/*
 * cmm.c
 *
 * DSP-BIOS Bridge driver support functions for TI OMAP processors.
 *
 * The Communication(Shared) Memory Management(CMM) module provides
 * shared memory management services for DSP/BIOS Bridge data streaming
 * and messaging.
 *
 * Multiple shared memory segments can be registered with CMM.
 * Each registered SM segment is represented by a SM "allocator" that
 * describes a block of physically contiguous shared memory used for
 * future allocations by CMM.
 *
 * Memory is coalesced back to the appropriate heap when a buffer is
 * freed.
 *
 * Notes:
 *   Va: Virtual address.
 *   Pa: Physical or kernel system address.
 *
 * 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>

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

/*  ----------------------------------- Trace & Debug */
#include <dspbridge/dbc.h>

/*  ----------------------------------- OS Adaptation Layer */
#include <dspbridge/sync.h>

/*  ----------------------------------- Platform Manager */
#include <dspbridge/dev.h>
#include <dspbridge/proc.h>

/*  ----------------------------------- This */
#include <dspbridge/cmm.h>

/*  ----------------------------------- Defines, Data Structures, Typedefs */
#define NEXT_PA(pnode)   (pnode->pa + pnode->size)

/* Other bus/platform translations */
#define DSPPA2GPPPA(base, x, y)  ((x)+(y))
#define GPPPA2DSPPA(base, x, y)  ((x)-(y))

/*
 *  Allocators define a block of contiguous memory used for future allocations.
 *
 *      sma - shared memory allocator.
 *      vma - virtual memory allocator.(not used).
 */
struct cmm_allocator {          /* sma */
        unsigned int shm_base;  /* Start of physical SM block */
        u32 sm_size;            /* Size of SM block in bytes */
        unsigned int vm_base;   /* Start of VM block. (Dev driver
                                         * context for 'sma') */
        u32 dsp_phys_addr_offset;       /* DSP PA to GPP PA offset for this
                                         * SM space */
        s8 c_factor;            /* DSPPa to GPPPa Conversion Factor */
        unsigned int dsp_base;  /* DSP virt base byte address */
        u32 dsp_size;   /* DSP seg size in bytes */
        struct cmm_object *cmm_mgr;     /* back ref to parent mgr */
        /* node list of available memory */
        struct list_head free_list;
        /* node list of memory in use */
        struct list_head in_use_list;
};

struct cmm_xlator {             /* Pa<->Va translator object */
        /* CMM object this translator associated */
        struct cmm_object *cmm_mgr;
        /*
         *  Client process virtual base address that corresponds to phys SM
         *  base address for translator's seg_id.
         *  Only 1 segment ID currently supported.
         */
        unsigned int virt_base; /* virtual base address */
        u32 virt_size;          /* size of virt space in bytes */
        u32 seg_id;             /* Segment Id */
};

/* CMM Mgr */
struct cmm_object {
        /*
         * Cmm Lock is used to serialize access mem manager for multi-threads.
         */
        struct mutex cmm_lock;  /* Lock to access cmm mgr */
        struct list_head node_free_list;        /* Free list of memory nodes */
        u32 min_block_size;     /* Min SM block; default 16 bytes */
        u32 page_size;  /* Memory Page size (1k/4k) */
        /* GPP SM segment ptrs */
        struct cmm_allocator *pa_gppsm_seg_tab[CMM_MAXGPPSEGS];
};

/* Default CMM Mgr attributes */
static struct cmm_mgrattrs cmm_dfltmgrattrs = {
        /* min_block_size, min block size(bytes) allocated by cmm mgr */
        16
};

/* Default allocation attributes */
static struct cmm_attrs cmm_dfltalctattrs = {
        1               /* seg_id, default segment Id for allocator */
};

/* Address translator default attrs */
static struct cmm_xlatorattrs cmm_dfltxlatorattrs = {
        /* seg_id, does not have to match cmm_dfltalctattrs ul_seg_id */
        1,
        0,                      /* dsp_bufs */
        0,                      /* dsp_buf_size */
        NULL,                   /* vm_base */
        0,                      /* vm_size */
};

/* SM node representing a block of memory. */
struct cmm_mnode {
        struct list_head link;  /* must be 1st element */
        u32 pa;         /* Phys addr */
        u32 va;                 /* Virtual address in device process context */
        u32 size;               /* SM block size in bytes */
        u32 client_proc;        /* Process that allocated this mem block */
};

/*  ----------------------------------- Globals */
static u32 refs;                /* module reference count */

/*  ----------------------------------- Function Prototypes */
static void add_to_free_list(struct cmm_allocator *allocator,
                             struct cmm_mnode *pnode);
static struct cmm_allocator *get_allocator(struct cmm_object *cmm_mgr_obj,
                                           u32 ul_seg_id);
static struct cmm_mnode *get_free_block(struct cmm_allocator *allocator,
                                        u32 usize);
static struct cmm_mnode *get_node(struct cmm_object *cmm_mgr_obj, u32 dw_pa,
                                  u32 dw_va, u32 ul_size);
/* get available slot for new allocator */
static s32 get_slot(struct cmm_object *cmm_mgr_obj);
static void un_register_gppsm_seg(struct cmm_allocator *psma);

/*
 *  ======== cmm_calloc_buf ========
 *  Purpose:
 *      Allocate a SM buffer, zero contents, and return the physical address
 *      and optional driver context virtual address(pp_buf_va).
 *
 *      The freelist is sorted in increasing size order. Get the first
 *      block that satifies the request and sort the remaining back on
 *      the freelist; if large enough. The kept block is placed on the
 *      inUseList.
 */
void *cmm_calloc_buf(struct cmm_object *hcmm_mgr, u32 usize,
                     struct cmm_attrs *pattrs, void **pp_buf_va)
{
        struct cmm_object *cmm_mgr_obj = (struct cmm_object *)hcmm_mgr;
        void *buf_pa = NULL;
        struct cmm_mnode *pnode = NULL;
        struct cmm_mnode *new_node = NULL;
        struct cmm_allocator *allocator = NULL;
        u32 delta_size;
        u8 *pbyte = NULL;
        s32 cnt;

        if (pattrs == NULL)
                pattrs = &cmm_dfltalctattrs;

        if (pp_buf_va != NULL)
                *pp_buf_va = NULL;

        if (cmm_mgr_obj && (usize != 0)) {
                if (pattrs->seg_id > 0) {
                        /* SegId > 0 is SM */
                        /* get the allocator object for this segment id */
                        allocator =
                            get_allocator(cmm_mgr_obj, pattrs->seg_id);
                        /* keep block size a multiple of min_block_size */
                        usize =
                            ((usize - 1) & ~(cmm_mgr_obj->min_block_size -
                                             1))
                            + cmm_mgr_obj->min_block_size;
                        mutex_lock(&cmm_mgr_obj->cmm_lock);
                        pnode = get_free_block(allocator, usize);
                }
                if (pnode) {
                        delta_size = (pnode->size - usize);
                        if (delta_size >= cmm_mgr_obj->min_block_size) {
                                /* create a new block with the leftovers and
                                 * add to freelist */
                                new_node =
                                    get_node(cmm_mgr_obj, pnode->pa + usize,
                                             pnode->va + usize,
                                             (u32) delta_size);
                                /* leftovers go free */
                                add_to_free_list(allocator, new_node);
                                /* adjust our node's size */
                                pnode->size = usize;
                        }
                        /* Tag node with client process requesting allocation
                         * We'll need to free up a process's alloc'd SM if the
                         * client process goes away.
                         */
                        /* Return TGID instead of process handle */
                        pnode->client_proc = current->tgid;

                        /* put our node on InUse list */
                        list_add_tail(&pnode->link, &allocator->in_use_list);
                        buf_pa = (void *)pnode->pa;     /* physical address */
                        /* clear mem */
                        pbyte = (u8 *) pnode->va;
                        for (cnt = 0; cnt < (s32) usize; cnt++, pbyte++)
                                *pbyte = 0;

                        if (pp_buf_va != NULL) {
                                /* Virtual address */
                                *pp_buf_va = (void *)pnode->va;
                        }
                }
                mutex_unlock(&cmm_mgr_obj->cmm_lock);
        }
        return buf_pa;
}

/*
 *  ======== cmm_create ========
 *  Purpose:
 *      Create a communication memory manager object.
 */
int cmm_create(struct cmm_object **ph_cmm_mgr,
                      struct dev_object *hdev_obj,
                      const struct cmm_mgrattrs *mgr_attrts)
{
        struct cmm_object *cmm_obj = NULL;
        int status = 0;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(ph_cmm_mgr != NULL);

        *ph_cmm_mgr = NULL;
        /* create, zero, and tag a cmm mgr object */
        cmm_obj = kzalloc(sizeof(struct cmm_object), GFP_KERNEL);
        if (!cmm_obj)
                return -ENOMEM;

        if (mgr_attrts == NULL)
                mgr_attrts = &cmm_dfltmgrattrs; /* set defaults */

        /* 4 bytes minimum */
        DBC_ASSERT(mgr_attrts->min_block_size >= 4);
        /* save away smallest block allocation for this cmm mgr */
        cmm_obj->min_block_size = mgr_attrts->min_block_size;
        cmm_obj->page_size = PAGE_SIZE;

        /* create node free list */
        INIT_LIST_HEAD(&cmm_obj->node_free_list);
        mutex_init(&cmm_obj->cmm_lock);
        *ph_cmm_mgr = cmm_obj;

        return status;
}

/*
 *  ======== cmm_destroy ========
 *  Purpose:
 *      Release the communication memory manager resources.
 */
int cmm_destroy(struct cmm_object *hcmm_mgr, bool force)
{
        struct cmm_object *cmm_mgr_obj = (struct cmm_object *)hcmm_mgr;
        struct cmm_info temp_info;
        int status = 0;
        s32 slot_seg;
        struct cmm_mnode *node, *tmp;

        DBC_REQUIRE(refs > 0);
        if (!hcmm_mgr) {
                status = -EFAULT;
                return status;
        }
        mutex_lock(&cmm_mgr_obj->cmm_lock);
        /* If not force then fail if outstanding allocations exist */
        if (!force) {
                /* Check for outstanding memory allocations */
                status = cmm_get_info(hcmm_mgr, &temp_info);
                if (!status) {
                        if (temp_info.total_in_use_cnt > 0) {
                                /* outstanding allocations */
                                status = -EPERM;
                        }
                }
        }
        if (!status) {
                /* UnRegister SM allocator */
                for (slot_seg = 0; slot_seg < CMM_MAXGPPSEGS; slot_seg++) {
                        if (cmm_mgr_obj->pa_gppsm_seg_tab[slot_seg] != NULL) {
                                un_register_gppsm_seg
                                    (cmm_mgr_obj->pa_gppsm_seg_tab[slot_seg]);
                                /* Set slot to NULL for future reuse */
                                cmm_mgr_obj->pa_gppsm_seg_tab[slot_seg] = NULL;
                        }
                }
        }
        list_for_each_entry_safe(node, tmp, &cmm_mgr_obj->node_free_list,
                        link) {
                list_del(&node->link);
                kfree(node);
        }
        mutex_unlock(&cmm_mgr_obj->cmm_lock);
        if (!status) {
                /* delete CS & cmm mgr object */
                mutex_destroy(&cmm_mgr_obj->cmm_lock);
                kfree(cmm_mgr_obj);
        }
        return status;
}

/*
 *  ======== cmm_exit ========
 *  Purpose:
 *      Discontinue usage of module; free resources when reference count
 *      reaches 0.
 */
void cmm_exit(void)
{
        DBC_REQUIRE(refs > 0);

        refs--;
}

/*
 *  ======== cmm_free_buf ========
 *  Purpose:
 *      Free the given buffer.
 */
int cmm_free_buf(struct cmm_object *hcmm_mgr, void *buf_pa, u32 ul_seg_id)
{
        struct cmm_object *cmm_mgr_obj = (struct cmm_object *)hcmm_mgr;
        int status = -EFAULT;
        struct cmm_mnode *curr, *tmp;
        struct cmm_allocator *allocator;
        struct cmm_attrs *pattrs;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(buf_pa != NULL);

        if (ul_seg_id == 0) {
                pattrs = &cmm_dfltalctattrs;
                ul_seg_id = pattrs->seg_id;
        }
        if (!hcmm_mgr || !(ul_seg_id > 0)) {
                status = -EFAULT;
                return status;
        }

        allocator = get_allocator(cmm_mgr_obj, ul_seg_id);
        if (!allocator)
                return status;

        mutex_lock(&cmm_mgr_obj->cmm_lock);
        list_for_each_entry_safe(curr, tmp, &allocator->in_use_list, link) {
                if (curr->pa == (u32) buf_pa) {
                        list_del(&curr->link);
                        add_to_free_list(allocator, curr);
                        status = 0;
                        break;
                }
        }
        mutex_unlock(&cmm_mgr_obj->cmm_lock);

        return status;
}

/*
 *  ======== cmm_get_handle ========
 *  Purpose:
 *      Return the communication memory manager object for this device.
 *      This is typically called from the client process.
 */
int cmm_get_handle(void *hprocessor, struct cmm_object ** ph_cmm_mgr)
{
        int status = 0;
        struct dev_object *hdev_obj;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(ph_cmm_mgr != NULL);
        if (hprocessor != NULL)
                status = proc_get_dev_object(hprocessor, &hdev_obj);
        else
                hdev_obj = dev_get_first();     /* default */

        if (!status)
                status = dev_get_cmm_mgr(hdev_obj, ph_cmm_mgr);

        return status;
}

/*
 *  ======== cmm_get_info ========
 *  Purpose:
 *      Return the current memory utilization information.
 */
int cmm_get_info(struct cmm_object *hcmm_mgr,
                        struct cmm_info *cmm_info_obj)
{
        struct cmm_object *cmm_mgr_obj = (struct cmm_object *)hcmm_mgr;
        u32 ul_seg;
        int status = 0;
        struct cmm_allocator *altr;
        struct cmm_mnode *curr;

        DBC_REQUIRE(cmm_info_obj != NULL);

        if (!hcmm_mgr) {
                status = -EFAULT;
                return status;
        }
        mutex_lock(&cmm_mgr_obj->cmm_lock);
        cmm_info_obj->num_gppsm_segs = 0;       /* # of SM segments */
        /* Total # of outstanding alloc */
        cmm_info_obj->total_in_use_cnt = 0;
        /* min block size */
        cmm_info_obj->min_block_size = cmm_mgr_obj->min_block_size;
        /* check SM memory segments */
        for (ul_seg = 1; ul_seg <= CMM_MAXGPPSEGS; ul_seg++) {
                /* get the allocator object for this segment id */
                altr = get_allocator(cmm_mgr_obj, ul_seg);
                if (!altr)
                        continue;
                cmm_info_obj->num_gppsm_segs++;
                cmm_info_obj->seg_info[ul_seg - 1].seg_base_pa =
                        altr->shm_base - altr->dsp_size;
                cmm_info_obj->seg_info[ul_seg - 1].total_seg_size =
                        altr->dsp_size + altr->sm_size;
                cmm_info_obj->seg_info[ul_seg - 1].gpp_base_pa =
                        altr->shm_base;
                cmm_info_obj->seg_info[ul_seg - 1].gpp_size =
                        altr->sm_size;
                cmm_info_obj->seg_info[ul_seg - 1].dsp_base_va =
                        altr->dsp_base;
                cmm_info_obj->seg_info[ul_seg - 1].dsp_size =
                        altr->dsp_size;
                cmm_info_obj->seg_info[ul_seg - 1].seg_base_va =
                        altr->vm_base - altr->dsp_size;
                cmm_info_obj->seg_info[ul_seg - 1].in_use_cnt = 0;

                list_for_each_entry(curr, &altr->in_use_list, link) {
                        cmm_info_obj->total_in_use_cnt++;
                        cmm_info_obj->seg_info[ul_seg - 1].in_use_cnt++;
                }
        }
        mutex_unlock(&cmm_mgr_obj->cmm_lock);
        return status;
}

/*
 *  ======== cmm_init ========
 *  Purpose:
 *      Initializes private state of CMM module.
 */
bool cmm_init(void)
{
        bool ret = true;

        DBC_REQUIRE(refs >= 0);
        if (ret)
                refs++;

        DBC_ENSURE((ret && (refs > 0)) || (!ret && (refs >= 0)));

        return ret;
}

/*
 *  ======== cmm_register_gppsm_seg ========
 *  Purpose:
 *      Register a block of SM with the CMM to be used for later GPP SM
 *      allocations.
 */
int cmm_register_gppsm_seg(struct cmm_object *hcmm_mgr,
                                  u32 dw_gpp_base_pa, u32 ul_size,
                                  u32 dsp_addr_offset, s8 c_factor,
                                  u32 dw_dsp_base, u32 ul_dsp_size,
                                  u32 *sgmt_id, u32 gpp_base_va)
{
        struct cmm_object *cmm_mgr_obj = (struct cmm_object *)hcmm_mgr;
        struct cmm_allocator *psma = NULL;
        int status = 0;
        struct cmm_mnode *new_node;
        s32 slot_seg;

        DBC_REQUIRE(ul_size > 0);
        DBC_REQUIRE(sgmt_id != NULL);
        DBC_REQUIRE(dw_gpp_base_pa != 0);
        DBC_REQUIRE(gpp_base_va != 0);
        DBC_REQUIRE((c_factor <= CMM_ADDTODSPPA) &&
                        (c_factor >= CMM_SUBFROMDSPPA));

        dev_dbg(bridge, "%s: dw_gpp_base_pa %x ul_size %x dsp_addr_offset %x "
                        "dw_dsp_base %x ul_dsp_size %x gpp_base_va %x\n",
                        __func__, dw_gpp_base_pa, ul_size, dsp_addr_offset,
                        dw_dsp_base, ul_dsp_size, gpp_base_va);

        if (!hcmm_mgr)
                return -EFAULT;

        /* make sure we have room for another allocator */
        mutex_lock(&cmm_mgr_obj->cmm_lock);

        slot_seg = get_slot(cmm_mgr_obj);
        if (slot_seg < 0) {
                status = -EPERM;
                goto func_end;
        }

        /* Check if input ul_size is big enough to alloc at least one block */
        if (ul_size < cmm_mgr_obj->min_block_size) {
                status = -EINVAL;
                goto func_end;
        }

        /* create, zero, and tag an SM allocator object */
        psma = kzalloc(sizeof(struct cmm_allocator), GFP_KERNEL);
        if (!psma) {
                status = -ENOMEM;
                goto func_end;
        }

        psma->cmm_mgr = hcmm_mgr;       /* ref to parent */
        psma->shm_base = dw_gpp_base_pa;        /* SM Base phys */
        psma->sm_size = ul_size;        /* SM segment size in bytes */
        psma->vm_base = gpp_base_va;
        psma->dsp_phys_addr_offset = dsp_addr_offset;
        psma->c_factor = c_factor;
        psma->dsp_base = dw_dsp_base;
        psma->dsp_size = ul_dsp_size;
        if (psma->vm_base == 0) {
                status = -EPERM;
                goto func_end;
        }
        /* return the actual segment identifier */
        *sgmt_id = (u32) slot_seg + 1;

        INIT_LIST_HEAD(&psma->free_list);
        INIT_LIST_HEAD(&psma->in_use_list);

        /* Get a mem node for this hunk-o-memory */
        new_node = get_node(cmm_mgr_obj, dw_gpp_base_pa,
                        psma->vm_base, ul_size);
        /* Place node on the SM allocator's free list */
        if (new_node) {
                list_add_tail(&new_node->link, &psma->free_list);
        } else {
                status = -ENOMEM;
                goto func_end;
        }
        /* make entry */
        cmm_mgr_obj->pa_gppsm_seg_tab[slot_seg] = psma;

func_end:
        /* Cleanup allocator */
        if (status && psma)
                un_register_gppsm_seg(psma);
        mutex_unlock(&cmm_mgr_obj->cmm_lock);

        return status;
}

/*
 *  ======== cmm_un_register_gppsm_seg ========
 *  Purpose:
 *      UnRegister GPP SM segments with the CMM.
 */
int cmm_un_register_gppsm_seg(struct cmm_object *hcmm_mgr,
                                     u32 ul_seg_id)
{
        struct cmm_object *cmm_mgr_obj = (struct cmm_object *)hcmm_mgr;
        int status = 0;
        struct cmm_allocator *psma;
        u32 ul_id = ul_seg_id;

        DBC_REQUIRE(ul_seg_id > 0);
        if (!hcmm_mgr)
                return -EFAULT;

        if (ul_seg_id == CMM_ALLSEGMENTS)
                ul_id = 1;

        if ((ul_id <= 0) || (ul_id > CMM_MAXGPPSEGS))
                return -EINVAL;

        /*
         * FIXME: CMM_MAXGPPSEGS == 1. why use a while cycle? Seems to me like
         * the ul_seg_id is not needed here. It must be always 1.
         */
        while (ul_id <= CMM_MAXGPPSEGS) {
                mutex_lock(&cmm_mgr_obj->cmm_lock);
                /* slot = seg_id-1 */
                psma = cmm_mgr_obj->pa_gppsm_seg_tab[ul_id - 1];
                if (psma != NULL) {
                        un_register_gppsm_seg(psma);
                        /* Set alctr ptr to NULL for future reuse */
                        cmm_mgr_obj->pa_gppsm_seg_tab[ul_id - 1] = NULL;
                } else if (ul_seg_id != CMM_ALLSEGMENTS) {
                        status = -EPERM;
                }
                mutex_unlock(&cmm_mgr_obj->cmm_lock);
                if (ul_seg_id != CMM_ALLSEGMENTS)
                        break;

                ul_id++;
        }       /* end while */
        return status;
}

/*
 *  ======== un_register_gppsm_seg ========
 *  Purpose:
 *      UnRegister the SM allocator by freeing all its resources and
 *      nulling cmm mgr table entry.
 *  Note:
 *      This routine is always called within cmm lock crit sect.
 */
static void un_register_gppsm_seg(struct cmm_allocator *psma)
{
        struct cmm_mnode *curr, *tmp;

        DBC_REQUIRE(psma != NULL);

        /* free nodes on free list */
        list_for_each_entry_safe(curr, tmp, &psma->free_list, link) {
                list_del(&curr->link);
                kfree(curr);
        }

        /* free nodes on InUse list */
        list_for_each_entry_safe(curr, tmp, &psma->in_use_list, link) {
                list_del(&curr->link);
                kfree(curr);
        }

        if ((void *)psma->vm_base != NULL)
                MEM_UNMAP_LINEAR_ADDRESS((void *)psma->vm_base);

        /* Free allocator itself */
        kfree(psma);
}

/*
 *  ======== get_slot ========
 *  Purpose:
 *      An available slot # is returned. Returns negative on failure.
 */
static s32 get_slot(struct cmm_object *cmm_mgr_obj)
{
        s32 slot_seg = -1;      /* neg on failure */
        DBC_REQUIRE(cmm_mgr_obj != NULL);
        /* get first available slot in cmm mgr SMSegTab[] */
        for (slot_seg = 0; slot_seg < CMM_MAXGPPSEGS; slot_seg++) {
                if (cmm_mgr_obj->pa_gppsm_seg_tab[slot_seg] == NULL)
                        break;

        }
        if (slot_seg == CMM_MAXGPPSEGS)
                slot_seg = -1;  /* failed */

        return slot_seg;
}

/*
 *  ======== get_node ========
 *  Purpose:
 *      Get a memory node from freelist or create a new one.
 */
static struct cmm_mnode *get_node(struct cmm_object *cmm_mgr_obj, u32 dw_pa,
                                  u32 dw_va, u32 ul_size)
{
        struct cmm_mnode *pnode;

        DBC_REQUIRE(cmm_mgr_obj != NULL);
        DBC_REQUIRE(dw_pa != 0);
        DBC_REQUIRE(dw_va != 0);
        DBC_REQUIRE(ul_size != 0);

        /* Check cmm mgr's node freelist */
        if (list_empty(&cmm_mgr_obj->node_free_list)) {
                pnode = kzalloc(sizeof(struct cmm_mnode), GFP_KERNEL);
                if (!pnode)
                        return NULL;
        } else {
                /* surely a valid element */
                pnode = list_first_entry(&cmm_mgr_obj->node_free_list,
                                struct cmm_mnode, link);
                list_del_init(&pnode->link);
        }

        pnode->pa = dw_pa;
        pnode->va = dw_va;
        pnode->size = ul_size;

        return pnode;
}

/*
 *  ======== delete_node ========
 *  Purpose:
 *      Put a memory node on the cmm nodelist for later use.
 *      Doesn't actually delete the node. Heap thrashing friendly.
 */
static void delete_node(struct cmm_object *cmm_mgr_obj, struct cmm_mnode *pnode)
{
        DBC_REQUIRE(pnode != NULL);
        list_add_tail(&pnode->link, &cmm_mgr_obj->node_free_list);
}

/*
 * ====== get_free_block ========
 *  Purpose:
 *      Scan the free block list and return the first block that satisfies
 *      the size.
 */
static struct cmm_mnode *get_free_block(struct cmm_allocator *allocator,
                                        u32 usize)
{
        struct cmm_mnode *node, *tmp;

        if (!allocator)
                return NULL;

        list_for_each_entry_safe(node, tmp, &allocator->free_list, link) {
                if (usize <= node->size) {
                        list_del(&node->link);
                        return node;
                }
        }

        return NULL;
}

/*
 *  ======== add_to_free_list ========
 *  Purpose:
 *      Coalesce node into the freelist in ascending size order.
 */
static void add_to_free_list(struct cmm_allocator *allocator,
                             struct cmm_mnode *node)
{
        struct cmm_mnode *curr;

        if (!node) {
                pr_err("%s: failed - node is NULL\n", __func__);
                return;
        }

        list_for_each_entry(curr, &allocator->free_list, link) {
                if (NEXT_PA(curr) == node->pa) {
                        curr->size += node->size;
                        delete_node(allocator->cmm_mgr, node);
                        return;
                }
                if (curr->pa == NEXT_PA(node)) {
                        curr->pa = node->pa;
                        curr->va = node->va;
                        curr->size += node->size;
                        delete_node(allocator->cmm_mgr, node);
                        return;
                }
        }
        list_for_each_entry(curr, &allocator->free_list, link) {
                if (curr->size >= node->size) {
                        list_add_tail(&node->link, &curr->link);
                        return;
                }
        }
        list_add_tail(&node->link, &allocator->free_list);
}

/*
 * ======== get_allocator ========
 *  Purpose:
 *      Return the allocator for the given SM Segid.
 *      SegIds:  1,2,3..max.
 */
static struct cmm_allocator *get_allocator(struct cmm_object *cmm_mgr_obj,
                                           u32 ul_seg_id)
{
        DBC_REQUIRE(cmm_mgr_obj != NULL);
        DBC_REQUIRE((ul_seg_id > 0) && (ul_seg_id <= CMM_MAXGPPSEGS));

        return cmm_mgr_obj->pa_gppsm_seg_tab[ul_seg_id - 1];
}

/*
 *  The CMM_Xlator[xxx] routines below are used by Node and Stream
 *  to perform SM address translation to the client process address space.
 *  A "translator" object is created by a node/stream for each SM seg used.
 */

/*
 *  ======== cmm_xlator_create ========
 *  Purpose:
 *      Create an address translator object.
 */
int cmm_xlator_create(struct cmm_xlatorobject **xlator,
                             struct cmm_object *hcmm_mgr,
                             struct cmm_xlatorattrs *xlator_attrs)
{
        struct cmm_xlator *xlator_object = NULL;
        int status = 0;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(xlator != NULL);
        DBC_REQUIRE(hcmm_mgr != NULL);

        *xlator = NULL;
        if (xlator_attrs == NULL)
                xlator_attrs = &cmm_dfltxlatorattrs;    /* set defaults */

        xlator_object = kzalloc(sizeof(struct cmm_xlator), GFP_KERNEL);
        if (xlator_object != NULL) {
                xlator_object->cmm_mgr = hcmm_mgr;      /* ref back to CMM */
                /* SM seg_id */
                xlator_object->seg_id = xlator_attrs->seg_id;
        } else {
                status = -ENOMEM;
        }
        if (!status)
                *xlator = (struct cmm_xlatorobject *)xlator_object;

        return status;
}

/*
 *  ======== cmm_xlator_alloc_buf ========
 */
void *cmm_xlator_alloc_buf(struct cmm_xlatorobject *xlator, void *va_buf,
                           u32 pa_size)
{
        struct cmm_xlator *xlator_obj = (struct cmm_xlator *)xlator;
        void *pbuf = NULL;
        void *tmp_va_buff;
        struct cmm_attrs attrs;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(xlator != NULL);
        DBC_REQUIRE(xlator_obj->cmm_mgr != NULL);
        DBC_REQUIRE(va_buf != NULL);
        DBC_REQUIRE(pa_size > 0);
        DBC_REQUIRE(xlator_obj->seg_id > 0);

        if (xlator_obj) {
                attrs.seg_id = xlator_obj->seg_id;
                __raw_writel(0, va_buf);
                /* Alloc SM */
                pbuf =
                    cmm_calloc_buf(xlator_obj->cmm_mgr, pa_size, &attrs, NULL);
                if (pbuf) {
                        /* convert to translator(node/strm) process Virtual
                         * address */
                         tmp_va_buff = cmm_xlator_translate(xlator,
                                                         pbuf, CMM_PA2VA);
                        __raw_writel((u32)tmp_va_buff, va_buf);
                }
        }
        return pbuf;
}

/*
 *  ======== cmm_xlator_free_buf ========
 *  Purpose:
 *      Free the given SM buffer and descriptor.
 *      Does not free virtual memory.
 */
int cmm_xlator_free_buf(struct cmm_xlatorobject *xlator, void *buf_va)
{
        struct cmm_xlator *xlator_obj = (struct cmm_xlator *)xlator;
        int status = -EPERM;
        void *buf_pa = NULL;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(buf_va != NULL);
        DBC_REQUIRE(xlator_obj->seg_id > 0);

        if (xlator_obj) {
                /* convert Va to Pa so we can free it. */
                buf_pa = cmm_xlator_translate(xlator, buf_va, CMM_VA2PA);
                if (buf_pa) {
                        status = cmm_free_buf(xlator_obj->cmm_mgr, buf_pa,
                                              xlator_obj->seg_id);
                        if (status) {
                                /* Uh oh, this shouldn't happen. Descriptor
                                 * gone! */
                                DBC_ASSERT(false);      /* CMM is leaking mem */
                        }
                }
        }
        return status;
}

/*
 *  ======== cmm_xlator_info ========
 *  Purpose:
 *      Set/Get translator info.
 */
int cmm_xlator_info(struct cmm_xlatorobject *xlator, u8 ** paddr,
                           u32 ul_size, u32 segm_id, bool set_info)
{
        struct cmm_xlator *xlator_obj = (struct cmm_xlator *)xlator;
        int status = 0;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(paddr != NULL);
        DBC_REQUIRE((segm_id > 0) && (segm_id <= CMM_MAXGPPSEGS));

        if (xlator_obj) {
                if (set_info) {
                        /* set translators virtual address range */
                        xlator_obj->virt_base = (u32) *paddr;
                        xlator_obj->virt_size = ul_size;
                } else {        /* return virt base address */
                        *paddr = (u8 *) xlator_obj->virt_base;
                }
        } else {
                status = -EFAULT;
        }
        return status;
}

/*
 *  ======== cmm_xlator_translate ========
 */
void *cmm_xlator_translate(struct cmm_xlatorobject *xlator, void *paddr,
                           enum cmm_xlatetype xtype)
{
        u32 dw_addr_xlate = 0;
        struct cmm_xlator *xlator_obj = (struct cmm_xlator *)xlator;
        struct cmm_object *cmm_mgr_obj = NULL;
        struct cmm_allocator *allocator = NULL;
        u32 dw_offset = 0;

        DBC_REQUIRE(refs > 0);
        DBC_REQUIRE(paddr != NULL);
        DBC_REQUIRE((xtype >= CMM_VA2PA) && (xtype <= CMM_DSPPA2PA));

        if (!xlator_obj)
                goto loop_cont;

        cmm_mgr_obj = (struct cmm_object *)xlator_obj->cmm_mgr;
        /* get this translator's default SM allocator */
        DBC_ASSERT(xlator_obj->seg_id > 0);
        allocator = cmm_mgr_obj->pa_gppsm_seg_tab[xlator_obj->seg_id - 1];
        if (!allocator)
                goto loop_cont;

        if ((xtype == CMM_VA2DSPPA) || (xtype == CMM_VA2PA) ||
            (xtype == CMM_PA2VA)) {
                if (xtype == CMM_PA2VA) {
                        /* Gpp Va = Va Base + offset */
                        dw_offset = (u8 *) paddr - (u8 *) (allocator->shm_base -
                                                           allocator->
                                                           dsp_size);
                        dw_addr_xlate = xlator_obj->virt_base + dw_offset;
                        /* Check if translated Va base is in range */
                        if ((dw_addr_xlate < xlator_obj->virt_base) ||
                            (dw_addr_xlate >=
                             (xlator_obj->virt_base +
                              xlator_obj->virt_size))) {
                                dw_addr_xlate = 0;      /* bad address */
                        }
                } else {
                        /* Gpp PA =  Gpp Base + offset */
                        dw_offset =
                            (u8 *) paddr - (u8 *) xlator_obj->virt_base;
                        dw_addr_xlate =
                            allocator->shm_base - allocator->dsp_size +
                            dw_offset;
                }
        } else {
                dw_addr_xlate = (u32) paddr;
        }
        /*Now convert address to proper target physical address if needed */
        if ((xtype == CMM_VA2DSPPA) || (xtype == CMM_PA2DSPPA)) {
                /* Got Gpp Pa now, convert to DSP Pa */
                dw_addr_xlate =
                    GPPPA2DSPPA((allocator->shm_base - allocator->dsp_size),
                                dw_addr_xlate,
                                allocator->dsp_phys_addr_offset *
                                allocator->c_factor);
        } else if (xtype == CMM_DSPPA2PA) {
                /* Got DSP Pa, convert to GPP Pa */

                dw_addr_xlate =
                    DSPPA2GPPPA(allocator->shm_base - allocator->dsp_size,
                                dw_addr_xlate,
                                allocator->dsp_phys_addr_offset *
                                allocator->c_factor);
        }
loop_cont:
        return (void *)dw_addr_xlate;
}