/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 2000-2007 Silicon Graphics, Inc.  All Rights Reserved.
 */

#include <linux/module.h>
#include <asm/sn/nodepda.h>
#include <asm/sn/addrs.h>
#include <asm/sn/arch.h>
#include <asm/sn/sn_cpuid.h>
#include <asm/sn/pda.h>
#include <asm/sn/shubio.h>
#include <asm/nodedata.h>
#include <asm/delay.h>

#include <linux/bootmem.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <asm/sn/bte.h>

#ifndef L1_CACHE_MASK
#define L1_CACHE_MASK (L1_CACHE_BYTES - 1)
#endif

/* two interfaces on two btes */
#define MAX_INTERFACES_TO_TRY           4
#define MAX_NODES_TO_TRY                2

static struct bteinfo_s *bte_if_on_node(nasid_t nasid, int interface)
{
        nodepda_t *tmp_nodepda;

        if (nasid_to_cnodeid(nasid) == -1)
                return (struct bteinfo_s *)NULL;

        tmp_nodepda = NODEPDA(nasid_to_cnodeid(nasid));
        return &tmp_nodepda->bte_if[interface];

}

static inline void bte_start_transfer(struct bteinfo_s *bte, u64 len, u64 mode)
{
        if (is_shub2()) {
                BTE_CTRL_STORE(bte, (IBLS_BUSY | ((len) | (mode) << 24)));
        } else {
                BTE_LNSTAT_STORE(bte, len);
                BTE_CTRL_STORE(bte, mode);
        }
}

/************************************************************************
 * Block Transfer Engine copy related functions.
 *
 ***********************************************************************/

/*
 * bte_copy(src, dest, len, mode, notification)
 *
 * Use the block transfer engine to move kernel memory from src to dest
 * using the assigned mode.
 *
 * Parameters:
 *   src - physical address of the transfer source.
 *   dest - physical address of the transfer destination.
 *   len - number of bytes to transfer from source to dest.
 *   mode - hardware defined.  See reference information
 *          for IBCT0/1 in the SHUB Programmers Reference
 *   notification - kernel virtual address of the notification cache
 *                  line.  If NULL, the default is used and
 *                  the bte_copy is synchronous.
 *
 * NOTE:  This function requires src, dest, and len to
 * be cacheline aligned.
 */
bte_result_t bte_copy(u64 src, u64 dest, u64 len, u64 mode, void *notification)
{
        u64 transfer_size;
        u64 transfer_stat;
        u64 notif_phys_addr;
        struct bteinfo_s *bte;
        bte_result_t bte_status;
        unsigned long irq_flags;
        unsigned long itc_end = 0;
        int nasid_to_try[MAX_NODES_TO_TRY];
        int my_nasid = cpuid_to_nasid(raw_smp_processor_id());
        int bte_if_index, nasid_index;
        int bte_first, btes_per_node = BTES_PER_NODE;

        BTE_PRINTK(("bte_copy(0x%lx, 0x%lx, 0x%lx, 0x%lx, 0x%p)\n",
                    src, dest, len, mode, notification));

        if (len == 0) {
                return BTE_SUCCESS;
        }

        BUG_ON(len & L1_CACHE_MASK);
        BUG_ON(src & L1_CACHE_MASK);
        BUG_ON(dest & L1_CACHE_MASK);
        BUG_ON(len > BTE_MAX_XFER);

        /*
         * Start with interface corresponding to cpu number
         */
        bte_first = raw_smp_processor_id() % btes_per_node;

        if (mode & BTE_USE_DEST) {
                /* try remote then local */
                nasid_to_try[0] = NASID_GET(dest);
                if (mode & BTE_USE_ANY) {
                        nasid_to_try[1] = my_nasid;
                } else {
                        nasid_to_try[1] = (int)NULL;
                }
        } else {
                /* try local then remote */
                nasid_to_try[0] = my_nasid;
                if (mode & BTE_USE_ANY) {
                        nasid_to_try[1] = NASID_GET(dest);
                } else {
                        nasid_to_try[1] = (int)NULL;
                }
        }

retry_bteop:
        do {
                local_irq_save(irq_flags);

                bte_if_index = bte_first;
                nasid_index = 0;

                /* Attempt to lock one of the BTE interfaces. */
                while (nasid_index < MAX_NODES_TO_TRY) {
                        bte = bte_if_on_node(nasid_to_try[nasid_index],bte_if_index);

                        if (bte == NULL) {
                                nasid_index++;
                                continue;
                        }

                        if (spin_trylock(&bte->spinlock)) {
                                if (!(*bte->most_rcnt_na & BTE_WORD_AVAILABLE) ||
                                    (BTE_LNSTAT_LOAD(bte) & BTE_ACTIVE)) {
                                        /* Got the lock but BTE still busy */
                                        spin_unlock(&bte->spinlock);
                                } else {
                                        /* we got the lock and it's not busy */
                                        break;
                                }
                        }

                        bte_if_index = (bte_if_index + 1) % btes_per_node; /* Next interface */
                        if (bte_if_index == bte_first) {
                                /*
                                 * We've tried all interfaces on this node
                                 */
                                nasid_index++;
                        }

                        bte = NULL;
                }

                if (bte != NULL) {
                        break;
                }

                local_irq_restore(irq_flags);

                if (!(mode & BTE_WACQUIRE)) {
                        return BTEFAIL_NOTAVAIL;
                }
        } while (1);

        if (notification == NULL) {
                /* User does not want to be notified. */
                bte->most_rcnt_na = &bte->notify;
        } else {
                bte->most_rcnt_na = notification;
        }

        /* Calculate the number of cache lines to transfer. */
        transfer_size = ((len >> L1_CACHE_SHIFT) & BTE_LEN_MASK);

        /* Initialize the notification to a known value. */
        *bte->most_rcnt_na = BTE_WORD_BUSY;
        notif_phys_addr = (u64)bte->most_rcnt_na;

        /* Set the source and destination registers */
        BTE_PRINTKV(("IBSA = 0x%lx)\n", src));
        BTE_SRC_STORE(bte, src);
        BTE_PRINTKV(("IBDA = 0x%lx)\n", dest));
        BTE_DEST_STORE(bte, dest);

        /* Set the notification register */
        BTE_PRINTKV(("IBNA = 0x%lx)\n", notif_phys_addr));
        BTE_NOTIF_STORE(bte, notif_phys_addr);

        /* Initiate the transfer */
        BTE_PRINTK(("IBCT = 0x%lx)\n", BTE_VALID_MODE(mode)));
        bte_start_transfer(bte, transfer_size, BTE_VALID_MODE(mode));

        itc_end = ia64_get_itc() + (40000000 * local_cpu_data->cyc_per_usec);

        spin_unlock_irqrestore(&bte->spinlock, irq_flags);

        if (notification != NULL) {
                return BTE_SUCCESS;
        }

        while ((transfer_stat = *bte->most_rcnt_na) == BTE_WORD_BUSY) {
                cpu_relax();
                if (ia64_get_itc() > itc_end) {
                        BTE_PRINTK(("BTE timeout nasid 0x%x bte%d IBLS = 0x%lx na 0x%lx\n",
                                NASID_GET(bte->bte_base_addr), bte->bte_num,
                                BTE_LNSTAT_LOAD(bte), *bte->most_rcnt_na) );
                        bte->bte_error_count++;
                        bte->bh_error = IBLS_ERROR;
                        bte_error_handler((unsigned long)NODEPDA(bte->bte_cnode));
                        *bte->most_rcnt_na = BTE_WORD_AVAILABLE;
                        goto retry_bteop;
                }
        }

        BTE_PRINTKV((" Delay Done.  IBLS = 0x%lx, most_rcnt_na = 0x%lx\n",
                     BTE_LNSTAT_LOAD(bte), *bte->most_rcnt_na));

        if (transfer_stat & IBLS_ERROR) {
                bte_status = BTE_GET_ERROR_STATUS(transfer_stat);
        } else {
                bte_status = BTE_SUCCESS;
        }
        *bte->most_rcnt_na = BTE_WORD_AVAILABLE;

        BTE_PRINTK(("Returning status is 0x%lx and most_rcnt_na is 0x%lx\n",
                    BTE_LNSTAT_LOAD(bte), *bte->most_rcnt_na));

        return bte_status;
}

EXPORT_SYMBOL(bte_copy);

/*
 * bte_unaligned_copy(src, dest, len, mode)
 *
 * use the block transfer engine to move kernel
 * memory from src to dest using the assigned mode.
 *
 * Parameters:
 *   src - physical address of the transfer source.
 *   dest - physical address of the transfer destination.
 *   len - number of bytes to transfer from source to dest.
 *   mode - hardware defined.  See reference information
 *          for IBCT0/1 in the SGI documentation.
 *
 * NOTE: If the source, dest, and len are all cache line aligned,
 * then it would be _FAR_ preferable to use bte_copy instead.
 */
bte_result_t bte_unaligned_copy(u64 src, u64 dest, u64 len, u64 mode)
{
        int destFirstCacheOffset;
        u64 headBteSource;
        u64 headBteLen;
        u64 headBcopySrcOffset;
        u64 headBcopyDest;
        u64 headBcopyLen;
        u64 footBteSource;
        u64 footBteLen;
        u64 footBcopyDest;
        u64 footBcopyLen;
        bte_result_t rv;
        char *bteBlock, *bteBlock_unaligned;

        if (len == 0) {
                return BTE_SUCCESS;
        }

        /* temporary buffer used during unaligned transfers */
        bteBlock_unaligned = kmalloc(len + 3 * L1_CACHE_BYTES, GFP_KERNEL);
        if (bteBlock_unaligned == NULL) {
                return BTEFAIL_NOTAVAIL;
        }
        bteBlock = (char *)L1_CACHE_ALIGN((u64) bteBlock_unaligned);

        headBcopySrcOffset = src & L1_CACHE_MASK;
        destFirstCacheOffset = dest & L1_CACHE_MASK;

        /*
         * At this point, the transfer is broken into
         * (up to) three sections.  The first section is
         * from the start address to the first physical
         * cache line, the second is from the first physical
         * cache line to the last complete cache line,
         * and the third is from the last cache line to the
         * end of the buffer.  The first and third sections
         * are handled by bte copying into a temporary buffer
         * and then bcopy'ing the necessary section into the
         * final location.  The middle section is handled with
         * a standard bte copy.
         *
         * One nasty exception to the above rule is when the
         * source and destination are not symmetrically
         * mis-aligned.  If the source offset from the first
         * cache line is different from the destination offset,
         * we make the first section be the entire transfer
         * and the bcopy the entire block into place.
         */
        if (headBcopySrcOffset == destFirstCacheOffset) {

                /*
                 * Both the source and destination are the same
                 * distance from a cache line boundary so we can
                 * use the bte to transfer the bulk of the
                 * data.
                 */
                headBteSource = src & ~L1_CACHE_MASK;
                headBcopyDest = dest;
                if (headBcopySrcOffset) {
                        headBcopyLen =
                            (len >
                             (L1_CACHE_BYTES -
                              headBcopySrcOffset) ? L1_CACHE_BYTES
                             - headBcopySrcOffset : len);
                        headBteLen = L1_CACHE_BYTES;
                } else {
                        headBcopyLen = 0;
                        headBteLen = 0;
                }

                if (len > headBcopyLen) {
                        footBcopyLen = (len - headBcopyLen) & L1_CACHE_MASK;
                        footBteLen = L1_CACHE_BYTES;

                        footBteSource = src + len - footBcopyLen;
                        footBcopyDest = dest + len - footBcopyLen;

                        if (footBcopyDest == (headBcopyDest + headBcopyLen)) {
                                /*
                                 * We have two contiguous bcopy
                                 * blocks.  Merge them.
                                 */
                                headBcopyLen += footBcopyLen;
                                headBteLen += footBteLen;
                        } else if (footBcopyLen > 0) {
                                rv = bte_copy(footBteSource,
                                              ia64_tpa((unsigned long)bteBlock),
                                              footBteLen, mode, NULL);
                                if (rv != BTE_SUCCESS) {
                                        kfree(bteBlock_unaligned);
                                        return rv;
                                }

                                memcpy(__va(footBcopyDest),
                                       (char *)bteBlock, footBcopyLen);
                        }
                } else {
                        footBcopyLen = 0;
                        footBteLen = 0;
                }

                if (len > (headBcopyLen + footBcopyLen)) {
                        /* now transfer the middle. */
                        rv = bte_copy((src + headBcopyLen),
                                      (dest +
                                       headBcopyLen),
                                      (len - headBcopyLen -
                                       footBcopyLen), mode, NULL);
                        if (rv != BTE_SUCCESS) {
                                kfree(bteBlock_unaligned);
                                return rv;
                        }

                }
        } else {

                /*
                 * The transfer is not symmetric, we will
                 * allocate a buffer large enough for all the
                 * data, bte_copy into that buffer and then
                 * bcopy to the destination.
                 */

                headBcopySrcOffset = src & L1_CACHE_MASK;
                headBcopyDest = dest;
                headBcopyLen = len;

                headBteSource = src - headBcopySrcOffset;
                /* Add the leading and trailing bytes from source */
                headBteLen = L1_CACHE_ALIGN(len + headBcopySrcOffset);
        }

        if (headBcopyLen > 0) {
                rv = bte_copy(headBteSource,
                              ia64_tpa((unsigned long)bteBlock), headBteLen,
                              mode, NULL);
                if (rv != BTE_SUCCESS) {
                        kfree(bteBlock_unaligned);
                        return rv;
                }

                memcpy(__va(headBcopyDest), ((char *)bteBlock +
                                             headBcopySrcOffset), headBcopyLen);
        }
        kfree(bteBlock_unaligned);
        return BTE_SUCCESS;
}

EXPORT_SYMBOL(bte_unaligned_copy);

/************************************************************************
 * Block Transfer Engine initialization functions.
 *
 ***********************************************************************/

/*
 * bte_init_node(nodepda, cnode)
 *
 * Initialize the nodepda structure with BTE base addresses and
 * spinlocks.
 */
void bte_init_node(nodepda_t * mynodepda, cnodeid_t cnode)
{
        int i;

        /*
         * Indicate that all the block transfer engines on this node
         * are available.
         */

        /*
         * Allocate one bte_recover_t structure per node.  It holds
         * the recovery lock for node.  All the bte interface structures
         * will point at this one bte_recover structure to get the lock.
         */
        spin_lock_init(&mynodepda->bte_recovery_lock);
        init_timer(&mynodepda->bte_recovery_timer);
        mynodepda->bte_recovery_timer.function = bte_error_handler;
        mynodepda->bte_recovery_timer.data = (unsigned long)mynodepda;

        for (i = 0; i < BTES_PER_NODE; i++) {
                u64 *base_addr;

                /* Which link status register should we use? */
                base_addr = (u64 *)
                    REMOTE_HUB_ADDR(cnodeid_to_nasid(cnode), BTE_BASE_ADDR(i));
                mynodepda->bte_if[i].bte_base_addr = base_addr;
                mynodepda->bte_if[i].bte_source_addr = BTE_SOURCE_ADDR(base_addr);
                mynodepda->bte_if[i].bte_destination_addr = BTE_DEST_ADDR(base_addr);
                mynodepda->bte_if[i].bte_control_addr = BTE_CTRL_ADDR(base_addr);
                mynodepda->bte_if[i].bte_notify_addr = BTE_NOTIF_ADDR(base_addr);

                /*
                 * Initialize the notification and spinlock
                 * so the first transfer can occur.
                 */
                mynodepda->bte_if[i].most_rcnt_na =
                    &(mynodepda->bte_if[i].notify);
                mynodepda->bte_if[i].notify = BTE_WORD_AVAILABLE;
                spin_lock_init(&mynodepda->bte_if[i].spinlock);

                mynodepda->bte_if[i].bte_cnode = cnode;
                mynodepda->bte_if[i].bte_error_count = 0;
                mynodepda->bte_if[i].bte_num = i;
                mynodepda->bte_if[i].cleanup_active = 0;
                mynodepda->bte_if[i].bh_error = 0;
        }

}