patch-2.4.20 linux-2.4.20/arch/x86_64/kernel/e820.c

• Lines: 555
• Date: Thu Nov 28 15:53:12 2002
• Orig file: linux-2.4.19/arch/x86_64/kernel/e820.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/x86_64/kernel/e820.c linux-2.4.20/arch/x86_64/kernel/e820.c
@@ -0,0 +1,554 @@
+/* 
+ * Handle the memory map.
+ * The functions here do the job until bootmem takes over.
+ * $Id: e820.c,v 1.4 2002/09/19 19:25:32 ak Exp $
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/ioport.h>
+#include <asm/page.h>
+#include <asm/e820.h>
+#include <asm/proto.h>
+#include <asm/bootsetup.h>
+
+extern unsigned long table_start, table_end;
+extern char _end[];
+
+extern struct resource code_resource, data_resource, vram_resource;
+
+/* Check for some hardcoded bad areas that early boot is not allowed to touch */ 
+static inline int bad_addr(unsigned long *addrp, unsigned long size)
+{ 
+	unsigned long addr = *addrp, last = addr + size; 
+
+	/* various gunk below that needed for SMP startup */
+	if (addr < 7*PAGE_SIZE) { 
+		*addrp = 7*PAGE_SIZE; 
+		return 1; 
+	}
+	/* direct mapping tables of the kernel */
+	if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) { 
+		*addrp = table_end << PAGE_SHIFT; 
+		return 1;
+	} 
+	/* initrd */ 
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (LOADER_TYPE && INITRD_START && last >= INITRD_START && 
+	    addr < INITRD_START+INITRD_SIZE) { 
+		*addrp = INITRD_START + INITRD_SIZE; 
+		return 1;
+	} 
+#endif
+	/* kernel code + 640k memory hole (later should not be needed, but 
+	   be paranoid for now) */
+	if (last >= 640*1024 && addr < __pa_symbol(&_end)) { 
+		*addrp = __pa_symbol(&_end);
+		return 1;
+	}
+	/* XXX ramdisk image here? */ 
+	return 0;
+} 
+
+int __init e820_mapped(unsigned long start, unsigned long end, int type) 
+{ 
+	int i;
+	for (i = 0; i < e820.nr_map; i++) { 
+		struct e820entry *ei = &e820.map[i]; 
+		if (type && ei->type != type) 
+			continue;
+		if (ei->addr >= end || ei->addr + ei->size < start) 
+			continue; 
+		return 1; 
+	} 
+	return 0;
+}
+
+/* 
+ * Find a free area in a specific range. 
+ */ 
+unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsigned size) 
+{ 
+	int i; 
+	for (i = 0; i < e820.nr_map; i++) { 
+		struct e820entry *ei = &e820.map[i]; 
+		unsigned long addr = ei->addr, last; 
+		if (ei->type != E820_RAM) 
+			continue; 
+		if (addr < start) 
+			addr = start;
+		if (addr > ei->addr + ei->size) 
+			continue; 
+		while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
+			;
+		last = addr + size;
+		if (last > ei->addr + ei->size)
+			continue;
+		if (last > end) 
+			continue;
+		return addr; 
+	} 
+	return -1UL;		
+} 
+
+/* 
+ * Free bootmem based on the e820 table for a node.
+ */
+void __init e820_bootmem_free(pg_data_t *pgdat, unsigned long start,unsigned long end)
+{
+	int i;
+	for (i = 0; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i]; 
+		unsigned long last, addr;
+
+		if (ei->type != E820_RAM || 
+		    ei->addr+ei->size <= start || 
+		    ei->addr > end)
+			continue;
+
+		addr = round_up(ei->addr, PAGE_SIZE);
+		if (addr < start) 
+			addr = start;
+
+		last = round_down(ei->addr + ei->size, PAGE_SIZE); 
+		if (last >= end)
+			last = end; 
+
+		if (last > addr && last-addr >= PAGE_SIZE)
+			free_bootmem_node(pgdat, addr, last-addr);
+	}
+}
+
+/*
+ * Find the highest page frame number we have available
+ */
+void __init e820_end_of_ram(void)
+{
+	int i;
+	end_pfn = 0;
+	for (i = 0; i < e820.nr_map; i++) {
+		struct e820entry *ei = &e820.map[i]; 
+		unsigned long start, end;
+
+		/* count all types of areas for now to map ACPI easily */
+		start = round_up(ei->addr, PAGE_SIZE); 
+		end = round_down(ei->addr + ei->size, PAGE_SIZE); 
+		if (start >= end)
+			continue;
+		if (end > end_pfn<<PAGE_SHIFT)
+			end_pfn = end>>PAGE_SHIFT;
+	}
+
+	if (end_pfn > MAXMEM >> PAGE_SHIFT)
+		end_pfn = MAXMEM >> PAGE_SHIFT;
+}
+
+/* 
+ * Mark e820 reserved areas as busy for the resource manager.
+ */
+void __init e820_reserve_resources(void)
+{
+	int i;
+	for (i = 0; i < e820.nr_map; i++) {
+		struct resource *res;
+		if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
+			continue;
+		res = alloc_bootmem_low(sizeof(struct resource));
+		switch (e820.map[i].type) {
+		case E820_RAM:	res->name = "System RAM"; break;
+		case E820_ACPI:	res->name = "ACPI Tables"; break;
+		case E820_NVS:	res->name = "ACPI Non-volatile Storage"; break;
+		default:	res->name = "reserved";
+		}
+		res->start = e820.map[i].addr;
+		res->end = res->start + e820.map[i].size - 1;
+		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+		request_resource(&iomem_resource, res);
+		if (e820.map[i].type == E820_RAM) {
+			/*
+			 *  We dont't know which RAM region contains kernel data,
+			 *  so we try it repeatedly and let the resource manager
+			 *  test it.
+			 */
+			request_resource(res, &code_resource);
+			request_resource(res, &data_resource);
+		}
+	}
+}
+
+/* 
+ * Add a memory region to the kernel e820 map.
+ */ 
+void __init add_memory_region(unsigned long start, unsigned long size, int type)
+{
+	int x = e820.nr_map;
+
+	if (x == E820MAX) {
+		printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
+		return;
+	}
+
+	e820.map[x].addr = start;
+	e820.map[x].size = size;
+	e820.map[x].type = type;
+	e820.nr_map++;
+}
+
+void __init e820_print_map(char *who)
+{
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		printk(" %s: %016Lx - %016Lx ", who,
+			(unsigned long long) e820.map[i].addr,
+			(unsigned long long) (e820.map[i].addr + e820.map[i].size));
+		switch (e820.map[i].type) {
+		case E820_RAM:	printk("(usable)\n");
+				break;
+		case E820_RESERVED:
+				printk("(reserved)\n");
+				break;
+		case E820_ACPI:
+				printk("(ACPI data)\n");
+				break;
+		case E820_NVS:
+				printk("(ACPI NVS)\n");
+				break;
+		default:	printk("type %u\n", e820.map[i].type);
+				break;
+		}
+	}
+}
+
+/*
+ * Sanitize the BIOS e820 map.
+ *
+ * Some e820 responses include overlapping entries.  The following 
+ * replaces the original e820 map with a new one, removing overlaps.
+ *
+ */
+static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
+{
+	struct change_member {
+		struct e820entry *pbios; /* pointer to original bios entry */
+		unsigned long long addr; /* address for this change point */
+	};
+	static struct change_member change_point_list[2*E820MAX] __initdata;
+	static struct change_member *change_point[2*E820MAX] __initdata;
+	static struct e820entry *overlap_list[E820MAX] __initdata;
+	static struct e820entry new_bios[E820MAX] __initdata;
+	struct change_member *change_tmp;
+	unsigned long current_type, last_type;
+	unsigned long long last_addr;
+	int chgidx, still_changing;
+	int overlap_entries;
+	int new_bios_entry;
+	int old_nr, new_nr;
+	int i;
+
+	/*
+		Visually we're performing the following (1,2,3,4 = memory types)...
+
+		Sample memory map (w/overlaps):
+		   ____22__________________
+		   ______________________4_
+		   ____1111________________
+		   _44_____________________
+		   11111111________________
+		   ____________________33__
+		   ___________44___________
+		   __________33333_________
+		   ______________22________
+		   ___________________2222_
+		   _________111111111______
+		   _____________________11_
+		   _________________4______
+
+		Sanitized equivalent (no overlap):
+		   1_______________________
+		   _44_____________________
+		   ___1____________________
+		   ____22__________________
+		   ______11________________
+		   _________1______________
+		   __________3_____________
+		   ___________44___________
+		   _____________33_________
+		   _______________2________
+		   ________________1_______
+		   _________________4______
+		   ___________________2____
+		   ____________________33__
+		   ______________________4_
+	*/
+
+	/* if there's only one memory region, don't bother */
+	if (*pnr_map < 2)
+		return -1;
+
+	old_nr = *pnr_map;
+
+	/* bail out if we find any unreasonable addresses in bios map */
+	for (i=0; i<old_nr; i++)
+		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
+			return -1;
+
+	/* create pointers for initial change-point information (for sorting) */
+	for (i=0; i < 2*old_nr; i++)
+		change_point[i] = &change_point_list[i];
+
+	/* record all known change-points (starting and ending addresses) */
+	chgidx = 0;
+	for (i=0; i < old_nr; i++)	{
+		change_point[chgidx]->addr = biosmap[i].addr;
+		change_point[chgidx++]->pbios = &biosmap[i];
+		change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
+		change_point[chgidx++]->pbios = &biosmap[i];
+	}
+
+	/* sort change-point list by memory addresses (low -> high) */
+	still_changing = 1;
+	while (still_changing)	{
+		still_changing = 0;
+		for (i=1; i < 2*old_nr; i++)  {
+			/* if <current_addr> > <last_addr>, swap */
+			/* or, if current=<start_addr> & last=<end_addr>, swap */
+			if ((change_point[i]->addr < change_point[i-1]->addr) ||
+				((change_point[i]->addr == change_point[i-1]->addr) &&
+				 (change_point[i]->addr == change_point[i]->pbios->addr) &&
+				 (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
+			   )
+			{
+				change_tmp = change_point[i];
+				change_point[i] = change_point[i-1];
+				change_point[i-1] = change_tmp;
+				still_changing=1;
+			}
+		}
+	}
+
+	/* create a new bios memory map, removing overlaps */
+	overlap_entries=0;	 /* number of entries in the overlap table */
+	new_bios_entry=0;	 /* index for creating new bios map entries */
+	last_type = 0;		 /* start with undefined memory type */
+	last_addr = 0;		 /* start with 0 as last starting address */
+	/* loop through change-points, determining affect on the new bios map */
+	for (chgidx=0; chgidx < 2*old_nr; chgidx++)
+	{
+		/* keep track of all overlapping bios entries */
+		if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
+		{
+			/* add map entry to overlap list (> 1 entry implies an overlap) */
+			overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
+		}
+		else
+		{
+			/* remove entry from list (order independent, so swap with last) */
+			for (i=0; i<overlap_entries; i++)
+			{
+				if (overlap_list[i] == change_point[chgidx]->pbios)
+					overlap_list[i] = overlap_list[overlap_entries-1];
+			}
+			overlap_entries--;
+		}
+		/* if there are overlapping entries, decide which "type" to use */
+		/* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
+		current_type = 0;
+		for (i=0; i<overlap_entries; i++)
+			if (overlap_list[i]->type > current_type)
+				current_type = overlap_list[i]->type;
+		/* continue building up new bios map based on this information */
+		if (current_type != last_type)	{
+			if (last_type != 0)	 {
+				new_bios[new_bios_entry].size =
+					change_point[chgidx]->addr - last_addr;
+				/* move forward only if the new size was non-zero */
+				if (new_bios[new_bios_entry].size != 0)
+					if (++new_bios_entry >= E820MAX)
+						break; 	/* no more space left for new bios entries */
+			}
+			if (current_type != 0)	{
+				new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
+				new_bios[new_bios_entry].type = current_type;
+				last_addr=change_point[chgidx]->addr;
+			}
+			last_type = current_type;
+		}
+	}
+	new_nr = new_bios_entry;   /* retain count for new bios entries */
+
+	/* copy new bios mapping into original location */
+	memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
+	*pnr_map = new_nr;
+
+	return 0;
+}
+
+/*
+ * Copy the BIOS e820 map into a safe place.
+ *
+ * Sanity-check it while we're at it..
+ *
+ * If we're lucky and live on a modern system, the setup code
+ * will have given us a memory map that we can use to properly
+ * set up memory.  If we aren't, we'll fake a memory map.
+ *
+ * We check to see that the memory map contains at least 2 elements
+ * before we'll use it, because the detection code in setup.S may
+ * not be perfect and most every PC known to man has two memory
+ * regions: one from 0 to 640k, and one from 1mb up.  (The IBM
+ * thinkpad 560x, for example, does not cooperate with the memory
+ * detection code.)
+ */
+static int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
+{
+	/* Only one memory region (or negative)? Ignore it */
+	if (nr_map < 2)
+		return -1;
+
+	do {
+		unsigned long start = biosmap->addr;
+		unsigned long size = biosmap->size;
+		unsigned long end = start + size;
+		unsigned long type = biosmap->type;
+
+		/* Overflow in 64 bits? Ignore the memory map. */
+		if (start > end)
+			return -1;
+
+		/*
+		 * Some BIOSes claim RAM in the 640k - 1M region.
+		 * Not right. Fix it up.
+		 * 
+		 * This should be removed on Hammer which is supposed to not
+		 * have non e820 covered ISA mappings there, but I had some strange
+		 * problems so it stays for now.  -AK
+		 */
+		if (type == E820_RAM) {
+			if (start < 0x100000ULL && end > 0xA0000ULL) {
+				if (start < 0xA0000ULL)
+					add_memory_region(start, 0xA0000ULL-start, type);
+				if (end <= 0x100000ULL)
+					continue;
+				start = 0x100000ULL;
+				size = end - start;
+			}
+		}
+
+		add_memory_region(start, size, type);
+	} while (biosmap++,--nr_map);
+	return 0;
+}
+
+void __init setup_memory_region(void)
+{
+	char *who = "BIOS-e820";
+
+	/*
+	 * Try to copy the BIOS-supplied E820-map.
+	 *
+	 * Otherwise fake a memory map; one section from 0k->640k,
+	 * the next section from 1mb->appropriate_mem_k
+	 */
+	sanitize_e820_map(E820_MAP, &E820_MAP_NR);
+	if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0) {
+		unsigned long mem_size;
+
+		/* compare results from other methods and take the greater */
+		if (ALT_MEM_K < EXT_MEM_K) {
+			mem_size = EXT_MEM_K;
+			who = "BIOS-88";
+		} else {
+			mem_size = ALT_MEM_K;
+			who = "BIOS-e801";
+		}
+
+		e820.nr_map = 0;
+		add_memory_region(0, LOWMEMSIZE(), E820_RAM);
+		add_memory_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
+  	}
+	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
+	e820_print_map(who);
+}
+
+extern char command_line[], saved_command_line[];
+extern int fallback_aper_order;
+extern int iommu_setup(char *opt);
+
+void __init parse_mem_cmdline (char ** cmdline_p)
+{
+	char c = ' ', *to = command_line, *from = COMMAND_LINE;
+	int len = 0;
+	int usermem = 0;
+
+	/* Save unparsed command line copy for /proc/cmdline */
+	memcpy(saved_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
+	saved_command_line[COMMAND_LINE_SIZE-1] = '\0';
+
+	for (;;) {
+		if (c != ' ') 
+			goto next;
+
+		/*
+		 * "mem=XXX[kKmM]" defines a memory region from HIGH_MEM
+		 * to <mem>, overriding the bios size.
+		 * "mem=XXX[KkmM]@XXX[KkmM]" defines a memory region from
+		 * <start> to <start>+<mem>, overriding the bios size.
+		 */
+		if (!memcmp(from, "mem=", 4)) {
+			if (to != command_line)
+				to--;
+			else if (!memcmp(from+4, "exactmap", 8)) {
+				from += 8+4;
+				e820.nr_map = 0;
+				usermem = 1;
+			} else {
+				/* If the user specifies memory size, we
+				 * blow away any automatically generated
+				 * size
+				 */
+				unsigned long long start_at, mem_size;
+ 
+				if (usermem == 0) {
+					/* first time in: zap the whitelist
+					 * and reinitialize it with the
+					 * standard low-memory region.
+					 */
+					e820.nr_map = 0;
+					usermem = 1;
+					add_memory_region(0, LOWMEMSIZE(), E820_RAM);
+				}
+				mem_size = memparse(from+4, &from);
+				if (*from == '@')
+					start_at = memparse(from+1, &from);
+				else {
+					start_at = HIGH_MEMORY;
+					mem_size -= HIGH_MEMORY;
+					usermem=0;
+				}
+				add_memory_region(start_at, mem_size, E820_RAM);
+			}
+		}
+#ifdef CONFIG_GART_IOMMU 
+		else if (!memcmp(from,"iommu=",6)) { 
+			iommu_setup(from+6); 
+		} 	
+		
+#endif
+	next:
+		c = *(from++);
+		if (!c)
+			break;
+		if (COMMAND_LINE_SIZE <= ++len)
+			break;
+		*(to++) = c;
+	}
+	*to = '\0';
+	*cmdline_p = command_line;
+	if (usermem) {
+		printk(KERN_INFO "user-defined physical RAM map:\n");
+		e820_print_map("user");
+	}
+}