cregit-Linux how code gets into the kernel

Release 4.14 arch/openrisc/mm/init.c

Directory: arch/openrisc/mm
/*
 * 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/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>
#include <asm/sections.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); }

Contributors

PersonTokensPropCommitsCommitProp
Jonas Bonn42100.00%1100.00%
Total42100.00%1100.00%

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 *) __va(memblock_alloc(PAGE_SIZE, 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_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__, region->base, region->base + region->size); } }

Contributors

PersonTokensPropCommitsCommitProp
Jonas Bonn27097.47%133.33%
Stafford Horne62.17%133.33%
Stefan Kristiansson10.36%133.33%
Total277100.00%3100.00%


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 "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(); }

Contributors

PersonTokensPropCommitsCommitProp
Jonas Bonn197100.00%2100.00%
Total197100.00%2100.00%

/* 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 */ free_all_bootmem(); mem_init_print_info(NULL); printk("mem_init_done ...........................................\n"); mem_init_done = 1; return; }

Contributors

PersonTokensPropCommitsCommitProp
Jonas Bonn5484.38%133.33%
Jiang Liu710.94%133.33%
Julia Lawall34.69%133.33%
Total64100.00%3100.00%

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end) { free_reserved_area((void *)start, (void *)end, -1, "initrd"); }

Contributors

PersonTokensPropCommitsCommitProp
Jonas Bonn1854.55%125.00%
Jiang Liu1545.45%375.00%
Total33100.00%4100.00%

#endif
void free_initmem(void) { free_initmem_default(-1); }

Contributors

PersonTokensPropCommitsCommitProp
Jonas Bonn1076.92%133.33%
Jiang Liu323.08%266.67%
Total13100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Jonas Bonn70194.86%222.22%
Jiang Liu283.79%444.44%
Stafford Horne60.81%111.11%
Julia Lawall30.41%111.11%
Stefan Kristiansson10.14%111.11%
Total739100.00%9100.00%
Directory: arch/openrisc/mm
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