source: mainline/uspace/drv/bus/usb/uhci/utils/malloc32.h@ f9599b9c

/*
 * Copyright (c) 2010 Jan Vesely
 * 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 drvusbuhci
 * @{
 */
/** @file
 * @brief UHCI driver
 */
#ifndef DRV_UHCI_UTILS_MALLOC32_H
#define DRV_UHCI_UTILS_MALLOC32_H

#include <as.h>
#include <ddi.h>
#include <errno.h>
#include <malloc.h>
#include <sys/types.h>

#define UHCI_STRUCTURES_ALIGNMENT 16
#define UHCI_REQUIRED_PAGE_SIZE 4096


/** Get physical address translation
 *
 * @param[in] addr Virtual address to translate
 * @return Physical address if exists, NULL otherwise.
 */
static inline uintptr_t addr_to_phys(const void *addr)
{
        if (addr == NULL)
                return 0;

        uintptr_t result;
        const int ret = as_get_physical_mapping(addr, &result);
        if (ret != EOK)
                return 0;

        return result;
}

/** DMA malloc simulator
 *
 * @param[in] size Size of the required memory space
 * @return Address of the aligned and big enough memory place, NULL on failure.
 */
static inline void * malloc32(size_t size)
{
        /* This works only when the host has less than 4GB of memory as
         * physical address needs to fit into 32 bits */

        /* If we need more than one page there is no guarantee that the
         * memory will be continuous */
        if (size > PAGE_SIZE)
                return NULL;
        /* Calculate alignment to make sure the block won't cross page
         * boundary */
        size_t alignment = UHCI_STRUCTURES_ALIGNMENT;
        while (alignment < size)
                alignment *= 2;
        return memalign(alignment, size);
}

/** DMA malloc simulator
 *
 * @param[in] addr Address of the place allocated by malloc32
 */
static inline void free32(void *addr)
{
        free(addr);
}

/** Create 4KB page mapping
 *
 * @return Address of the mapped page, NULL on failure.
 */
static inline void *get_page(void)
{
        uintptr_t phys;
        void *address = AS_AREA_ANY;

        const int ret = dmamem_map_anonymous(UHCI_REQUIRED_PAGE_SIZE,
            DMAMEM_4GiB, AS_AREA_READ | AS_AREA_WRITE, 0, &phys,
            &address);

        return ((ret == EOK) ? address : NULL);
}

static inline void return_page(void *page)
{
        dmamem_unmap_anonymous(page);
}

#endif
/**
 * @}
 */