/*
* OpenRISC idle.c
*
* Linux architectural port borrowing liberally from similar works of
* others. All original copyrights apply as per the original source
* declaration.
*
* Modifications for the OpenRISC architecture:
* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/bootmem.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/blkdev.h> /* for initrd_* */
#include <linux/pagemap.h>
#include <linux/memblock.h>
#include <asm/system.h>
#include <asm/segment.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
#include <asm/kmap_types.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
int mem_init_done;
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
static void __init zone_sizes_init(void)
{
unsigned long zones_size[MAX_NR_ZONES];
/* Clear the zone sizes */
memset(zones_size, 0, sizeof(zones_size));
/*
* We use only ZONE_NORMAL
*/
zones_size[ZONE_NORMAL] = max_low_pfn;
free_area_init(zones_size);
}
extern const char _s_kernel_ro[], _e_kernel_ro[];
/*
* Map all physical memory into kernel's address space.
*
* This is explicitly coded for two-level page tables, so if you need
* something else then this needs to change.
*/
static void __init map_ram(void)
{
unsigned long v, p, e;
pgprot_t prot;
pgd_t *pge;
pud_t *pue;
pmd_t *pme;
pte_t *pte;
/* These mark extents of read-only kernel pages...
* ...from vmlinux.lds.S
*/
struct memblock_region *region;
v = PAGE_OFFSET;
for_each_memblock(memory, region) {
p = (u32) region->base & PAGE_MASK;
e = p + (u32) region->size;
v = (u32) __va(p);
pge = pgd_offset_k(v);
while (p < e) {
int j;
pue = pud_offset(pge, v);
pme = pmd_offset(pue, v);
if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
panic("%s: OR1K kernel hardcoded for "
"two-level page tables",
__func__);
}
/* Alloc one page for holding PTE's... */
pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte)));
/* Fill the newly allocated page with PTE'S */
for (j = 0; p < e && j < PTRS_PER_PGD;
v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
if (v >= (u32) _e_kernel_ro ||
v < (u32) _s_kernel_ro)
prot = PAGE_KERNEL;
else
prot = PAGE_KERNEL_RO;
set_pte(pte, mk_pte_phys(p, prot));
}
pge++;
}
printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
region->base, region->base + region->size);
}
}
void __init paging_init(void)
{
extern void tlb_init(void);
unsigned long end;
int i;
printk(KERN_INFO "Setting up paging and PTEs.\n");
/* clear out the init_mm.pgd that will contain the kernel's mappings */
for (i = 0; i < PTRS_PER_PGD; i++)
swapper_pg_dir[i] = __pgd(0);
/* make sure the current pgd table points to something sane
* (even if it is most probably not used until the next
* switch_mm)
*/
current_pgd = init_mm.pgd;
end = (unsigned long)__va(max_low_pfn * PAGE_SIZE);
map_ram();
zone_sizes_init();
/* self modifying code ;) */
/* Since the old TLB miss handler has been running up until now,
* the kernel pages are still all RW, so we can still modify the
* text directly... after this change and a TLB flush, the kernel
* pages will become RO.
*/
{
extern unsigned long dtlb_miss_handler;
extern unsigned long itlb_miss_handler;
unsigned long *dtlb_vector = __va(0x900);
unsigned long *itlb_vector = __va(0xa00);
printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler);
*dtlb_vector = ((unsigned long)&dtlb_miss_handler -
(unsigned long)dtlb_vector) >> 2;
printk(KERN_INFO "itlb_miss_handler %p\n", &itlb_miss_handler);
*itlb_vector = ((unsigned long)&itlb_miss_handler -
(unsigned long)itlb_vector) >> 2;
}
/* Invalidate instruction caches after code modification */
mtspr(SPR_ICBIR, 0x900);
mtspr(SPR_ICBIR, 0xa00);
/* New TLB miss handlers and kernel page tables are in now place.
* Make sure that page flags get updated for all pages in TLB by
* flushing the TLB and forcing all TLB entries to be recreated
* from their page table flags.
*/
flush_tlb_all();
}
/* References to section boundaries */
extern char _stext, _etext, _edata, __bss_start, _end;
extern char __init_begin, __init_end;
static int __init free_pages_init(void)
{
int reservedpages, pfn;
/* this will put all low memory onto the freelists */
totalram_pages = free_all_bootmem();
reservedpages = 0;
for (pfn = 0; pfn < max_low_pfn; pfn++) {
/*
* Only count reserved RAM pages
*/
if (PageReserved(mem_map + pfn))
reservedpages++;
}
return reservedpages;
}
static void __init set_max_mapnr_init(void)
{
max_mapnr = num_physpages = max_low_pfn;
}
void __init mem_init(void)
{
int codesize, reservedpages, datasize, initsize;
if (!mem_map)
BUG();
set_max_mapnr_init();
high_memory = (void *)__va(max_low_pfn * PAGE_SIZE);
/* clear the zero-page */
memset((void *)empty_zero_page, 0, PAGE_SIZE);
reservedpages = free_pages_init();
codesize = (unsigned long)&_etext - (unsigned long)&_stext;
datasize = (unsigned long)&_edata - (unsigned long)&_etext;
initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
printk(KERN_INFO
"Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
(unsigned long)nr_free_pages() << (PAGE_SHIFT - 10),
max_mapnr << (PAGE_SHIFT - 10), codesize >> 10,
reservedpages << (PAGE_SHIFT - 10), datasize >> 10,
initsize >> 10, (unsigned long)(0 << (PAGE_SHIFT - 10))
);
printk("mem_init_done ...........................................\n");
mem_init_done = 1;
return;
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
(end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
totalram_pages++;
}
}
#endif
void free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)(&__init_begin);
for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
printk(KERN_INFO "Freeing unused kernel memory: %luk freed\n",
((unsigned long)&__init_end -
(unsigned long)&__init_begin) >> 10);
}