cregit-Linux how code gets into the kernel

Release 4.14 arch/alpha/mm/init.c

Directory: arch/alpha/mm
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/alpha/mm/init.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 */

/* 2.3.x zone allocator, 1999 Andrea Arcangeli <andrea@suse.de> */

#include <linux/pagemap.h>
#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/init.h>
#include <linux/bootmem.h> /* max_low_pfn */
#include <linux/vmalloc.h>
#include <linux/gfp.h>

#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/hwrpb.h>
#include <asm/dma.h>
#include <asm/mmu_context.h>
#include <asm/console.h>
#include <asm/tlb.h>
#include <asm/setup.h>
#include <asm/sections.h>

extern void die_if_kernel(char *,struct pt_regs *,long);


static struct pcb_struct original_pcb;


pgd_t * pgd_alloc(struct mm_struct *mm) { pgd_t *ret, *init; ret = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); init = pgd_offset(&init_mm, 0UL); if (ret) { #ifdef CONFIG_ALPHA_LARGE_VMALLOC memcpy (ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD, (PTRS_PER_PGD - USER_PTRS_PER_PGD - 1)*sizeof(pgd_t)); #else pgd_val(ret[PTRS_PER_PGD-2]) = pgd_val(init[PTRS_PER_PGD-2]); #endif /* The last PGD entry is the VPTB self-map. */ pgd_val(ret[PTRS_PER_PGD-1]) = pte_val(mk_pte(virt_to_page(ret), PAGE_KERNEL)); } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)11894.40%133.33%
Richard Henderson54.00%133.33%
Christoph Lameter21.60%133.33%
Total125100.00%3100.00%

/* * BAD_PAGE is the page that is used for page faults when linux * is out-of-memory. Older versions of linux just did a * do_exit(), but using this instead means there is less risk * for a process dying in kernel mode, possibly leaving an inode * unused etc.. * * BAD_PAGETABLE is the accompanying page-table: it is initialized * to point to BAD_PAGE entries. * * ZERO_PAGE is a special page that is used for zero-initialized * data and COW. */
pmd_t * __bad_pagetable(void) { memset((void *) EMPTY_PGT, 0, PAGE_SIZE); return (pmd_t *) EMPTY_PGT; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)28100.00%3100.00%
Total28100.00%3100.00%


pte_t __bad_page(void) { memset((void *) EMPTY_PGE, 0, PAGE_SIZE); return pte_mkdirty(mk_pte(virt_to_page(EMPTY_PGE), PAGE_SHARED)); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)34100.00%4100.00%
Total34100.00%4100.00%


static inline unsigned long load_PCB(struct pcb_struct *pcb) { register unsigned long sp __asm__("$30"); pcb->ksp = sp; return __reload_thread(pcb); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)3397.06%685.71%
Richard Henderson12.94%114.29%
Total34100.00%7100.00%

/* Set up initial PCB, VPTB, and other such nicities. */
static inline void switch_to_system_map(void) { unsigned long newptbr; unsigned long original_pcb_ptr; /* Initialize the kernel's page tables. Linux puts the vptb in the last slot of the L1 page table. */ memset(swapper_pg_dir, 0, PAGE_SIZE); newptbr = ((unsigned long) swapper_pg_dir - PAGE_OFFSET) >> PAGE_SHIFT; pgd_val(swapper_pg_dir[1023]) = (newptbr << 32) | pgprot_val(PAGE_KERNEL); /* Set the vptb. This is often done by the bootloader, but shouldn't be required. */ if (hwrpb->vptb != 0xfffffffe00000000UL) { wrvptptr(0xfffffffe00000000UL); hwrpb->vptb = 0xfffffffe00000000UL; hwrpb_update_checksum(hwrpb); } /* Also set up the real kernel PCB while we're at it. */ init_thread_info.pcb.ptbr = newptbr; init_thread_info.pcb.flags = 1; /* set FEN, clear everything else */ original_pcb_ptr = load_PCB(&init_thread_info.pcb); tbia(); /* Save off the contents of the original PCB so that we can restore the original console's page tables for a clean reboot. Note that the PCB is supposed to be a physical address, but since KSEG values also happen to work, folks get confused. Check this here. */ if (original_pcb_ptr < PAGE_OFFSET) { original_pcb_ptr = (unsigned long) phys_to_virt(original_pcb_ptr); } original_pcb = *(struct pcb_struct *) original_pcb_ptr; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13792.57%1083.33%
Richard Henderson85.41%18.33%
Al Viro32.03%18.33%
Total148100.00%12100.00%

int callback_init_done;
void * __init callback_init(void * kernel_end) { struct crb_struct * crb; pgd_t *pgd; pmd_t *pmd; void *two_pages; /* Starting at the HWRPB, locate the CRB. */ crb = (struct crb_struct *)((char *)hwrpb + hwrpb->crb_offset); if (alpha_using_srm) { /* Tell the console whither it is to be remapped. */ if (srm_fixup(VMALLOC_START, (unsigned long)hwrpb)) __halt(); /* "We're boned." --Bender */ /* Edit the procedure descriptors for DISPATCH and FIXUP. */ crb->dispatch_va = (struct procdesc_struct *) (VMALLOC_START + (unsigned long)crb->dispatch_va - crb->map[0].va); crb->fixup_va = (struct procdesc_struct *) (VMALLOC_START + (unsigned long)crb->fixup_va - crb->map[0].va); } switch_to_system_map(); /* Allocate one PGD and one PMD. In the case of SRM, we'll need these to actually remap the console. There is an assumption here that only one of each is needed, and this allows for 8MB. On systems with larger consoles, additional pages will be allocated as needed during the mapping process. In the case of not SRM, but not CONFIG_ALPHA_LARGE_VMALLOC, we need to allocate the PGD we use for vmalloc before we start forking other tasks. */ two_pages = (void *) (((unsigned long)kernel_end + ~PAGE_MASK) & PAGE_MASK); kernel_end = two_pages + 2*PAGE_SIZE; memset(two_pages, 0, 2*PAGE_SIZE); pgd = pgd_offset_k(VMALLOC_START); pgd_set(pgd, (pmd_t *)two_pages); pmd = pmd_offset(pgd, VMALLOC_START); pmd_set(pmd, (pte_t *)(two_pages + PAGE_SIZE)); if (alpha_using_srm) { static struct vm_struct console_remap_vm; unsigned long nr_pages = 0; unsigned long vaddr; unsigned long i, j; /* calculate needed size */ for (i = 0; i < crb->map_entries; ++i) nr_pages += crb->map[i].count; /* register the vm area */ console_remap_vm.flags = VM_ALLOC; console_remap_vm.size = nr_pages << PAGE_SHIFT; vm_area_register_early(&console_remap_vm, PAGE_SIZE); vaddr = (unsigned long)console_remap_vm.addr; /* Set up the third level PTEs and update the virtual addresses of the CRB entries. */ for (i = 0; i < crb->map_entries; ++i) { unsigned long pfn = crb->map[i].pa >> PAGE_SHIFT; crb->map[i].va = vaddr; for (j = 0; j < crb->map[i].count; ++j) { /* Newer consoles (especially on larger systems) may require more pages of PTEs. Grab additional pages as needed. */ if (pmd != pmd_offset(pgd, vaddr)) { memset(kernel_end, 0, PAGE_SIZE); pmd = pmd_offset(pgd, vaddr); pmd_set(pmd, (pte_t *)kernel_end); kernel_end += PAGE_SIZE; } set_pte(pte_offset_kernel(pmd, vaddr), pfn_pte(pfn, PAGE_KERNEL)); pfn++; vaddr += PAGE_SIZE; } } } callback_init_done = 1; return kernel_end; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)32772.67%111.11%
Tejun Heo6614.67%333.33%
Jay Estabrook4710.44%111.11%
Roman Zippel71.56%111.11%
Richard Henderson20.44%222.22%
Simon Arlott10.22%111.11%
Total450100.00%9100.00%

#ifndef CONFIG_DISCONTIGMEM /* * paging_init() sets up the memory map. */
void __init paging_init(void) { unsigned long zones_size[MAX_NR_ZONES] = {0, }; unsigned long dma_pfn, high_pfn; dma_pfn = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; high_pfn = max_pfn = max_low_pfn; if (dma_pfn >= high_pfn) zones_size[ZONE_DMA] = high_pfn; else { zones_size[ZONE_DMA] = dma_pfn; zones_size[ZONE_NORMAL] = high_pfn - dma_pfn; } /* Initialize mem_map[]. */ free_area_init(zones_size); /* Initialize the kernel's ZERO_PGE. */ memset((void *)ZERO_PGE, 0, PAGE_SIZE); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9093.75%120.00%
Sam Ravnborg22.08%120.00%
Al Viro22.08%120.00%
Linus Torvalds11.04%120.00%
Christoph Lameter11.04%120.00%
Total96100.00%5100.00%

#endif /* CONFIG_DISCONTIGMEM */ #if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_SRM)
void srm_paging_stop (void) { /* Move the vptb back to where the SRM console expects it. */ swapper_pg_dir[1] = swapper_pg_dir[1023]; tbia(); wrvptptr(0x200000000UL); hwrpb->vptb = 0x200000000UL; hwrpb_update_checksum(hwrpb); /* Reload the page tables that the console had in use. */ load_PCB(&original_pcb); tbia(); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4595.74%150.00%
Al Viro24.26%150.00%
Total47100.00%2100.00%

#endif
void __init mem_init(void) { set_max_mapnr(max_low_pfn); high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); free_all_bootmem(); mem_init_print_info(NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2470.59%466.67%
Jiang Liu1029.41%233.33%
Total34100.00%6100.00%


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

Contributors

PersonTokensPropCommitsCommitProp
Ivan Kokshaysky646.15%120.00%
Linus Torvalds (pre-git)430.77%240.00%
Jiang Liu323.08%240.00%
Total13100.00%5100.00%

#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
Linus Torvalds (pre-git)1957.58%342.86%
Jiang Liu1339.39%342.86%
Ivan Kokshaysky13.03%114.29%
Total33100.00%7100.00%

#endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)96282.22%2649.06%
Tejun Heo695.90%47.55%
Jay Estabrook474.02%11.89%
Jiang Liu292.48%59.43%
Richard Henderson181.54%35.66%
Linus Torvalds110.94%35.66%
Ivan Kokshaysky70.60%11.89%
Roman Zippel70.60%11.89%
Al Viro70.60%23.77%
Andrew Morton30.26%11.89%
David Howells30.26%11.89%
Christoph Lameter30.26%23.77%
Sam Ravnborg20.17%11.89%
Simon Arlott10.09%11.89%
Greg Kroah-Hartman10.09%11.89%
Total1170100.00%53100.00%
Directory: arch/alpha/mm
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