drv.c

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/*
 * drv.c
 *
 * DSP-BIOS Bridge driver support functions for TI OMAP processors.
 *
 * DSP/BIOS Bridge resource allocation module.
 *
 * Copyright (C) 2005-2006 Texas Instruments, Inc.
 *
 * This package is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
#include <linux/types.h>
#include <linux/list.h>

/*  ----------------------------------- Host OS */
#include <dspbridge/host_os.h>

/*  ----------------------------------- DSP/BIOS Bridge */
#include <dspbridge/dbdefs.h>

/*  ----------------------------------- This */
#include <dspbridge/drv.h>
#include <dspbridge/dev.h>

#include <dspbridge/node.h>
#include <dspbridge/proc.h>
#include <dspbridge/strm.h>
#include <dspbridge/nodepriv.h>
#include <dspbridge/dspchnl.h>
#include <dspbridge/resourcecleanup.h>

/*  ----------------------------------- Defines, Data Structures, Typedefs */
struct drv_object {
    struct list_head dev_list;
    struct list_head dev_node_string;
};

/*
 *  This is the Device Extension. Named with the Prefix
 *  DRV_ since it is living in this module
 */
struct drv_ext {
    struct list_head link;
    char sz_string[MAXREGPATHLENGTH];
};

/*  ----------------------------------- Globals */
static bool ext_phys_mem_pool_enabled;
struct ext_phys_mem_pool {
    u32 phys_mem_base;
    u32 phys_mem_size;
    u32 virt_mem_base;
    u32 next_phys_alloc_ptr;
};
static struct ext_phys_mem_pool ext_mem_pool;

/*  ----------------------------------- Function Prototypes */
static int request_bridge_resources(struct cfg_hostres *res);


/* GPP PROCESS CLEANUP CODE */

static int drv_proc_free_node_res(int id, void *p, void *data);

/* Allocate and add a node resource element
* This function is called from .Node_Allocate. */
int drv_insert_node_res_element(void *hnode, void *node_resource,
                       void *process_ctxt)
{
    struct node_res_object **node_res_obj =
        (struct node_res_object **)node_resource;
    struct process_context *ctxt = (struct process_context *)process_ctxt;
    int status = 0;
    int retval;

    *node_res_obj = kzalloc(sizeof(struct node_res_object), GFP_KERNEL);
    if (!*node_res_obj) {
        status = -ENOMEM;
        goto func_end;
    }

    (*node_res_obj)->node = hnode;
    retval = idr_get_new(ctxt->node_id, *node_res_obj,
                        &(*node_res_obj)->id);
    if (retval == -EAGAIN) {
        if (!idr_pre_get(ctxt->node_id, GFP_KERNEL)) {
            pr_err("%s: OUT OF MEMORY\n", __func__);
            status = -ENOMEM;
            goto func_end;
        }

        retval = idr_get_new(ctxt->node_id, *node_res_obj,
                        &(*node_res_obj)->id);
    }
    if (retval) {
        pr_err("%s: FAILED, IDR is FULL\n", __func__);
        status = -EFAULT;
    }
func_end:
    if (status)
        kfree(*node_res_obj);

    return status;
}

/* Release all Node resources and its context
 * Actual Node De-Allocation */
static int drv_proc_free_node_res(int id, void *p, void *data)
{
    struct process_context *ctxt = data;
    int status;
    struct node_res_object *node_res_obj = p;
    u32 node_state;

    if (node_res_obj->node_allocated) {
        node_state = node_get_state(node_res_obj->node);
        if (node_state <= NODE_DELETING) {
            if ((node_state == NODE_RUNNING) ||
                (node_state == NODE_PAUSED) ||
                (node_state == NODE_TERMINATING))
                node_terminate
                    (node_res_obj->node, &status);

            node_delete(node_res_obj, ctxt);
        }
    }

    return 0;
}

/* Release all Mapped and Reserved DMM resources */
int drv_remove_all_dmm_res_elements(void *process_ctxt)
{
    struct process_context *ctxt = (struct process_context *)process_ctxt;
    int status = 0;
    struct dmm_map_object *temp_map, *map_obj;
    struct dmm_rsv_object *temp_rsv, *rsv_obj;

    /* Free DMM mapped memory resources */
    list_for_each_entry_safe(map_obj, temp_map, &ctxt->dmm_map_list, link) {
        status = proc_un_map(ctxt->processor,
                     (void *)map_obj->dsp_addr, ctxt);
        if (status)
            pr_err("%s: proc_un_map failed!"
                   " status = 0x%xn", __func__, status);
    }

    /* Free DMM reserved memory resources */
    list_for_each_entry_safe(rsv_obj, temp_rsv, &ctxt->dmm_rsv_list, link) {
        status = proc_un_reserve_memory(ctxt->processor, (void *)
                        rsv_obj->dsp_reserved_addr,
                        ctxt);
        if (status)
            pr_err("%s: proc_un_reserve_memory failed!"
                   " status = 0x%xn", __func__, status);
    }
    return status;
}

/* Update Node allocation status */
void drv_proc_node_update_status(void *node_resource, s32 status)
{
    struct node_res_object *node_res_obj =
        (struct node_res_object *)node_resource;
    node_res_obj->node_allocated = status;
}

/* Update Node Heap status */
void drv_proc_node_update_heap_status(void *node_resource, s32 status)
{
    struct node_res_object *node_res_obj =
        (struct node_res_object *)node_resource;
    node_res_obj->heap_allocated = status;
}

/* Release all Node resources and its context
* This is called from .bridge_release.
 */
int drv_remove_all_node_res_elements(void *process_ctxt)
{
    struct process_context *ctxt = process_ctxt;

    idr_for_each(ctxt->node_id, drv_proc_free_node_res, ctxt);
    idr_destroy(ctxt->node_id);

    return 0;
}

/* Allocate the STRM resource element
* This is called after the actual resource is allocated
 */
int drv_proc_insert_strm_res_element(void *stream_obj,
                        void *strm_res, void *process_ctxt)
{
    struct strm_res_object **pstrm_res =
        (struct strm_res_object **)strm_res;
    struct process_context *ctxt = (struct process_context *)process_ctxt;
    int status = 0;
    int retval;

    *pstrm_res = kzalloc(sizeof(struct strm_res_object), GFP_KERNEL);
    if (*pstrm_res == NULL) {
        status = -EFAULT;
        goto func_end;
    }

    (*pstrm_res)->stream = stream_obj;
    retval = idr_get_new(ctxt->stream_id, *pstrm_res,
                        &(*pstrm_res)->id);
    if (retval == -EAGAIN) {
        if (!idr_pre_get(ctxt->stream_id, GFP_KERNEL)) {
            pr_err("%s: OUT OF MEMORY\n", __func__);
            status = -ENOMEM;
            goto func_end;
        }

        retval = idr_get_new(ctxt->stream_id, *pstrm_res,
                        &(*pstrm_res)->id);
    }
    if (retval) {
        pr_err("%s: FAILED, IDR is FULL\n", __func__);
        status = -EPERM;
    }

func_end:
    return status;
}

static int drv_proc_free_strm_res(int id, void *p, void *process_ctxt)
{
    struct process_context *ctxt = process_ctxt;
    struct strm_res_object *strm_res = p;
    struct stream_info strm_info;
    struct dsp_streaminfo user;
    u8 **ap_buffer = NULL;
    u8 *buf_ptr;
    u32 ul_bytes;
    u32 dw_arg;
    s32 ul_buf_size;

    if (strm_res->num_bufs) {
        ap_buffer = kmalloc((strm_res->num_bufs *
                       sizeof(u8 *)), GFP_KERNEL);
        if (ap_buffer) {
            strm_free_buffer(strm_res,
                          ap_buffer,
                          strm_res->num_bufs,
                          ctxt);
            kfree(ap_buffer);
        }
    }
    strm_info.user_strm = &user;
    user.number_bufs_in_stream = 0;
    strm_get_info(strm_res->stream, &strm_info, sizeof(strm_info));
    while (user.number_bufs_in_stream--)
        strm_reclaim(strm_res->stream, &buf_ptr, &ul_bytes,
                 (u32 *) &ul_buf_size, &dw_arg);
    strm_close(strm_res, ctxt);
    return 0;
}

/* Release all Stream resources and its context
* This is called from .bridge_release.
 */
int drv_remove_all_strm_res_elements(void *process_ctxt)
{
    struct process_context *ctxt = process_ctxt;

    idr_for_each(ctxt->stream_id, drv_proc_free_strm_res, ctxt);
    idr_destroy(ctxt->stream_id);

    return 0;
}

/* Updating the stream resource element */
int drv_proc_update_strm_res(u32 num_bufs, void *strm_resources)
{
    int status = 0;
    struct strm_res_object **strm_res =
        (struct strm_res_object **)strm_resources;

    (*strm_res)->num_bufs = num_bufs;
    return status;
}

/* GPP PROCESS CLEANUP CODE END */

/*
 *  ======== = drv_create ======== =
 *  Purpose:
 *      DRV Object gets created only once during Driver Loading.
 */
int drv_create(struct drv_object **drv_obj)
{
    int status = 0;
    struct drv_object *pdrv_object = NULL;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    pdrv_object = kzalloc(sizeof(struct drv_object), GFP_KERNEL);
    if (pdrv_object) {
        /* Create and Initialize List of device objects */
        INIT_LIST_HEAD(&pdrv_object->dev_list);
        INIT_LIST_HEAD(&pdrv_object->dev_node_string);
    } else {
        status = -ENOMEM;
    }
    /* Store the DRV Object in the driver data */
    if (!status) {
        if (drv_datap) {
            drv_datap->drv_object = (void *)pdrv_object;
        } else {
            status = -EPERM;
            pr_err("%s: Failed to store DRV object\n", __func__);
        }
    }

    if (!status) {
        *drv_obj = pdrv_object;
    } else {
        /* Free the DRV Object */
        kfree(pdrv_object);
    }

    return status;
}

/*
 *  ======== = drv_destroy ======== =
 *  purpose:
 *      Invoked during bridge de-initialization
 */
int drv_destroy(struct drv_object *driver_obj)
{
    int status = 0;
    struct drv_object *pdrv_object = (struct drv_object *)driver_obj;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    kfree(pdrv_object);
    /* Update the DRV Object in the driver data */
    if (drv_datap) {
        drv_datap->drv_object = NULL;
    } else {
        status = -EPERM;
        pr_err("%s: Failed to store DRV object\n", __func__);
    }

    return status;
}

/*
 *  ======== drv_get_dev_object ========
 *  Purpose:
 *      Given a index, returns a handle to DevObject from the list.
 */
int drv_get_dev_object(u32 index, struct drv_object *hdrv_obj,
                  struct dev_object **device_obj)
{
    int status = 0;
    struct dev_object *dev_obj;
    u32 i;

    dev_obj = (struct dev_object *)drv_get_first_dev_object();
    for (i = 0; i < index; i++) {
        dev_obj =
            (struct dev_object *)drv_get_next_dev_object((u32) dev_obj);
    }
    if (dev_obj) {
        *device_obj = (struct dev_object *)dev_obj;
    } else {
        *device_obj = NULL;
        status = -EPERM;
    }

    return status;
}

/*
 *  ======== drv_get_first_dev_object ========
 *  Purpose:
 *      Retrieve the first Device Object handle from an internal linked list of
 *      of DEV_OBJECTs maintained by DRV.
 */
u32 drv_get_first_dev_object(void)
{
    u32 dw_dev_object = 0;
    struct drv_object *pdrv_obj;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    if (drv_datap && drv_datap->drv_object) {
        pdrv_obj = drv_datap->drv_object;
        if (!list_empty(&pdrv_obj->dev_list))
            dw_dev_object = (u32) pdrv_obj->dev_list.next;
    } else {
        pr_err("%s: Failed to retrieve the object handle\n", __func__);
    }

    return dw_dev_object;
}

/*
 *  ======== DRV_GetFirstDevNodeString ========
 *  Purpose:
 *      Retrieve the first Device Extension from an internal linked list of
 *      of Pointer to dev_node Strings maintained by DRV.
 */
u32 drv_get_first_dev_extension(void)
{
    u32 dw_dev_extension = 0;
    struct drv_object *pdrv_obj;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    if (drv_datap && drv_datap->drv_object) {
        pdrv_obj = drv_datap->drv_object;
        if (!list_empty(&pdrv_obj->dev_node_string)) {
            dw_dev_extension =
                (u32) pdrv_obj->dev_node_string.next;
        }
    } else {
        pr_err("%s: Failed to retrieve the object handle\n", __func__);
    }

    return dw_dev_extension;
}

/*
 *  ======== drv_get_next_dev_object ========
 *  Purpose:
 *      Retrieve the next Device Object handle from an internal linked list of
 *      of DEV_OBJECTs maintained by DRV, after having previously called
 *      drv_get_first_dev_object() and zero or more DRV_GetNext.
 */
u32 drv_get_next_dev_object(u32 hdev_obj)
{
    u32 dw_next_dev_object = 0;
    struct drv_object *pdrv_obj;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);
    struct list_head *curr;

    if (drv_datap && drv_datap->drv_object) {
        pdrv_obj = drv_datap->drv_object;
        if (!list_empty(&pdrv_obj->dev_list)) {
            curr = (struct list_head *)hdev_obj;
            if (list_is_last(curr, &pdrv_obj->dev_list))
                return 0;
            dw_next_dev_object = (u32) curr->next;
        }
    } else {
        pr_err("%s: Failed to retrieve the object handle\n", __func__);
    }

    return dw_next_dev_object;
}

/*
 *  ======== drv_get_next_dev_extension ========
 *  Purpose:
 *      Retrieve the next Device Extension from an internal linked list of
 *      of pointer to DevNodeString maintained by DRV, after having previously
 *      called drv_get_first_dev_extension() and zero or more
 *      drv_get_next_dev_extension().
 */
u32 drv_get_next_dev_extension(u32 dev_extension)
{
    u32 dw_dev_extension = 0;
    struct drv_object *pdrv_obj;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);
    struct list_head *curr;

    if (drv_datap && drv_datap->drv_object) {
        pdrv_obj = drv_datap->drv_object;
        if (!list_empty(&pdrv_obj->dev_node_string)) {
            curr = (struct list_head *)dev_extension;
            if (list_is_last(curr, &pdrv_obj->dev_node_string))
                return 0;
            dw_dev_extension = (u32) curr->next;
        }
    } else {
        pr_err("%s: Failed to retrieve the object handle\n", __func__);
    }

    return dw_dev_extension;
}

/*
 *  ======== drv_insert_dev_object ========
 *  Purpose:
 *      Insert a DevObject into the list of Manager object.
 */
int drv_insert_dev_object(struct drv_object *driver_obj,
                 struct dev_object *hdev_obj)
{
    struct drv_object *pdrv_object = (struct drv_object *)driver_obj;

    list_add_tail((struct list_head *)hdev_obj, &pdrv_object->dev_list);

    return 0;
}

/*
 *  ======== drv_remove_dev_object ========
 *  Purpose:
 *      Search for and remove a DeviceObject from the given list of DRV
 *      objects.
 */
int drv_remove_dev_object(struct drv_object *driver_obj,
                 struct dev_object *hdev_obj)
{
    int status = -EPERM;
    struct drv_object *pdrv_object = (struct drv_object *)driver_obj;
    struct list_head *cur_elem;

    /* Search list for p_proc_object: */
    list_for_each(cur_elem, &pdrv_object->dev_list) {
        /* If found, remove it. */
        if ((struct dev_object *)cur_elem == hdev_obj) {
            list_del(cur_elem);
            status = 0;
            break;
        }
    }

    return status;
}

/*
 *  ======== drv_request_resources ========
 *  Purpose:
 *      Requests  resources from the OS.
 */
int drv_request_resources(u32 dw_context, u32 *dev_node_strg)
{
    int status = 0;
    struct drv_object *pdrv_object;
    struct drv_ext *pszdev_node;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    /*
     *  Allocate memory to hold the string. This will live until
     *  it is freed in the Release resources. Update the driver object
     *  list.
     */

    if (!drv_datap || !drv_datap->drv_object)
        status = -ENODATA;
    else
        pdrv_object = drv_datap->drv_object;

    if (!status) {
        pszdev_node = kzalloc(sizeof(struct drv_ext), GFP_KERNEL);
        if (pszdev_node) {
            strncpy(pszdev_node->sz_string,
                (char *)dw_context, MAXREGPATHLENGTH - 1);
            pszdev_node->sz_string[MAXREGPATHLENGTH - 1] = '\0';
            /* Update the Driver Object List */
            *dev_node_strg = (u32) pszdev_node->sz_string;
            list_add_tail(&pszdev_node->link,
                    &pdrv_object->dev_node_string);
        } else {
            status = -ENOMEM;
            *dev_node_strg = 0;
        }
    } else {
        dev_dbg(bridge, "%s: Failed to get Driver Object from Registry",
            __func__);
        *dev_node_strg = 0;
    }

    return status;
}

/*
 *  ======== drv_release_resources ========
 *  Purpose:
 *      Releases  resources from the OS.
 */
int drv_release_resources(u32 dw_context, struct drv_object *hdrv_obj)
{
    int status = 0;
    struct drv_ext *pszdev_node;

    /*
     *  Irrespective of the status go ahead and clean it
     *  The following will over write the status.
     */
    for (pszdev_node = (struct drv_ext *)drv_get_first_dev_extension();
         pszdev_node != NULL; pszdev_node = (struct drv_ext *)
         drv_get_next_dev_extension((u32) pszdev_node)) {
        if ((u32) pszdev_node == dw_context) {
            /* Found it */
            /* Delete from the Driver object list */
            list_del(&pszdev_node->link);
            kfree(pszdev_node);
            break;
        }
    }
    return status;
}

/*
 *  ======== request_bridge_resources ========
 *  Purpose:
 *      Reserves shared memory for bridge.
 */
static int request_bridge_resources(struct cfg_hostres *res)
{
    struct cfg_hostres *host_res = res;

    /* num_mem_windows must not be more than CFG_MAXMEMREGISTERS */
    host_res->num_mem_windows = 2;

    /* First window is for DSP internal memory */
    dev_dbg(bridge, "mem_base[0] 0x%x\n", host_res->mem_base[0]);
    dev_dbg(bridge, "mem_base[3] 0x%x\n", host_res->mem_base[3]);
    dev_dbg(bridge, "dmmu_base %p\n", host_res->dmmu_base);

    /* for 24xx base port is not mapping the mamory for DSP
     * internal memory TODO Do a ioremap here */
    /* Second window is for DSP external memory shared with MPU */

    /* These are hard-coded values */
    host_res->birq_registers = 0;
    host_res->birq_attrib = 0;
    host_res->offset_for_monitor = 0;
    host_res->chnl_offset = 0;
    /* CHNL_MAXCHANNELS */
    host_res->num_chnls = CHNL_MAXCHANNELS;
    host_res->chnl_buf_size = 0x400;

    return 0;
}

/*
 *  ======== drv_request_bridge_res_dsp ========
 *  Purpose:
 *      Reserves shared memory for bridge.
 */
int drv_request_bridge_res_dsp(void **phost_resources)
{
    int status = 0;
    struct cfg_hostres *host_res;
    u32 dw_buff_size;
    u32 dma_addr;
    u32 shm_size;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    dw_buff_size = sizeof(struct cfg_hostres);

    host_res = kzalloc(dw_buff_size, GFP_KERNEL);

    if (host_res != NULL) {
        request_bridge_resources(host_res);
        /* num_mem_windows must not be more than CFG_MAXMEMREGISTERS */
        host_res->num_mem_windows = 4;

        host_res->mem_base[0] = 0;
        host_res->mem_base[2] = (u32) ioremap(OMAP_DSP_MEM1_BASE,
                             OMAP_DSP_MEM1_SIZE);
        host_res->mem_base[3] = (u32) ioremap(OMAP_DSP_MEM2_BASE,
                             OMAP_DSP_MEM2_SIZE);
        host_res->mem_base[4] = (u32) ioremap(OMAP_DSP_MEM3_BASE,
                             OMAP_DSP_MEM3_SIZE);
        host_res->per_base = ioremap(OMAP_PER_CM_BASE,
                        OMAP_PER_CM_SIZE);
        host_res->per_pm_base = ioremap(OMAP_PER_PRM_BASE,
                        OMAP_PER_PRM_SIZE);
        host_res->core_pm_base = ioremap(OMAP_CORE_PRM_BASE,
                            OMAP_CORE_PRM_SIZE);
        host_res->dmmu_base = ioremap(OMAP_DMMU_BASE,
                         OMAP_DMMU_SIZE);

        dev_dbg(bridge, "mem_base[0] 0x%x\n",
            host_res->mem_base[0]);
        dev_dbg(bridge, "mem_base[1] 0x%x\n",
            host_res->mem_base[1]);
        dev_dbg(bridge, "mem_base[2] 0x%x\n",
            host_res->mem_base[2]);
        dev_dbg(bridge, "mem_base[3] 0x%x\n",
            host_res->mem_base[3]);
        dev_dbg(bridge, "mem_base[4] 0x%x\n",
            host_res->mem_base[4]);
        dev_dbg(bridge, "dmmu_base %p\n", host_res->dmmu_base);

        shm_size = drv_datap->shm_size;
        if (shm_size >= 0x10000) {
            /* Allocate Physically contiguous,
             * non-cacheable  memory */
            host_res->mem_base[1] =
                (u32) mem_alloc_phys_mem(shm_size, 0x100000,
                             &dma_addr);
            if (host_res->mem_base[1] == 0) {
                status = -ENOMEM;
                pr_err("shm reservation Failed\n");
            } else {
                host_res->mem_length[1] = shm_size;
                host_res->mem_phys[1] = dma_addr;

                dev_dbg(bridge, "%s: Bridge shm address 0x%x "
                    "dma_addr %x size %x\n", __func__,
                    host_res->mem_base[1],
                    dma_addr, shm_size);
            }
        }
        if (!status) {
            /* These are hard-coded values */
            host_res->birq_registers = 0;
            host_res->birq_attrib = 0;
            host_res->offset_for_monitor = 0;
            host_res->chnl_offset = 0;
            /* CHNL_MAXCHANNELS */
            host_res->num_chnls = CHNL_MAXCHANNELS;
            host_res->chnl_buf_size = 0x400;
            dw_buff_size = sizeof(struct cfg_hostres);
        }
        *phost_resources = host_res;
    }
    /* End Mem alloc */
    return status;
}

void mem_ext_phys_pool_init(u32 pool_phys_base, u32 pool_size)
{
    u32 pool_virt_base;

    /* get the virtual address for the physical memory pool passed */
    pool_virt_base = (u32) ioremap(pool_phys_base, pool_size);

    if ((void **)pool_virt_base == NULL) {
        pr_err("%s: external physical memory map failed\n", __func__);
        ext_phys_mem_pool_enabled = false;
    } else {
        ext_mem_pool.phys_mem_base = pool_phys_base;
        ext_mem_pool.phys_mem_size = pool_size;
        ext_mem_pool.virt_mem_base = pool_virt_base;
        ext_mem_pool.next_phys_alloc_ptr = pool_phys_base;
        ext_phys_mem_pool_enabled = true;
    }
}

void mem_ext_phys_pool_release(void)
{
    if (ext_phys_mem_pool_enabled) {
        iounmap((void *)(ext_mem_pool.virt_mem_base));
        ext_phys_mem_pool_enabled = false;
    }
}

/*
 *  ======== mem_ext_phys_mem_alloc ========
 *  Purpose:
 *     Allocate physically contiguous, uncached memory from external memory pool
 */

static void *mem_ext_phys_mem_alloc(u32 bytes, u32 align, u32 * phys_addr)
{
    u32 new_alloc_ptr;
    u32 offset;
    u32 virt_addr;

    if (align == 0)
        align = 1;

    if (bytes > ((ext_mem_pool.phys_mem_base + ext_mem_pool.phys_mem_size)
             - ext_mem_pool.next_phys_alloc_ptr)) {
        phys_addr = NULL;
        return NULL;
    } else {
        offset = (ext_mem_pool.next_phys_alloc_ptr & (align - 1));
        if (offset == 0)
            new_alloc_ptr = ext_mem_pool.next_phys_alloc_ptr;
        else
            new_alloc_ptr = (ext_mem_pool.next_phys_alloc_ptr) +
                (align - offset);
        if ((new_alloc_ptr + bytes) <=
            (ext_mem_pool.phys_mem_base + ext_mem_pool.phys_mem_size)) {
            /* we can allocate */
            *phys_addr = new_alloc_ptr;
            ext_mem_pool.next_phys_alloc_ptr =
                new_alloc_ptr + bytes;
            virt_addr =
                ext_mem_pool.virt_mem_base + (new_alloc_ptr -
                              ext_mem_pool.
                              phys_mem_base);
            return (void *)virt_addr;
        } else {
            *phys_addr = 0;
            return NULL;
        }
    }
}

/*
 *  ======== mem_alloc_phys_mem ========
 *  Purpose:
 *      Allocate physically contiguous, uncached memory
 */
void *mem_alloc_phys_mem(u32 byte_size, u32 align_mask,
                u32 *physical_address)
{
    void *va_mem = NULL;
    dma_addr_t pa_mem;

    if (byte_size > 0) {
        if (ext_phys_mem_pool_enabled) {
            va_mem = mem_ext_phys_mem_alloc(byte_size, align_mask,
                            (u32 *) &pa_mem);
        } else
            va_mem = dma_alloc_coherent(NULL, byte_size, &pa_mem,
                                GFP_KERNEL);
        if (va_mem == NULL)
            *physical_address = 0;
        else
            *physical_address = pa_mem;
    }
    return va_mem;
}

/*
 *  ======== mem_free_phys_mem ========
 *  Purpose:
 *      Free the given block of physically contiguous memory.
 */
void mem_free_phys_mem(void *virtual_address, u32 physical_address,
               u32 byte_size)
{
    if (!ext_phys_mem_pool_enabled)
        dma_free_coherent(NULL, byte_size, virtual_address,
                  physical_address);
}