/*
 * VMware PVSCSI header file
 *
 * Copyright (C) 2008-2014, VMware, Inc. 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 of the License and no later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#ifndef _VMW_PVSCSI_H_
#define _VMW_PVSCSI_H_

#include <linux/types.h>

#define PVSCSI_DRIVER_VERSION_STRING   "1.0.7.0-k"

#define PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT 128

#define MASK(n)        ((1 << (n)) - 1)        /* make an n-bit mask */

#define PCI_DEVICE_ID_VMWARE_PVSCSI     0x07C0

/*
 * host adapter status/error codes
 */
enum HostBusAdapterStatus {
        BTSTAT_SUCCESS       = 0x00,  /* CCB complete normally with no errors */
        BTSTAT_LINKED_COMMAND_COMPLETED           = 0x0a,
        BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG = 0x0b,
        BTSTAT_DATA_UNDERRUN = 0x0c,
        BTSTAT_SELTIMEO      = 0x11,  /* SCSI selection timeout */
        BTSTAT_DATARUN       = 0x12,  /* data overrun/underrun */
        BTSTAT_BUSFREE       = 0x13,  /* unexpected bus free */
        BTSTAT_INVPHASE      = 0x14,  /* invalid bus phase or sequence
                                       * requested by target */
        BTSTAT_LUNMISMATCH   = 0x17,  /* linked CCB has different LUN from
                                       * first CCB */
        BTSTAT_INVPARAM      = 0x1a,  /* invalid parameter in CCB or segment
                                       * list */
        BTSTAT_SENSFAILED    = 0x1b,  /* auto request sense failed */
        BTSTAT_TAGREJECT     = 0x1c,  /* SCSI II tagged queueing message
                                       * rejected by target */
        BTSTAT_BADMSG        = 0x1d,  /* unsupported message received by the
                                       * host adapter */
        BTSTAT_HAHARDWARE    = 0x20,  /* host adapter hardware failed */
        BTSTAT_NORESPONSE    = 0x21,  /* target did not respond to SCSI ATN,
                                       * sent a SCSI RST */
        BTSTAT_SENTRST       = 0x22,  /* host adapter asserted a SCSI RST */
        BTSTAT_RECVRST       = 0x23,  /* other SCSI devices asserted a SCSI
                                       * RST */
        BTSTAT_DISCONNECT    = 0x24,  /* target device reconnected improperly
                                       * (w/o tag) */
        BTSTAT_BUSRESET      = 0x25,  /* host adapter issued BUS device reset */
        BTSTAT_ABORTQUEUE    = 0x26,  /* abort queue generated */
        BTSTAT_HASOFTWARE    = 0x27,  /* host adapter software error */
        BTSTAT_HATIMEOUT     = 0x30,  /* host adapter hardware timeout error */
        BTSTAT_SCSIPARITY    = 0x34,  /* SCSI parity error detected */
};

/*
 * SCSI device status values.
 */
enum ScsiDeviceStatus {
        SDSTAT_GOOD  = 0x00, /* No errors. */
        SDSTAT_CHECK = 0x02, /* Check condition. */
};

/*
 * Register offsets.
 *
 * These registers are accessible both via i/o space and mm i/o.
 */

enum PVSCSIRegOffset {
        PVSCSI_REG_OFFSET_COMMAND        =    0x0,
        PVSCSI_REG_OFFSET_COMMAND_DATA   =    0x4,
        PVSCSI_REG_OFFSET_COMMAND_STATUS =    0x8,
        PVSCSI_REG_OFFSET_LAST_STS_0     =  0x100,
        PVSCSI_REG_OFFSET_LAST_STS_1     =  0x104,
        PVSCSI_REG_OFFSET_LAST_STS_2     =  0x108,
        PVSCSI_REG_OFFSET_LAST_STS_3     =  0x10c,
        PVSCSI_REG_OFFSET_INTR_STATUS    = 0x100c,
        PVSCSI_REG_OFFSET_INTR_MASK      = 0x2010,
        PVSCSI_REG_OFFSET_KICK_NON_RW_IO = 0x3014,
        PVSCSI_REG_OFFSET_DEBUG          = 0x3018,
        PVSCSI_REG_OFFSET_KICK_RW_IO     = 0x4018,
};

/*
 * Virtual h/w commands.
 */

enum PVSCSICommands {
        PVSCSI_CMD_FIRST             = 0, /* has to be first */

        PVSCSI_CMD_ADAPTER_RESET     = 1,
        PVSCSI_CMD_ISSUE_SCSI        = 2,
        PVSCSI_CMD_SETUP_RINGS       = 3,
        PVSCSI_CMD_RESET_BUS         = 4,
        PVSCSI_CMD_RESET_DEVICE      = 5,
        PVSCSI_CMD_ABORT_CMD         = 6,
        PVSCSI_CMD_CONFIG            = 7,
        PVSCSI_CMD_SETUP_MSG_RING    = 8,
        PVSCSI_CMD_DEVICE_UNPLUG     = 9,
        PVSCSI_CMD_SETUP_REQCALLTHRESHOLD     = 10,

        PVSCSI_CMD_LAST              = 11  /* has to be last */
};

/*
 * Command descriptor for PVSCSI_CMD_RESET_DEVICE --
 */

struct PVSCSICmdDescResetDevice {
        u32     target;
        u8      lun[8];
} __packed;

/*
 * Command descriptor for PVSCSI_CMD_CONFIG --
 */

struct PVSCSICmdDescConfigCmd {
        u64 cmpAddr;
        u64 configPageAddress;
        u32 configPageNum;
        u32 _pad;
} __packed;

/*
 * Command descriptor for PVSCSI_CMD_SETUP_REQCALLTHRESHOLD --
 */

struct PVSCSICmdDescSetupReqCall {
        u32 enable;
} __packed;

enum PVSCSIConfigPageType {
        PVSCSI_CONFIG_PAGE_CONTROLLER = 0x1958,
        PVSCSI_CONFIG_PAGE_PHY        = 0x1959,
        PVSCSI_CONFIG_PAGE_DEVICE     = 0x195a,
};

enum PVSCSIConfigPageAddressType {
        PVSCSI_CONFIG_CONTROLLER_ADDRESS = 0x2120,
        PVSCSI_CONFIG_BUSTARGET_ADDRESS  = 0x2121,
        PVSCSI_CONFIG_PHY_ADDRESS        = 0x2122,
};

/*
 * Command descriptor for PVSCSI_CMD_ABORT_CMD --
 *
 * - currently does not support specifying the LUN.
 * - _pad should be 0.
 */

struct PVSCSICmdDescAbortCmd {
        u64     context;
        u32     target;
        u32     _pad;
} __packed;

/*
 * Command descriptor for PVSCSI_CMD_SETUP_RINGS --
 *
 * Notes:
 * - reqRingNumPages and cmpRingNumPages need to be power of two.
 * - reqRingNumPages and cmpRingNumPages need to be different from 0,
 * - reqRingNumPages and cmpRingNumPages need to be inferior to
 *   PVSCSI_SETUP_RINGS_MAX_NUM_PAGES.
 */

#define PVSCSI_SETUP_RINGS_MAX_NUM_PAGES        32
struct PVSCSICmdDescSetupRings {
        u32     reqRingNumPages;
        u32     cmpRingNumPages;
        u64     ringsStatePPN;
        u64     reqRingPPNs[PVSCSI_SETUP_RINGS_MAX_NUM_PAGES];
        u64     cmpRingPPNs[PVSCSI_SETUP_RINGS_MAX_NUM_PAGES];
} __packed;

/*
 * Command descriptor for PVSCSI_CMD_SETUP_MSG_RING --
 *
 * Notes:
 * - this command was not supported in the initial revision of the h/w
 *   interface. Before using it, you need to check that it is supported by
 *   writing PVSCSI_CMD_SETUP_MSG_RING to the 'command' register, then
 *   immediately after read the 'command status' register:
 *       * a value of -1 means that the cmd is NOT supported,
 *       * a value != -1 means that the cmd IS supported.
 *   If it's supported the 'command status' register should return:
 *      sizeof(PVSCSICmdDescSetupMsgRing) / sizeof(u32).
 * - this command should be issued _after_ the usual SETUP_RINGS so that the
 *   RingsState page is already setup. If not, the command is a nop.
 * - numPages needs to be a power of two,
 * - numPages needs to be different from 0,
 * - _pad should be zero.
 */

#define PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES  16

struct PVSCSICmdDescSetupMsgRing {
        u32     numPages;
        u32     _pad;
        u64     ringPPNs[PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES];
} __packed;

enum PVSCSIMsgType {
        PVSCSI_MSG_DEV_ADDED          = 0,
        PVSCSI_MSG_DEV_REMOVED        = 1,
        PVSCSI_MSG_LAST               = 2,
};

/*
 * Msg descriptor.
 *
 * sizeof(struct PVSCSIRingMsgDesc) == 128.
 *
 * - type is of type enum PVSCSIMsgType.
 * - the content of args depend on the type of event being delivered.
 */

struct PVSCSIRingMsgDesc {
        u32     type;
        u32     args[31];
} __packed;

struct PVSCSIMsgDescDevStatusChanged {
        u32     type;  /* PVSCSI_MSG_DEV _ADDED / _REMOVED */
        u32     bus;
        u32     target;
        u8      lun[8];
        u32     pad[27];
} __packed;

/*
 * Rings state.
 *
 * - the fields:
 *    . msgProdIdx,
 *    . msgConsIdx,
 *    . msgNumEntriesLog2,
 *   .. are only used once the SETUP_MSG_RING cmd has been issued.
 * - '_pad' helps to ensure that the msg related fields are on their own
 *   cache-line.
 */

struct PVSCSIRingsState {
        u32     reqProdIdx;
        u32     reqConsIdx;
        u32     reqNumEntriesLog2;

        u32     cmpProdIdx;
        u32     cmpConsIdx;
        u32     cmpNumEntriesLog2;

        u32     reqCallThreshold;

        u8      _pad[100];

        u32     msgProdIdx;
        u32     msgConsIdx;
        u32     msgNumEntriesLog2;
} __packed;

/*
 * Request descriptor.
 *
 * sizeof(RingReqDesc) = 128
 *
 * - context: is a unique identifier of a command. It could normally be any
 *   64bit value, however we currently store it in the serialNumber variable
 *   of struct SCSI_Command, so we have the following restrictions due to the
 *   way this field is handled in the vmkernel storage stack:
 *    * this value can't be 0,
 *    * the upper 32bit need to be 0 since serialNumber is as a u32.
 *   Currently tracked as PR 292060.
 * - dataLen: contains the total number of bytes that need to be transferred.
 * - dataAddr:
 *   * if PVSCSI_FLAG_CMD_WITH_SG_LIST is set: dataAddr is the PA of the first
 *     s/g table segment, each s/g segment is entirely contained on a single
 *     page of physical memory,
 *   * if PVSCSI_FLAG_CMD_WITH_SG_LIST is NOT set, then dataAddr is the PA of
 *     the buffer used for the DMA transfer,
 * - flags:
 *   * PVSCSI_FLAG_CMD_WITH_SG_LIST: see dataAddr above,
 *   * PVSCSI_FLAG_CMD_DIR_NONE: no DMA involved,
 *   * PVSCSI_FLAG_CMD_DIR_TOHOST: transfer from device to main memory,
 *   * PVSCSI_FLAG_CMD_DIR_TODEVICE: transfer from main memory to device,
 *   * PVSCSI_FLAG_CMD_OUT_OF_BAND_CDB: reserved to handle CDBs larger than
 *     16bytes. To be specified.
 * - vcpuHint: vcpuId of the processor that will be most likely waiting for the
 *   completion of the i/o. For guest OSes that use lowest priority message
 *   delivery mode (such as windows), we use this "hint" to deliver the
 *   completion action to the proper vcpu. For now, we can use the vcpuId of
 *   the processor that initiated the i/o as a likely candidate for the vcpu
 *   that will be waiting for the completion..
 * - bus should be 0: we currently only support bus 0 for now.
 * - unused should be zero'd.
 */

#define PVSCSI_FLAG_CMD_WITH_SG_LIST        (1 << 0)
#define PVSCSI_FLAG_CMD_OUT_OF_BAND_CDB     (1 << 1)
#define PVSCSI_FLAG_CMD_DIR_NONE            (1 << 2)
#define PVSCSI_FLAG_CMD_DIR_TOHOST          (1 << 3)
#define PVSCSI_FLAG_CMD_DIR_TODEVICE        (1 << 4)

struct PVSCSIRingReqDesc {
        u64     context;
        u64     dataAddr;
        u64     dataLen;
        u64     senseAddr;
        u32     senseLen;
        u32     flags;
        u8      cdb[16];
        u8      cdbLen;
        u8      lun[8];
        u8      tag;
        u8      bus;
        u8      target;
        u8      vcpuHint;
        u8      unused[59];
} __packed;

/*
 * Scatter-gather list management.
 *
 * As described above, when PVSCSI_FLAG_CMD_WITH_SG_LIST is set in the
 * RingReqDesc.flags, then RingReqDesc.dataAddr is the PA of the first s/g
 * table segment.
 *
 * - each segment of the s/g table contain a succession of struct
 *   PVSCSISGElement.
 * - each segment is entirely contained on a single physical page of memory.
 * - a "chain" s/g element has the flag PVSCSI_SGE_FLAG_CHAIN_ELEMENT set in
 *   PVSCSISGElement.flags and in this case:
 *     * addr is the PA of the next s/g segment,
 *     * length is undefined, assumed to be 0.
 */

struct PVSCSISGElement {
        u64     addr;
        u32     length;
        u32     flags;
} __packed;

/*
 * Completion descriptor.
 *
 * sizeof(RingCmpDesc) = 32
 *
 * - context: identifier of the command. The same thing that was specified
 *   under "context" as part of struct RingReqDesc at initiation time,
 * - dataLen: number of bytes transferred for the actual i/o operation,
 * - senseLen: number of bytes written into the sense buffer,
 * - hostStatus: adapter status,
 * - scsiStatus: device status,
 * - _pad should be zero.
 */

struct PVSCSIRingCmpDesc {
        u64     context;
        u64     dataLen;
        u32     senseLen;
        u16     hostStatus;
        u16     scsiStatus;
        u32     _pad[2];
} __packed;

struct PVSCSIConfigPageHeader {
        u32 pageNum;
        u16 numDwords;
        u16 hostStatus;
        u16 scsiStatus;
        u16 reserved[3];
} __packed;

struct PVSCSIConfigPageController {
        struct PVSCSIConfigPageHeader header;
        u64 nodeWWN; /* Device name as defined in the SAS spec. */
        u16 manufacturer[64];
        u16 serialNumber[64];
        u16 opromVersion[32];
        u16 hwVersion[32];
        u16 firmwareVersion[32];
        u32 numPhys;
        u8  useConsecutivePhyWWNs;
        u8  reserved[3];
} __packed;

/*
 * Interrupt status / IRQ bits.
 */

#define PVSCSI_INTR_CMPL_0                 (1 << 0)
#define PVSCSI_INTR_CMPL_1                 (1 << 1)
#define PVSCSI_INTR_CMPL_MASK              MASK(2)

#define PVSCSI_INTR_MSG_0                  (1 << 2)
#define PVSCSI_INTR_MSG_1                  (1 << 3)
#define PVSCSI_INTR_MSG_MASK               (MASK(2) << 2)

#define PVSCSI_INTR_ALL_SUPPORTED          MASK(4)

/*
 * Number of MSI-X vectors supported.
 */
#define PVSCSI_MAX_INTRS        24

/*
 * Misc constants for the rings.
 */

#define PVSCSI_MAX_NUM_PAGES_REQ_RING   PVSCSI_SETUP_RINGS_MAX_NUM_PAGES
#define PVSCSI_MAX_NUM_PAGES_CMP_RING   PVSCSI_SETUP_RINGS_MAX_NUM_PAGES
#define PVSCSI_MAX_NUM_PAGES_MSG_RING   PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES

#define PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE \
                                (PAGE_SIZE / sizeof(struct PVSCSIRingReqDesc))

#define PVSCSI_MAX_REQ_QUEUE_DEPTH \
        (PVSCSI_MAX_NUM_PAGES_REQ_RING * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE)

#define PVSCSI_MEM_SPACE_COMMAND_NUM_PAGES     1
#define PVSCSI_MEM_SPACE_INTR_STATUS_NUM_PAGES 1
#define PVSCSI_MEM_SPACE_MISC_NUM_PAGES        2
#define PVSCSI_MEM_SPACE_KICK_IO_NUM_PAGES     2
#define PVSCSI_MEM_SPACE_MSIX_NUM_PAGES        2

enum PVSCSIMemSpace {
        PVSCSI_MEM_SPACE_COMMAND_PAGE           = 0,
        PVSCSI_MEM_SPACE_INTR_STATUS_PAGE       = 1,
        PVSCSI_MEM_SPACE_MISC_PAGE              = 2,
        PVSCSI_MEM_SPACE_KICK_IO_PAGE           = 4,
        PVSCSI_MEM_SPACE_MSIX_TABLE_PAGE        = 6,
        PVSCSI_MEM_SPACE_MSIX_PBA_PAGE          = 7,
};

#define PVSCSI_MEM_SPACE_NUM_PAGES \
        (PVSCSI_MEM_SPACE_COMMAND_NUM_PAGES +       \
         PVSCSI_MEM_SPACE_INTR_STATUS_NUM_PAGES +   \
         PVSCSI_MEM_SPACE_MISC_NUM_PAGES +          \
         PVSCSI_MEM_SPACE_KICK_IO_NUM_PAGES +       \
         PVSCSI_MEM_SPACE_MSIX_NUM_PAGES)

#define PVSCSI_MEM_SPACE_SIZE        (PVSCSI_MEM_SPACE_NUM_PAGES * PAGE_SIZE)

#endif /* _VMW_PVSCSI_H_ */