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- /*
- * 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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