drivers/misc/mediatek/gpu/mt8127/mali/ump/linux/ump_kernel_random_mapping.c

   1 /*
   2  * This confidential and proprietary software may be used only as
   3  * authorised by a licensing agreement from ARM Limited
   4  * (C) COPYRIGHT 2008-2011, 2013-2015 ARM Limited
   5  * ALL RIGHTS RESERVED
   6  * The entire notice above must be reproduced on all authorised
   7  * copies and copies may only be made to the extent permitted
   8  * by a licensing agreement from ARM Limited.
   9  */
  10
  11 #include "mali_kernel_common.h"
  12 #include "mali_osk.h"
  13 #include "ump_osk.h"
  14 #include "ump_kernel_common.h"
  15 #include "ump_kernel_types.h"
  16 #include "ump_kernel_random_mapping.h"
  17
  18 #include <linux/random.h>
  19 #include <linux/rbtree.h>
  20 #include <linux/sched.h>
  21 #include <linux/jiffies.h>
  22
  23
  24 static ump_dd_mem *search(struct rb_root *root, int id)
  25 {
  26         struct rb_node *node = root->rb_node;
  27
  28         while (node) {
  29                 ump_dd_mem *e = container_of(node, ump_dd_mem, node);
  30
  31                 if (id < e->secure_id) {
  32                         node = node->rb_left;
  33                 } else if (id > e->secure_id) {
  34                         node = node->rb_right;
  35                 } else {
  36                         return e;
  37                 }
  38         }
  39
  40         return NULL;
  41 }
  42
  43 static mali_bool insert(struct rb_root *root, int id, ump_dd_mem *mem)
  44 {
  45         struct rb_node **new = &(root->rb_node);
  46         struct rb_node *parent = NULL;
  47
  48         while (*new) {
  49                 ump_dd_mem *this = container_of(*new, ump_dd_mem, node);
  50
  51                 parent = *new;
  52                 if (id < this->secure_id) {
  53                         new = &((*new)->rb_left);
  54                 } else if (id > this->secure_id) {
  55                         new = &((*new)->rb_right);
  56                 } else {
  57                         pr_warn("UMP: ID already used %x\n", id);
  58                         return MALI_FALSE;
  59                 }
  60         }
  61
  62         rb_link_node(&mem->node, parent, new);
  63         rb_insert_color(&mem->node, root);
  64
  65         return MALI_TRUE;
  66 }
  67
  68
  69 ump_random_mapping *ump_random_mapping_create(void)
  70 {
  71         ump_random_mapping *map = _mali_osk_calloc(1, sizeof(ump_random_mapping));
  72
  73         if (NULL == map)
  74                 return NULL;
  75
  76         map->lock = _mali_osk_mutex_rw_init(_MALI_OSK_LOCKFLAG_ORDERED,
  77                                             _MALI_OSK_LOCK_ORDER_DESCRIPTOR_MAP);
  78         if (NULL != map->lock) {
  79                 map->root = RB_ROOT;
  80 #if UMP_RANDOM_MAP_DELAY
  81                 map->failed.count = 0;
  82                 map->failed.timestamp = jiffies;
  83 #endif
  84                 return map;
  85         }
  86         return NULL;
  87 }
  88
  89 void ump_random_mapping_destroy(ump_random_mapping *map)
  90 {
  91         _mali_osk_mutex_rw_term(map->lock);
  92         _mali_osk_free(map);
  93 }
  94
  95 int ump_random_mapping_insert(ump_random_mapping *map, ump_dd_mem *mem)
  96 {
  97         _mali_osk_mutex_rw_wait(map->lock, _MALI_OSK_LOCKMODE_RW);
  98
  99         while (1) {
 100                 u32 id;
 101
 102                 get_random_bytes(&id, sizeof(id));
 103
 104                 /* Try a new random number if id happened to be the invalid
 105                  * secure ID (-1). */
 106                 if (unlikely(id == UMP_INVALID_SECURE_ID))
 107                         continue;
 108
 109                 /* Insert into the tree. If the id was already in use, get a
 110                  * new random id and try again. */
 111                 if (insert(&map->root, id, mem)) {
 112                         mem->secure_id = id;
 113                         break;
 114                 }
 115         }
 116         _mali_osk_mutex_rw_signal(map->lock, _MALI_OSK_LOCKMODE_RW);
 117
 118         return 0;
 119 }
 120
 121 ump_dd_mem *ump_random_mapping_get(ump_random_mapping *map, int id)
 122 {
 123         ump_dd_mem *mem = NULL;
 124 #if UMP_RANDOM_MAP_DELAY
 125         int do_delay = 0;
 126 #endif
 127
 128         DEBUG_ASSERT(map);
 129
 130         _mali_osk_mutex_rw_wait(map->lock, _MALI_OSK_LOCKMODE_RO);
 131         mem = search(&map->root, id);
 132
 133         if (unlikely(NULL == mem)) {
 134 #if UMP_RANDOM_MAP_DELAY
 135                 map->failed.count++;
 136
 137                 if (time_is_before_jiffies(map->failed.timestamp +
 138                                            UMP_FAILED_LOOKUP_DELAY * HZ)) {
 139                         /* If it is a long time since last failure, reset
 140                          * the counter and skip the delay this time. */
 141                         map->failed.count = 0;
 142                 } else if (map->failed.count > UMP_FAILED_LOOKUPS_ALLOWED) {
 143                         do_delay = 1;
 144                 }
 145
 146                 map->failed.timestamp = jiffies;
 147 #endif /* UMP_RANDOM_MAP_DELAY */
 148         } else {
 149                 ump_dd_reference_add(mem);
 150         }
 151         _mali_osk_mutex_rw_signal(map->lock, _MALI_OSK_LOCKMODE_RO);
 152
 153 #if UMP_RANDOM_MAP_DELAY
 154         if (do_delay) {
 155                 /* Apply delay */
 156                 schedule_timeout_killable(UMP_FAILED_LOOKUP_DELAY);
 157         }
 158 #endif /* UMP_RANDOM_MAP_DELAY */
 159
 160         return mem;
 161 }
 162
 163 static ump_dd_mem *ump_random_mapping_remove_internal(ump_random_mapping *map, int id)
 164 {
 165         ump_dd_mem *mem = NULL;
 166
 167         mem = search(&map->root, id);
 168
 169         if (mem) {
 170                 rb_erase(&mem->node, &map->root);
 171         }
 172
 173         return mem;
 174 }
 175
 176 void ump_random_mapping_put(ump_dd_mem *mem)
 177 {
 178         int new_ref;
 179
 180         _mali_osk_mutex_rw_wait(device.secure_id_map->lock, _MALI_OSK_LOCKMODE_RW);
 181
 182         new_ref = _ump_osk_atomic_dec_and_read(&mem->ref_count);
 183         DBG_MSG(5, ("Memory reference decremented. ID: %u, new value: %d\n",
 184                     mem->secure_id, new_ref));
 185
 186         if (0 == new_ref) {
 187                 DBG_MSG(3, ("Final release of memory. ID: %u\n", mem->secure_id));
 188
 189                 ump_random_mapping_remove_internal(device.secure_id_map, mem->secure_id);
 190
 191                 mem->release_func(mem->ctx, mem);
 192                 _mali_osk_free(mem);
 193         }
 194
 195         _mali_osk_mutex_rw_signal(device.secure_id_map->lock, _MALI_OSK_LOCKMODE_RW);
 196 }
 197
 198 ump_dd_mem *ump_random_mapping_remove(ump_random_mapping *map, int descriptor)
 199 {
 200         ump_dd_mem *mem;
 201
 202         _mali_osk_mutex_rw_wait(map->lock, _MALI_OSK_LOCKMODE_RW);
 203         mem = ump_random_mapping_remove_internal(map, descriptor);
 204         _mali_osk_mutex_rw_signal(map->lock, _MALI_OSK_LOCKMODE_RW);
 205
 206         return mem;
 207 }