xref: /openbmc/linux/arch/mips/ar7/memory.c (revision 132db935)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
4  * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
5  */
6 #include <linux/memblock.h>
7 #include <linux/init.h>
8 #include <linux/mm.h>
9 #include <linux/pfn.h>
10 #include <linux/proc_fs.h>
11 #include <linux/string.h>
12 #include <linux/swap.h>
13 
14 #include <asm/bootinfo.h>
15 #include <asm/page.h>
16 #include <asm/sections.h>
17 
18 #include <asm/mach-ar7/ar7.h>
19 
20 static int __init memsize(void)
21 {
22 	u32 size = (64 << 20);
23 	u32 *addr = (u32 *)KSEG1ADDR(AR7_SDRAM_BASE + size - 4);
24 	u32 *kernel_end = (u32 *)KSEG1ADDR(CPHYSADDR((u32)&_end));
25 	u32 *tmpaddr = addr;
26 
27 	while (tmpaddr > kernel_end) {
28 		*tmpaddr = (u32)tmpaddr;
29 		size >>= 1;
30 		tmpaddr -= size >> 2;
31 	}
32 
33 	do {
34 		tmpaddr += size >> 2;
35 		if (*tmpaddr != (u32)tmpaddr)
36 			break;
37 		size <<= 1;
38 	} while (size < (64 << 20));
39 
40 	writel((u32)tmpaddr, &addr);
41 
42 	return size;
43 }
44 
45 void __init prom_meminit(void)
46 {
47 	unsigned long pages;
48 
49 	pages = memsize() >> PAGE_SHIFT;
50 	add_memory_region(PHYS_OFFSET, pages << PAGE_SHIFT, BOOT_MEM_RAM);
51 }
52 
53 void __init prom_free_prom_memory(void)
54 {
55 	/* Nothing to free */
56 }
57