page.c

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/*
 * Copyright (C) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#include <arch/mm/page.h>
#include <genarch/mm/page_pt.h>
#include <arch/mm/frame.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <mm/as.h>
#include <arch/types.h>
#include <align.h>
#include <config.h>
#include <func.h>
#include <arch/interrupt.h>
#include <arch/asm.h>
#include <debug.h>
#include <memstr.h>
#include <print.h>
#include <interrupt.h>

void page_arch_init(void)
{
        __address cur;
        int flags;

        if (config.cpu_active == 1) {
                page_mapping_operations = &pt_mapping_operations;
        
                /*
                 * PA2KA(identity) mapping for all frames until last_frame.
                 */
                for (cur = 0; cur < last_frame; cur += FRAME_SIZE) {
                        flags = PAGE_CACHEABLE;
                        if ((PA2KA(cur) >= config.base) && (PA2KA(cur) < config.base + config.kernel_size))
                                flags |= PAGE_GLOBAL;
                        page_mapping_insert(AS_KERNEL, PA2KA(cur), cur, flags);
                }

                exc_register(14, "page_fault", (iroutine) page_fault);
                write_cr3((__address) AS_KERNEL->page_table);
        }
        else {
                write_cr3((__address) AS_KERNEL->page_table);
        }

        paging_on();
}


__address hw_map(__address physaddr, size_t size)
{
        if (last_frame + ALIGN_UP(size, PAGE_SIZE) > KA2PA(KERNEL_ADDRESS_SPACE_END_ARCH))
                panic("Unable to map physical memory %p (%d bytes)", physaddr, size)
        
        __address virtaddr = PA2KA(last_frame);
        pfn_t i;
        for (i = 0; i < ADDR2PFN(ALIGN_UP(size, PAGE_SIZE)); i++)
                page_mapping_insert(AS_KERNEL, virtaddr + PFN2ADDR(i), physaddr + PFN2ADDR(i), PAGE_NOT_CACHEABLE);
        
        last_frame = ALIGN_UP(last_frame + size, FRAME_SIZE);
        
        return virtaddr;
}

void page_fault(int n, istate_t *istate)
{
        __address page;
        pf_access_t access;
        
        page = read_cr2();
                
        if (istate->error_word & PFERR_CODE_RSVD)
                panic("Reserved bit set in page directory.\n");

        if (istate->error_word & PFERR_CODE_RW)
                access = PF_ACCESS_WRITE;
        else
                access = PF_ACCESS_READ;

        if (as_page_fault(page, access, istate) == AS_PF_FAULT) {
                fault_if_from_uspace(istate, "Page fault: %#x", page);

                PRINT_INFO_ERRCODE(istate);
                printf("page fault address: %#x\n", page);
                panic("page fault\n");
        }
}

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