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Diffstat (limited to 'sound/oss/emu10k1/emuadxmg.c')
-rw-r--r--sound/oss/emu10k1/emuadxmg.c104
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 00000000000..d7d2d4caf7b
--- /dev/null
+++ b/sound/oss/emu10k1/emuadxmg.c
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+
+/*
+ **********************************************************************
+ * 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;
+}