arch/mips/ar7/memory.c

   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 }