/*
 * SRAM allocator for Blackfin on-chip memory
 *
 * Copyright 2004-2009 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/rtc.h>
#include <asm/blackfin.h>
#include <asm/mem_map.h>
#include "blackfin_sram.h"

/* the data structure for L1 scratchpad and DATA SRAM */
struct sram_piece {
        void *paddr;
        int size;
        pid_t pid;
        struct sram_piece *next;
};

static DEFINE_PER_CPU_SHARED_ALIGNED(spinlock_t, l1sram_lock);
static DEFINE_PER_CPU(struct sram_piece, free_l1_ssram_head);
static DEFINE_PER_CPU(struct sram_piece, used_l1_ssram_head);

#if L1_DATA_A_LENGTH != 0
static DEFINE_PER_CPU(struct sram_piece, free_l1_data_A_sram_head);
static DEFINE_PER_CPU(struct sram_piece, used_l1_data_A_sram_head);
#endif

#if L1_DATA_B_LENGTH != 0
static DEFINE_PER_CPU(struct sram_piece, free_l1_data_B_sram_head);
static DEFINE_PER_CPU(struct sram_piece, used_l1_data_B_sram_head);
#endif

#if L1_DATA_A_LENGTH || L1_DATA_B_LENGTH
static DEFINE_PER_CPU_SHARED_ALIGNED(spinlock_t, l1_data_sram_lock);
#endif

#if L1_CODE_LENGTH != 0
static DEFINE_PER_CPU_SHARED_ALIGNED(spinlock_t, l1_inst_sram_lock);
static DEFINE_PER_CPU(struct sram_piece, free_l1_inst_sram_head);
static DEFINE_PER_CPU(struct sram_piece, used_l1_inst_sram_head);
#endif

#if L2_LENGTH != 0
static spinlock_t l2_sram_lock ____cacheline_aligned_in_smp;
static struct sram_piece free_l2_sram_head, used_l2_sram_head;
#endif

static struct kmem_cache *sram_piece_cache;

/* L1 Scratchpad SRAM initialization function */
static void __init l1sram_init(void)
{
        unsigned int cpu;
        unsigned long reserve;

#ifdef CONFIG_SMP
        reserve = 0;
#else
        reserve = sizeof(struct l1_scratch_task_info);
#endif

        for (cpu = 0; cpu < num_possible_cpus(); ++cpu) {
                per_cpu(free_l1_ssram_head, cpu).next =
                        kmem_cache_alloc(sram_piece_cache, GFP_KERNEL);
                if (!per_cpu(free_l1_ssram_head, cpu).next) {
                        printk(KERN_INFO "Fail to initialize Scratchpad data SRAM.\n");
                        return;
                }

                per_cpu(free_l1_ssram_head, cpu).next->paddr = (void *)get_l1_scratch_start_cpu(cpu) + reserve;
                per_cpu(free_l1_ssram_head, cpu).next->size = L1_SCRATCH_LENGTH - reserve;
                per_cpu(free_l1_ssram_head, cpu).next->pid = 0;
                per_cpu(free_l1_ssram_head, cpu).next->next = NULL;

                per_cpu(used_l1_ssram_head, cpu).next = NULL;

                /* mutex initialize */
                spin_lock_init(&per_cpu(l1sram_lock, cpu));
                printk(KERN_INFO "Blackfin Scratchpad data SRAM: %d KB\n",
                        L1_SCRATCH_LENGTH >> 10);
        }
}

static void __init l1_data_sram_init(void)
{
#if L1_DATA_A_LENGTH != 0 || L1_DATA_B_LENGTH != 0
        unsigned int cpu;
#endif
#if L1_DATA_A_LENGTH != 0
        for (cpu = 0; cpu < num_possible_cpus(); ++cpu) {
                per_cpu(free_l1_data_A_sram_head, cpu).next =
                        kmem_cache_alloc(sram_piece_cache, GFP_KERNEL);
                if (!per_cpu(free_l1_data_A_sram_head, cpu).next) {
                        printk(KERN_INFO "Fail to initialize L1 Data A SRAM.\n");
                        return;
                }

                per_cpu(free_l1_data_A_sram_head, cpu).next->paddr =
                        (void *)get_l1_data_a_start_cpu(cpu) + (_ebss_l1 - _sdata_l1);
                per_cpu(free_l1_data_A_sram_head, cpu).next->size =
                        L1_DATA_A_LENGTH - (_ebss_l1 - _sdata_l1);
                per_cpu(free_l1_data_A_sram_head, cpu).next->pid = 0;
                per_cpu(free_l1_data_A_sram_head, cpu).next->next = NULL;

                per_cpu(used_l1_data_A_sram_head, cpu).next = NULL;

                printk(KERN_INFO "Blackfin L1 Data A SRAM: %d KB (%d KB free)\n",
                        L1_DATA_A_LENGTH >> 10,
                        per_cpu(free_l1_data_A_sram_head, cpu).next->size >> 10);
        }
#endif
#if L1_DATA_B_LENGTH != 0
        for (cpu = 0; cpu < num_possible_cpus(); ++cpu) {
                per_cpu(free_l1_data_B_sram_head, cpu).next =
                        kmem_cache_alloc(sram_piece_cache, GFP_KERNEL);
                if (!per_cpu(free_l1_data_B_sram_head, cpu).next) {
                        printk(KERN_INFO "Fail to initialize L1 Data B SRAM.\n");
                        return;
                }

                per_cpu(free_l1_data_B_sram_head, cpu).next->paddr =
                        (void *)get_l1_data_b_start_cpu(cpu) + (_ebss_b_l1 - _sdata_b_l1);
                per_cpu(free_l1_data_B_sram_head, cpu).next->size =
                        L1_DATA_B_LENGTH - (_ebss_b_l1 - _sdata_b_l1);
                per_cpu(free_l1_data_B_sram_head, cpu).next->pid = 0;
                per_cpu(free_l1_data_B_sram_head, cpu).next->next = NULL;

                per_cpu(used_l1_data_B_sram_head, cpu).next = NULL;

                printk(KERN_INFO "Blackfin L1 Data B SRAM: %d KB (%d KB free)\n",
                        L1_DATA_B_LENGTH >> 10,
                        per_cpu(free_l1_data_B_sram_head, cpu).next->size >> 10);
                /* mutex initialize */
        }
#endif

#if L1_DATA_A_LENGTH != 0 || L1_DATA_B_LENGTH != 0
        for (cpu = 0; cpu < num_possible_cpus(); ++cpu)
                spin_lock_init(&per_cpu(l1_data_sram_lock, cpu));
#endif
}

static void __init l1_inst_sram_init(void)
{
#if L1_CODE_LENGTH != 0
        unsigned int cpu;
        for (cpu = 0; cpu < num_possible_cpus(); ++cpu) {
                per_cpu(free_l1_inst_sram_head, cpu).next =
                        kmem_cache_alloc(sram_piece_cache, GFP_KERNEL);
                if (!per_cpu(free_l1_inst_sram_head, cpu).next) {
                        printk(KERN_INFO "Failed to initialize L1 Instruction SRAM\n");
                        return;
                }

                per_cpu(free_l1_inst_sram_head, cpu).next->paddr =
                        (void *)get_l1_code_start_cpu(cpu) + (_etext_l1 - _stext_l1);
                per_cpu(free_l1_inst_sram_head, cpu).next->size =
                        L1_CODE_LENGTH - (_etext_l1 - _stext_l1);
                per_cpu(free_l1_inst_sram_head, cpu).next->pid = 0;
                per_cpu(free_l1_inst_sram_head, cpu).next->next = NULL;

                per_cpu(used_l1_inst_sram_head, cpu).next = NULL;

                printk(KERN_INFO "Blackfin L1 Instruction SRAM: %d KB (%d KB free)\n",
                        L1_CODE_LENGTH >> 10,
                        per_cpu(free_l1_inst_sram_head, cpu).next->size >> 10);

                /* mutex initialize */
                spin_lock_init(&per_cpu(l1_inst_sram_lock, cpu));
        }
#endif
}

static void __init l2_sram_init(void)
{
#if L2_LENGTH != 0
        free_l2_sram_head.next =
                kmem_cache_alloc(sram_piece_cache, GFP_KERNEL);
        if (!free_l2_sram_head.next) {
                printk(KERN_INFO "Fail to initialize L2 SRAM.\n");
                return;
        }

        free_l2_sram_head.next->paddr =
                (void *)L2_START + (_ebss_l2 - _stext_l2);
        free_l2_sram_head.next->size =
                L2_LENGTH - (_ebss_l2 - _stext_l2);
        free_l2_sram_head.next->pid = 0;
        free_l2_sram_head.next->next = NULL;

        used_l2_sram_head.next = NULL;

        printk(KERN_INFO "Blackfin L2 SRAM: %d KB (%d KB free)\n",
                L2_LENGTH >> 10,
                free_l2_sram_head.next->size >> 10);

        /* mutex initialize */
        spin_lock_init(&l2_sram_lock);
#endif
}

static int __init bfin_sram_init(void)
{
        sram_piece_cache = kmem_cache_create("sram_piece_cache",
                                sizeof(struct sram_piece),
                                0, SLAB_PANIC, NULL);

        l1sram_init();
        l1_data_sram_init();
        l1_inst_sram_init();
        l2_sram_init();

        return 0;
}
pure_initcall(bfin_sram_init);

/* SRAM allocate function */
static void *_sram_alloc(size_t size, struct sram_piece *pfree_head,
                struct sram_piece *pused_head)
{
        struct sram_piece *pslot, *plast, *pavail;

        if (size <= 0 || !pfree_head || !pused_head)
                return NULL;

        /* Align the size */
        size = (size + 3) & ~3;

        pslot = pfree_head->next;
        plast = pfree_head;

        /* search an available piece slot */
        while (pslot != NULL && size > pslot->size) {
                plast = pslot;
                pslot = pslot->next;
        }

        if (!pslot)
                return NULL;

        if (pslot->size == size) {
                plast->next = pslot->next;
                pavail = pslot;
        } else {
                pavail = kmem_cache_alloc(sram_piece_cache, GFP_KERNEL);

                if (!pavail)
                        return NULL;

                pavail->paddr = pslot->paddr;
                pavail->size = size;
                pslot->paddr += size;
                pslot->size -= size;
        }

        pavail->pid = current->pid;

        pslot = pused_head->next;
        plast = pused_head;

        /* insert new piece into used piece list !!! */
        while (pslot != NULL && pavail->paddr < pslot->paddr) {
                plast = pslot;
                pslot = pslot->next;
        }

        pavail->next = pslot;
        plast->next = pavail;

        return pavail->paddr;
}

/* Allocate the largest available block.  */
static void *_sram_alloc_max(struct sram_piece *pfree_head,
                                struct sram_piece *pused_head,
                                unsigned long *psize)
{
        struct sram_piece *pslot, *pmax;

        if (!pfree_head || !pused_head)
                return NULL;

        pmax = pslot = pfree_head->next;

        /* search an available piece slot */
        while (pslot != NULL) {
                if (pslot->size > pmax->size)
                        pmax = pslot;
                pslot = pslot->next;
        }

        if (!pmax)
                return NULL;

        *psize = pmax->size;

        return _sram_alloc(*psize, pfree_head, pused_head);
}

/* SRAM free function */
static int _sram_free(const void *addr,
                        struct sram_piece *pfree_head,
                        struct sram_piece *pused_head)
{
        struct sram_piece *pslot, *plast, *pavail;

        if (!pfree_head || !pused_head)
                return -1;

        /* search the relevant memory slot */
        pslot = pused_head->next;
        plast = pused_head;

        /* search an available piece slot */
        while (pslot != NULL && pslot->paddr != addr) {
                plast = pslot;
                pslot = pslot->next;
        }

        if (!pslot)
                return -1;

        plast->next = pslot->next;
        pavail = pslot;
        pavail->pid = 0;

        /* insert free pieces back to the free list */
        pslot = pfree_head->next;
        plast = pfree_head;

        while (pslot != NULL && addr > pslot->paddr) {
                plast = pslot;
                pslot = pslot->next;
        }

        if (plast != pfree_head && plast->paddr + plast->size == pavail->paddr) {
                plast->size += pavail->size;
                kmem_cache_free(sram_piece_cache, pavail);
        } else {
                pavail->next = plast->next;
                plast->next = pavail;
                plast = pavail;
        }

        if (pslot && plast->paddr + plast->size == pslot->paddr) {
                plast->size += pslot->size;
                plast->next = pslot->next;
                kmem_cache_free(sram_piece_cache, pslot);
        }

        return 0;
}

int sram_free(const void *addr)
{

#if L1_CODE_LENGTH != 0
        if (addr >= (void *)get_l1_code_start()
                 && addr < (void *)(get_l1_code_start() + L1_CODE_LENGTH))
                return l1_inst_sram_free(addr);
        else
#endif
#if L1_DATA_A_LENGTH != 0
        if (addr >= (void *)get_l1_data_a_start()
                 && addr < (void *)(get_l1_data_a_start() + L1_DATA_A_LENGTH))
                return l1_data_A_sram_free(addr);
        else
#endif
#if L1_DATA_B_LENGTH != 0
        if (addr >= (void *)get_l1_data_b_start()
                 && addr < (void *)(get_l1_data_b_start() + L1_DATA_B_LENGTH))
                return l1_data_B_sram_free(addr);
        else
#endif
#if L2_LENGTH != 0
        if (addr >= (void *)L2_START
                 && addr < (void *)(L2_START + L2_LENGTH))
                return l2_sram_free(addr);
        else
#endif
                return -1;
}
EXPORT_SYMBOL(sram_free);

void *l1_data_A_sram_alloc(size_t size)
{
#if L1_DATA_A_LENGTH != 0
        unsigned long flags;
        void *addr;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1_data_sram_lock, cpu), flags);

        addr = _sram_alloc(size, &per_cpu(free_l1_data_A_sram_head, cpu),
                        &per_cpu(used_l1_data_A_sram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1_data_sram_lock, cpu), flags);
        put_cpu();

        pr_debug("Allocated address in l1_data_A_sram_alloc is 0x%lx+0x%lx\n",
                 (long unsigned int)addr, size);

        return addr;
#else
        return NULL;
#endif
}
EXPORT_SYMBOL(l1_data_A_sram_alloc);

int l1_data_A_sram_free(const void *addr)
{
#if L1_DATA_A_LENGTH != 0
        unsigned long flags;
        int ret;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1_data_sram_lock, cpu), flags);

        ret = _sram_free(addr, &per_cpu(free_l1_data_A_sram_head, cpu),
                        &per_cpu(used_l1_data_A_sram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1_data_sram_lock, cpu), flags);
        put_cpu();

        return ret;
#else
        return -1;
#endif
}
EXPORT_SYMBOL(l1_data_A_sram_free);

void *l1_data_B_sram_alloc(size_t size)
{
#if L1_DATA_B_LENGTH != 0
        unsigned long flags;
        void *addr;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1_data_sram_lock, cpu), flags);

        addr = _sram_alloc(size, &per_cpu(free_l1_data_B_sram_head, cpu),
                        &per_cpu(used_l1_data_B_sram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1_data_sram_lock, cpu), flags);
        put_cpu();

        pr_debug("Allocated address in l1_data_B_sram_alloc is 0x%lx+0x%lx\n",
                 (long unsigned int)addr, size);

        return addr;
#else
        return NULL;
#endif
}
EXPORT_SYMBOL(l1_data_B_sram_alloc);

int l1_data_B_sram_free(const void *addr)
{
#if L1_DATA_B_LENGTH != 0
        unsigned long flags;
        int ret;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1_data_sram_lock, cpu), flags);

        ret = _sram_free(addr, &per_cpu(free_l1_data_B_sram_head, cpu),
                        &per_cpu(used_l1_data_B_sram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1_data_sram_lock, cpu), flags);
        put_cpu();

        return ret;
#else
        return -1;
#endif
}
EXPORT_SYMBOL(l1_data_B_sram_free);

void *l1_data_sram_alloc(size_t size)
{
        void *addr = l1_data_A_sram_alloc(size);

        if (!addr)
                addr = l1_data_B_sram_alloc(size);

        return addr;
}
EXPORT_SYMBOL(l1_data_sram_alloc);

void *l1_data_sram_zalloc(size_t size)
{
        void *addr = l1_data_sram_alloc(size);

        if (addr)
                memset(addr, 0x00, size);

        return addr;
}
EXPORT_SYMBOL(l1_data_sram_zalloc);

int l1_data_sram_free(const void *addr)
{
        int ret;
        ret = l1_data_A_sram_free(addr);
        if (ret == -1)
                ret = l1_data_B_sram_free(addr);
        return ret;
}
EXPORT_SYMBOL(l1_data_sram_free);

void *l1_inst_sram_alloc(size_t size)
{
#if L1_CODE_LENGTH != 0
        unsigned long flags;
        void *addr;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1_inst_sram_lock, cpu), flags);

        addr = _sram_alloc(size, &per_cpu(free_l1_inst_sram_head, cpu),
                        &per_cpu(used_l1_inst_sram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1_inst_sram_lock, cpu), flags);
        put_cpu();

        pr_debug("Allocated address in l1_inst_sram_alloc is 0x%lx+0x%lx\n",
                 (long unsigned int)addr, size);

        return addr;
#else
        return NULL;
#endif
}
EXPORT_SYMBOL(l1_inst_sram_alloc);

int l1_inst_sram_free(const void *addr)
{
#if L1_CODE_LENGTH != 0
        unsigned long flags;
        int ret;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1_inst_sram_lock, cpu), flags);

        ret = _sram_free(addr, &per_cpu(free_l1_inst_sram_head, cpu),
                        &per_cpu(used_l1_inst_sram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1_inst_sram_lock, cpu), flags);
        put_cpu();

        return ret;
#else
        return -1;
#endif
}
EXPORT_SYMBOL(l1_inst_sram_free);

/* L1 Scratchpad memory allocate function */
void *l1sram_alloc(size_t size)
{
        unsigned long flags;
        void *addr;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1sram_lock, cpu), flags);

        addr = _sram_alloc(size, &per_cpu(free_l1_ssram_head, cpu),
                        &per_cpu(used_l1_ssram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1sram_lock, cpu), flags);
        put_cpu();

        return addr;
}

/* L1 Scratchpad memory allocate function */
void *l1sram_alloc_max(size_t *psize)
{
        unsigned long flags;
        void *addr;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1sram_lock, cpu), flags);

        addr = _sram_alloc_max(&per_cpu(free_l1_ssram_head, cpu),
                        &per_cpu(used_l1_ssram_head, cpu), psize);

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1sram_lock, cpu), flags);
        put_cpu();

        return addr;
}

/* L1 Scratchpad memory free function */
int l1sram_free(const void *addr)
{
        unsigned long flags;
        int ret;
        unsigned int cpu;

        cpu = get_cpu();
        /* add mutex operation */
        spin_lock_irqsave(&per_cpu(l1sram_lock, cpu), flags);

        ret = _sram_free(addr, &per_cpu(free_l1_ssram_head, cpu),
                        &per_cpu(used_l1_ssram_head, cpu));

        /* add mutex operation */
        spin_unlock_irqrestore(&per_cpu(l1sram_lock, cpu), flags);
        put_cpu();

        return ret;
}

void *l2_sram_alloc(size_t size)
{
#if L2_LENGTH != 0
        unsigned long flags;
        void *addr;

        /* add mutex operation */
        spin_lock_irqsave(&l2_sram_lock, flags);

        addr = _sram_alloc(size, &free_l2_sram_head,
                        &used_l2_sram_head);

        /* add mutex operation */
        spin_unlock_irqrestore(&l2_sram_lock, flags);

        pr_debug("Allocated address in l2_sram_alloc is 0x%lx+0x%lx\n",
                 (long unsigned int)addr, size);

        return addr;
#else
        return NULL;
#endif
}
EXPORT_SYMBOL(l2_sram_alloc);

void *l2_sram_zalloc(size_t size)
{
        void *addr = l2_sram_alloc(size);

        if (addr)
                memset(addr, 0x00, size);

        return addr;
}
EXPORT_SYMBOL(l2_sram_zalloc);

int l2_sram_free(const void *addr)
{
#if L2_LENGTH != 0
        unsigned long flags;
        int ret;

        /* add mutex operation */
        spin_lock_irqsave(&l2_sram_lock, flags);

        ret = _sram_free(addr, &free_l2_sram_head,
                        &used_l2_sram_head);

        /* add mutex operation */
        spin_unlock_irqrestore(&l2_sram_lock, flags);

        return ret;
#else
        return -1;
#endif
}
EXPORT_SYMBOL(l2_sram_free);

int sram_free_with_lsl(const void *addr)
{
        struct sram_list_struct *lsl, **tmp;
        struct mm_struct *mm = current->mm;

        for (tmp = &mm->context.sram_list; *tmp; tmp = &(*tmp)->next)
                if ((*tmp)->addr == addr)
                        goto found;
        return -1;
found:
        lsl = *tmp;
        sram_free(addr);
        *tmp = lsl->next;
        kfree(lsl);

        return 0;
}
EXPORT_SYMBOL(sram_free_with_lsl);

/* Allocate memory and keep in L1 SRAM List (lsl) so that the resources are
 * tracked.  These are designed for userspace so that when a process exits,
 * we can safely reap their resources.
 */
void *sram_alloc_with_lsl(size_t size, unsigned long flags)
{
        void *addr = NULL;
        struct sram_list_struct *lsl = NULL;
        struct mm_struct *mm = current->mm;

        lsl = kzalloc(sizeof(struct sram_list_struct), GFP_KERNEL);
        if (!lsl)
                return NULL;

        if (flags & L1_INST_SRAM)
                addr = l1_inst_sram_alloc(size);

        if (addr == NULL && (flags & L1_DATA_A_SRAM))
                addr = l1_data_A_sram_alloc(size);

        if (addr == NULL && (flags & L1_DATA_B_SRAM))
                addr = l1_data_B_sram_alloc(size);

        if (addr == NULL && (flags & L2_SRAM))
                addr = l2_sram_alloc(size);

        if (addr == NULL) {
                kfree(lsl);
                return NULL;
        }
        lsl->addr = addr;
        lsl->length = size;
        lsl->next = mm->context.sram_list;
        mm->context.sram_list = lsl;
        return addr;
}
EXPORT_SYMBOL(sram_alloc_with_lsl);

#ifdef CONFIG_PROC_FS
/* Once we get a real allocator, we'll throw all of this away.
 * Until then, we need some sort of visibility into the L1 alloc.
 */
/* Need to keep line of output the same.  Currently, that is 44 bytes
 * (including newline).
 */
static int _sram_proc_read(char *buf, int *len, int count, const char *desc,
                struct sram_piece *pfree_head,
                struct sram_piece *pused_head)
{
        struct sram_piece *pslot;

        if (!pfree_head || !pused_head)
                return -1;

        *len += sprintf(&buf[*len], "--- SRAM %-14s Size   PID State     \n", desc);

        /* search the relevant memory slot */
        pslot = pused_head->next;

        while (pslot != NULL) {
                *len += sprintf(&buf[*len], "%p-%p %10i %5i %-10s\n",
                        pslot->paddr, pslot->paddr + pslot->size,
                        pslot->size, pslot->pid, "ALLOCATED");

                pslot = pslot->next;
        }

        pslot = pfree_head->next;

        while (pslot != NULL) {
                *len += sprintf(&buf[*len], "%p-%p %10i %5i %-10s\n",
                        pslot->paddr, pslot->paddr + pslot->size,
                        pslot->size, pslot->pid, "FREE");

                pslot = pslot->next;
        }

        return 0;
}
static int sram_proc_read(char *buf, char **start, off_t offset, int count,
                int *eof, void *data)
{
        int len = 0;
        unsigned int cpu;

        for (cpu = 0; cpu < num_possible_cpus(); ++cpu) {
                if (_sram_proc_read(buf, &len, count, "Scratchpad",
                        &per_cpu(free_l1_ssram_head, cpu), &per_cpu(used_l1_ssram_head, cpu)))
                        goto not_done;
#if L1_DATA_A_LENGTH != 0
                if (_sram_proc_read(buf, &len, count, "L1 Data A",
                        &per_cpu(free_l1_data_A_sram_head, cpu),
                        &per_cpu(used_l1_data_A_sram_head, cpu)))
                        goto not_done;
#endif
#if L1_DATA_B_LENGTH != 0
                if (_sram_proc_read(buf, &len, count, "L1 Data B",
                        &per_cpu(free_l1_data_B_sram_head, cpu),
                        &per_cpu(used_l1_data_B_sram_head, cpu)))
                        goto not_done;
#endif
#if L1_CODE_LENGTH != 0
                if (_sram_proc_read(buf, &len, count, "L1 Instruction",
                        &per_cpu(free_l1_inst_sram_head, cpu),
                        &per_cpu(used_l1_inst_sram_head, cpu)))
                        goto not_done;
#endif
        }
#if L2_LENGTH != 0
        if (_sram_proc_read(buf, &len, count, "L2", &free_l2_sram_head,
                &used_l2_sram_head))
                goto not_done;
#endif
        *eof = 1;
 not_done:
        return len;
}

static int __init sram_proc_init(void)
{
        struct proc_dir_entry *ptr;
        ptr = create_proc_entry("sram", S_IFREG | S_IRUGO, NULL);
        if (!ptr) {
                printk(KERN_WARNING "unable to create /proc/sram\n");
                return -1;
        }
        ptr->read_proc = sram_proc_read;
        return 0;
}
late_initcall(sram_proc_init);
#endif