--- /dev/null
+/*
+ * Copyright 2010 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+/**
+ * @file drivers/xgbe/impl.h
+ * Implementation details for the NetIO library.
+ */
+
+#ifndef __DRV_XGBE_IMPL_H__
+#define __DRV_XGBE_IMPL_H__
+
+#include <hv/netio_errors.h>
+#include <hv/netio_intf.h>
+#include <hv/drv_xgbe_intf.h>
+
+
+/** How many groups we have (log2). */
+#define LOG2_NUM_GROUPS (12)
+/** How many groups we have. */
+#define NUM_GROUPS (1 << LOG2_NUM_GROUPS)
+
+/** Number of output requests we'll buffer per tile. */
+#define EPP_REQS_PER_TILE (32)
+
+/** Words used in an eDMA command without checksum acceleration. */
+#define EDMA_WDS_NO_CSUM 8
+/** Words used in an eDMA command with checksum acceleration. */
+#define EDMA_WDS_CSUM 10
+/** Total available words in the eDMA command FIFO. */
+#define EDMA_WDS_TOTAL 128
+
+
+/*
+ * FIXME: These definitions are internal and should have underscores!
+ * NOTE: The actual numeric values here are intentional and allow us to
+ * optimize the concept "if small ... else if large ... else ...", by
+ * checking for the low bit being set, and then for non-zero.
+ * These are used as array indices, so they must have the values (0, 1, 2)
+ * in some order.
+ */
+#define SIZE_SMALL (1) /**< Small packet queue. */
+#define SIZE_LARGE (2) /**< Large packet queue. */
+#define SIZE_JUMBO (0) /**< Jumbo packet queue. */
+
+/** The number of "SIZE_xxx" values. */
+#define NETIO_NUM_SIZES 3
+
+
+/*
+ * Default numbers of packets for IPP drivers. These values are chosen
+ * such that CIPP1 will not overflow its L2 cache.
+ */
+
+/** The default number of small packets. */
+#define NETIO_DEFAULT_SMALL_PACKETS 2750
+/** The default number of large packets. */
+#define NETIO_DEFAULT_LARGE_PACKETS 2500
+/** The default number of jumbo packets. */
+#define NETIO_DEFAULT_JUMBO_PACKETS 250
+
+
+/** Log2 of the size of a memory arena. */
+#define NETIO_ARENA_SHIFT 24 /* 16 MB */
+/** Size of a memory arena. */
+#define NETIO_ARENA_SIZE (1 << NETIO_ARENA_SHIFT)
+
+
+/** A queue of packets.
+ *
+ * This structure partially defines a queue of packets waiting to be
+ * processed. The queue as a whole is written to by an interrupt handler and
+ * read by non-interrupt code; this data structure is what's touched by the
+ * interrupt handler. The other part of the queue state, the read offset, is
+ * kept in user space, not in hypervisor space, so it is in a separate data
+ * structure.
+ *
+ * The read offset (__packet_receive_read in the user part of the queue
+ * structure) points to the next packet to be read. When the read offset is
+ * equal to the write offset, the queue is empty; therefore the queue must
+ * contain one more slot than the required maximum queue size.
+ *
+ * Here's an example of all 3 state variables and what they mean. All
+ * pointers move left to right.
+ *
+ * @code
+ * I I V V V V I I I I
+ * 0 1 2 3 4 5 6 7 8 9 10
+ * ^ ^ ^ ^
+ * | | |
+ * | | __last_packet_plus_one
+ * | __buffer_write
+ * __packet_receive_read
+ * @endcode
+ *
+ * This queue has 10 slots, and thus can hold 9 packets (_last_packet_plus_one
+ * = 10). The read pointer is at 2, and the write pointer is at 6; thus,
+ * there are valid, unread packets in slots 2, 3, 4, and 5. The remaining
+ * slots are invalid (do not contain a packet).
+ */
+typedef struct {
+ /** Byte offset of the next notify packet to be written: zero for the first
+ * packet on the queue, sizeof (netio_pkt_t) for the second packet on the
+ * queue, etc. */
+ volatile uint32_t __packet_write;
+
+ /** Offset of the packet after the last valid packet (i.e., when any
+ * pointer is incremented to this value, it wraps back to zero). */
+ uint32_t __last_packet_plus_one;
+}
+__netio_packet_queue_t;
+
+
+/** A queue of buffers.
+ *
+ * This structure partially defines a queue of empty buffers which have been
+ * obtained via requests to the IPP. (The elements of the queue are packet
+ * handles, which are transformed into a full netio_pkt_t when the buffer is
+ * retrieved.) The queue as a whole is written to by an interrupt handler and
+ * read by non-interrupt code; this data structure is what's touched by the
+ * interrupt handler. The other parts of the queue state, the read offset and
+ * requested write offset, are kept in user space, not in hypervisor space, so
+ * they are in a separate data structure.
+ *
+ * The read offset (__buffer_read in the user part of the queue structure)
+ * points to the next buffer to be read. When the read offset is equal to the
+ * write offset, the queue is empty; therefore the queue must contain one more
+ * slot than the required maximum queue size.
+ *
+ * The requested write offset (__buffer_requested_write in the user part of
+ * the queue structure) points to the slot which will hold the next buffer we
+ * request from the IPP, once we get around to sending such a request. When
+ * the requested write offset is equal to the write offset, no requests for
+ * new buffers are outstanding; when the requested write offset is one greater
+ * than the read offset, no more requests may be sent.
+ *
+ * Note that, unlike the packet_queue, the buffer_queue places incoming
+ * buffers at decreasing addresses. This makes the check for "is it time to
+ * wrap the buffer pointer" cheaper in the assembly code which receives new
+ * buffers, and means that the value which defines the queue size,
+ * __last_buffer, is different than in the packet queue. Also, the offset
+ * used in the packet_queue is already scaled by the size of a packet; here we
+ * use unscaled slot indices for the offsets. (These differences are
+ * historical, and in the future it's possible that the packet_queue will look
+ * more like this queue.)
+ *
+ * @code
+ * Here's an example of all 4 state variables and what they mean. Remember:
+ * all pointers move right to left.
+ *
+ * V V V I I R R V V V
+ * 0 1 2 3 4 5 6 7 8 9
+ * ^ ^ ^ ^
+ * | | | |
+ * | | | __last_buffer
+ * | | __buffer_write
+ * | __buffer_requested_write
+ * __buffer_read
+ * @endcode
+ *
+ * This queue has 10 slots, and thus can hold 9 buffers (_last_buffer = 9).
+ * The read pointer is at 2, and the write pointer is at 6; thus, there are
+ * valid, unread buffers in slots 2, 1, 0, 9, 8, and 7. The requested write
+ * pointer is at 4; thus, requests have been made to the IPP for buffers which
+ * will be placed in slots 6 and 5 when they arrive. Finally, the remaining
+ * slots are invalid (do not contain a buffer).
+ */
+typedef struct
+{
+ /** Ordinal number of the next buffer to be written: 0 for the first slot in
+ * the queue, 1 for the second slot in the queue, etc. */
+ volatile uint32_t __buffer_write;
+
+ /** Ordinal number of the last buffer (i.e., when any pointer is decremented
+ * below zero, it is reloaded with this value). */
+ uint32_t __last_buffer;
+}
+__netio_buffer_queue_t;
+
+
+/**
+ * An object for providing Ethernet packets to a process.
+ */
+typedef struct __netio_queue_impl_t
+{
+ /** The queue of packets waiting to be received. */
+ __netio_packet_queue_t __packet_receive_queue;
+ /** The intr bit mask that IDs this device. */
+ unsigned int __intr_id;
+ /** Offset to queues of empty buffers, one per size. */
+ uint32_t __buffer_queue[NETIO_NUM_SIZES];
+ /** The address of the first EPP tile, or -1 if no EPP. */
+ /* ISSUE: Actually this is always "0" or "~0". */
+ uint32_t __epp_location;
+ /** The queue ID that this queue represents. */
+ unsigned int __queue_id;
+ /** Number of acknowledgements received. */
+ volatile uint32_t __acks_received;
+ /** Last completion number received for packet_sendv. */
+ volatile uint32_t __last_completion_rcv;
+ /** Number of packets allowed to be outstanding. */
+ uint32_t __max_outstanding;
+ /** First VA available for packets. */
+ void* __va_0;
+ /** First VA in second range available for packets. */
+ void* __va_1;
+ /** Padding to align the "__packets" field to the size of a netio_pkt_t. */
+ uint32_t __padding[3];
+ /** The packets themselves. */
+ netio_pkt_t __packets[0];
+}
+netio_queue_impl_t;
+
+
+/**
+ * An object for managing the user end of a NetIO queue.
+ */
+typedef struct __netio_queue_user_impl_t
+{
+ /** The next incoming packet to be read. */
+ uint32_t __packet_receive_read;
+ /** The next empty buffers to be read, one index per size. */
+ uint8_t __buffer_read[NETIO_NUM_SIZES];
+ /** Where the empty buffer we next request from the IPP will go, one index
+ * per size. */
+ uint8_t __buffer_requested_write[NETIO_NUM_SIZES];
+ /** PCIe interface flag. */
+ uint8_t __pcie;
+ /** Number of packets left to be received before we send a credit update. */
+ uint32_t __receive_credit_remaining;
+ /** Value placed in __receive_credit_remaining when it reaches zero. */
+ uint32_t __receive_credit_interval;
+ /** First fast I/O routine index. */
+ uint32_t __fastio_index;
+ /** Number of acknowledgements expected. */
+ uint32_t __acks_outstanding;
+ /** Last completion number requested. */
+ uint32_t __last_completion_req;
+ /** File descriptor for driver. */
+ int __fd;
+}
+netio_queue_user_impl_t;
+
+
+#define NETIO_GROUP_CHUNK_SIZE 64 /**< Max # groups in one IPP request */
+#define NETIO_BUCKET_CHUNK_SIZE 64 /**< Max # buckets in one IPP request */
+
+
+/** Internal structure used to convey packet send information to the
+ * hypervisor. FIXME: Actually, it's not used for that anymore, but
+ * netio_packet_send() still uses it internally.
+ */
+typedef struct
+{
+ uint16_t flags; /**< Packet flags (__NETIO_SEND_FLG_xxx) */
+ uint16_t transfer_size; /**< Size of packet */
+ uint32_t va; /**< VA of start of packet */
+ __netio_pkt_handle_t handle; /**< Packet handle */
+ uint32_t csum0; /**< First checksum word */
+ uint32_t csum1; /**< Second checksum word */
+}
+__netio_send_cmd_t;
+
+
+/** Flags used in two contexts:
+ * - As the "flags" member in the __netio_send_cmd_t, above; used only
+ * for netio_pkt_send_{prepare,commit}.
+ * - As part of the flags passed to the various send packet fast I/O calls.
+ */
+
+/** Need acknowledgement on this packet. Note that some code in the
+ * normal send_pkt fast I/O handler assumes that this is equal to 1. */
+#define __NETIO_SEND_FLG_ACK 0x1
+
+/** Do checksum on this packet. (Only used with the __netio_send_cmd_t;
+ * normal packet sends use a special fast I/O index to denote checksumming,
+ * and multi-segment sends test the checksum descriptor.) */
+#define __NETIO_SEND_FLG_CSUM 0x2
+
+/** Get a completion on this packet. Only used with multi-segment sends. */
+#define __NETIO_SEND_FLG_COMPLETION 0x4
+
+/** Position of the number-of-extra-segments value in the flags word.
+ Only used with multi-segment sends. */
+#define __NETIO_SEND_FLG_XSEG_SHIFT 3
+
+/** Width of the number-of-extra-segments value in the flags word. */
+#define __NETIO_SEND_FLG_XSEG_WIDTH 2
+
+#endif /* __DRV_XGBE_IMPL_H__ */
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