drivers/misc/samsung/scsc/mifmboxman.c

   1 /****************************************************************************
   2  *
   3  * Copyright (c) 2014 - 2016 Samsung Electronics Co., Ltd. All rights reserved
   4  *
   5  ****************************************************************************/
   6
   7 /* uses */
   8 #include <linux/kernel.h>
   9 #include <linux/printk.h>
  10 #include <linux/slab.h>
  11 #include <linux/mutex.h>
  12 #include <scsc/scsc_logring.h>
  13 #include "scsc_mif_abs.h"
  14
  15 /* Implements */
  16 #include "mifmboxman.h"
  17
  18 int mifmboxman_init(struct mifmboxman *mbox)
  19 {
  20         if (mbox->in_use)
  21                 return -EBUSY;
  22
  23         mutex_init(&mbox->lock);
  24         mbox->mbox_free = MIFMBOX_NUM;
  25         mbox->in_use = true;
  26         bitmap_zero(mbox->bitmap, MIFMBOX_NUM);
  27
  28         return 0;
  29 }
  30
  31 bool mifmboxman_alloc_mboxes(struct mifmboxman *mbox, int n, int *first_mbox_index)
  32 {
  33         unsigned int index = 0;
  34         unsigned int available;
  35         u8           i;
  36
  37         mutex_lock(&mbox->lock);
  38
  39         if ((n > MIFMBOX_NUM) || (n == 0) || !mbox->in_use)
  40                 goto error;
  41
  42         while (index <= (MIFMBOX_NUM - n)) {
  43                 available = 0;
  44
  45                 /* Search consecutive blocks */
  46                 for (i = 0; i < n; i++) {
  47                         if (test_bit((i + index), mbox->bitmap))
  48                                 break;
  49                         available++;
  50                 }
  51
  52                 if (available == n) {
  53                         *first_mbox_index = index;
  54
  55                         for (i = 0; i < n; i++)
  56                                 set_bit(index++, mbox->bitmap);
  57
  58                         mbox->mbox_free -= n;
  59                         goto exit;
  60                 } else
  61                         index = index + available + 1;
  62         }
  63 error:
  64         SCSC_TAG_ERR(MIF, "Error allocating mbox\n");
  65         mutex_unlock(&mbox->lock);
  66         return false;
  67 exit:
  68         mutex_unlock(&mbox->lock);
  69         return true;
  70
  71 }
  72
  73 void mifmboxman_free_mboxes(struct mifmboxman *mbox, int first_mbox_index, int n)
  74 {
  75         int index = 0;
  76         int total_free = 0;
  77
  78         mutex_lock(&mbox->lock);
  79         if ((n > MIFMBOX_NUM) ||
  80             ((n + first_mbox_index) > MIFMBOX_NUM) ||
  81             (n == 0) ||
  82             !mbox->in_use)
  83                 goto error;
  84
  85         for (index = first_mbox_index; index < (first_mbox_index + n); index++)
  86                 if (test_bit(index, mbox->bitmap)) {
  87                         clear_bit(index, mbox->bitmap);
  88                         total_free++;
  89                 }
  90
  91         mbox->mbox_free += total_free;
  92         mutex_unlock(&mbox->lock);
  93         return;
  94 error:
  95         SCSC_TAG_ERR(MIF, "Error freeing mbox\n");
  96         mutex_unlock(&mbox->lock);
  97 }
  98
  99 u32 *mifmboxman_get_mbox_ptr(struct mifmboxman *mbox,  struct scsc_mif_abs *mif_abs, int mbox_index)
 100 {
 101         /* Avoid unused parameter error */
 102         (void)mbox;
 103
 104         return mif_abs->get_mbox_ptr(mif_abs, mbox_index);
 105 }
 106
 107
 108 int mifmboxman_deinit(struct mifmboxman *mbox)
 109 {
 110         mutex_lock(&mbox->lock);
 111         if (!mbox->in_use)
 112                 return -ENODEV;
 113         mbox->in_use = false;
 114         mutex_unlock(&mbox->lock);
 115         return 0;
 116 }