patch-2.3.30 linux/arch/ppc/mm/mem_pieces.c

• Lines: 225
• Date: Sat Nov 27 15:41:59 1999
• Orig file: v2.3.29/linux/arch/ppc/mm/mem_pieces.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.29/linux/arch/ppc/mm/mem_pieces.c linux/arch/ppc/mm/mem_pieces.c
@@ -0,0 +1,224 @@
+/*
+ *    Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
+ *      Changes to accomodate Power Macintoshes.
+ *    Cort Dougan <cort@cs.nmt.edu>
+ *      Rewrites.
+ *    Grant Erickson <grant@lcse.umn.edu>
+ *      General rework and split from mm/init.c.
+ *
+ *    Module name: mem_pieces.c
+ *
+ *    Description:
+ *      Routines and data structures for manipulating and representing
+ *      phyiscal memory extents (i.e. address/length pairs).
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/blk.h>
+
+#include <asm/page.h>
+#include <asm/prom.h>
+
+#include "mem_pieces.h"
+
+extern char _start[], _end[];
+extern char _stext[], etext[];
+
+char *klimit = _end;
+
+struct mem_pieces phys_avail;
+
+static void mem_pieces_print(struct mem_pieces *);
+
+/*
+ * Scan a region for a piece of a given size with the required alignment.
+ */
+void __init *
+mem_pieces_find(unsigned int size, unsigned int align)
+{
+	int i;
+	unsigned a, e;
+	struct mem_pieces *mp = &phys_avail;
+
+	for (i = 0; i < mp->n_regions; ++i) {
+		a = mp->regions[i].address;
+		e = a + mp->regions[i].size;
+		a = (a + align - 1) & -align;
+		if (a + size <= e) {
+			mem_pieces_remove(mp, a, size, 1);
+			return __va(a);
+		}
+	}
+	panic("Couldn't find %u bytes at %u alignment\n", size, align);
+	
+	return NULL;
+}
+
+/*
+ * Remove some memory from an array of pieces
+ */
+void __init 
+mem_pieces_remove(struct mem_pieces *mp, unsigned int start, unsigned int size,
+		  int must_exist)
+{
+	int i, j;
+	unsigned int end, rs, re;
+	struct reg_property *rp;
+
+	end = start + size;
+	for (i = 0, rp = mp->regions; i < mp->n_regions; ++i, ++rp) {
+		if (end > rp->address && start < rp->address + rp->size)
+			break;
+	}
+	if (i >= mp->n_regions) {
+		if (must_exist)
+			printk("mem_pieces_remove: [%x,%x) not in any region\n",
+			       start, end);
+		return;
+	}
+	for (; i < mp->n_regions && end > rp->address; ++i, ++rp) {
+		rs = rp->address;
+		re = rs + rp->size;
+		if (must_exist && (start < rs || end > re)) {
+			printk("mem_pieces_remove: bad overlap [%x,%x) with",
+			       start, end);
+			mem_pieces_print(mp);
+			must_exist = 0;
+		}
+		if (start > rs) {
+			rp->size = start - rs;
+			if (end < re) {
+				/* need to split this entry */
+				if (mp->n_regions >= MEM_PIECES_MAX)
+					panic("eek... mem_pieces overflow");
+				for (j = mp->n_regions; j > i + 1; --j)
+					mp->regions[j] = mp->regions[j-1];
+				++mp->n_regions;
+				rp[1].address = end;
+				rp[1].size = re - end;
+			}
+		} else {
+			if (end < re) {
+				rp->address = end;
+				rp->size = re - end;
+			} else {
+				/* need to delete this entry */
+				for (j = i; j < mp->n_regions - 1; ++j)
+					mp->regions[j] = mp->regions[j+1];
+				--mp->n_regions;
+				--i;
+				--rp;
+			}
+		}
+	}
+}
+
+static void __init
+mem_pieces_print(struct mem_pieces *mp)
+{
+	int i;
+
+	for (i = 0; i < mp->n_regions; ++i)
+		printk(" [%x, %x)", mp->regions[i].address,
+		       mp->regions[i].address + mp->regions[i].size);
+	printk("\n");
+}
+
+#if defined(CONFIG_PREP) || defined(CONFIG_APUS) || defined(CONFIG_ALL_PPC)
+/*
+ * Add some memory to an array of pieces
+ */
+void __init
+mem_pieces_append(struct mem_pieces *mp, unsigned int start, unsigned int size)
+{
+	struct reg_property *rp;
+
+	if (mp->n_regions >= MEM_PIECES_MAX)
+		return;
+	rp = &mp->regions[mp->n_regions++];
+	rp->address = start;
+	rp->size = size;
+}
+#endif
+
+void __init
+mem_pieces_sort(struct mem_pieces *mp)
+{
+	unsigned long a, s;
+	int i, j;
+
+	for (i = 1; i < mp->n_regions; ++i) {
+		a = mp->regions[i].address;
+		s = mp->regions[i].size;
+		for (j = i - 1; j >= 0; --j) {
+			if (a >= mp->regions[j].address)
+				break;
+			mp->regions[j+1] = mp->regions[j];
+		}
+		mp->regions[j+1].address = a;
+		mp->regions[j+1].size = s;
+	}
+}
+
+void __init
+mem_pieces_coalesce(struct mem_pieces *mp)
+{
+	unsigned long a, s, ns;
+	int i, j, d;
+
+	d = 0;
+	for (i = 0; i < mp->n_regions; i = j) {
+		a = mp->regions[i].address;
+		s = mp->regions[i].size;
+		for (j = i + 1; j < mp->n_regions
+			     && mp->regions[j].address - a <= s; ++j) {
+			ns = mp->regions[j].address + mp->regions[j].size - a;
+			if (ns > s)
+				s = ns;
+		}
+		mp->regions[d].address = a;
+		mp->regions[d].size = s;
+		++d;
+	}
+	mp->n_regions = d;
+}
+
+/*
+ * Set phys_avail to phys_mem less the kernel text/data/bss.
+ */
+void __init
+set_phys_avail(struct mem_pieces *mp)
+{
+	unsigned long kstart, ksize;
+
+	/*
+	 * Initially, available phyiscal memory is equivalent to all
+	 * physical memory.
+	 */
+
+	phys_avail = *mp;
+
+	/*
+	 * Map out the kernel text/data/bss from the available physical
+	 * memory.
+	 */
+
+	kstart = __pa(_stext);	/* should be 0 */
+	ksize = PAGE_ALIGN(klimit - _stext);
+
+	printk("kstart = 0x%08lx, ksize = 0x%08lx\n", kstart, ksize);
+
+	mem_pieces_remove(&phys_avail, kstart, ksize, 0);
+	mem_pieces_remove(&phys_avail, 0, 0x4000, 0);
+
+#if defined(CONFIG_BLK_DEV_INITRD)
+	/* Remove the init RAM disk from the available memory. */
+	if (initrd_start) {
+		mem_pieces_remove(&phys_avail, __pa(initrd_start),
+				  initrd_end - initrd_start, 1);
+	}
+#endif /* CONFIG_BLK_DEV_INITRD */
+}