diff options
Diffstat (limited to 'drivers/base/ump/src/common/ump_kernel_descriptor_mapping.c')
| -rwxr-xr-x | drivers/base/ump/src/common/ump_kernel_descriptor_mapping.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/base/ump/src/common/ump_kernel_descriptor_mapping.c b/drivers/base/ump/src/common/ump_kernel_descriptor_mapping.c new file mode 100755 index 00000000000..148ef1246c5 --- /dev/null +++ b/drivers/base/ump/src/common/ump_kernel_descriptor_mapping.c @@ -0,0 +1,160 @@ +/* + * + * (C) COPYRIGHT 2008-2012 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 <common/ump_kernel_descriptor_mapping.h> +#include <common/ump_kernel_priv.h> + +#define MALI_PAD_INT(x) (((x) + (BITS_PER_LONG - 1)) & ~(BITS_PER_LONG - 1)) + +/** + * Allocate a descriptor table capable of holding 'count' mappings + * @param count Number of mappings in the table + * @return Pointer to a new table, NULL on error + */ +static umpp_descriptor_table * descriptor_table_alloc(unsigned int count); + +/** + * Free a descriptor table + * @param table The table to free + */ +static void descriptor_table_free(umpp_descriptor_table * table); + +umpp_descriptor_mapping * umpp_descriptor_mapping_create(unsigned int init_entries, unsigned int max_entries) +{ + umpp_descriptor_mapping * map = kzalloc(sizeof(umpp_descriptor_mapping), GFP_KERNEL); + + init_entries = MALI_PAD_INT(init_entries); + max_entries = MALI_PAD_INT(max_entries); + + if (NULL != map) + { + map->table = descriptor_table_alloc(init_entries); + if (NULL != map->table) + { + init_rwsem( &map->lock); + set_bit(0, map->table->usage); + map->max_nr_mappings_allowed = max_entries; + map->current_nr_mappings = init_entries; + return map; + + descriptor_table_free(map->table); + } + kfree(map); + } + return NULL; +} + +void umpp_descriptor_mapping_destroy(umpp_descriptor_mapping * map) +{ + UMP_ASSERT(NULL != map); + descriptor_table_free(map->table); + kfree(map); +} + +unsigned int umpp_descriptor_mapping_allocate(umpp_descriptor_mapping * map, void * target) +{ + int descriptor = 0; + UMP_ASSERT(NULL != map); + down_write( &map->lock); + descriptor = find_first_zero_bit(map->table->usage, map->current_nr_mappings); + if (descriptor == map->current_nr_mappings) + { + /* no free descriptor, try to expand the table */ + umpp_descriptor_table * new_table; + umpp_descriptor_table * old_table = map->table; + int nr_mappings_new = map->current_nr_mappings + BITS_PER_LONG; + + if (map->current_nr_mappings >= map->max_nr_mappings_allowed) + { + descriptor = 0; + goto unlock_and_exit; + } + + new_table = descriptor_table_alloc(nr_mappings_new); + if (NULL == new_table) + { + descriptor = 0; + goto unlock_and_exit; + } + + memcpy(new_table->usage, old_table->usage, (sizeof(unsigned long)*map->current_nr_mappings) / BITS_PER_LONG); + memcpy(new_table->mappings, old_table->mappings, map->current_nr_mappings * sizeof(void*)); + + map->table = new_table; + map->current_nr_mappings = nr_mappings_new; + descriptor_table_free(old_table); + } + + /* we have found a valid descriptor, set the value and usage bit */ + set_bit(descriptor, map->table->usage); + map->table->mappings[descriptor] = target; + +unlock_and_exit: + up_write(&map->lock); + return descriptor; +} + +int umpp_descriptor_mapping_lookup(umpp_descriptor_mapping * map, unsigned int descriptor, void** const target) +{ + int result = -EINVAL; + UMP_ASSERT(map); + UMP_ASSERT(target); + down_read(&map->lock); + if ( (descriptor > 0) && (descriptor < map->current_nr_mappings) && test_bit(descriptor, map->table->usage) ) + { + *target = map->table->mappings[descriptor]; + result = 0; + } + /* keep target untouched if the descriptor was not found */ + up_read(&map->lock); + return result; +} + +void umpp_descriptor_mapping_remove(umpp_descriptor_mapping * map, unsigned int descriptor) +{ + UMP_ASSERT(map); + down_write(&map->lock); + if ( (descriptor > 0) && (descriptor < map->current_nr_mappings) && test_bit(descriptor, map->table->usage) ) + { + map->table->mappings[descriptor] = NULL; + clear_bit(descriptor, map->table->usage); + } + up_write(&map->lock); +} + +static umpp_descriptor_table * descriptor_table_alloc(unsigned int count) +{ + umpp_descriptor_table * table; + + table = kzalloc(sizeof(umpp_descriptor_table) + ((sizeof(unsigned long) * count)/BITS_PER_LONG) + (sizeof(void*) * count), __GFP_HARDWALL | GFP_KERNEL ); + + if (NULL != table) + { + table->usage = (unsigned long*)((u8*)table + sizeof(umpp_descriptor_table)); + table->mappings = (void**)((u8*)table + sizeof(umpp_descriptor_table) + ((sizeof(unsigned long) * count)/BITS_PER_LONG)); + } + + return table; +} + +static void descriptor_table_free(umpp_descriptor_table * table) +{ + UMP_ASSERT(table); + kfree(table); +} + |