patch-2.3.99-pre6 linux/drivers/sound/emu10k1/emuadxmg.c

• Lines: 102
• Date: Fri Apr 21 16:08:45 2000
• Orig file: v2.3.99-pre5/linux/drivers/sound/emu10k1/emuadxmg.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre5/linux/drivers/sound/emu10k1/emuadxmg.c linux/drivers/sound/emu10k1/emuadxmg.c
@@ -0,0 +1,101 @@
+
+/*     
+ **********************************************************************
+ *     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);
+
+	while (index < (MAXPAGES - RESERVED - 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) {
+				spin_lock_irqsave(&card->lock, flags);
+
+				/* 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];
+			}
+		}
+	}
+
+	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;
+}