root/sys/arch/hp300/hp300/pmap_bootstrap.c
/*      $NetBSD: pmap_bootstrap.c,v 1.70 2026/04/05 14:35:48 thorpej Exp $      */

/*
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)pmap_bootstrap.c    8.1 (Berkeley) 6/10/93
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap_bootstrap.c,v 1.70 2026/04/05 14:35:48 thorpej Exp $");

#include <sys/param.h>
#include <uvm/uvm_extern.h>

#include <machine/cpu.h>
#include <machine/hp300spu.h>
#include <machine/pte.h>
#include <machine/vmparam.h>

#include <hp300/hp300/clockreg.h>

#define RELOC(v, t)     *((t*)((uintptr_t)&(v) + firstpa))

extern char *etext;

extern vaddr_t kernel_reloc_offset;

/*
 * Special purpose kernel virtual addresses, used for mapping
 * physical pages for a variety of temporary or permanent purposes:
 *
 *      CADDR1, CADDR2: pmap zero/copy operations
 *      vmmap:          /dev/mem, crash dumps, parity error checking
 *      msgbufaddr:     kernel message buffer
 */
void *CADDR1, *CADDR2;
char *vmmap;
extern void *msgbufaddr;

paddr_t pmap_bootstrap1(paddr_t, paddr_t);

/*
 * Bootstrap the VM system.
 *
 * Called with MMU off so we must relocate all global references by `firstpa'
 * (don't call any functions here!)  `nextpa' is the first available physical
 * memory address.  Returns an updated first PA reflecting the memory we
 * have allocated.  MMU is still off when we return.
 *
 * XXX assumes sizeof(u_int) == sizeof(pt_entry_t)
 * XXX a PIC compiler would make this much easier.
 */
paddr_t __attribute__((no_instrument_function))
pmap_bootstrap1(paddr_t nextpa, paddr_t firstpa)
{
        paddr_t lwp0upa, kstpa, kptmpa, kptpa;
        paddr_t lkptpa;
        u_int nptpages, kstsize;
        st_entry_t protoste, *ste, *este;
        pt_entry_t protopte, *pte, *epte;
        u_int stfree = 0;       /* XXX: gcc -Wuninitialized */

        nextpa = m68k_round_page(nextpa);

        /*
         * Calculate important physical addresses:
         *
         *      lwp0upa         lwp0 u-area             UPAGES pages
         *
         *      kstpa           kernel segment table    1 page (!040)
         *                                              N pages (040)
         *
         *      kptmpa          kernel PT map           1 page
         *
         *      lkptpa          last kernel PT page     1 page
         *
         *      kptpa           statically allocated
         *                      kernel PT pages         Sysptsize+ pages
         *
         * [ Sysptsize is the number of pages of PT, and IIOMAPSIZE and
         *   EIOMAPSIZE are the number of PTEs, hence we need to round
         *   the total to a page boundary with IO maps at the end. ]
         *
         * The KVA corresponding to any of these PAs is:
         *      (PA - firstpa + KERNBASE).
         */
        RELOC(kernel_reloc_offset, vaddr_t) = firstpa;

        lwp0upa = nextpa;
        nextpa += USPACE;
        if (RELOC(mmutype, int) == MMU_68040)
                kstsize = MAXKL2SIZE / (NPTEPG/SG4_LEV2SIZE);
        else
                kstsize = 1;
        kstpa = nextpa;
        nextpa += kstsize * PAGE_SIZE;
        kptmpa = nextpa;
        nextpa += PAGE_SIZE;
        lkptpa = nextpa;
        nextpa += PAGE_SIZE;
        kptpa = nextpa;
        nptpages = RELOC(Sysptsize, int) +
            howmany(RELOC(physmem, psize_t), NPTEPG) +
            (IIOMAPSIZE + EIOMAPSIZE + NPTEPG - 1) / NPTEPG;
        nextpa += nptpages * PAGE_SIZE;

        /*
         * Initialize segment table and kernel page table map.
         *
         * On 68030s and earlier MMUs the two are identical except for
         * the valid bits so both are initialized with essentially the
         * same values.  On the 68040, which has a mandatory 3-level
         * structure, the segment table holds the level 1 table and part
         * (or all) of the level 2 table and hence is considerably
         * different.  Here the first level consists of 128 descriptors
         * (512 bytes) each mapping 32mb of address space.  Each of these
         * points to blocks of 128 second level descriptors (512 bytes)
         * each mapping 256kb.  Note that there may be additional "segment
         * table" pages depending on how large MAXKL2SIZE is.
         *
         * Portions of the last two segment of KVA space (0xFF800000 -
         * 0xFFFFFFFF) are mapped for a couple of purposes.
         * The first segment (0xFF800000 - 0xFFBFFFFF) is mapped
         * for the kernel page tables.
         * The very last page (0xFFFFF000) in the second segment is mapped
         * to the last physical page of RAM to give us a region in which
         * PA == VA.  We use the first part of this page for enabling
         * and disabling mapping.  The last part of this page also contains
         * info left by the boot ROM.
         *
         * XXX cramming two levels of mapping into the single "segment"
         * table on the 68040 is intended as a temporary hack to get things
         * working.  The 224mb of address space that this allows will most
         * likely be insufficient in the future (at least for the kernel).
         */
        if (RELOC(mmutype, int) == MMU_68040) {
                int nl1desc, nl2desc, i;

                /*
                 * First invalidate the entire "segment table" pages
                 * (levels 1 and 2 have the same "invalid" value).
                 */
                ste = (st_entry_t *)kstpa;
                este = &ste[kstsize * NPTEPG];
                while (ste < este)
                        *ste++ = SG_NV;
                /*
                 * Initialize level 2 descriptors (which immediately
                 * follow the level 1 table).  We need:
                 *      NPTEPG / SG4_LEV3SIZE
                 * level 2 descriptors to map each of the nptpages
                 * pages of PTEs.  Note that we set the "used" bit
                 * now to save the HW the expense of doing it.
                 */
                nl2desc = nptpages * (NPTEPG / SG4_LEV3SIZE);
                ste = (st_entry_t *)kstpa;
                ste = &ste[SG4_LEV1SIZE];
                este = &ste[nl2desc];
                protoste = kptpa | SG_U | SG_RW | SG_V;
                while (ste < este) {
                        *ste++ = protoste;
                        protoste += (SG4_LEV3SIZE * sizeof(st_entry_t));
                }
                /*
                 * Initialize level 1 descriptors.  We need:
                 *      howmany(nl2desc, SG4_LEV2SIZE)
                 * level 1 descriptors to map the `nl2desc' level 2's.
                 */
                nl1desc = howmany(nl2desc, SG4_LEV2SIZE);
                ste = (st_entry_t *)kstpa;
                este = &ste[nl1desc];
                protoste = (paddr_t)&ste[SG4_LEV1SIZE] | SG_U | SG_RW | SG_V;
                while (ste < este) {
                        *ste++ = protoste;
                        protoste += (SG4_LEV2SIZE * sizeof(st_entry_t));
                }
                /*
                 * Initialize the final level 1 descriptor to map the next
                 * block of level 2 descriptors for Sysptmap.
                 */
                ste = (st_entry_t *)kstpa;
                ste = &ste[SG4_LEV1SIZE - 1];
                *ste = protoste;
                /*
                 * Now initialize the final portion of that block of
                 * descriptors to map Sysmap and the "last PT page".
                 */
                i = SG4_LEV1SIZE + (nl1desc * SG4_LEV2SIZE);
                ste = (st_entry_t *)kstpa;
                ste = &ste[i + SG4_LEV2SIZE - (NPTEPG / SG4_LEV3SIZE) * 2];
                este = &ste[NPTEPG / SG4_LEV3SIZE];
                protoste = kptmpa | SG_U | SG_RW | SG_V;
                while (ste < este) {
                        *ste++ = protoste;
                        protoste += (SG4_LEV3SIZE * sizeof(st_entry_t));
                }
                este = &ste[NPTEPG / SG4_LEV3SIZE];
                protoste = lkptpa | SG_U | SG_RW | SG_V;
                while (ste < este) {
                        *ste++ = protoste;
                        protoste += (SG4_LEV3SIZE * sizeof(st_entry_t));
                }
                /*
                 * Calculate the free level 2 descriptor mask
                 * noting that we have used:
                 *      0:              level 1 table
                 *      1 to nl1desc:   map page tables
                 *      nl1desc + 1:    maps kptmpa and last-page page table
                 */
                /* mark an entry for level 1 table */
                stfree = ~l2tobm(0);
                /* mark entries for map page tables */
                for (i = 1; i <= nl1desc; i++)
                        stfree &= ~l2tobm(i);
                /* mark an entry for kptmpa and lkptpa */
                stfree &= ~l2tobm(i);
                /* mark entries not available */
                for (i = MAXKL2SIZE; i < sizeof(stfree) * NBBY; i++)
                        stfree &= ~l2tobm(i);

                /*
                 * Initialize Sysptmap
                 */
                pte = (pt_entry_t *)kptmpa;
                epte = &pte[nptpages];
                protopte = kptpa | PG_RW | PG_CI | PG_V;
                while (pte < epte) {
                        *pte++ = protopte;
                        protopte += PAGE_SIZE;
                }
                /*
                 * Invalidate all remaining entries.
                 */
                epte = (pt_entry_t *)kptmpa;
                epte = &epte[TIB_SIZE];
                while (pte < epte) {
                        *pte++ = PG_NV;
                }
                /*
                 * Initialize the last ones to point to Sysptmap and the page
                 * table page allocated earlier.
                 */
                pte = (pt_entry_t *)kptmpa;
                pte = &pte[SYSMAP_VA >> SEGSHIFT];
                *pte = kptmpa | PG_RW | PG_CI | PG_V;
                pte = (pt_entry_t *)kptmpa;
                pte = &pte[MAXADDR >> SEGSHIFT];
                *pte = lkptpa | PG_RW | PG_CI | PG_V;
        } else {
                /*
                 * Map the page table pages in both the HW segment table
                 * and the software Sysptmap.
                 */
                ste = (st_entry_t *)kstpa;
                pte = (pt_entry_t *)kptmpa;
                epte = &pte[nptpages];
                protoste = kptpa | SG_RW | SG_V;
                protopte = kptpa | PG_RW | PG_CI | PG_V;
                while (pte < epte) {
                        *ste++ = protoste;
                        *pte++ = protopte;
                        protoste += PAGE_SIZE;
                        protopte += PAGE_SIZE;
                }
                /*
                 * Invalidate all remaining entries in both.
                 */
                este = (st_entry_t *)kstpa;
                este = &este[TIA_SIZE];
                while (ste < este)
                        *ste++ = SG_NV;
                epte = (pt_entry_t *)kptmpa;
                epte = &epte[TIB_SIZE];
                while (pte < epte)
                        *pte++ = PG_NV;
                /*
                 * Initialize the last ones to point to Sysptmap and the page
                 * table page allocated earlier.
                 */
                ste = (st_entry_t *)kstpa;
                ste = &ste[SYSMAP_VA >> SEGSHIFT];
                pte = (pt_entry_t *)kptmpa;
                pte = &pte[SYSMAP_VA >> SEGSHIFT];
                *ste = kptmpa | SG_RW | SG_V;
                *pte = kptmpa | PG_RW | PG_CI | PG_V;
                ste = (st_entry_t *)kstpa;
                ste = &ste[MAXADDR >> SEGSHIFT];
                pte = (pt_entry_t *)kptmpa;
                pte = &pte[MAXADDR >> SEGSHIFT];
                *ste = lkptpa | SG_RW | SG_V;
                *pte = lkptpa | PG_RW | PG_CI | PG_V;
        }

        /*
         * Invalidate all but the final entry in the last kernel PT page.
         * The final entry maps the last page of physical memory to
         * prepare a page that is PA == VA to turn on the MMU.
         */
        pte = (pt_entry_t *)lkptpa;
        epte = &pte[NPTEPG - 1];
        while (pte < epte)
                *pte++ = PG_NV;
        *pte = MAXADDR | PG_RW | PG_CI | PG_V;
        /*
         * Initialize kernel page table.
         * Start by invalidating the `nptpages' that we have allocated.
         */
        pte = (pt_entry_t *)kptpa;
        epte = &pte[nptpages * NPTEPG];
        while (pte < epte)
                *pte++ = PG_NV;
        /*
         * Validate PTEs for kernel text (RO).
         * The first page of kernel text remains invalid; see locore.s
         */
        pte = (pt_entry_t *)kptpa;
        pte = &pte[m68k_btop(KERNBASE + PAGE_SIZE)];
        epte = &pte[m68k_btop(m68k_trunc_page(&etext))];
        protopte = (firstpa + PAGE_SIZE) | PG_RO | PG_V;
        while (pte < epte) {
                *pte++ = protopte;
                protopte += PAGE_SIZE;
        }
        /*
         * Validate PTEs for kernel data/bss, dynamic data allocated
         * by us so far (kstpa - firstpa bytes), and pages for lwp0
         * u-area and page table allocated below (RW).
         */
        epte = (pt_entry_t *)kptpa;
        epte = &epte[m68k_btop(kstpa - firstpa)];
        protopte = (protopte & ~PG_PROT) | PG_RW;
        /*
         * Enable copy-back caching of data pages
         */
        if (RELOC(mmutype, int) == MMU_68040)
                protopte |= PG_CCB;
        while (pte < epte) {
                *pte++ = protopte;
                protopte += PAGE_SIZE;
        }
        /*
         * Map the kernel segment table cache invalidated for 68040/68060.
         * (for the 68040 not strictly necessary, but recommended by Motorola;
         *  for the 68060 mandatory)
         */
        epte = (pt_entry_t *)kptpa;
        epte = &epte[m68k_btop(nextpa - firstpa)];
        protopte = (protopte & ~PG_PROT) | PG_RW;
        if (RELOC(mmutype, int) == MMU_68040) {
                protopte &= ~PG_CCB;
                protopte |= PG_CIN;
        }
        while (pte < epte) {
                *pte++ = protopte;
                protopte += PAGE_SIZE;
        }

        /*
         * Finally, validate the internal IO space PTEs (RW+CI).
         * We do this here since the 320/350 MMU registers (also
         * used, but to a lesser extent, on other models) are mapped
         * in this range and it would be nice to be able to access
         * them after the MMU is turned on.
         */

#define PTE2VA(pte)     m68k_ptob(pte - ((pt_entry_t *)kptpa))

        protopte = INTIOBASE | PG_RW | PG_CI | PG_V;
        epte = &pte[IIOMAPSIZE];
        RELOC(intiobase, uint8_t *) = (uint8_t *)PTE2VA(pte);
        while (pte < epte) {
                *pte++ = protopte;
                protopte += PAGE_SIZE;
        }
        RELOC(extiobase, uint8_t *) = (uint8_t *)PTE2VA(pte);
        pte += EIOMAPSIZE;
        RELOC(virtual_avail, vaddr_t) = PTE2VA(pte);

        /*
         * Calculate important exported kernel addresses and related values.
         */
        /*
         * Sysseg: base of kernel segment table
         */
        RELOC(Sysseg, st_entry_t *) = (st_entry_t *)(kstpa - firstpa);
        RELOC(Sysseg_pa, paddr_t) = kstpa;
#if defined(M68040)
        if (RELOC(mmutype, int) == MMU_68040)
                RELOC(protostfree, u_int) = stfree;
#endif
        /*
         * Sysptmap: base of kernel page table map
         */
        RELOC(Sysptmap, pt_entry_t *) = (pt_entry_t *)(kptmpa - firstpa);
        /*
         * Sysmap: kernel page table (as mapped through Sysptmap)
         * Allocated at the end of KVA space.
         */
        RELOC(Sysmap, pt_entry_t *) = (pt_entry_t *)SYSMAP_VA;

        /*
         * Remember the u-area address so it can be loaded in the lwp0
         * via uvm_lwp_setuarea() later in pmap_bootstrap2().
         */
        RELOC(lwp0uarea, vaddr_t) = lwp0upa - firstpa;

        /*
         * VM data structures are now initialized, set up data for
         * the pmap module.
         *
         * Note about avail_end: msgbuf is initialized just after
         * avail_end in machdep.c.
         * Since the last page is used for rebooting the system
         * (code is copied there and execution continues from copied code
         * before the MMU is disabled), the msgbuf will get trounced
         * between reboots if it's placed in the last physical page.
         * To work around this, we move avail_end back one more
         * page so the msgbuf can be preserved.
         */

        RELOC(virtual_end, vaddr_t) = VM_MAX_KERNEL_ADDRESS;

        /*
         * Allocate some fixed, special purpose kernel virtual addresses
         */
        {
                vaddr_t va = RELOC(virtual_avail, vaddr_t);

                RELOC(CADDR1, void *) = (void *)va;
                va += PAGE_SIZE;
                RELOC(CADDR2, void *) = (void *)va;
                va += PAGE_SIZE;
                RELOC(vmmap, void *) = (void *)va;
                va += PAGE_SIZE;
                RELOC(msgbufaddr, void *) = (void *)va;
                va += m68k_round_page(MSGBUFSIZE);
                RELOC(virtual_avail, vaddr_t) = va;
        }

        return nextpa;
}