common/os/bp_map.c

	bp_map.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2005 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/sysmacros.h>
#include <sys/systm.h>
#include <sys/mman.h>
#include <sys/buf.h>
#include <sys/vmem.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/machparam.h>
#include <vm/page.h>
#include <vm/seg_kmem.h>

#ifdef __sparc
#include <sys/cpu_module.h>
#define BP_FLUSH(addr, size)    flush_instr_mem((void *)addr, size);
#else
#define BP_FLUSH(addr, size)
#endif

static vmem_t *bp_map_arena;
static size_t bp_align;
static uint_t bp_devload_flags = PROT_READ | PROT_WRITE | HAT_NOSYNC;
int bp_max_cache = 1 << 17;     /* 128K default; tunable */

static void *
bp_vmem_alloc(vmem_t *vmp, size_t size, int vmflag)
{
    return (vmem_xalloc(vmp, size, bp_align, 0, 0, NULL, NULL, vmflag));
}

void
bp_init(size_t align, uint_t devload_flags)
{
    bp_align = MAX(align, PAGESIZE);
    bp_devload_flags |= devload_flags;

    if (bp_align <= bp_max_cache)
        bp_map_arena = vmem_create("bp_map", NULL, 0, bp_align,
            bp_vmem_alloc, vmem_free, heap_arena,
            MIN(8 * bp_align, bp_max_cache), VM_SLEEP);
}

/*
 * common routine so can be called with/without VM_SLEEP
 */
void *
bp_mapin_common(struct buf *bp, int flag)
{
    struct as *as;
    pfn_t pfnum;
    page_t *pp = NULL;
    page_t **pplist = NULL;
    caddr_t kaddr;
    caddr_t addr = (caddr_t)bp->b_un.b_addr;
    uintptr_t off = (uintptr_t)addr & PAGEOFFSET;
    size_t size = P2ROUNDUP(bp->b_bcount + off, PAGESIZE);
    pgcnt_t npages = btop(size);
    int color;

    /* return if already mapped in, no pageio/physio, or physio to kas */
    if ((bp->b_flags & B_REMAPPED) ||
        !(bp->b_flags & (B_PAGEIO | B_PHYS)) ||
        (((bp->b_flags & (B_PAGEIO | B_PHYS)) == B_PHYS) &&
        ((bp->b_proc == NULL) || (bp->b_proc->p_as == &kas))))
        return (bp->b_un.b_addr);

    ASSERT((bp->b_flags & (B_PAGEIO | B_PHYS)) != (B_PAGEIO | B_PHYS));

    /*
     * Allocate kernel virtual space for remapping.
     */
    color = bp_color(bp);
    ASSERT(color < bp_align);

    if (bp_map_arena != NULL) {
        kaddr = (caddr_t)vmem_alloc(bp_map_arena,
            P2ROUNDUP(color + size, bp_align), flag);
        if (kaddr == NULL)
            return (NULL);
        kaddr += color;
    } else {
        kaddr = vmem_xalloc(heap_arena, size, bp_align, color,
            0, NULL, NULL, flag);
        if (kaddr == NULL)
            return (NULL);
    }

    ASSERT(P2PHASE((uintptr_t)kaddr, bp_align) == color);

    /*
     * Map bp into the virtual space we just allocated.
     */
    if (bp->b_flags & B_PAGEIO) {
        pp = bp->b_pages;
    } else if (bp->b_flags & B_SHADOW) {
        pplist = bp->b_shadow;
    } else {
        if (bp->b_proc == NULL || (as = bp->b_proc->p_as) == NULL)
            as = &kas;
    }

    bp->b_flags |= B_REMAPPED;
    bp->b_un.b_addr = kaddr + off;

    while (npages-- != 0) {
        if (pp) {
            pfnum = pp->p_pagenum;
            pp = pp->p_next;
        } else if (pplist == NULL) {
            if ((pfnum = hat_getpfnum(as->a_hat, addr - off)) ==
                PFN_INVALID)
                panic("bp_mapin_common: hat_getpfnum for"
                    " addr %p failed\n", (void *)addr);
            addr += PAGESIZE;
        } else {
            pfnum = (*pplist)->p_pagenum;
            pplist++;
        }

        hat_devload(kas.a_hat, kaddr, PAGESIZE, pfnum,
            bp_devload_flags, HAT_LOAD_LOCK);

        kaddr += PAGESIZE;
    }
    return (bp->b_un.b_addr);
}

/*
 * Convert bp for pageio/physio to a kernel addressable location.
 */
void
bp_mapin(struct buf *bp)
{
    (void) bp_mapin_common(bp, VM_SLEEP);
}

/*
 * Release all the resources associated with a previous bp_mapin() call.
 */
void
bp_mapout(struct buf *bp)
{
    if (bp->b_flags & B_REMAPPED) {
        uintptr_t addr = (uintptr_t)bp->b_un.b_addr;
        uintptr_t off = addr & PAGEOFFSET;
        uintptr_t base = addr - off;
        uintptr_t color = P2PHASE(base, bp_align);
        size_t size = P2ROUNDUP(bp->b_bcount + off, PAGESIZE);
        bp->b_un.b_addr = (caddr_t)off;     /* debugging aid */
        BP_FLUSH(base, size);
        hat_unload(kas.a_hat, (void *)base, size,
            HAT_UNLOAD_NOSYNC | HAT_UNLOAD_UNLOCK);
        if (bp_map_arena != NULL)
            vmem_free(bp_map_arena, (void *)(base - color),
                P2ROUNDUP(color + size, bp_align));
        else
            vmem_free(heap_arena, (void *)base, size);
        bp->b_flags &= ~B_REMAPPED;
    }
}