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877b2cedc7
A 16-bit device number or id further distinguishes a device on the system in addition to the device type. This is meant to be used for the very first identification of the device for further probing. Any further info is available by userspace mapping and probing.
88 lines
1.9 KiB
C
88 lines
1.9 KiB
C
/*
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* Used for thread and space ids, and also for
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* utcb tracking in page-sized-chunks.
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*
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* Copyright (C) 2009 B Labs Ltd.
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*/
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#include <l4lib/idpool.h>
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#include <stdio.h>
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#include <l4/api/errno.h>
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#include <malloc/malloc.h>
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struct id_pool *id_pool_new_init(int totalbits)
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{
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int nwords = BITWISE_GETWORD(totalbits) + 1;
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struct id_pool *new = kzalloc((nwords * SZ_WORD)
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+ sizeof(struct id_pool));
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if (!new)
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return PTR_ERR(-ENOMEM);
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new->nwords = nwords;
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new->bitlimit = totalbits;
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return new;
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}
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/* Search for a free slot up to the limit given */
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int id_new(struct id_pool *pool)
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{
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return find_and_set_first_free_bit(pool->bitmap, pool->bitlimit);
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}
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/* This finds n contiguous free ids, allocates and returns the first one */
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int ids_new_contiguous(struct id_pool *pool, int numids)
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{
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int id = find_and_set_first_free_contig_bits(pool->bitmap,
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pool->bitlimit,
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numids);
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if (id < 0)
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printf("%s: Warning! New id alloc failed\n", __FUNCTION__);
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return id;
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}
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/* This deletes a list of contiguous ids given the first one and number of ids */
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int ids_del_contiguous(struct id_pool *pool, int first, int numids)
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{
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int ret;
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if (pool->nwords * WORD_BITS < first + numids)
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return -1;
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if ((ret = check_and_clear_contig_bits(pool->bitmap, first, numids)))
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printf("%s: Error: Invalid argument range.\n", __FUNCTION__);
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return ret;
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}
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int id_del(struct id_pool *pool, int id)
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{
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int ret;
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if (pool->nwords * WORD_BITS < id)
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return -1;
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if ((ret = check_and_clear_bit(pool->bitmap, id) < 0))
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printf("%s: Error: Could not delete id.\n", __FUNCTION__);
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return ret;
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}
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/* Return a specific id, if available */
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int id_get(struct id_pool *pool, int id)
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{
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int ret;
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ret = check_and_set_bit(pool->bitmap, id);
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if (ret < 0)
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return ret;
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else
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return id;
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}
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int id_is_empty(struct id_pool *pool)
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{
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for (int i = 0; i < pool->nwords; i++)
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if (pool->bitmap[i])
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return 0;
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return 1;
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}
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