/*
**********************************************************************
* emuadxmg.c - Address space manager for emu10k1 driver
* Copyright 1999, 2000 Creative Labs, Inc.
*
**********************************************************************
*
* Date Author Summary of changes
* ---- ------ ------------------
* October 20, 1999 Bertrand Lee base code release
*
**********************************************************************
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
* USA.
*
**********************************************************************
*/
#include "hwaccess.h"
/* Allocates emu address space */
int emu10k1_addxmgr_alloc(u32 size, struct emu10k1_card *card)
{
u16 *pagetable = card->emupagetable;
u16 index = 0;
u16 numpages;
unsigned long flags;
/* Convert bytes to pages */
numpages = (size / EMUPAGESIZE) + ((size % EMUPAGESIZE) ? 1 : 0);
spin_lock_irqsave(&card->lock, flags);
while (index < (MAXPAGES - 1)) {
if (pagetable[index] & 0x8000) {
/* This block of pages is in use, jump to the start of the next block. */
index += (pagetable[index] & 0x7fff);
} else {
/* Found free block */
if (pagetable[index] >= numpages) {
/* Block is large enough */
/* If free block is larger than the block requested
* then adjust the size of the block remaining */
if (pagetable[index] > numpages)
pagetable[index + numpages] = pagetable[index] - numpages;
pagetable[index] = (numpages | 0x8000); /* Mark block as used */
spin_unlock_irqrestore(&card->lock, flags);
return index;
} else {
/* Block too small, jump to the start of the next block */
index += pagetable[index];
}
}
}
spin_unlock_irqrestore(&card->lock, flags);
return -1;
}
/* Frees a previously allocated emu address space. */
void emu10k1_addxmgr_free(struct emu10k1_card *card, int index)
{
u16 *pagetable = card->emupagetable;
u16 origsize = 0;
unsigned long flags;
spin_lock_irqsave(&card->lock, flags);
if (pagetable[index] & 0x8000) {
/* Block is allocated - mark block as free */
origsize = pagetable[index] & 0x7fff;
pagetable[index] = origsize;
/* If next block is free, we concat both blocks */
if (!(pagetable[index + origsize] & 0x8000))
pagetable[index] += pagetable[index + origsize] & 0x7fff;
}
spin_unlock_irqrestore(&card->lock, flags);
return;
}
