cregit-Linux how code gets into the kernel

Release 4.14 arch/powerpc/mm/pgtable_32.c

Directory: arch/powerpc/mm
/*
 * This file contains the routines setting up the linux page tables.
 *  -- paulus
 *
 *  Derived from arch/ppc/mm/init.c:
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  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/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>

#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/fixmap.h>
#include <asm/io.h>
#include <asm/setup.h>
#include <asm/sections.h>

#include "mmu_decl.h"


unsigned long ioremap_bot;

EXPORT_SYMBOL(ioremap_bot);	
/* aka VMALLOC_END */

extern char etext[], _stext[], _sinittext[], _einittext[];


__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) { pte_t *pte; if (slab_is_available()) { pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO); } else { pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE)); if (pte) clear_page(pte); } return pte; }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras5582.09%125.00%
Anton Blanchard913.43%125.00%
Michael Ellerman22.99%125.00%
Fabian Frederick11.49%125.00%
Total67100.00%4100.00%


pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) { struct page *ptepage; gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT; ptepage = alloc_pages(flags, 0); if (!ptepage) return NULL; if (!pgtable_page_ctor(ptepage)) { __free_page(ptepage); return NULL; } return ptepage; }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras4466.67%240.00%
Kirill A. Shutemov1319.70%120.00%
Martin Schwidefsky710.61%120.00%
Balbir Singh23.03%120.00%
Total66100.00%5100.00%


void __iomem * ioremap(phys_addr_t addr, unsigned long size) { return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras2374.19%133.33%
Benjamin Herrenschmidt825.81%266.67%
Total31100.00%3100.00%

EXPORT_SYMBOL(ioremap);
void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size) { return __ioremap_caller(addr, size, _PAGE_NO_CACHE, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Anton Blanchard2689.66%150.00%
Paul Mackerras310.34%150.00%
Total29100.00%2100.00%

EXPORT_SYMBOL(ioremap_wc);
void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags) { /* writeable implies dirty for kernel addresses */ if ((flags & (_PAGE_RW | _PAGE_RO)) != _PAGE_RO) flags |= _PAGE_DIRTY | _PAGE_HWWRITE; /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ flags &= ~(_PAGE_USER | _PAGE_EXEC); #ifdef _PAGE_BAP_SR /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format * which means that we just cleared supervisor access... oops ;-) This * restores it */ flags |= _PAGE_BAP_SR; #endif return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt6283.78%457.14%
Christophe Leroy810.81%114.29%
Anton Blanchard45.41%228.57%
Total74100.00%7100.00%

EXPORT_SYMBOL(ioremap_prot);
void __iomem * __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) { return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt1957.58%266.67%
Paul Mackerras1442.42%133.33%
Total33100.00%3100.00%


void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, void *caller) { unsigned long v, i; phys_addr_t p; int err; /* Make sure we have the base flags */ if ((flags & _PAGE_PRESENT) == 0) flags |= pgprot_val(PAGE_KERNEL); /* Non-cacheable page cannot be coherent */ if (flags & _PAGE_NO_CACHE) flags &= ~_PAGE_COHERENT; /* * Choose an address to map it to. * Once the vmalloc system is running, we use it. * Before then, we use space going down from IOREMAP_TOP * (ioremap_bot records where we're up to). */ p = addr & PAGE_MASK; size = PAGE_ALIGN(addr + size) - p; /* * If the address lies within the first 16 MB, assume it's in ISA * memory space */ if (p < 16*1024*1024) p += _ISA_MEM_BASE; #ifndef CONFIG_CRASH_DUMP /* * Don't allow anybody to remap normal RAM that we're using. * mem_init() sets high_memory so only do the check after that. */ if (slab_is_available() && (p < virt_to_phys(high_memory)) && !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) { printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n", (unsigned long long)p, __builtin_return_address(0)); return NULL; } #endif if (size == 0) return NULL; /* * Is it already mapped? Perhaps overlapped by a previous * mapping. */ v = p_block_mapped(p); if (v) goto out; if (slab_is_available()) { struct vm_struct *area; area = get_vm_area_caller(size, VM_IOREMAP, caller); if (area == 0) return NULL; area->phys_addr = p; v = (unsigned long) area->addr; } else { v = (ioremap_bot -= size); } /* * Should check if it is a candidate for a BAT mapping */ err = 0; for (i = 0; i < size && err == 0; i += PAGE_SIZE) err = map_kernel_page(v+i, p+i, flags); if (err) { if (slab_is_available()) vunmap((void *)v); return NULL; } out: return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras22470.44%16.67%
Benjamin Herrenschmidt5116.04%320.00%
Michael Ellerman154.72%320.00%
Albert Herranz113.46%16.67%
Christophe Leroy51.57%320.00%
David Gibson51.57%16.67%
Anton Vorontsov51.57%16.67%
Yinghai Lu10.31%16.67%
Scott Wood10.31%16.67%
Total318100.00%15100.00%

EXPORT_SYMBOL(__ioremap);
void iounmap(volatile void __iomem *addr) { /* * If mapped by BATs then there is nothing to do. * Calling vfree() generates a benign warning. */ if (v_block_mapped((unsigned long)addr)) return; if (addr > high_memory && (unsigned long) addr < ioremap_bot) vunmap((void *) (PAGE_MASK & (unsigned long)addr)); }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras5498.18%150.00%
Christophe Leroy11.82%150.00%
Total55100.00%2100.00%

EXPORT_SYMBOL(iounmap);
int map_kernel_page(unsigned long va, phys_addr_t pa, int flags) { pmd_t *pd; pte_t *pg; int err = -ENOMEM; /* Use upper 10 bits of VA to index the first level map */ pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); /* Use middle 10 bits of VA to index the second-level map */ pg = pte_alloc_kernel(pd, va); if (pg != 0) { err = 0; /* The PTE should never be already set nor present in the * hash table */ BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) && flags); set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); } smp_wmb(); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras8774.36%114.29%
Benjamin Herrenschmidt1714.53%228.57%
David Gibson54.27%114.29%
Anton Vorontsov43.42%114.29%
Scott Wood32.56%114.29%
Christophe Leroy10.85%114.29%
Total117100.00%7100.00%

/* * Map in a chunk of physical memory starting at start. */
static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) { unsigned long v, s, f; phys_addr_t p; int ktext; s = offset; v = PAGE_OFFSET + s; p = memstart_addr + s; for (; s < top; s += PAGE_SIZE) { ktext = ((char *)v >= _stext && (char *)v < etext) || ((char *)v >= _sinittext && (char *)v < _einittext); f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL); map_kernel_page(v, p, f); #ifdef CONFIG_PPC_STD_MMU_32 if (ktext) hash_preload(&init_mm, v, 0, 0x300); #endif v += PAGE_SIZE; p += PAGE_SIZE; } }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras7450.00%110.00%
Benjamin Herrenschmidt3322.30%220.00%
Christophe Leroy2013.51%330.00%
Albert Herranz106.76%110.00%
Michael Ellerman64.05%110.00%
Kumar Gala42.70%110.00%
Dale Farnsworth10.68%110.00%
Total148100.00%10100.00%


void __init mapin_ram(void) { unsigned long s, top; #ifndef CONFIG_WII top = total_lowmem; s = mmu_mapin_ram(top); __mapin_ram_chunk(s, top); #else if (!wii_hole_size) { s = mmu_mapin_ram(total_lowmem); __mapin_ram_chunk(s, total_lowmem); } else { top = wii_hole_start; s = mmu_mapin_ram(top); __mapin_ram_chunk(s, top); top = memblock_end_of_DRAM(); s = wii_mmu_mapin_mem2(top); __mapin_ram_chunk(s, top); } #endif }

Contributors

PersonTokensPropCommitsCommitProp
Albert Herranz9999.00%150.00%
Yinghai Lu11.00%150.00%
Total100100.00%2100.00%

/* Scan the real Linux page tables and return a PTE pointer for * a virtual address in a context. * Returns true (1) if PTE was found, zero otherwise. The pointer to * the PTE pointer is unmodified if PTE is not found. */
static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; int retval = 0; pgd = pgd_offset(mm, addr & PAGE_MASK); if (pgd) { pud = pud_offset(pgd, addr & PAGE_MASK); if (pud && pud_present(*pud)) { pmd = pmd_offset(pud, addr & PAGE_MASK); if (pmd_present(*pmd)) { pte = pte_offset_map(pmd, addr & PAGE_MASK); if (pte) { retval = 1; *ptep = pte; if (pmdp) *pmdp = pmd; /* XXX caller needs to do pte_unmap, yuck */ } } } } return(retval); }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras10570.95%125.00%
David Gibson2818.92%125.00%
Eugene Surovegin149.46%125.00%
Christophe Leroy10.68%125.00%
Total148100.00%4100.00%


static int __change_page_attr_noflush(struct page *page, pgprot_t prot) { pte_t *kpte; pmd_t *kpmd; unsigned long address; BUG_ON(PageHighMem(page)); address = (unsigned long)page_address(page); if (v_block_mapped(address)) return 0; if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) return -EINVAL; __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); pte_unmap(kpte); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt10198.06%250.00%
Christophe Leroy21.94%250.00%
Total103100.00%4100.00%

/* * Change the page attributes of an page in the linear mapping. * * THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY */
static int change_page_attr(struct page *page, int numpages, pgprot_t prot) { int i, err = 0; unsigned long flags; struct page *start = page; local_irq_save(flags); for (i = 0; i < numpages; i++, page++) { err = __change_page_attr_noflush(page, prot); if (err) break; } wmb(); local_irq_restore(flags); flush_tlb_kernel_range((unsigned long)page_address(start), (unsigned long)page_address(page)); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt6865.38%133.33%
Christophe Leroy3129.81%133.33%
Guenter Roeck54.81%133.33%
Total104100.00%3100.00%


void mark_initmem_nx(void) { struct page *page = virt_to_page(_sinittext); unsigned long numpages = PFN_UP((unsigned long)_einittext) - PFN_DOWN((unsigned long)_sinittext); change_page_attr(page, numpages, PAGE_KERNEL); }

Contributors

PersonTokensPropCommitsCommitProp
Christophe Leroy48100.00%1100.00%
Total48100.00%1100.00%

#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void) { struct page *page; unsigned long numpages; page = virt_to_page(_stext); numpages = PFN_UP((unsigned long)_etext) - PFN_DOWN((unsigned long)_stext); change_page_attr(page, numpages, PAGE_KERNEL_ROX); /* * mark .rodata as read only. Use __init_begin rather than __end_rodata * to cover NOTES and EXCEPTION_TABLE. */ page = virt_to_page(__start_rodata); numpages = PFN_UP((unsigned long)__init_begin) - PFN_DOWN((unsigned long)__start_rodata); change_page_attr(page, numpages, PAGE_KERNEL_RO); }

Contributors

PersonTokensPropCommitsCommitProp
Christophe Leroy89100.00%1100.00%
Total89100.00%1100.00%

#endif #ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable) { if (PageHighMem(page)) return; change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt3997.50%150.00%
JoonSoo Kim12.50%150.00%
Total40100.00%2100.00%

#endif /* CONFIG_DEBUG_PAGEALLOC */

Overall Contributors

PersonTokensPropCommitsCommitProp
Paul Mackerras72943.34%24.08%
Benjamin Herrenschmidt40524.08%918.37%
Christophe Leroy22413.32%918.37%
Albert Herranz1237.31%24.08%
Anton Blanchard452.68%36.12%
David Gibson392.32%36.12%
Michael Ellerman231.37%36.12%
Olaf Hering211.25%12.04%
Eugene Surovegin140.83%12.04%
Kirill A. Shutemov130.77%12.04%
Anton Vorontsov90.54%24.08%
Kumar Gala70.42%24.08%
Martin Schwidefsky70.42%12.04%
Guenter Roeck50.30%12.04%
Scott Wood40.24%24.08%
Yinghai Lu30.18%12.04%
David Howells30.18%12.04%
Tejun Heo30.18%12.04%
Balbir Singh20.12%12.04%
Fabian Frederick10.06%12.04%
JoonSoo Kim10.06%12.04%
Dale Farnsworth10.06%12.04%
Total1682100.00%49100.00%
Directory: arch/powerpc/mm
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