source: mainline/uspace/lib/usb/src/usbmem.c@ 62066b4

/*
 * Copyright (c) 2011 Matus Dekanek
 * 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.
 */

/** @addtogroup libc
 * @{
 */
/** @file implementation of special memory management, used mostly in usb stack
 */

#include <adt/hash_table.h>
#include <adt/list.h>
#include <as.h>
#include <errno.h>
#include <malloc.h>

#include "usb/usbmem.h"

#define ADDR_BUCKETS 1537

//address translation tables
static hash_table_t * pa2va_table = NULL;
static hash_table_t * va2pa_table = NULL;

/**
 * address translation hashtable item
 */
typedef struct{
        unsigned long addr;
        unsigned long translation;
        link_t link;

}addr_node_t;

static hash_index_t addr_hash(unsigned long key[])
{
        return (3*key[0]<<4) % ADDR_BUCKETS;
}

static int addr_compare(unsigned long key[], hash_count_t keys,
    link_t *item)
{
        addr_node_t *addr_node = hash_table_get_instance(item, addr_node_t, link);
        return (addr_node->addr == key[0]);
}

static void addr_remove_callback(link_t * item)
{
        //delete item
        addr_node_t *addr_node = hash_table_get_instance(item, addr_node_t, link);
        free(addr_node);
}


static hash_table_operations_t addr_devices_ops = {
        .hash = addr_hash,
        .compare = addr_compare,
        .remove_callback = addr_remove_callback
};

/**
 * create node for address translation hashtable
 * @param addr
 * @param translation
 * @return
 */
static addr_node_t * create_addr_node(void * addr, void * translation){
        addr_node_t * node = (addr_node_t*)malloc(sizeof(addr_node_t));
        node->addr = (unsigned long)addr;
        node->translation = (unsigned long)translation;
        return node;
}

/**
 * allocate size on heap and register it`s pa<->va translation
 *
 * If physical address + size is 2GB or higher, nothing is allocated and NULL
 * is returned.
 * @param size
 * @param alignment
 * @return
 */
void * mman_malloc(
        size_t size,
        size_t alignment,
        unsigned long max_physical_address)
{
        if (size == 0)
                return NULL;
        if (alignment == 0)
                return NULL;
        //check if tables were initialized
        if(!pa2va_table){
                pa2va_table = (hash_table_t*)malloc(sizeof(hash_table_t*));
                va2pa_table = (hash_table_t*)malloc(sizeof(hash_table_t*));
                hash_table_create(pa2va_table, ADDR_BUCKETS, 1,
                    &addr_devices_ops);
                hash_table_create(va2pa_table, ADDR_BUCKETS, 1,
                    &addr_devices_ops);
        }
        //allocate
        void * vaddr = memalign(alignment, size);
        
        //get translation
        void * paddr = NULL;
        int opResult = as_get_physical_mapping(vaddr,(uintptr_t*)&paddr);
        if(opResult != EOK){
                //something went wrong
                free(vaddr);
                return NULL;
        }
        if((unsigned long)paddr + size > max_physical_address){
                //unusable address for usb
                free(vaddr);
                return NULL;
        }
        //store translation
        addr_node_t * pa2vaNode = create_addr_node(paddr,vaddr);
        addr_node_t * va2paNode = create_addr_node(vaddr,paddr);

        unsigned long keypaddr = (unsigned long)paddr;
        unsigned long keyvaddr = (unsigned long)vaddr;
        hash_table_insert(pa2va_table, (&keypaddr), &pa2vaNode->link);
        hash_table_insert(va2pa_table, (&keyvaddr), &va2paNode->link);
        //return
        return vaddr;

}

/**
 * get virtual address from physical
 * @param addr
 * @return translated virtual address or null
 */
void * mman_getVA(void * addr){
        unsigned long keypaddr = (unsigned long)addr;
        link_t * link = hash_table_find(pa2va_table, &keypaddr);
        if(!link) return NULL;
        addr_node_t * node = hash_table_get_instance(link, addr_node_t, link);
        return (void*)node->translation;
}

/**
 * get physical address from virtual
 * @param addr
 * @return physical address or null
 */
void * mman_getPA(void * addr){
        unsigned long keyvaddr = (unsigned long)addr;
        link_t * link = hash_table_find(va2pa_table, &keyvaddr);
        if(!link) return NULL;
        addr_node_t * node = hash_table_get_instance(link, addr_node_t, link);
        return (void*)node->translation;
}

/**
 * free the address and deregister it from pa<->va translation
 * @param vaddr if NULL, nothing happens
 */
void mman_free(void * vaddr){
        if(!vaddr)
                return;
        //get paddress
        void * paddr = mman_getPA(vaddr);
        unsigned long keypaddr = (unsigned long)paddr;
        unsigned long keyvaddr = (unsigned long)vaddr;
        //remove mapping
        hash_table_remove(pa2va_table,&keypaddr, 1);
        hash_table_remove(va2pa_table,&keyvaddr, 1);
        //free address
        free(vaddr);
}



/** @}
 */