diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /sound/oss/emu10k1/emuadxmg.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'sound/oss/emu10k1/emuadxmg.c')
-rw-r--r-- | sound/oss/emu10k1/emuadxmg.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/sound/oss/emu10k1/emuadxmg.c b/sound/oss/emu10k1/emuadxmg.c new file mode 100644 index 000000000000..d7d2d4caf7ba --- /dev/null +++ b/sound/oss/emu10k1/emuadxmg.c @@ -0,0 +1,104 @@ + +/* + ********************************************************************** + * 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; +} |