/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I%     %E% SMI"

#include <sys/types.h>
#include <sys/cpr.h>
#include <sys/fs/ufs_fs.h>
#include <sys/prom_plat.h>
#include "cprboot.h"


/*
 * max space for a copy of physavail data
 * prop size is usually 80 to 128 bytes
 */
#define PA_BUFSIZE      1024

#define CB_SETBIT       1
#define CB_ISSET        2
#define CB_ISCLR        3

/*
 * globals
 */
int cb_nbitmaps;

/*
 * file scope
 */
static arange_t *cb_physavail;
static char pabuf[PA_BUFSIZE];
static caddr_t high_virt;

static cbd_t cb_bmda[CPR_MAX_BMDESC];
static int tracking_init;


static int
cb_bitop(pfn_t ppn, int op)
{
        int rel, rval = 0;
        char *bitmap;
        cbd_t *dp;

        for (dp = cb_bmda; dp->cbd_size; dp++) {
                if (PPN_IN_RANGE(ppn, dp)) {
                        bitmap = (char *)dp->cbd_reg_bitmap;
                        rel = ppn - dp->cbd_spfn;
                        if (op == CB_SETBIT)
                                setbit(bitmap, rel);
                        else if (op == CB_ISSET)
                                rval = isset(bitmap, rel);
                        else if (op == CB_ISCLR)
                                rval = isclr(bitmap, rel);
                        break;
                }
        }

        return (rval);
}


/*
 * count pages that are isolated from the kernel
 * within each available range
 */
static void
count_free_pages(void)
{
        arange_t *arp;
        pfn_t bitno;
        int cnt;

        for (arp = cb_physavail; arp->high; arp++) {
                cnt = 0;
                for (bitno = arp->low; bitno <= arp->high; bitno++) {
                        if (cb_bitop(bitno, CB_ISCLR))
                                cnt++;
                }
                arp->nfree = cnt;
        }
}


/*
 * scan the physavail list for a page
 * that doesn't clash with the kernel
 */
static pfn_t
search_phav_pages(void)
{
        static arange_t *arp;
        static pfn_t bitno;
        int rescan;

        if (arp == NULL) {
                count_free_pages();
                arp = cb_physavail;
                bitno = arp->low;
        }

        /*
         * begin scanning from the previous position and if the scan
         * reaches the end of the list, scan a second time from the top;
         * nfree is checked to eliminate scanning overhead when most
         * of the available space gets used up.  when a page is found,
         * set a bit so the page wont be found by another scan.
         */
        for (rescan = 0; rescan < 2; rescan++) {
                for (; arp->high; bitno = (++arp)->low) {
                        if (arp->nfree == 0)
                                continue;
                        for (; bitno <= arp->high; bitno++) {
                                if (cb_bitop(bitno, CB_ISCLR)) {
                                        (void) cb_bitop(bitno, CB_SETBIT);
                                        arp->nfree--;
                                        return (bitno++);
                                }
                        }
                }
                arp = cb_physavail;
                bitno = arp->low;
        }

        return (PFN_INVALID);
}


/*
 * scan statefile buffer pages for reusable tmp space
 */
static pfn_t
search_buf_pages(void)
{
        size_t coff, src_base;
        static size_t lboff;
        pfn_t ppn;

        if (tracking_init == 0)
                return (PFN_INVALID);

        /*
         * when scanning the list of statefile buffer ppns, we know that
         * all pages from lboff to the page boundary of buf_offset have
         * already been restored; when the associated page bit is clear,
         * that page is isolated from the kernel and we can reuse it for
         * tmp space; otherwise, when SF_DIFF_PPN indicates a page had
         * been moved, we know the page bit was previously clear and
         * later set, and we can reuse the new page.
         */
        src_base = sfile.buf_offset & MMU_PAGEMASK;
        while (lboff < src_base) {
                coff = lboff;
                lboff += MMU_PAGESIZE;
                ppn = SF_ORIG_PPN(coff);
                if (cb_bitop(ppn, CB_ISCLR)) {
                        (void) cb_bitop(ppn, CB_SETBIT);
                        SF_STAT_INC(recycle);
                        return (ppn);
                } else if (SF_DIFF_PPN(coff)) {
                        SF_STAT_INC(recycle);
                        return (SF_BUF_PPN(coff));
                }
        }

        return (PFN_INVALID);
}


/*
 * scan physavail and statefile buffer page lists
 * for a page that doesn't clash with the kernel
 */
pfn_t
find_apage(void)
{
        pfn_t ppn;

        ppn = search_phav_pages();
        if (ppn != PFN_INVALID)
                return (ppn);
        ppn = search_buf_pages();
        if (ppn != PFN_INVALID)
                return (ppn);

        prom_printf("\n%s: ran out of available/free pages!\n%s\n",
            prog, rsvp);
        cb_exit_to_mon();

        /* NOTREACHED */
        return (PFN_INVALID);
}


/*
 * reserve virt range, find available phys pages,
 * and map-in each phys starting at vaddr
 */
static caddr_t
map_free_phys(caddr_t vaddr, size_t size, char *name)
{
        int pages, ppn, err;
        physaddr_t phys;
        caddr_t virt;
        char *str;

        str = "map_free_phys";
        virt = prom_claim_virt(size, vaddr);
        CB_VPRINTF(("\n%s: claim vaddr 0x%p, size 0x%lx, ret 0x%p\n",
            str, (void *)vaddr, size, (void *)virt));
        if (virt != vaddr) {
                prom_printf("\n%s: cant reserve (0x%p - 0x%p) for \"%s\"\n",
                    str, (void *)vaddr, (void *)(vaddr + size), name);
                return (virt);
        }

        for (pages = mmu_btop(size); pages--; virt += MMU_PAGESIZE) {
                /*
                 * map virt page to free phys
                 */
                ppn = find_apage();
                phys = PN_TO_ADDR(ppn);

                err = prom_map_phys(-1, MMU_PAGESIZE, virt, phys);
                if (err || verbose) {
                        prom_printf("    map virt 0x%p, phys 0x%llx, "
                            "ppn 0x%x, ret %d\n", (void *)virt, phys, ppn, err);
                }
                if (err)
                        return ((caddr_t)ERR);
        }

        return (vaddr);
}


/*
 * check bitmap desc and relocate bitmap data
 * to pages isolated from the kernel
 *
 * sets globals:
 *      high_virt
 */
int
cb_set_bitmap(void)
{
        size_t bmda_size, all_bitmap_size, alloc_size;
        caddr_t newvirt, src, dst, base;
        cbd_t *dp;
        char *str;

        str = "cb_set_bitmap";
        CB_VPRINTF((ent_fmt, str, entry));

        /*
         * max is checked in the cpr module;
         * this condition should never occur
         */
        if (cb_nbitmaps > (CPR_MAX_BMDESC - 1)) {
                prom_printf("%s: too many bitmap descriptors %d, max %d\n",
                    str, cb_nbitmaps, (CPR_MAX_BMDESC - 1));
                return (ERR);
        }

        /*
         * copy bitmap descriptors to aligned space, check magic numbers,
         * and set the total size of all bitmaps
         */
        bmda_size = cb_nbitmaps * sizeof (cbd_t);
        src = SF_DATA();
        bcopy(src, cb_bmda, bmda_size);
        base = src + bmda_size;
        all_bitmap_size = 0;
        for (dp = cb_bmda; dp < &cb_bmda[cb_nbitmaps]; dp++) {
                if (dp->cbd_magic != CPR_BITMAP_MAGIC) {
                        prom_printf("%s: bad magic 0x%x, expect 0x%x\n",
                            str, dp->cbd_magic, CPR_BITMAP_MAGIC);
                        return (ERR);
                }
                all_bitmap_size += dp->cbd_size;
                dp->cbd_reg_bitmap = (cpr_ptr)base;
                base += dp->cbd_size;
        }

        /*
         * reserve new space for bitmaps
         */
        alloc_size = PAGE_ROUNDUP(all_bitmap_size);
        if (verbose || CPR_DBG(7)) {
                prom_printf("%s: nbitmaps %d, bmda_size 0x%lx\n",
                    str, cb_nbitmaps, bmda_size);
                prom_printf("%s: all_bitmap_size 0x%lx, alloc_size 0x%lx\n",
                    str, all_bitmap_size, alloc_size);
        }
        high_virt = (caddr_t)CB_HIGH_VIRT;
        newvirt = map_free_phys(high_virt, alloc_size, "bitmaps");
        if (newvirt != high_virt)
                return (ERR);

        /*
         * copy the bitmaps, clear any unused space trailing them,
         * and set references into the new space
         */
        base = src + bmda_size;
        dst = newvirt;
        bcopy(base, dst, all_bitmap_size);
        if (alloc_size > all_bitmap_size)
                bzero(dst + all_bitmap_size, alloc_size - all_bitmap_size);
        for (dp = cb_bmda; dp->cbd_size; dp++) {
                dp->cbd_reg_bitmap = (cpr_ptr)dst;
                dst += dp->cbd_size;
        }

        /* advance past all the bitmap data */
        SF_ADV(bmda_size + all_bitmap_size);
        high_virt += alloc_size;

        return (0);
}


/*
 * create a new stack for cprboot;
 * this stack is used to avoid clashes with kernel pages and
 * to avoid exceptions while remapping cprboot virt pages
 */
int
cb_get_newstack(void)
{
        caddr_t newstack;

        CB_VENTRY(cb_get_newstack);
        newstack = map_free_phys((caddr_t)CB_STACK_VIRT,
            CB_STACK_SIZE, "new stack");
        if (newstack != (caddr_t)CB_STACK_VIRT)
                return (ERR);
        return (0);
}


/*
 * since kernel phys pages span most of the installed memory range,
 * some statefile buffer pages will likely clash with the kernel
 * and need to be moved before kernel pages are restored; a list
 * of buf phys page numbers is created here and later updated as
 * buf pages are moved
 *
 * sets globals:
 *      sfile.buf_map
 *      tracking_init
 */
int
cb_tracking_setup(void)
{
        pfn_t ppn, lppn;
        uint_t *imap;
        caddr_t newvirt;
        size_t size;
        int pages;

        CB_VENTRY(cb_tracking_setup);

        pages = mmu_btop(sfile.size);
        size = PAGE_ROUNDUP(pages * sizeof (*imap));
        newvirt = map_free_phys(high_virt, size, "buf tracking");
        if (newvirt != high_virt)
                return (ERR);
        sfile.buf_map = (uint_t *)newvirt;
        high_virt += size;

        /*
         * create identity map of sfile.buf phys pages
         */
        imap = sfile.buf_map;
        lppn = sfile.low_ppn + pages;
        for (ppn = sfile.low_ppn; ppn < lppn; ppn++, imap++)
                *imap = (uint_t)ppn;
        tracking_init = 1;

        return (0);
}


/*
 * get "available" prop from /memory node
 *
 * sets globals:
 *      cb_physavail
 */
int
cb_get_physavail(void)
{
        int len, glen, scnt, need, space;
        char *str, *pdev, *mem_prop;
        pnode_t mem_node;
        physaddr_t phys;
        pgcnt_t pages;
        arange_t *arp;
        pphav_t *pap;
        size_t size;
        pfn_t ppn;
        int err;

        str = "cb_get_physavail";
        CB_VPRINTF((ent_fmt, str, entry));

        /*
         * first move cprboot pages off the physavail list
         */
        size = PAGE_ROUNDUP((uintptr_t)_end) - (uintptr_t)_start;
        ppn = cpr_vatopfn((caddr_t)_start);
        phys = PN_TO_ADDR(ppn);
        err = prom_claim_phys(size, phys);
        CB_VPRINTF(("    text/data claim (0x%lx - 0x%lx) = %d\n",
            ppn, ppn + mmu_btop(size) - 1, err));
        if (err)
                return (ERR);

        pdev = "/memory";
        mem_node = prom_finddevice(pdev);
        if (mem_node == OBP_BADNODE) {
                prom_printf("%s: cant find \"%s\" node\n", str, pdev);
                return (ERR);
        }
        mem_prop = "available";

        /*
         * prop data is treated as a struct array;
         * verify pabuf has enough room for the array
         * in the original and converted forms
         */
        len = prom_getproplen(mem_node, mem_prop);
        scnt = len / sizeof (*pap);
        need = len + (sizeof (*arp) * (scnt + 1));
        space = sizeof (pabuf);
        CB_VPRINTF(("    %s node 0x%x, len %d\n", pdev, mem_node, len));
        if (len == -1 || need > space) {
                prom_printf("\n%s: bad \"%s\" length %d, min %d, max %d\n",
                    str, mem_prop, len, need, space);
                return (ERR);
        }

        /*
         * read-in prop data and clear trailing space
         */
        glen = prom_getprop(mem_node, mem_prop, pabuf);
        if (glen != len) {
                prom_printf("\n%s: 0x%x,%s: expected len %d, got %d\n",
                    str, mem_node, mem_prop, len, glen);
                return (ERR);
        }
        bzero(&pabuf[len], space - len);

        /*
         * convert the physavail list in place
         * from (phys_base, phys_size) to (low_ppn, high_ppn)
         */
        if (verbose)
                prom_printf("\nphysavail list:\n");
        cb_physavail = (arange_t *)pabuf;
        arp = cb_physavail + scnt - 1;
        pap = (pphav_t *)cb_physavail + scnt - 1;
        for (; scnt--; pap--, arp--) {
                pages = mmu_btop(pap->size);
                arp->low = ADDR_TO_PN(pap->base);
                arp->high = arp->low + pages - 1;
                if (verbose) {
                        prom_printf("  %d: (0x%lx - 0x%lx),\tpages %ld\n",
                            (int)(arp - cb_physavail),
                            arp->low, arp->high, (arp->high - arp->low + 1));
                }
        }

        return (0);
}


/*
 * search for an available phys page,
 * copy the old phys page to the new one
 * and remap the virt page to the new phys
 */
static int
move_page(caddr_t vaddr, pfn_t oldppn)
{
        physaddr_t oldphys, newphys;
        pfn_t newppn;
        int err;

        newppn = find_apage();
        newphys = PN_TO_ADDR(newppn);
        oldphys = PN_TO_ADDR(oldppn);
        CB_VPRINTF(("    remap vaddr 0x%p, old 0x%lx/0x%llx,"
            "   new 0x%lx/0x%llx\n",
            (void *)vaddr, oldppn, oldphys, newppn, newphys));
        phys_xcopy(oldphys, newphys, MMU_PAGESIZE);
        err = prom_remap(MMU_PAGESIZE, vaddr, newphys);
        if (err)
                prom_printf("\nmove_page: remap error\n");
        return (err);
}


/*
 * physically relocate any text/data pages that clash
 * with the kernel; since we're already running on
 * a new stack, the original stack area is skipped
 */
int
cb_relocate(void)
{
        int is_ostk, is_clash, clash_cnt, ok_cnt;
        char *str, *desc, *skip_fmt;
        caddr_t ostk_low, ostk_high;
        caddr_t virt, saddr, eaddr;
        pfn_t ppn;

        str = "cb_relocate";
        CB_VPRINTF((ent_fmt, str, entry));

        ostk_low  = (caddr_t)&estack - CB_STACK_SIZE;
        ostk_high = (caddr_t)&estack - MMU_PAGESIZE;
        saddr = (caddr_t)_start;
        eaddr = (caddr_t)PAGE_ROUNDUP((uintptr_t)_end);

        install_remap();

        skip_fmt = "    skip  vaddr 0x%p, clash=%d, %s\n";
        clash_cnt = ok_cnt = 0;
        ppn = cpr_vatopfn(saddr);

        for (virt = saddr; virt < eaddr; virt += MMU_PAGESIZE, ppn++) {
                is_clash = (cb_bitop(ppn, CB_ISSET) != 0);
                if (is_clash)
                        clash_cnt++;
                else
                        ok_cnt++;

                is_ostk = (virt >= ostk_low && virt <= ostk_high);
                if (is_ostk)
                        desc = "orig stack";
                else
                        desc = "text/data";

                /*
                 * page logic:
                 *
                 * if (original stack page)
                 *      clash doesn't matter, just skip the page
                 * else (not original stack page)
                 *      if (no clash)
                 *              setbit to avoid later alloc and overwrite
                 *      else (clash)
                 *              relocate phys page
                 */
                if (is_ostk) {
                        CB_VPRINTF((skip_fmt, virt, is_clash, desc));
                } else if (is_clash == 0) {
                        CB_VPRINTF((skip_fmt, virt, is_clash, desc));
                        (void) cb_bitop(ppn, CB_SETBIT);
                } else if (move_page(virt, ppn))
                        return (ERR);
        }
        CB_VPRINTF(("%s: total %d, clash %d, ok %d\n",
            str, clash_cnt + ok_cnt, clash_cnt, ok_cnt));

        /*
         * free original stack area for reuse
         */
        ppn = cpr_vatopfn(ostk_low);
        prom_free_phys(CB_STACK_SIZE, PN_TO_ADDR(ppn));
        CB_VPRINTF(("%s: free old stack (0x%lx - 0x%lx)\n",
            str, ppn, ppn + mmu_btop(CB_STACK_SIZE) - 1));

        return (0);
}