diff options
Diffstat (limited to 'drivers/gpu/mali/ump/linux/ump_kernel_random_mapping.c')
| -rw-r--r-- | drivers/gpu/mali/ump/linux/ump_kernel_random_mapping.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/gpu/mali/ump/linux/ump_kernel_random_mapping.c b/drivers/gpu/mali/ump/linux/ump_kernel_random_mapping.c new file mode 100644 index 00000000..95bcb956 --- /dev/null +++ b/drivers/gpu/mali/ump/linux/ump_kernel_random_mapping.c @@ -0,0 +1,207 @@ +/* + * Copyright (C) 2010-2011, 2013-2014 ARM Limited. All rights reserved. + * + * This program is free software and is provided to you under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation, and any use by you of this program is subject to the terms of such GNU licence. + * + * A copy of the licence is included with the program, and can also be obtained from Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include "mali_kernel_common.h" +#include "mali_osk.h" +#include "ump_osk.h" +#include "ump_kernel_common.h" +#include "ump_kernel_types.h" +#include "ump_kernel_random_mapping.h" + +#include <linux/random.h> +#include <linux/rbtree.h> +#include <linux/sched.h> +#include <linux/jiffies.h> + + +static ump_dd_mem *search(struct rb_root *root, int id) +{ + struct rb_node *node = root->rb_node; + + while (node) { + ump_dd_mem *e = container_of(node, ump_dd_mem, node); + + if (id < e->secure_id) { + node = node->rb_left; + } else if (id > e->secure_id) { + node = node->rb_right; + } else { + return e; + } + } + + return NULL; +} + +static mali_bool insert(struct rb_root *root, int id, ump_dd_mem *mem) +{ + struct rb_node **new = &(root->rb_node); + struct rb_node *parent = NULL; + + while (*new) { + ump_dd_mem *this = container_of(*new, ump_dd_mem, node); + + parent = *new; + if (id < this->secure_id) { + new = &((*new)->rb_left); + } else if (id > this->secure_id) { + new = &((*new)->rb_right); + } else { + printk(KERN_ERR "UMP: ID already used %x\n", id); + return MALI_FALSE; + } + } + + rb_link_node(&mem->node, parent, new); + rb_insert_color(&mem->node, root); + + return MALI_TRUE; +} + + +ump_random_mapping *ump_random_mapping_create(void) +{ + ump_random_mapping *map = _mali_osk_calloc(1, sizeof(ump_random_mapping)); + + if (NULL == map) + return NULL; + + map->lock = _mali_osk_mutex_rw_init(_MALI_OSK_LOCKFLAG_ORDERED, + _MALI_OSK_LOCK_ORDER_DESCRIPTOR_MAP); + if (NULL != map->lock) { + map->root = RB_ROOT; +#if UMP_RANDOM_MAP_DELAY + map->failed.count = 0; + map->failed.timestamp = jiffies; +#endif + return map; + } + return NULL; +} + +void ump_random_mapping_destroy(ump_random_mapping *map) +{ + _mali_osk_mutex_rw_term(map->lock); + _mali_osk_free(map); +} + +int ump_random_mapping_insert(ump_random_mapping *map, ump_dd_mem *mem) +{ + _mali_osk_mutex_rw_wait(map->lock, _MALI_OSK_LOCKMODE_RW); + + while (1) { + u32 id; + + get_random_bytes(&id, sizeof(id)); + + /* Try a new random number if id happened to be the invalid + * secure ID (-1). */ + if (unlikely(id == UMP_INVALID_SECURE_ID)) + continue; + + /* Insert into the tree. If the id was already in use, get a + * new random id and try again. */ + if (insert(&map->root, id, mem)) { + mem->secure_id = id; + break; + } + } + _mali_osk_mutex_rw_signal(map->lock, _MALI_OSK_LOCKMODE_RW); + + return 0; +} + +ump_dd_mem *ump_random_mapping_get(ump_random_mapping *map, int id) +{ + ump_dd_mem *mem = NULL; +#if UMP_RANDOM_MAP_DELAY + int do_delay = 0; +#endif + + DEBUG_ASSERT(map); + + _mali_osk_mutex_rw_wait(map->lock, _MALI_OSK_LOCKMODE_RO); + mem = search(&map->root, id); + + if (unlikely(NULL == mem)) { +#if UMP_RANDOM_MAP_DELAY + map->failed.count++; + + if (time_is_before_jiffies(map->failed.timestamp + + UMP_FAILED_LOOKUP_DELAY * HZ)) { + /* If it is a long time since last failure, reset + * the counter and skip the delay this time. */ + map->failed.count = 0; + } else if (map->failed.count > UMP_FAILED_LOOKUPS_ALLOWED) { + do_delay = 1; + } + + map->failed.timestamp = jiffies; +#endif /* UMP_RANDOM_MAP_DELAY */ + } else { + ump_dd_reference_add(mem); + } + _mali_osk_mutex_rw_signal(map->lock, _MALI_OSK_LOCKMODE_RO); + +#if UMP_RANDOM_MAP_DELAY + if (do_delay) { + /* Apply delay */ + schedule_timeout_killable(UMP_FAILED_LOOKUP_DELAY); + } +#endif /* UMP_RANDOM_MAP_DELAY */ + + return mem; +} + +static ump_dd_mem *ump_random_mapping_remove_internal(ump_random_mapping *map, int id) +{ + ump_dd_mem *mem = NULL; + + mem = search(&map->root, id); + + if (mem) { + rb_erase(&mem->node, &map->root); + } + + return mem; +} + +void ump_random_mapping_put(ump_dd_mem *mem) +{ + int new_ref; + + _mali_osk_mutex_rw_wait(device.secure_id_map->lock, _MALI_OSK_LOCKMODE_RW); + + new_ref = _ump_osk_atomic_dec_and_read(&mem->ref_count); + DBG_MSG(5, ("Memory reference decremented. ID: %u, new value: %d\n", + mem->secure_id, new_ref)); + + if (0 == new_ref) { + DBG_MSG(3, ("Final release of memory. ID: %u\n", mem->secure_id)); + + ump_random_mapping_remove_internal(device.secure_id_map, mem->secure_id); + + mem->release_func(mem->ctx, mem); + _mali_osk_free(mem); + } + + _mali_osk_mutex_rw_signal(device.secure_id_map->lock, _MALI_OSK_LOCKMODE_RW); +} + +ump_dd_mem *ump_random_mapping_remove(ump_random_mapping *map, int descriptor) +{ + ump_dd_mem *mem; + + _mali_osk_mutex_rw_wait(map->lock, _MALI_OSK_LOCKMODE_RW); + mem = ump_random_mapping_remove_internal(map, descriptor); + _mali_osk_mutex_rw_signal(map->lock, _MALI_OSK_LOCKMODE_RW); + + return mem; +} |