/*
* 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__ */