X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fstaging%2Funisys%2Finclude%2Fiochannel.h;fp=kernel%2Fdrivers%2Fstaging%2Funisys%2Finclude%2Fiochannel.h;h=14e656ff73ecde3d825b8d30c7d1019905082e43;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=0000000000000000000000000000000000000000;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git diff --git a/kernel/drivers/staging/unisys/include/iochannel.h b/kernel/drivers/staging/unisys/include/iochannel.h new file mode 100644 index 000000000..14e656ff7 --- /dev/null +++ b/kernel/drivers/staging/unisys/include/iochannel.h @@ -0,0 +1,644 @@ +/* Copyright (C) 2010 - 2013 UNISYS CORPORATION */ +/* All rights reserved. */ +#ifndef __IOCHANNEL_H__ +#define __IOCHANNEL_H__ + +/* + * Everything needed for IOPart-GuestPart communication is define in + * this file. Note: Everything is OS-independent because this file is + * used by Windows, Linux and possible EFI drivers. */ + +/* + * Communication flow between the IOPart and GuestPart uses the channel headers + * channel state. The following states are currently being used: + * UNINIT(All Zeroes), CHANNEL_ATTACHING, CHANNEL_ATTACHED, CHANNEL_OPENED + * + * additional states will be used later. No locking is needed to switch between + * states due to the following rules: + * + * 1. IOPart is only the only partition allowed to change from UNIT + * 2. IOPart is only the only partition allowed to change from + * CHANNEL_ATTACHING + * 3. GuestPart is only the only partition allowed to change from + * CHANNEL_ATTACHED + * + * The state changes are the following: IOPart sees the channel is in UNINIT, + * UNINIT -> CHANNEL_ATTACHING (performed only by IOPart) + * CHANNEL_ATTACHING -> CHANNEL_ATTACHED (performed only by IOPart) + * CHANNEL_ATTACHED -> CHANNEL_OPENED (performed only by GuestPart) + */ + +#include + +#include +#include "channel.h" +#include "channel_guid.h" + +#define ULTRA_VHBA_CHANNEL_PROTOCOL_SIGNATURE ULTRA_CHANNEL_PROTOCOL_SIGNATURE +#define ULTRA_VNIC_CHANNEL_PROTOCOL_SIGNATURE ULTRA_CHANNEL_PROTOCOL_SIGNATURE +#define ULTRA_VSWITCH_CHANNEL_PROTOCOL_SIGNATURE \ + ULTRA_CHANNEL_PROTOCOL_SIGNATURE + +/* Must increment these whenever you insert or delete fields within this channel + * struct. Also increment whenever you change the meaning of fields within this + * channel struct so as to break pre-existing software. Note that you can + * usually add fields to the END of the channel struct withOUT needing to + * increment this. + */ +#define ULTRA_VHBA_CHANNEL_PROTOCOL_VERSIONID 2 +#define ULTRA_VNIC_CHANNEL_PROTOCOL_VERSIONID 2 +#define ULTRA_VSWITCH_CHANNEL_PROTOCOL_VERSIONID 1 + +#define SPAR_VHBA_CHANNEL_OK_CLIENT(ch) \ + (spar_check_channel_client(ch, spar_vhba_channel_protocol_uuid, \ + "vhba", MIN_IO_CHANNEL_SIZE, \ + ULTRA_VHBA_CHANNEL_PROTOCOL_VERSIONID, \ + ULTRA_VHBA_CHANNEL_PROTOCOL_SIGNATURE)) + +#define SPAR_VNIC_CHANNEL_OK_CLIENT(ch) \ + (spar_check_channel_client(ch, spar_vnic_channel_protocol_uuid, \ + "vnic", MIN_IO_CHANNEL_SIZE, \ + ULTRA_VNIC_CHANNEL_PROTOCOL_VERSIONID, \ + ULTRA_VNIC_CHANNEL_PROTOCOL_SIGNATURE)) + +/* + * Everything necessary to handle SCSI & NIC traffic between Guest Partition and + * IO Partition is defined below. + */ + +/* + * Defines and enums. + */ + +#define MINNUM(a, b) (((a) < (b)) ? (a) : (b)) +#define MAXNUM(a, b) (((a) > (b)) ? (a) : (b)) + +/* these define the two queues per data channel between iopart and + * ioguestparts + */ +#define IOCHAN_TO_IOPART 0 /* used by ioguestpart to 'insert' signals to + * iopart */ + +#define IOCHAN_FROM_IOPART 1 /* used by ioguestpart to 'remove' signals from + * iopart - same queue as previous queue */ + +/* size of cdb - i.e., scsi cmnd */ +#define MAX_CMND_SIZE 16 + +#define MAX_SENSE_SIZE 64 + +#define MAX_PHYS_INFO 64 + +/* various types of network packets that can be sent in cmdrsp */ +enum net_types { + NET_RCV_POST = 0, /* submit buffer to hold receiving + * incoming packet */ + /* virtnic -> uisnic */ + NET_RCV, /* incoming packet received */ + /* uisnic -> virtpci */ + NET_XMIT, /* for outgoing net packets */ + /* virtnic -> uisnic */ + NET_XMIT_DONE, /* outgoing packet xmitted */ + /* uisnic -> virtpci */ + NET_RCV_ENBDIS, /* enable/disable packet reception */ + /* virtnic -> uisnic */ + NET_RCV_ENBDIS_ACK, /* acknowledge enable/disable packet + * reception */ + /* uisnic -> virtnic */ + NET_RCV_PROMISC, /* enable/disable promiscuous mode */ + /* virtnic -> uisnic */ + NET_CONNECT_STATUS, /* indicate the loss or restoration of a network + * connection */ + /* uisnic -> virtnic */ + NET_MACADDR, /* indicates the client has requested to update + * its MAC addr */ + NET_MACADDR_ACK, /* MAC address */ + +}; + +#define ETH_HEADER_SIZE 14 /* size of ethernet header */ + +#define ETH_MIN_DATA_SIZE 46 /* minimum eth data size */ +#define ETH_MIN_PACKET_SIZE (ETH_HEADER_SIZE + ETH_MIN_DATA_SIZE) + +#define ETH_MAX_MTU 16384 /* maximum data size */ + +#ifndef MAX_MACADDR_LEN +#define MAX_MACADDR_LEN 6 /* number of bytes in MAC address */ +#endif /* MAX_MACADDR_LEN */ + +/* various types of scsi task mgmt commands */ +enum task_mgmt_types { + TASK_MGMT_ABORT_TASK = 1, + TASK_MGMT_BUS_RESET, + TASK_MGMT_LUN_RESET, + TASK_MGMT_TARGET_RESET, +}; + +/* various types of vdisk mgmt commands */ +enum vdisk_mgmt_types { + VDISK_MGMT_ACQUIRE = 1, + VDISK_MGMT_RELEASE, +}; + +struct phys_info { + u64 pi_pfn; + u16 pi_off; + u16 pi_len; +} __packed; + +#define MIN_NUMSIGNALS 64 + +/* structs with pragma pack */ + +struct guest_phys_info { + u64 address; + u64 length; +} __packed; + +#define GPI_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct guest_phys_info)) + +struct uisscsi_dest { + u32 channel; /* channel == bus number */ + u32 id; /* id == target number */ + u32 lun; /* lun == logical unit number */ +} __packed; + +struct vhba_wwnn { + u32 wwnn1; + u32 wwnn2; +} __packed; + +/* WARNING: Values stired in this structure must contain maximum counts (not + * maximum values). */ +struct vhba_config_max { /* 20 bytes */ + u32 max_channel; /* maximum channel for devices attached to this + * bus */ + u32 max_id; /* maximum SCSI ID for devices attached to this + * bus */ + u32 max_lun; /* maximum SCSI LUN for devices attached to this + * bus */ + u32 cmd_per_lun; /* maximum number of outstanding commands per + * lun that are allowed at one time */ + u32 max_io_size; /* maximum io size for devices attached to this + * bus */ + /* max io size is often determined by the resource of the hba. e.g */ + /* max scatter gather list length * page size / sector size */ +} __packed; + +struct uiscmdrsp_scsi { + u64 handle; /* the handle to the cmd that was received - + * send it back as is in the rsp packet. */ + u8 cmnd[MAX_CMND_SIZE]; /* the cdb for the command */ + u32 bufflen; /* length of data to be transferred out or in */ + u16 guest_phys_entries; /* Number of entries in scatter-gather (sg) + * list */ + struct guest_phys_info gpi_list[MAX_PHYS_INFO]; /* physical address + * information for each + * fragment */ + enum dma_data_direction data_dir; /* direction of the data, if any */ + struct uisscsi_dest vdest; /* identifies the virtual hba, id, + * channel, lun to which cmd was sent */ + + /* the following fields are needed to queue the rsp back to cmd + * originator */ + int linuxstat; /* the original Linux status - for use by linux + * vdisk code */ + u8 scsistat; /* the scsi status */ + u8 addlstat; /* non-scsi status - covers cases like timeout + * needed by windows guests */ +#define ADDL_SEL_TIMEOUT 4 + + /* the following fields are need to determine the result of command */ + u8 sensebuf[MAX_SENSE_SIZE]; /* sense info in case cmd failed; */ + /* it holds the sense_data struct; */ + /* see that struct for details. */ + void *vdisk; /* contains pointer to the vdisk so that we can clean up + * when the IO completes. */ + int no_disk_result; + /* used to return no disk inquiry result + * when no_disk_result is set to 1, + * scsi.scsistat is SAM_STAT_GOOD + * scsi.addlstat is 0 + * scsi.linuxstat is SAM_STAT_GOOD + * That is, there is NO error. + */ +} __packed; + +/* Defines to support sending correct inquiry result when no disk is + * configured. + */ + +/* From SCSI SPC2 - + * + * If the target is not capable of supporting a device on this logical unit, the + * device server shall set this field to 7Fh (PERIPHERAL QUALIFIER set to 011b + * and PERIPHERAL DEVICE TYPE set to 1Fh). + * + *The device server is capable of supporting the specified peripheral device + *type on this logical unit. However, the physical device is not currently + *connected to this logical unit. + */ + +#define DEV_NOT_CAPABLE 0x7f /* peripheral qualifier of 0x3 */ + /* peripheral type of 0x1f */ + /* specifies no device but target present */ + +#define DEV_DISK_CAPABLE_NOT_PRESENT 0x20 /* peripheral qualifier of 0x1 */ + /* peripheral type of 0 - disk */ + /* specifies device capable, but not present */ + +#define DEV_HISUPPORT 0x10 /* HiSup = 1; shows support for report luns */ + /* must be returned for lun 0. */ + +/* NOTE: Linux code assumes inquiry contains 36 bytes. Without checking length + * in buf[4] some linux code accesses bytes beyond 5 to retrieve vendor, product + * & revision. Yikes! So let us always send back 36 bytes, the minimum for + * inquiry result. + */ +#define NO_DISK_INQUIRY_RESULT_LEN 36 + +#define MIN_INQUIRY_RESULT_LEN 5 /* we need at least 5 bytes minimum for inquiry + * result */ + +/* SCSI device version for no disk inquiry result */ +#define SCSI_SPC2_VER 4 /* indicates SCSI SPC2 (SPC3 is 5) */ + +/* Windows and Linux want different things for a non-existent lun. So, we'll let + * caller pass in the peripheral qualifier and type. + * NOTE:[4] SCSI returns (n-4); so we return length-1-4 or length-5. */ + +#define SET_NO_DISK_INQUIRY_RESULT(buf, len, lun, lun0notpresent, notpresent) \ + do { \ + memset(buf, 0, \ + MINNUM(len, \ + (unsigned int)NO_DISK_INQUIRY_RESULT_LEN)); \ + buf[2] = (u8)SCSI_SPC2_VER; \ + if (lun == 0) { \ + buf[0] = (u8)lun0notpresent; \ + buf[3] = (u8)DEV_HISUPPORT; \ + } else \ + buf[0] = (u8)notpresent; \ + buf[4] = (u8)( \ + MINNUM(len, \ + (unsigned int)NO_DISK_INQUIRY_RESULT_LEN) - 5);\ + if (len >= NO_DISK_INQUIRY_RESULT_LEN) { \ + buf[8] = 'D'; \ + buf[9] = 'E'; \ + buf[10] = 'L'; \ + buf[11] = 'L'; \ + buf[16] = 'P'; \ + buf[17] = 'S'; \ + buf[18] = 'E'; \ + buf[19] = 'U'; \ + buf[20] = 'D'; \ + buf[21] = 'O'; \ + buf[22] = ' '; \ + buf[23] = 'D'; \ + buf[24] = 'E'; \ + buf[25] = 'V'; \ + buf[26] = 'I'; \ + buf[27] = 'C'; \ + buf[28] = 'E'; \ + buf[30] = ' '; \ + buf[31] = '.'; \ + } \ + } while (0) + +/* + * Struct & Defines to support sense information. + */ + +/* The following struct is returned in sensebuf field in uiscmdrsp_scsi. It is + * initialized in exactly the manner that is recommended in Windows (hence the + * odd values). + * When set, these fields will have the following values: + * ErrorCode = 0x70 indicates current error + * Valid = 1 indicates sense info is valid + * SenseKey contains sense key as defined by SCSI specs. + * AdditionalSenseCode contains sense key as defined by SCSI specs. + * AdditionalSenseCodeQualifier contains qualifier to sense code as defined by + * scsi docs. + * AdditionalSenseLength contains will be sizeof(sense_data)-8=10. + */ +struct sense_data { + u8 errorcode:7; + u8 valid:1; + u8 segment_number; + u8 sense_key:4; + u8 reserved:1; + u8 incorrect_length:1; + u8 end_of_media:1; + u8 file_mark:1; + u8 information[4]; + u8 additional_sense_length; + u8 command_specific_information[4]; + u8 additional_sense_code; + u8 additional_sense_code_qualifier; + u8 fru_code; + u8 sense_key_specific[3]; +} __packed; + +struct net_pkt_xmt { + int len; /* full length of data in the packet */ + int num_frags; /* number of fragments in frags containing data */ + struct phys_info frags[MAX_PHYS_INFO]; /* physical page information for + * each fragment */ + char ethhdr[ETH_HEADER_SIZE]; /* the ethernet header */ + struct { + /* these are needed for csum at uisnic end */ + u8 valid; /* 1 = rest of this struct is valid - else + * ignore */ + u8 hrawoffv; /* 1 = hwrafoff is valid */ + u8 nhrawoffv; /* 1 = nhwrafoff is valid */ + u16 protocol; /* specifies packet protocol */ + u32 csum; /* value used to set skb->csum at IOPart */ + u32 hrawoff; /* value used to set skb->h.raw at IOPart */ + /* hrawoff points to the start of the TRANSPORT LAYER HEADER */ + u32 nhrawoff; /* value used to set skb->nh.raw at IOPart */ + /* nhrawoff points to the start of the NETWORK LAYER HEADER */ + } lincsum; + + /* **** NOTE **** + * The full packet is described in frags but the ethernet header is + * separately kept in ethhdr so that uisnic doesn't have "MAP" the + * guest memory to get to the header. uisnic needs ethhdr to + * determine how to route the packet. + */ +} __packed; + +struct net_pkt_xmtdone { + u32 xmt_done_result; /* result of NET_XMIT */ +} __packed; + +/* RCVPOST_BUF_SIZe must be at most page_size(4096) - cache_line_size (64) The + * reason is because dev_skb_alloc which is used to generate RCV_POST skbs in + * virtnic requires that there is "overhead" in the buffer, and pads 16 bytes. I + * prefer to use 1 full cache line size for "overhead" so that transfers are + * better. IOVM requires that a buffer be represented by 1 phys_info structure + * which can only cover page_size. + */ +#define RCVPOST_BUF_SIZE 4032 +#define MAX_NET_RCV_CHAIN \ + ((ETH_MAX_MTU+ETH_HEADER_SIZE + RCVPOST_BUF_SIZE-1) / RCVPOST_BUF_SIZE) + +struct net_pkt_rcvpost { + /* rcv buf size must be large enough to include ethernet data len + + * ethernet header len - we are choosing 2K because it is guaranteed + * to be describable */ + struct phys_info frag; /* physical page information for the + * single fragment 2K rcv buf */ + u64 unique_num; /* This is used to make sure that + * receive posts are returned to */ + /* the Adapter which we sent them originally. */ +} __packed; + +struct net_pkt_rcv { + /* the number of receive buffers that can be chained */ + /* is based on max mtu and size of each rcv buf */ + u32 rcv_done_len; /* length of received data */ + u8 numrcvbufs; /* number of receive buffers that contain the */ + /* incoming data; guest end MUST chain these together. */ + void *rcvbuf[MAX_NET_RCV_CHAIN]; /* the list of receive buffers + * that must be chained; */ + /* each entry is a receive buffer provided by NET_RCV_POST. */ + /* NOTE: first rcvbuf in the chain will also be provided in net.buf. */ + u64 unique_num; + u32 rcvs_dropped_delta; +} __packed; + +struct net_pkt_enbdis { + void *context; + u16 enable; /* 1 = enable, 0 = disable */ +} __packed; + +struct net_pkt_macaddr { + void *context; + u8 macaddr[MAX_MACADDR_LEN]; /* 6 bytes */ +} __packed; + +/* cmd rsp packet used for VNIC network traffic */ +struct uiscmdrsp_net { + enum net_types type; + void *buf; + union { + struct net_pkt_xmt xmt; /* used for NET_XMIT */ + struct net_pkt_xmtdone xmtdone; /* used for NET_XMIT_DONE */ + struct net_pkt_rcvpost rcvpost; /* used for NET_RCV_POST */ + struct net_pkt_rcv rcv; /* used for NET_RCV */ + struct net_pkt_enbdis enbdis; /* used for NET_RCV_ENBDIS, */ + /* NET_RCV_ENBDIS_ACK, */ + /* NET_RCV_PROMSIC, */ + /* and NET_CONNECT_STATUS */ + struct net_pkt_macaddr macaddr; + }; +} __packed; + +struct uiscmdrsp_scsitaskmgmt { + enum task_mgmt_types tasktype; + + /* the type of task */ + struct uisscsi_dest vdest; + + /* the vdisk for which this task mgmt is generated */ + u64 handle; + + /* This is a handle that the guest has saved off for its own use. + * Its value is preserved by iopart & returned as is in the task + * mgmt rsp. + */ + u64 notify_handle; + + /* For linux guests, this is a pointer to wait_queue_head that a + * thread is waiting on to see if the taskmgmt command has completed. + * When the rsp is received by guest, the thread receiving the + * response uses this to notify the thread waiting for taskmgmt + * command completion. Its value is preserved by iopart & returned + * as is in the task mgmt rsp. + */ + u64 notifyresult_handle; + + /* this is a handle to location in guest where the result of the + * taskmgmt command (result field) is to saved off when the response + * is handled. Its value is preserved by iopart & returned as is in + * the task mgmt rsp. + */ + char result; + + /* result of taskmgmt command - set by IOPart - values are: */ +#define TASK_MGMT_FAILED 0 +} __packed; + +/* The following is used by uissd to send disk add/remove notifications to + * Guest */ +/* Note that the vHba pointer is not used by the Client/Guest side. */ +struct uiscmdrsp_disknotify { + u8 add; /* 0-remove, 1-add */ + void *v_hba; /* Pointer to vhba_info for channel info to + * route msg */ + u32 channel, id, lun; /* SCSI Path of Disk to added or removed */ +} __packed; + +/* The following is used by virthba/vSCSI to send the Acquire/Release commands + * to the IOVM. */ +struct uiscmdrsp_vdiskmgmt { + enum vdisk_mgmt_types vdisktype; + + /* the type of task */ + struct uisscsi_dest vdest; + + /* the vdisk for which this task mgmt is generated */ + u64 handle; + + /* This is a handle that the guest has saved off for its own use. + * Its value is preserved by iopart & returned as is in the task + * mgmt rsp. + */ + u64 notify_handle; + + /* For linux guests, this is a pointer to wait_queue_head that a + * thread is waiting on to see if the tskmgmt command has completed. + * When the rsp is received by guest, the thread receiving the + * response uses this to notify the thread waiting for taskmgmt + * command completion. Its value is preserved by iopart & returned + * as is in the task mgmt rsp. + */ + u64 notifyresult_handle; + + /* this is a handle to location in guest where the result of the + * taskmgmt command (result field) is to saved off when the response + * is handled. Its value is preserved by iopart & returned as is in + * the task mgmt rsp. + */ + char result; + + /* result of taskmgmt command - set by IOPart - values are: */ +#define VDISK_MGMT_FAILED 0 +} __packed; + +/* keeping cmd & rsp info in one structure for now cmd rsp packet for scsi */ +struct uiscmdrsp { + char cmdtype; + +/* describes what type of information is in the struct */ +#define CMD_SCSI_TYPE 1 +#define CMD_NET_TYPE 2 +#define CMD_SCSITASKMGMT_TYPE 3 +#define CMD_NOTIFYGUEST_TYPE 4 +#define CMD_VDISKMGMT_TYPE 5 + union { + struct uiscmdrsp_scsi scsi; + struct uiscmdrsp_net net; + struct uiscmdrsp_scsitaskmgmt scsitaskmgmt; + struct uiscmdrsp_disknotify disknotify; + struct uiscmdrsp_vdiskmgmt vdiskmgmt; + }; + void *private_data; /* used to send the response when the cmd is + * done (scsi & scsittaskmgmt). */ + struct uiscmdrsp *next; /* General Purpose Queue Link */ + struct uiscmdrsp *activeQ_next; /* Used to track active commands */ + struct uiscmdrsp *activeQ_prev; /* Used to track active commands */ +} __packed; + +struct iochannel_vhba { + struct vhba_wwnn wwnn; /* 8 bytes */ + struct vhba_config_max max; /* 20 bytes */ +} __packed; /* total = 28 bytes */ +struct iochannel_vnic { + u8 macaddr[6]; /* 6 bytes */ + u32 num_rcv_bufs; /* 4 bytes */ + u32 mtu; /* 4 bytes */ + uuid_le zone_uuid; /* 16 bytes */ +} __packed; +/* This is just the header of the IO channel. It is assumed that directly after + * this header there is a large region of memory which contains the command and + * response queues as specified in cmd_q and rsp_q SIGNAL_QUEUE_HEADERS. + */ +struct spar_io_channel_protocol { + struct channel_header channel_header; + struct signal_queue_header cmd_q; + struct signal_queue_header rsp_q; + union { + struct iochannel_vhba vhba; + struct iochannel_vnic vnic; + } __packed; + +#define MAX_CLIENTSTRING_LEN 1024 + u8 client_string[MAX_CLIENTSTRING_LEN];/* NULL terminated - so holds + * max - 1 bytes */ +} __packed; + + +/* + * INLINE functions for initializing and accessing I/O data channels + */ + +#define SIZEOF_PROTOCOL (COVER(sizeof(struct spar_io_channel_protocol), 64)) +#define SIZEOF_CMDRSP (COVER(sizeof(struct uiscmdrsp), 64)) + +#define MIN_IO_CHANNEL_SIZE COVER(SIZEOF_PROTOCOL + \ + 2 * MIN_NUMSIGNALS * SIZEOF_CMDRSP, 4096) + +/* + * INLINE function for expanding a guest's pfn-off-size into multiple 4K page + * pfn-off-size entires. + */ + +/* we deal with 4K page sizes when we it comes to passing page information + * between */ +/* Guest and IOPartition. */ +#define PI_PAGE_SIZE 0x1000 +#define PI_PAGE_MASK 0x0FFF + +/* returns next non-zero index on success or zero on failure (i.e. out of + * room) + */ +static inline u16 +add_physinfo_entries(u32 inp_pfn, /* input - specifies the pfn to be used + * to add entries */ + u16 inp_off, /* input - specifies the off to be used + * to add entries */ + u32 inp_len, /* input - specifies the len to be used + * to add entries */ + u16 index, /* input - index in array at which new + * entries are added */ + u16 max_pi_arr_entries, /* input - specifies the maximum + * entries pi_arr can hold */ + struct phys_info pi_arr[]) /* input & output - array to + * which entries are added */ +{ + u32 len; + u16 i, firstlen; + + firstlen = PI_PAGE_SIZE - inp_off; + if (inp_len <= firstlen) { + /* the input entry spans only one page - add as is */ + if (index >= max_pi_arr_entries) + return 0; + pi_arr[index].pi_pfn = inp_pfn; + pi_arr[index].pi_off = (u16)inp_off; + pi_arr[index].pi_len = (u16)inp_len; + return index + 1; + } + + /* this entry spans multiple pages */ + for (len = inp_len, i = 0; len; + len -= pi_arr[index + i].pi_len, i++) { + if (index + i >= max_pi_arr_entries) + return 0; + pi_arr[index + i].pi_pfn = inp_pfn + i; + if (i == 0) { + pi_arr[index].pi_off = inp_off; + pi_arr[index].pi_len = firstlen; + } + + else { + pi_arr[index + i].pi_off = 0; + pi_arr[index + i].pi_len = + (u16)MINNUM(len, (u32)PI_PAGE_SIZE); + } + } + return index + i; +} + +#endif /* __IOCHANNEL_H__ */