hpilo.h

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/*
 * linux/drivers/char/hpilo.h
 *
 * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
 *  David Altobelli <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef __HPILO_H
#define __HPILO_H

#define ILO_NAME "hpilo"

/* max number of open channel control blocks per device, hw limited to 32 */
#define MAX_CCB        24
/* min number of open channel control blocks per device, hw limited to 32 */
#define MIN_CCB     8
/* max number of supported devices */
#define MAX_ILO_DEV 1
/* max number of files */
#define MAX_OPEN    (MAX_CCB * MAX_ILO_DEV)
/* total wait time in usec */
#define MAX_WAIT_TIME   10000
/* per spin wait time in usec */
#define WAIT_TIME   10
/* spin counter for open/close delay */
#define MAX_WAIT    (MAX_WAIT_TIME / WAIT_TIME)

/*
 * Per device, used to track global memory allocations.
 */
struct ilo_hwinfo {
    /* mmio registers on device */
    char __iomem *mmio_vaddr;

    /* doorbell registers on device */
    char __iomem *db_vaddr;

    /* shared memory on device used for channel control blocks */
    char __iomem *ram_vaddr;

    /* files corresponding to this device */
    struct ccb_data *ccb_alloc[MAX_CCB];

    struct pci_dev *ilo_dev;

    /*
     * open_lock      serializes ccb_cnt during open and close
     * [ irq disabled ]
     * -> alloc_lock  used when adding/removing/searching ccb_alloc,
     *                which represents all ccbs open on the device
     * --> fifo_lock  controls access to fifo queues shared with hw
     *
     * Locks must be taken in this order, but open_lock and alloc_lock
     * are optional, they do not need to be held in order to take a
     * lower level lock.
     */
    spinlock_t open_lock;
    spinlock_t alloc_lock;
    spinlock_t fifo_lock;

    struct cdev cdev;
};

/* offset from mmio_vaddr for enabling doorbell interrupts */
#define DB_IRQ      0xB2
/* offset from mmio_vaddr for outbound communications */
#define DB_OUT      0xD4
/* DB_OUT reset bit */
#define DB_RESET    26

/*
 * Channel control block. Used to manage hardware queues.
 * The format must match hw's version.  The hw ccb is 128 bytes,
 * but the context area shouldn't be touched by the driver.
 */
#define ILOSW_CCB_SZ    64
#define ILOHW_CCB_SZ    128
struct ccb {
    union {
        char *send_fifobar;
        u64 send_fifobar_pa;
    } ccb_u1;
    union {
        char *send_desc;
        u64 send_desc_pa;
    } ccb_u2;
    u64 send_ctrl;

    union {
        char *recv_fifobar;
        u64 recv_fifobar_pa;
    } ccb_u3;
    union {
        char *recv_desc;
        u64 recv_desc_pa;
    } ccb_u4;
    u64 recv_ctrl;

    union {
        char __iomem *db_base;
        u64 padding5;
    } ccb_u5;

    u64 channel;

    /* unused context area (64 bytes) */
};

/* ccb queue parameters */
#define SENDQ       1
#define RECVQ       2
#define NR_QENTRY       4
#define L2_QENTRY_SZ    12

/* ccb ctrl bitfields */
#define CTRL_BITPOS_L2SZ             0
#define CTRL_BITPOS_FIFOINDEXMASK    4
#define CTRL_BITPOS_DESCLIMIT        18
#define CTRL_BITPOS_A                30
#define CTRL_BITPOS_G                31

/* ccb doorbell macros */
#define L2_DB_SIZE      14
#define ONE_DB_SIZE     (1 << L2_DB_SIZE)

/*
 * Per fd structure used to track the ccb allocated to that dev file.
 */
struct ccb_data {
    /* software version of ccb, using virtual addrs */
    struct ccb  driver_ccb;

    /* hardware version of ccb, using physical addrs */
    struct ccb  ilo_ccb;

    /* hardware ccb is written to this shared mapped device memory */
    struct ccb __iomem *mapped_ccb;

    /* dma'able memory used for send/recv queues */
    void       *dma_va;
    dma_addr_t  dma_pa;
    size_t      dma_size;

    /* pointer to hardware device info */
    struct ilo_hwinfo *ilo_hw;

    /* queue for this ccb to wait for recv data */
    wait_queue_head_t ccb_waitq;

    /* usage count, to allow for shared ccb's */
    int     ccb_cnt;

    /* open wanted exclusive access to this ccb */
    int     ccb_excl;
};

/*
 * FIFO queue structure, shared with hw.
 */
#define ILO_START_ALIGN 4096
#define ILO_CACHE_SZ     128
struct fifo {
    u64 nrents; /* user requested number of fifo entries */
    u64 imask;  /* mask to extract valid fifo index */
    u64 merge;  /*  O/C bits to merge in during enqueue operation */
    u64 reset;  /* set to non-zero when the target device resets */
    u8  pad_0[ILO_CACHE_SZ - (sizeof(u64) * 4)];

    u64 head;
    u8  pad_1[ILO_CACHE_SZ - (sizeof(u64))];

    u64 tail;
    u8  pad_2[ILO_CACHE_SZ - (sizeof(u64))];

    u64 fifobar[1];
};

/* convert between struct fifo, and the fifobar, which is saved in the ccb */
#define FIFOHANDLESIZE (sizeof(struct fifo) - sizeof(u64))
#define FIFOBARTOHANDLE(_fifo) \
    ((struct fifo *)(((char *)(_fifo)) - FIFOHANDLESIZE))

/* the number of qwords to consume from the entry descriptor */
#define ENTRY_BITPOS_QWORDS      0
/* descriptor index number (within a specified queue) */
#define ENTRY_BITPOS_DESCRIPTOR  10
/* state bit, fifo entry consumed by consumer */
#define ENTRY_BITPOS_C           22
/* state bit, fifo entry is occupied */
#define ENTRY_BITPOS_O           23

#define ENTRY_BITS_QWORDS        10
#define ENTRY_BITS_DESCRIPTOR    12
#define ENTRY_BITS_C             1
#define ENTRY_BITS_O             1
#define ENTRY_BITS_TOTAL    \
    (ENTRY_BITS_C + ENTRY_BITS_O + \
     ENTRY_BITS_QWORDS + ENTRY_BITS_DESCRIPTOR)

/* extract various entry fields */
#define ENTRY_MASK ((1 << ENTRY_BITS_TOTAL) - 1)
#define ENTRY_MASK_C (((1 << ENTRY_BITS_C) - 1) << ENTRY_BITPOS_C)
#define ENTRY_MASK_O (((1 << ENTRY_BITS_O) - 1) << ENTRY_BITPOS_O)
#define ENTRY_MASK_QWORDS \
    (((1 << ENTRY_BITS_QWORDS) - 1) << ENTRY_BITPOS_QWORDS)
#define ENTRY_MASK_DESCRIPTOR \
    (((1 << ENTRY_BITS_DESCRIPTOR) - 1) << ENTRY_BITPOS_DESCRIPTOR)

#define ENTRY_MASK_NOSTATE (ENTRY_MASK >> (ENTRY_BITS_C + ENTRY_BITS_O))

#endif /* __HPILO_H */