patch-1.3.94 linux/arch/m68k/amiga/chipram.c

• Lines: 159
• Date: Thu Mar 7 18:19:55 1996
• Orig file: v1.3.93/linux/arch/m68k/amiga/chipram.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.93/linux/arch/m68k/amiga/chipram.c linux/arch/m68k/amiga/chipram.c
@@ -0,0 +1,158 @@
+/*
+**  linux/amiga/chipram.c
+**
+**      Modified 03-May-94 by Geert Uytterhoeven
+**                           (Geert.Uytterhoeven@cs.kuleuven.ac.be)
+**          - 64-bit aligned allocations for full AGA compatibility
+*/
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/bootinfo.h>
+#include <asm/amigahw.h>
+
+struct chip_desc {
+	unsigned first   :  1;
+	unsigned last    :  1;
+	unsigned alloced :  1;
+	unsigned length  : 24;
+	long pad;					/* We suppose this makes this struct 64 bits long!! */
+};
+
+#define DP(ptr) ((struct chip_desc *)(ptr))
+
+static unsigned long chipsize;
+
+void amiga_chip_init (void)
+{
+  struct chip_desc *dp;
+
+  if (!AMIGAHW_PRESENT(CHIP_RAM))
+    return;
+
+  chipsize = boot_info.bi_amiga.chip_size;
+
+  /* initialize start boundary */
+
+  custom.color[0] = 0xfff;
+
+  dp = DP(chipaddr);
+  dp->first = 1;
+
+  custom.color[0] = 0x0f00;
+
+  dp->alloced = 0;
+  dp->length = chipsize - 2*sizeof(*dp);
+
+  /* initialize end boundary */
+  dp = DP(chipaddr + chipsize) - 1;
+  dp->last = 1;
+  
+  custom.color[0] = 0x00f0;
+
+  dp->alloced = 0;
+  dp->length = chipsize - 2*sizeof(*dp);
+
+  custom.color[0] = 0x000f;
+
+#ifdef DEBUG
+  printk ("chipram end boundary is %p, length is %d\n", dp,
+	  dp->length);
+#endif
+}
+
+void *amiga_chip_alloc (long size)
+{
+	/* last chunk */
+	struct chip_desc *dp;
+	void *ptr;
+
+	/* round off */
+	size = (size + 7) & ~7;
+
+#ifdef DEBUG
+	printk ("chip_alloc: allocate %ld bytes\n", size);
+#endif
+
+	/*
+	 * get pointer to descriptor for last chunk by 
+	 * going backwards from end chunk
+	 */
+	dp = DP(chipaddr + chipsize) - 1;
+	dp = DP((unsigned long)dp - dp->length) - 1;
+	
+	while ((dp->alloced || dp->length < size)
+	       && !dp->first)
+		dp = DP ((unsigned long)dp - dp[-1].length) - 2;
+
+	if (dp->alloced || dp->length < size) {
+		printk ("no chipmem available for %ld allocation\n", size);
+		return NULL;
+	}
+
+	if (dp->length < (size + 2*sizeof(*dp))) {
+		/* length too small to split; allocate the whole thing */
+		dp->alloced = 1;
+		ptr = (void *)(dp+1);
+		dp = DP((unsigned long)ptr + dp->length);
+		dp->alloced = 1;
+#ifdef DEBUG
+		printk ("chip_alloc: no split\n");
+#endif
+	} else {
+		/* split the extent; use the end part */
+		long newsize = dp->length - (2*sizeof(*dp) + size);
+
+#ifdef DEBUG
+		printk ("chip_alloc: splitting %d to %ld\n", dp->length,
+			newsize);
+#endif
+		dp->length = newsize;
+		dp = DP((unsigned long)(dp+1) + newsize);
+		dp->first = dp->last = 0;
+		dp->alloced = 0;
+		dp->length = newsize;
+		dp++;
+		dp->first = dp->last = 0;
+		dp->alloced = 1;
+		dp->length = size;
+		ptr = (void *)(dp+1);
+		dp = DP((unsigned long)ptr + size);
+		dp->alloced = 1;
+		dp->length = size;
+	}
+
+#ifdef DEBUG
+	printk ("chip_alloc: returning %p\n", ptr);
+#endif
+
+	if ((unsigned long)ptr & 7)
+		panic("chip_alloc: alignment violation\n");
+
+	return ptr;
+}
+
+void amiga_chip_free (void *ptr)
+{
+	struct chip_desc *sdp = DP(ptr) - 1, *dp2;
+	struct chip_desc *edp = DP((unsigned long)ptr + sdp->length);
+
+	/* deallocate the chunk */
+	sdp->alloced = edp->alloced = 0;
+
+	/* check if we should merge with the previous chunk */
+	if (!sdp->first && !sdp[-1].alloced) {
+		dp2 = DP((unsigned long)sdp - sdp[-1].length) - 2;
+		dp2->length += sdp->length + 2*sizeof(*sdp);
+		edp->length = dp2->length;
+		sdp = dp2;
+	}
+
+	/* check if we should merge with the following chunk */
+	if (!edp->last && !edp[1].alloced) {
+		dp2 = DP((unsigned long)edp + edp[1].length) + 2;
+		dp2->length += edp->length + 2*sizeof(*sdp);
+		sdp->length = dp2->length;
+		edp = dp2;
+	}
+}