xref: /src/sys/arch/sun68k/stand/libsa/sun2.c

/*	$NetBSD: sun2.c,v 1.13 2020/06/20 18:45:06 riastradh Exp $	*/

/*-
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Gordon W. Ross and Matthew Fredette.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Standalone functions specific to the Sun2.
 */

/*
 * We need to get the sun2 NBSG definition, even if we're
 * building this with a different sun68k target.
 */
#include <arch/sun2/include/pmap.h>

#include <sys/param.h>
#include <machine/idprom.h>
#include <machine/mon.h>

#include <arch/sun2/include/pte.h>
#include <arch/sun2/sun2/control.h>
#ifdef notyet
#include <arch/sun3/sun3/vme.h>
#else
#define VME16_BASE MBIO_BASE
#define VME16_MASK MBIO_MASK
#endif
#include <arch/sun2/sun2/mbmem.h>
#include <arch/sun2/sun2/mbio.h>

#include <stand.h>

#include "libsa.h"
#include "dvma.h"
#include "saio.h"	/* enum MAPTYPES */

#define OBIO_MASK 0xFFFFFF

static u_int	sun2_get_pte(vaddr_t);
static void	sun2_set_pte(vaddr_t, u_int);
static void	dvma2_init(void);
static char *	dvma2_alloc(int);
static void	dvma2_free(char *, int);
static char *	dvma2_mapin(char *, int);
static void	dvma2_mapout(char *, int);
static char *	dev2_mapin(int, u_long, int);
static int	sun2_get_segmap(vaddr_t);
static void	sun2_set_segmap(vaddr_t, int);

struct mapinfo {
	int maptype;
	int pgtype;
	u_int base;
	u_int mask;
};

#ifdef	notyet
struct mapinfo
sun2_mapinfo[MAP__NTYPES] = {
	/* On-board memory, I/O */
	{ MAP_MAINMEM,   PGT_OBMEM,   0,          ~0 },
	{ MAP_OBIO,      PGT_OBIO,    0,          OBIO_MASK },
	/* Multibus memory, I/O */
	{ MAP_MBMEM,     PGT_MBMEM, MBMEM_BASE, MBMEM_MASK },
	{ MAP_MBIO,      PGT_MBIO,  MBIO_BASE, MBIO_MASK },
	/* VME A16 */
	{ MAP_VME16A16D, PGT_VME_D16, VME16_BASE, VME16_MASK },
	{ MAP_VME16A32D, 0, 0, 0 },
	/* VME A24 */
	{ MAP_VME24A16D, 0, 0, 0 },
	{ MAP_VME24A32D, 0, 0, 0 },
	/* VME A32 */
	{ MAP_VME32A16D, 0, 0, 0 },
	{ MAP_VME32A32D, 0, 0, 0 },
};
#endif

/* The virtual address we will use for PROM device mappings. */
int sun2_devmap = SUN3_MONSHORTSEG;

static char *
dev2_mapin(int maptype, u_long physaddr, int length)
{
#ifdef	notyet
	u_int i, pa, pte, pgva, va;

	if ((sun2_devmap + length) > SUN3_MONSHORTPAGE)
		panic("dev2_mapin: length=%d", length);

	for (i = 0; i < MAP__NTYPES; i++)
		if (sun2_mapinfo[i].maptype == maptype)
			goto found;
	panic("dev2_mapin: bad maptype");
found:

	if (physaddr & ~(sun2_mapinfo[i].mask))
		panic("dev2_mapin: bad address");
	pa = sun2_mapinfo[i].base += physaddr;

	pte = PA_PGNUM(pa) | PG_PERM |
		sun2_mapinfo[i].pgtype;

	va = pgva = sun2_devmap;
	do {
		sun2_set_pte(pgva, pte);
		pgva += NBPG;
		pte += 1;
		length -= NBPG;
	} while (length > 0);
	sun2_devmap = pgva;
	va += (physaddr & PGOFSET);

#ifdef	DEBUG_PROM
	if (debug)
		printf("dev2_mapin: va=0x%x pte=0x%x\n",
			   va, sun2_get_pte(va));
#endif
	return ((char*)va);
#else
	panic("dev2_mapin");
	return(NULL);
#endif
}

/*****************************************************************
 * DVMA support
 */

/*
 * The easiest way to deal with the need for DVMA mappings is to
 * create a DVMA alias mapping of the entire address range used by
 * the boot program.  That way, dvma_mapin can just compute the
 * DVMA alias address, and dvma_mapout does nothing.
 *
 * Note that this assumes that standalone programs will do I/O
 * operations only within range (SA_MIN_VA .. SA_MAX_VA) checked.
 */

#define DVMA_BASE 0x00f00000
#define DVMA_MAPLEN  0x38000	/* 256K - 32K (save MONSHORTSEG) */

#define SA_MIN_VA	0x220000
#define SA_MAX_VA	(SA_MIN_VA + DVMA_MAPLEN)

/* This points to the end of the free DVMA space. */
u_int dvma2_end = DVMA_BASE + DVMA_MAPLEN;

static void
dvma2_init(void)
{
	int segva, dmava, sme;

	segva = SA_MIN_VA;
	dmava = DVMA_BASE;

	while (segva < SA_MAX_VA) {
		sme = sun2_get_segmap(segva);
		sun2_set_segmap(dmava, sme);
		segva += NBSG;
		dmava += NBSG;
	}
}

/* Convert a local address to a DVMA address. */
static char *
dvma2_mapin(char *addr, int len)
{
	int va = (int)addr;

	/* Make sure the address is in the DVMA map. */
	if ((va < SA_MIN_VA) || (va >= SA_MAX_VA))
		panic("dvma2_mapin: 0x%x outside 0x%x..0x%x",
		    va, SA_MIN_VA, SA_MAX_VA);

	va -= SA_MIN_VA;
	va += DVMA_BASE;

	return ((char *) va);
}

/* Destroy a DVMA address alias. */
void
dvma2_mapout(char *addr, int len)
{
	int va = (int)addr;

	/* Make sure the address is in the DVMA map. */
	if ((va < DVMA_BASE) || (va >= (DVMA_BASE + DVMA_MAPLEN)))
		panic("dvma2_mapout");
}

static char *
dvma2_alloc(int len)
{
	len = m68k_round_page(len);
	dvma2_end -= len;
	return((char*)dvma2_end);
}

void
dvma2_free(char *dvma, int len)
{
	/* not worth the trouble */
}

/*****************************************************************
 * Control space stuff...
 */

static u_int
sun2_get_pte(vaddr_t va)
{
	u_int pte;

	pte = get_control_word(CONTROL_ADDR_BUILD(PGMAP_BASE, va));
	if (pte & PG_VALID) {
		/*
		 * This clears bit 30 (the kernel readable bit, which
		 * should always be set), bit 28 (which should always
		 * be set) and bit 26 (the user writable bit, which we
		 * always have tracking the kernel writable bit).  In
		 * the protection, this leaves bit 29 (the kernel
		 * writable bit) and bit 27 (the user readable bit).
		 * See pte2.h for more about this hack.
		 */
		pte &= ~(0x54000000);
		/*
		 * Flip bit 27 (the user readable bit) to become bit
		 * 27 (the PG_SYSTEM bit).
		 */
		pte ^= (PG_SYSTEM);
	}
	return (pte);
}

static void
sun2_set_pte(vaddr_t va, u_int pte)
{
	if (pte & PG_VALID) {
		/* Clear bit 26 (the user writable bit).  */
		pte &= (~0x04000000);
		/*
		 * Flip bit 27 (the PG_SYSTEM bit) to become bit 27
		 * (the user readable bit).
		 */
		pte ^= (PG_SYSTEM);
		/*
		 * Always set bits 30 (the kernel readable bit) and
		 * bit 28, and set bit 26 (the user writable bit) iff
		 * bit 29 (the kernel writable bit) is set *and* bit
		 * 27 (the user readable bit) is set.  This latter bit
		 * of logic is expressed in the bizarre second term
		 * below, chosen because it needs no branches.
		 */
#if (PG_WRITE >> 2) != PG_SYSTEM
#error	"PG_WRITE and PG_SYSTEM definitions don't match!"
#endif
		pte |= 0x50000000
		    | ((((pte & PG_WRITE) >> 2) & pte) >> 1);
	}
	set_control_word(CONTROL_ADDR_BUILD(PGMAP_BASE, va), pte);
}

static int
sun2_get_segmap(vaddr_t va)
{
	va = CONTROL_ADDR_BUILD(SEGMAP_BASE, va);
	return (get_control_byte(va));
}

static void
sun2_set_segmap(vaddr_t va, int sme)
{
	va = CONTROL_ADDR_BUILD(SEGMAP_BASE, va);
	set_control_byte(va, sme);
}

/*
 * Copy the IDPROM contents into the passed buffer.
 * The caller (idprom.c) will do the checksum.
 */
void
sun2_getidprom(u_char *dst)
{
	vaddr_t src;	/* control space address */
	int len, x;

	src = IDPROM_BASE;
	len = sizeof(struct idprom);
	do {
		x = get_control_byte(src);
		src += NBPG;
		*dst++ = x;
	} while (--len > 0);
}

/*****************************************************************
 * Init our function pointers, etc.
 */

/*
 * For booting, the PROM in fredette's Sun 2/120 doesn't map
 * much main memory, and what is mapped is mapped strangely.
 * Low virtual memory is mapped like:
 *
 * 0x000000 - 0x0bffff virtual -> 0x000000 - 0x0bffff physical
 * 0x0c0000 - 0x0fffff virtual -> invalid
 * 0x100000 - 0x13ffff virtual -> 0x0c0000 - 0x0fffff physical
 * 0x200800 - 0x3fffff virtual -> 0x200800 - 0x3fffff physical
 *
 * I think the SunOS authors wanted to load kernels starting at
 * physical zero, and assumed that kernels would be less
 * than 768K (0x0c0000) long.  Also, the PROM maps physical
 * 0x0c0000 - 0x0fffff into DVMA space, so we can't take the
 * easy road and just add more mappings to use that physical
 * memory while loading (the PROM might do DMA there).
 *
 * What we do, then, is assume a 4MB machine (you'll really
 * need that to run NetBSD at all anyways), and we map two
 * chunks of physical and virtual space:
 *
 * 0x400000 - 0x4bffff virtual -> 0x000000 - 0x0bffff physical
 * 0x4c0000 - 0x600000 virtual -> 0x2c0000 - 0x3fffff physical
 *
 * And then we load starting at virtual 0x400000.  We will do
 * all of this mapping just by copying PMEGs.
 *
 * After the load is done, but before we enter the kernel, we're
 * done with the PROM, so we copy the part of the kernel that
 * got loaded at physical 0x2c0000 down to physical 0x0c0000.
 * This can't just be a PMEG copy; we've actually got to move
 * bytes in physical memory.
 *
 * These two chunks of physical and virtual space are defined
 * in macros below.  Some of the macros are only for completeness:
 */
#define MEM_CHUNK0_SIZE			(0x0c0000)
#define MEM_CHUNK0_LOAD_PHYS		(0x000000)
#define MEM_CHUNK0_LOAD_VIRT		(0x400000)
#define MEM_CHUNK0_LOAD_VIRT_PROM	MEM_CHUNK0_LOAD_PHYS
#define MEM_CHUNK0_COPY_PHYS		MEM_CHUNK0_LOAD_PHYS
#define MEM_CHUNK0_COPY_VIRT		MEM_CHUNK0_COPY_PHYS

#define MEM_CHUNK1_SIZE			(0x140000)
#define MEM_CHUNK1_LOAD_PHYS		(0x2c0000)
#define MEM_CHUNK1_LOAD_VIRT		(MEM_CHUNK0_LOAD_VIRT + MEM_CHUNK0_SIZE)
#define MEM_CHUNK1_LOAD_VIRT_PROM	MEM_CHUNK1_LOAD_PHYS
#define MEM_CHUNK1_COPY_PHYS		(MEM_CHUNK0_LOAD_PHYS + MEM_CHUNK0_SIZE)
#define MEM_CHUNK1_COPY_VIRT		MEM_CHUNK1_COPY_PHYS

/* Maps memory for loading. */
u_long
sun2_map_mem_load(void)
{
	vaddr_t off;

	/* Map chunk zero for loading. */
	for(off = 0; off < MEM_CHUNK0_SIZE; off += NBSG)
		sun2_set_segmap(MEM_CHUNK0_LOAD_VIRT + off,
			   sun2_get_segmap(MEM_CHUNK0_LOAD_VIRT_PROM + off));

	/* Map chunk one for loading. */
	for(off = 0; off < MEM_CHUNK1_SIZE; off += NBSG)
		sun2_set_segmap(MEM_CHUNK1_LOAD_VIRT + off,
			   sun2_get_segmap(MEM_CHUNK1_LOAD_VIRT_PROM + off));

	/* Tell our caller where in virtual space to load. */
	return MEM_CHUNK0_LOAD_VIRT;
}

/* Remaps memory for running. */
void *
sun2_map_mem_run(void *entry)
{
	vaddr_t off, off_end;
	int sme;
	u_int pte;

	/* Chunk zero is already mapped and copied. */

	/* Chunk one needs to be mapped and copied. */
	pte = (sun2_get_pte(0) & ~PG_FRAME);
	for(off = 0; off < MEM_CHUNK1_SIZE; ) {

		/*
		 * We use the PMEG immediately before the
		 * segment we're copying in the PROM virtual
		 * mapping of the chunk.  If this is the first
		 * segment, this is the PMEG the PROM used to
		 * map 0x2b8000 virtual to 0x2b8000 physical,
		 * which I'll assume is unused.  For the second
		 * and subsequent segments, this will be the
		 * PMEG used to map the previous segment, which
		 * is now (since we already copied it) unused.
		 */
		sme = sun2_get_segmap((MEM_CHUNK1_LOAD_VIRT_PROM + off) - NBSG);
		sun2_set_segmap(MEM_CHUNK1_COPY_VIRT + off, sme);

		/* Set the PTEs in this new PMEG. */
		for(off_end = off + NBSG; off < off_end; off += NBPG)
			sun2_set_pte(MEM_CHUNK1_COPY_VIRT + off,
				pte | PA_PGNUM(MEM_CHUNK1_COPY_PHYS + off));

		/* Copy this segment. */
		memcpy((void *)(MEM_CHUNK1_COPY_VIRT + (off - NBSG)),
		       (void *)(MEM_CHUNK1_LOAD_VIRT + (off - NBSG)),
		       NBSG);
	}

	/* Tell our caller where in virtual space to enter. */
	return ((char *)entry) - MEM_CHUNK0_LOAD_VIRT;
}

void
sun2_init(void)
{
	/* Set the function pointers. */
	dev_mapin_p   = dev2_mapin;
	dvma_alloc_p  = dvma2_alloc;
	dvma_free_p   = dvma2_free;
	dvma_mapin_p  = dvma2_mapin;
	dvma_mapout_p = dvma2_mapout;

	/* Prepare DVMA segment. */
	dvma2_init();
}