475 lines
10 KiB
C
475 lines
10 KiB
C
/*
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* PUPA -- Preliminary Universal Programming Architecture for GRUB
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* Copyright (C) 2002 Yoshinori K. Okuji <okuji@enbug.org>
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*
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* PUPA is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with PUPA; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <pupa/disk.h>
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#include <pupa/err.h>
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#include <pupa/mm.h>
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#include <pupa/types.h>
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#include <pupa/machine/partition.h>
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#include <pupa/misc.h>
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/* Disk cache. */
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struct pupa_disk_cache
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{
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unsigned long id;
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unsigned long sector;
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char *data;
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int lock;
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};
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static struct pupa_disk_cache pupa_disk_cache_table[PUPA_DISK_CACHE_NUM];
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#if 0
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static unsigned long pupa_disk_cache_hits;
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static unsigned long pupa_disk_cache_misses;
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void
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pupa_disk_cache_get_performance (unsigned long *hits, unsigned long *misses)
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{
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*hits = pupa_disk_cache_hits;
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*misses = pupa_disk_cache_misses;
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}
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#endif
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static unsigned
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pupa_disk_cache_get_index (unsigned long id, unsigned long sector)
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{
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return ((id * 2606459 + (sector >> PUPA_DISK_CACHE_BITS))
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% PUPA_DISK_CACHE_NUM);
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}
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static void
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pupa_disk_cache_invalidate (unsigned long id, unsigned long sector)
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{
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unsigned index;
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struct pupa_disk_cache *cache;
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sector &= ~(PUPA_DISK_CACHE_SIZE - 1);
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index = pupa_disk_cache_get_index (id, sector);
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cache = pupa_disk_cache_table + index;
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if (cache->id == id && cache->sector == sector && cache->data)
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{
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cache->lock = 1;
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pupa_free (cache->data);
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cache->data = 0;
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cache->lock = 0;
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}
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}
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void
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pupa_disk_cache_invalidate_all (void)
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{
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unsigned i;
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for (i = 0; i < PUPA_DISK_CACHE_NUM; i++)
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{
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struct pupa_disk_cache *cache = pupa_disk_cache_table + i;
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if (cache->data && ! cache->lock)
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{
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pupa_free (cache->data);
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cache->data = 0;
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}
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}
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}
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static char *
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pupa_disk_cache_fetch (unsigned long id, unsigned long sector)
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{
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struct pupa_disk_cache *cache;
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unsigned index;
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index = pupa_disk_cache_get_index (id, sector);
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cache = pupa_disk_cache_table + index;
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if (cache->id == id && cache->sector == sector)
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{
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cache->lock = 1;
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#if 0
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pupa_disk_cache_hits++;
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#endif
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return cache->data;
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}
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#if 0
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pupa_disk_cache_misses++;
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#endif
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return 0;
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}
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static void
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pupa_disk_cache_unlock (unsigned long id, unsigned long sector)
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{
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struct pupa_disk_cache *cache;
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unsigned index;
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index = pupa_disk_cache_get_index (id, sector);
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cache = pupa_disk_cache_table + index;
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if (cache->id == id && cache->sector == sector)
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cache->lock = 0;
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}
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static pupa_err_t
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pupa_disk_cache_store (unsigned long id, unsigned long sector,
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const char *data)
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{
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unsigned index;
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struct pupa_disk_cache *cache;
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pupa_disk_cache_invalidate (id, sector);
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index = pupa_disk_cache_get_index (id, sector);
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cache = pupa_disk_cache_table + index;
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cache->data = pupa_malloc (PUPA_DISK_SECTOR_SIZE << PUPA_DISK_CACHE_BITS);
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if (! cache->data)
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return pupa_errno;
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pupa_memcpy (cache->data, data,
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PUPA_DISK_SECTOR_SIZE << PUPA_DISK_CACHE_BITS);
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cache->id = id;
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cache->sector = sector;
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return PUPA_ERR_NONE;
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}
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static pupa_disk_dev_t pupa_disk_dev_list;
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void
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pupa_disk_dev_register (pupa_disk_dev_t dev)
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{
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dev->next = pupa_disk_dev_list;
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pupa_disk_dev_list = dev;
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}
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void
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pupa_disk_dev_unregister (pupa_disk_dev_t dev)
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{
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pupa_disk_dev_t *p, q;
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for (p = &pupa_disk_dev_list, q = *p; q; p = &(q->next), q = q->next)
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if (q == dev)
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{
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*p = q->next;
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break;
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}
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}
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void
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pupa_disk_dev_iterate (int (*hook) (const char *name))
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{
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pupa_disk_dev_t p;
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for (p = pupa_disk_dev_list; p; p = p->next)
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if ((p->iterate) (hook))
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break;
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}
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pupa_disk_t
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pupa_disk_open (const char *name)
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{
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char *p;
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pupa_disk_t disk;
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pupa_disk_dev_t dev;
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char *raw = (char *) name;
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disk = (pupa_disk_t) pupa_malloc (sizeof (*disk));
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if (! disk)
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return 0;
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disk->dev = 0;
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disk->read_hook = 0;
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disk->partition = 0;
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disk->data = 0;
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disk->name = pupa_strdup (name);
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if (! disk->name)
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goto fail;
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p = pupa_strchr (name, ',');
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if (p)
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{
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pupa_size_t len = p - name;
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raw = pupa_malloc (len + 1);
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if (! raw)
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goto fail;
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pupa_memcpy (raw, name, len);
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raw[len] = '\0';
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}
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for (dev = pupa_disk_dev_list; dev; dev = dev->next)
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{
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if ((dev->open) (raw, disk) == PUPA_ERR_NONE)
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break;
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else if (pupa_errno == PUPA_ERR_UNKNOWN_DEVICE)
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pupa_errno = PUPA_ERR_NONE;
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else
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goto fail;
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}
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if (! dev)
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{
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pupa_error (PUPA_ERR_UNKNOWN_DEVICE, "no such disk");
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goto fail;
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}
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if (p && ! disk->has_partitions)
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{
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pupa_error (PUPA_ERR_BAD_DEVICE, "no partition on this disk");
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goto fail;
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}
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disk->dev = dev;
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if (p)
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disk->partition = pupa_partition_probe (disk, p + 1);
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fail:
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if (raw && raw != name)
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pupa_free (raw);
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if (pupa_errno != PUPA_ERR_NONE)
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{
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pupa_disk_close (disk);
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return 0;
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}
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return disk;
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}
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void
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pupa_disk_close (pupa_disk_t disk)
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{
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if (disk->dev && disk->dev->close)
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(disk->dev->close) (disk);
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pupa_free (disk->partition);
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pupa_free ((void *) disk->name);
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pupa_free (disk);
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}
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static pupa_err_t
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pupa_disk_check_range (pupa_disk_t disk, unsigned long *sector,
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unsigned long *offset, pupa_ssize_t size)
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{
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*sector += *offset >> PUPA_DISK_SECTOR_BITS;
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*offset &= PUPA_DISK_SECTOR_SIZE - 1;
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if (disk->partition)
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{
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unsigned long start, len;
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start = pupa_partition_get_start (disk->partition);
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len = pupa_partition_get_len (disk->partition);
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if (*sector >= len
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|| len - *sector < ((*offset + size + PUPA_DISK_SECTOR_SIZE - 1)
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>> PUPA_DISK_SECTOR_BITS))
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return pupa_error (PUPA_ERR_OUT_OF_RANGE, "out of partition");
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*sector += start;
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}
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if (disk->total_sectors <= *sector
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|| ((*offset + size + PUPA_DISK_SECTOR_SIZE - 1)
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>> PUPA_DISK_SECTOR_BITS) > disk->total_sectors - *sector)
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return pupa_error (PUPA_ERR_OUT_OF_RANGE, "out of disk");
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return PUPA_ERR_NONE;
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}
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/* Read data from the disk. */
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pupa_err_t
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pupa_disk_read (pupa_disk_t disk, unsigned long sector,
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unsigned long offset, unsigned long size, char *buf)
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{
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char *tmp_buf;
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/* First of all, check if the region is within the disk. */
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if (pupa_disk_check_range (disk, §or, &offset, size) != PUPA_ERR_NONE)
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return pupa_errno;
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/* Allocate a temporary buffer. */
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tmp_buf = pupa_malloc (PUPA_DISK_SECTOR_SIZE << PUPA_DISK_CACHE_BITS);
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if (! tmp_buf)
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return pupa_errno;
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/* Until SIZE is zero... */
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while (size)
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{
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char *data;
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unsigned long start_sector;
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unsigned long len;
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unsigned long pos;
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/* For reading bulk data. */
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start_sector = sector & ~(PUPA_DISK_CACHE_SIZE - 1);
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pos = (sector - start_sector) << PUPA_DISK_SECTOR_BITS;
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len = (PUPA_DISK_SECTOR_SIZE << PUPA_DISK_CACHE_BITS) - pos - offset;
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if (len > size)
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len = size;
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/* Fetch the cache. */
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data = pupa_disk_cache_fetch (disk->id, start_sector);
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if (data)
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{
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/* Just copy it! */
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pupa_memcpy (buf, data + pos + offset, len);
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pupa_disk_cache_unlock (disk->id, start_sector);
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}
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else
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{
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/* Otherwise read data from the disk actually. */
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if ((disk->dev->read) (disk, start_sector,
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PUPA_DISK_CACHE_SIZE, tmp_buf)
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!= PUPA_ERR_NONE)
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{
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/* Uggh... Failed. Instead, just read necessary data. */
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unsigned num;
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/* If more data is required, no way. */
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if (pos + size
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>= (PUPA_DISK_SECTOR_SIZE << PUPA_DISK_CACHE_BITS))
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goto finish;
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num = ((size + PUPA_DISK_SECTOR_SIZE - 1)
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>> PUPA_DISK_SECTOR_BITS);
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if ((disk->dev->read) (disk, sector, num, tmp_buf))
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goto finish;
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pupa_memcpy (buf, tmp_buf + offset, size);
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/* Call the read hook, if any. */
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if (disk->read_hook)
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while (size)
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{
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(disk->read_hook) (sector, offset,
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((size > PUPA_DISK_SECTOR_SIZE)
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? PUPA_DISK_SECTOR_SIZE
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: size));
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sector++;
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size -= PUPA_DISK_SECTOR_SIZE - offset;
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offset = 0;
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}
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/* This must be the end. */
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goto finish;
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}
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/* Copy it and store it in the disk cache. */
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pupa_memcpy (buf, tmp_buf + pos + offset, len);
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pupa_disk_cache_store (disk->id, start_sector, tmp_buf);
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}
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/* Call the read hook, if any. */
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if (disk->read_hook)
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{
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unsigned long s = sector;
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unsigned long l = len;
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while (l)
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{
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(disk->read_hook) (s, offset,
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((l > PUPA_DISK_SECTOR_SIZE)
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? PUPA_DISK_SECTOR_SIZE
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: l));
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s++;
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l -= PUPA_DISK_SECTOR_SIZE - offset;
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offset = 0;
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}
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}
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sector = start_sector + PUPA_DISK_CACHE_SIZE;
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buf += len;
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size -= len;
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offset = 0;
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}
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finish:
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pupa_free (tmp_buf);
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return pupa_errno;
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}
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pupa_err_t
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pupa_disk_write (pupa_disk_t disk, unsigned long sector,
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unsigned long offset, unsigned long size, const char *buf)
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{
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if (pupa_disk_check_range (disk, §or, &offset, size) != PUPA_ERR_NONE)
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return -1;
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while (size)
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{
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if (offset != 0 || (size < PUPA_DISK_SECTOR_SIZE && size != 0))
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{
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char tmp_buf[PUPA_DISK_SECTOR_SIZE];
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unsigned long len;
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if (pupa_disk_read (disk, sector, 0, PUPA_DISK_SECTOR_SIZE, tmp_buf)
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!= PUPA_ERR_NONE)
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goto finish;
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len = PUPA_DISK_SECTOR_SIZE - offset;
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if (len > size)
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len = size;
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pupa_memcpy (tmp_buf + offset, buf, len);
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pupa_disk_cache_invalidate (disk->id, sector);
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if ((disk->dev->write) (disk, sector, 1, tmp_buf) != PUPA_ERR_NONE)
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goto finish;
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sector++;
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buf += len;
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size -= len;
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offset = 0;
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}
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else
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{
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unsigned long len;
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unsigned long n;
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len = size & ~(PUPA_DISK_SECTOR_SIZE - 1);
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n = size >> PUPA_DISK_SECTOR_BITS;
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if ((disk->dev->write) (disk, sector, n, buf) != PUPA_ERR_NONE)
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goto finish;
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while (n--)
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pupa_disk_cache_invalidate (disk->id, sector++);
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buf += len;
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size -= len;
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}
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}
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finish:
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return pupa_errno;
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}
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