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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*/
#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/memblock.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pagemap.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
int mem_init_done;
static void __init zone_sizes_init(void)
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
/*
* We use only ZONE_NORMAL
*/
max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
free_area_init(max_zone_pfn);
}
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)
{
phys_addr_t start, end;
unsigned long v, p, e;
pgprot_t prot;
pgd_t *pge;
p4d_t *p4e;
pud_t *pue;
pmd_t *pme;
pte_t *pte;
u64 i;
/* These mark extents of read-only kernel pages...
* ...from vmlinux.lds.S
*/
v = PAGE_OFFSET;
for_each_mem_range(i, &start, &end) {
p = (u32) start & PAGE_MASK;
e = (u32) end;
v = (u32) __va(p);
pge = pgd_offset_k(v);
while (p < e) {
int j;
p4e = p4d_offset(pge, v);
pue = pud_offset(p4e, 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 = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
if (!pte)
panic("%s: Failed to allocate page for PTEs\n",
__func__);
set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte)));
/* Fill the newly allocated page with PTE'S */
for (j = 0; p < e && j < PTRS_PER_PTE;
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__,
start, end);
}
}
void __init paging_init(void)
{
extern void tlb_init(void);
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[smp_processor_id()] = init_mm.pgd;
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 "itlb_miss_handler %p\n", &itlb_miss_handler);
*itlb_vector = ((unsigned long)&itlb_miss_handler -
(unsigned long)itlb_vector) >> 2;
/* Soft ordering constraint to ensure that dtlb_vector is
* the last thing updated
*/
barrier();
printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler);
*dtlb_vector = ((unsigned long)&dtlb_miss_handler -
(unsigned long)dtlb_vector) >> 2;
}
/* Soft ordering constraint to ensure that cache invalidation and
* TLB flush really happen _after_ code has been modified.
*/
barrier();
/* 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 */
void __init mem_init(void)
{
BUG_ON(!mem_map);
max_mapnr = max_low_pfn;
high_memory = (void *)__va(max_low_pfn * PAGE_SIZE);
/* clear the zero-page */
memset((void *)empty_zero_page, 0, PAGE_SIZE);
/* this will put all low memory onto the freelists */
memblock_free_all();
printk("mem_init_done ...........................................\n");
mem_init_done = 1;
return;
}
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