, "memif%u", i);
+  return s;
+}
+
+static u8 *
+format_memif_device (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  int verbose = va_arg (*args, int);
+  uword indent = format_get_indent (s);
+
+  s = format (s, "MEMIF interface");
+  if (verbose)
+    {
+      s = format (s, "\n%U instance %u", format_white_space, indent + 2,
+		  dev_instance);
+    }
+  return s;
+}
+
+static u8 *
+format_memif_tx_trace (u8 * s, va_list * args)
+{
+  s = format (s, "Unimplemented...");
+  return s;
+}
+
+static_always_inline void
+memif_interface_lock (memif_if_t * mif)
+{
+  if (PREDICT_FALSE (mif->lockp != 0))
+    {
+      while (__sync_lock_test_and_set (mif->lockp, 1))
+	;
+    }
+}
+
+static_always_inline void
+memif_interface_unlock (memif_if_t * mif)
+{
+  if (PREDICT_FALSE (mif->lockp != 0))
+    *mif->lockp = 0;
+}
+
+static_always_inline void
+memif_prefetch_buffer_and_data (vlib_main_t * vm, u32 bi)
+{
+  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  vlib_prefetch_buffer_header (b, LOAD);
+  CLIB_PREFETCH (b->data, CLIB_CACHE_LINE_BYTES, LOAD);
+}
+
+static_always_inline uword
+memif_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+			   vlib_frame_t * frame, memif_if_t * mif,
+			   memif_ring_type_t type)
+{
+  u8 rid = 0;
+  memif_ring_t *ring = memif_get_ring (mif, type, rid);
+  u32 *buffers = vlib_frame_args (frame);
+  u32 n_left = frame->n_vectors;
+  u16 ring_size = 1 << mif->log2_ring_size;
+  u16 mask = ring_size - 1;
+  u16 head, tail;
+  u16 free_slots;
+
+  memif_interface_lock (mif);
+
+  /* free consumed buffers */
+
+  head = ring->head;
+  tail = ring->tail;
+
+  if (tail > head)
+    free_slots = tail - head;
+  else
+    free_slots = ring_size - head + tail;
+
+  while (n_left > 5 && free_slots > 1)
+    {
+      if (PREDICT_TRUE (head + 5 < ring_size))
+	{
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, head + 2),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, head + 3),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[head + 4], CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[head + 5], CLIB_CACHE_LINE_BYTES, STORE);
+	}
+      else
+	{
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 2) % mask),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 3) % mask),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[(head + 4) % mask],
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[(head + 5) % mask],
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	}
+
+      memif_prefetch_buffer_and_data (vm, buffers[2]);
+      memif_prefetch_buffer_and_data (vm, buffers[3]);
+
+      vlib_buffer_t *b0 = vlib_get_buffer (vm, buffers[0]);
+      vlib_buffer_t *b1 = vlib_get_buffer (vm, buffers[1]);
+
+      void *mb0 = memif_get_buffer (mif, ring, head);
+      clib_memcpy (mb0, vlib_buffer_get_current (b0), CLIB_CACHE_LINE_BYTES);
+      ring->desc[head].length = b0->current_length;
+      head = (head + 1) & mask;
+
+      void *mb1 = memif_get_buffer (mif, ring, head);
+      clib_memcpy (mb1, vlib_buffer_get_current (b1), CLIB_CACHE_LINE_BYTES);
+      ring->desc[head].length = b1->current_length;
+      head = (head + 1) & mask;
+
+      if (b0->current_length > CLIB_CACHE_LINE_BYTES)
+	{
+	  clib_memcpy (mb0 + CLIB_CACHE_LINE_BYTES,
+		       vlib_buffer_get_current (b0) + CLIB_CACHE_LINE_BYTES,
+		       b0->current_length - CLIB_CACHE_LINE_BYTES);
+	}
+      if (b1->current_length > CLIB_CACHE_LINE_BYTES)
+	{
+	  clib_memcpy (mb1 + CLIB_CACHE_LINE_BYTES,
+		       vlib_buffer_get_current (b1) + CLIB_CACHE_LINE_BYTES,
+		       b1->current_length - CLIB_CACHE_LINE_BYTES);
+	}
+
+
+      buffers += 2;
+      n_left -= 2;
+      free_slots -= 2;
+    }
+
+  while (n_left && free_slots)
+    {
+      vlib_buffer_t *b0 = vlib_get_buffer (vm, buffers[0]);
+      void *mb0 = memif_get_buffer (mif, ring, head);
+      clib_memcpy (mb0, vlib_buffer_get_current (b0), CLIB_CACHE_LINE_BYTES);
+
+      if (b0->current_length > CLIB_CACHE_LINE_BYTES)
+	{
+	  clib_memcpy (mb0 + CLIB_CACHE_LINE_BYTES,
+		       vlib_buffer_get_current (b0) + CLIB_CACHE_LINE_BYTES,
+		       b0->current_length - CLIB_CACHE_LINE_BYTES);
+	}
+      ring->desc[head].length = b0->current_length;
+      head = (head + 1) & mask;
+
+      buffers++;
+      n_left--;
+      free_slots--;
+    }
+
+  CLIB_MEMORY_STORE_BARRIER ();
+  ring->head = head;
+
+  memif_interface_unlock (mif);
+
+  if (n_left)
+    {
+      vlib_error_count (vm, node->node_index, MEMIF_TX_ERROR_NO_FREE_SLOTS,
+			n_left);
+      vlib_buffer_free (vm, buffers, n_left);
+    }
+
+  vlib_buffer_free (vm, vlib_frame_args (frame), frame->n_vectors);
+  if (mif->interrupt_line.fd > 0)
+    {
+      u8 b = rid;
+      CLIB_UNUSED (int r) = write (mif->interrupt_line.fd, &b, sizeof (b));
+    }
+
+  return frame->n_vectors;
+}
+
+static uword
+memif_interface_tx (vlib_main_t * vm,
+		    vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  memif_main_t *nm = &memif_main;
+  vnet_interface_output_runtime_t *rund = (void *) node->runtime_data;
+  memif_if_t *mif = pool_elt_at_index (nm->interfaces, rund->dev_instance);
+
+  if (mif->flags & MEMIF_IF_FLAG_IS_SLAVE)
+    return memif_interface_tx_inline (vm, node, frame, mif, MEMIF_RING_S2M);
+  else
+    return memif_interface_tx_inline (vm, node, frame, mif, MEMIF_RING_M2S);
+}
+
+static void
+memif_set_interface_next_node (vnet_main_t * vnm, u32 hw_if_index,
+			       u32 node_index)
+{
+  memif_main_t *apm = &memif_main;
+  vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
+  memif_if_t *mif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
+
+  /* Shut off redirection */
+  if (node_index == ~0)
+    {
+      mif->per_interface_next_index = node_index;
+      return;
+    }
+
+  mif->per_interface_next_index =
+    vlib_node_add_next (vlib_get_main (), memif_input_node.index, node_index);
+}
+
+static void
+memif_clear_hw_interface_counters (u32 instance)
+{
+  /* Nothing for now */
+}
+
+static clib_error_t *
+memif_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  memif_main_t *apm = &memif_main;
+  memif_msg_t msg;
+  vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
+  memif_if_t *mif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
+
+  if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
+    mif->flags |= MEMIF_IF_FLAG_ADMIN_UP;
+  else
+    {
+      mif->flags &= ~MEMIF_IF_FLAG_ADMIN_UP;
+      if (!(mif->flags & MEMIF_IF_FLAG_DELETING)
+	  && mif->connection.index != ~0)
+	{
+	  msg.version = MEMIF_VERSION;
+	  msg.type = MEMIF_MSG_TYPE_DISCONNECT;
+	  send (mif->connection.fd, &msg, sizeof (msg), 0);
+	}
+    }
+
+  return 0;
+}
+
+static clib_error_t *
+memif_subif_add_del_function (vnet_main_t * vnm,
+			      u32 hw_if_index,
+			      struct vnet_sw_interface_t *st, int is_add)
+{
+  /* Nothing for now */
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VNET_DEVICE_CLASS (memif_device_class) = {
+  .name = "memif",
+  .tx_function = memif_interface_tx,
+  .format_device_name = format_memif_device_name,
+  .format_device = format_memif_device,
+  .format_tx_trace = format_memif_tx_trace,
+  .tx_function_n_errors = MEMIF_TX_N_ERROR,
+  .tx_function_error_strings = memif_tx_func_error_strings,
+  .rx_redirect_to_node = memif_set_interface_next_node,
+  .clear_counters = memif_clear_hw_interface_counters,
+  .admin_up_down_function = memif_interface_admin_up_down,
+  .subif_add_del_function = memif_subif_add_del_function,
+};
+
+VLIB_DEVICE_TX_FUNCTION_MULTIARCH(memif_device_class,
+				  memif_interface_tx)
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */