cregit-Linux how code gets into the kernel

Release 4.11 arch/x86/mm/ioremap.c

Directory: arch/x86/mm
/*
 * Re-map IO memory to kernel address space so that we can access it.
 * This is needed for high PCI addresses that aren't mapped in the
 * 640k-1MB IO memory area on PC's
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 */

#include <linux/bootmem.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mmiotrace.h>

#include <asm/cacheflush.h>
#include <asm/e820.h>
#include <asm/fixmap.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
#include <asm/pat.h>

#include "physaddr.h"

/*
 * Fix up the linear direct mapping of the kernel to avoid cache attribute
 * conflicts.
 */

int ioremap_change_attr(unsigned long vaddr, unsigned long size, enum page_cache_mode pcm) { unsigned long nrpages = size >> PAGE_SHIFT; int err; switch (pcm) { case _PAGE_CACHE_MODE_UC: default: err = _set_memory_uc(vaddr, nrpages); break; case _PAGE_CACHE_MODE_WC: err = _set_memory_wc(vaddr, nrpages); break; case _PAGE_CACHE_MODE_WT: err = _set_memory_wt(vaddr, nrpages); break; case _PAGE_CACHE_MODE_WB: err = _set_memory_wb(vaddr, nrpages); break; } return err; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2831.11%333.33%
Andi Kleen2527.78%111.11%
Venkatesh Pallipadi1415.56%222.22%
Toshi Kani1314.44%111.11%
Juergen Gross77.78%111.11%
Harvey Harrison33.33%111.11%
Total90100.00%9100.00%


static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, void *arg) { unsigned long i; for (i = 0; i < nr_pages; ++i) if (pfn_valid(start_pfn + i) && !PageReserved(pfn_to_page(start_pfn + i))) return 1; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Roland Dreier61100.00%1100.00%
Total61100.00%1100.00%

/* * Remap an arbitrary physical address space into the kernel virtual * address space. It transparently creates kernel huge I/O mapping when * the physical address is aligned by a huge page size (1GB or 2MB) and * the requested size is at least the huge page size. * * NOTE: MTRRs can override PAT memory types with a 4KB granularity. * Therefore, the mapping code falls back to use a smaller page toward 4KB * when a mapping range is covered by non-WB type of MTRRs. * * NOTE! We need to allow non-page-aligned mappings too: we will obviously * have to convert them into an offset in a page-aligned mapping, but the * caller shouldn't need to know that small detail. */
static void __iomem *__ioremap_caller(resource_size_t phys_addr, unsigned long size, enum page_cache_mode pcm, void *caller) { unsigned long offset, vaddr; resource_size_t pfn, last_pfn, last_addr; const resource_size_t unaligned_phys_addr = phys_addr; const unsigned long unaligned_size = size; struct vm_struct *area; enum page_cache_mode new_pcm; pgprot_t prot; int retval; void __iomem *ret_addr; /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; if (!size || last_addr < phys_addr) return NULL; if (!phys_addr_valid(phys_addr)) { printk(KERN_WARNING "ioremap: invalid physical address %llx\n", (unsigned long long)phys_addr); WARN_ON_ONCE(1); return NULL; } /* * Don't remap the low PCI/ISA area, it's always mapped.. */ if (is_ISA_range(phys_addr, last_addr)) return (__force void __iomem *)phys_to_virt(phys_addr); /* * Don't allow anybody to remap normal RAM that we're using.. */ pfn = phys_addr >> PAGE_SHIFT; last_pfn = last_addr >> PAGE_SHIFT; if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, __ioremap_check_ram) == 1) { WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", &phys_addr, &last_addr); return NULL; } /* * Mappings have to be page-aligned */ offset = phys_addr & ~PAGE_MASK; phys_addr &= PHYSICAL_PAGE_MASK; size = PAGE_ALIGN(last_addr+1) - phys_addr; retval = reserve_memtype(phys_addr, (u64)phys_addr + size, pcm, &new_pcm); if (retval) { printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval); return NULL; } if (pcm != new_pcm) { if (!is_new_memtype_allowed(phys_addr, size, pcm, new_pcm)) { printk(KERN_ERR "ioremap error for 0x%llx-0x%llx, requested 0x%x, got 0x%x\n", (unsigned long long)phys_addr, (unsigned long long)(phys_addr + size), pcm, new_pcm); goto err_free_memtype; } pcm = new_pcm; } prot = PAGE_KERNEL_IO; switch (pcm) { case _PAGE_CACHE_MODE_UC: default: prot = __pgprot(pgprot_val(prot) | cachemode2protval(_PAGE_CACHE_MODE_UC)); break; case _PAGE_CACHE_MODE_UC_MINUS: prot = __pgprot(pgprot_val(prot) | cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS)); break; case _PAGE_CACHE_MODE_WC: prot = __pgprot(pgprot_val(prot) | cachemode2protval(_PAGE_CACHE_MODE_WC)); break; case _PAGE_CACHE_MODE_WT: prot = __pgprot(pgprot_val(prot) | cachemode2protval(_PAGE_CACHE_MODE_WT)); break; case _PAGE_CACHE_MODE_WB: break; } /* * Ok, go for it.. */ area = get_vm_area_caller(size, VM_IOREMAP, caller); if (!area) goto err_free_memtype; area->phys_addr = phys_addr; vaddr = (unsigned long) area->addr; if (kernel_map_sync_memtype(phys_addr, size, pcm)) goto err_free_area; if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) goto err_free_area; ret_addr = (void __iomem *) (vaddr + offset); mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr); /* * Check if the request spans more than any BAR in the iomem resource * tree. */ if (iomem_map_sanity_check(unaligned_phys_addr, unaligned_size)) pr_warn("caller %pS mapping multiple BARs\n", caller); return ret_addr; err_free_area: free_vm_area(area); err_free_memtype: free_memtype(phys_addr, phys_addr + size); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen12423.26%511.63%
Venkatesh Pallipadi8816.51%511.63%
Juergen Gross6311.82%24.65%
Thomas Gleixner529.76%920.93%
Xiaotian Feng336.19%12.33%
Pekka Paalanen326.00%24.65%
Toshi Kani305.63%24.65%
Roland Dreier173.19%12.33%
Randy Dunlap173.19%12.33%
Suresh B. Siddha142.63%24.65%
Tim Gardner101.88%12.33%
Kenji Kaneshige91.69%12.33%
Ingo Molnar91.69%36.98%
Christoph Lameter81.50%12.33%
Al Viro81.50%12.33%
Laura Abbott71.31%12.33%
Andreas Herrmann40.75%12.33%
H. Peter Anvin40.75%12.33%
Håvard Skinnemoen20.38%12.33%
Mike Travis10.19%12.33%
Linus Torvalds10.19%12.33%
Total533100.00%43100.00%

/** * ioremap_nocache - map bus memory into CPU space * @phys_addr: bus address of the memory * @size: size of the resource to map * * ioremap_nocache performs a platform specific sequence of operations to * make bus memory CPU accessible via the readb/readw/readl/writeb/ * writew/writel functions and the other mmio helpers. The returned * address is not guaranteed to be usable directly as a virtual * address. * * This version of ioremap ensures that the memory is marked uncachable * on the CPU as well as honouring existing caching rules from things like * the PCI bus. Note that there are other caches and buffers on many * busses. In particular driver authors should read up on PCI writes * * It's useful if some control registers are in such an area and * write combining or read caching is not desirable: * * Must be freed with iounmap. */
void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size) { /* * Ideally, this should be: * pat_enabled() ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS; * * Till we fix all X drivers to use ioremap_wc(), we will use * UC MINUS. Drivers that are certain they need or can already * be converted over to strong UC can use ioremap_uc(). */ enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS; return __ioremap_caller(phys_addr, size, pcm, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen2055.56%225.00%
Christoph Lameter616.67%112.50%
Juergen Gross513.89%112.50%
Suresh B. Siddha25.56%112.50%
Luis R. Rodriguez12.78%112.50%
Al Viro12.78%112.50%
Linus Torvalds12.78%112.50%
Total36100.00%8100.00%

EXPORT_SYMBOL(ioremap_nocache); /** * ioremap_uc - map bus memory into CPU space as strongly uncachable * @phys_addr: bus address of the memory * @size: size of the resource to map * * ioremap_uc performs a platform specific sequence of operations to * make bus memory CPU accessible via the readb/readw/readl/writeb/ * writew/writel functions and the other mmio helpers. The returned * address is not guaranteed to be usable directly as a virtual * address. * * This version of ioremap ensures that the memory is marked with a strong * preference as completely uncachable on the CPU when possible. For non-PAT * systems this ends up setting page-attribute flags PCD=1, PWT=1. For PAT * systems this will set the PAT entry for the pages as strong UC. This call * will honor existing caching rules from things like the PCI bus. Note that * there are other caches and buffers on many busses. In particular driver * authors should read up on PCI writes. * * It's useful if some control registers are in such an area and * write combining or read caching is not desirable: * * Must be freed with iounmap. */
void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size) { enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC; return __ioremap_caller(phys_addr, size, pcm, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Luis R. Rodriguez35100.00%1100.00%
Total35100.00%1100.00%

EXPORT_SYMBOL_GPL(ioremap_uc); /** * ioremap_wc - map memory into CPU space write combined * @phys_addr: bus address of the memory * @size: size of the resource to map * * This version of ioremap ensures that the memory is marked write combining. * Write combining allows faster writes to some hardware devices. * * Must be freed with iounmap. */
void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Venkatesh Pallipadi2275.86%250.00%
Christoph Lameter620.69%125.00%
Juergen Gross13.45%125.00%
Total29100.00%4100.00%

EXPORT_SYMBOL(ioremap_wc); /** * ioremap_wt - map memory into CPU space write through * @phys_addr: bus address of the memory * @size: size of the resource to map * * This version of ioremap ensures that the memory is marked write through. * Write through stores data into memory while keeping the cache up-to-date. * * Must be freed with iounmap. */
void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Toshi Kani2172.41%150.00%
Venkatesh Pallipadi827.59%150.00%
Total29100.00%2100.00%

EXPORT_SYMBOL(ioremap_wt);
void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB, __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2172.41%125.00%
Christoph Lameter620.69%125.00%
Juergen Gross13.45%125.00%
Linus Torvalds13.45%125.00%
Total29100.00%4100.00%

EXPORT_SYMBOL(ioremap_cache);
void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size, unsigned long prot_val) { return __ioremap_caller(phys_addr, size, pgprot2cachemode(__pgprot(prot_val)), __builtin_return_address(0)); }

Contributors

PersonTokensPropCommitsCommitProp
Rik Van Riel3384.62%150.00%
Juergen Gross615.38%150.00%
Total39100.00%2100.00%

EXPORT_SYMBOL(ioremap_prot); /** * iounmap - Free a IO remapping * @addr: virtual address from ioremap_* * * Caller must ensure there is only one unmapping for the same pointer. */
void iounmap(volatile void __iomem *addr) { struct vm_struct *p, *o; if ((void __force *)addr <= high_memory) return; /* * __ioremap special-cases the PCI/ISA range by not instantiating a * vm_area and by simply returning an address into the kernel mapping * of ISA space. So handle that here. */ if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) && (void __force *)addr < phys_to_virt(ISA_END_ADDRESS)) return; addr = (volatile void __iomem *) (PAGE_MASK & (unsigned long __force)addr); mmiotrace_iounmap(addr); /* Use the vm area unlocked, assuming the caller ensures there isn't another iounmap for the same address in parallel. Reuse of the virtual address is prevented by leaving it in the global lists until we're done with it. cpa takes care of the direct mappings. */ p = find_vm_area((void __force *)addr); if (!p) { printk(KERN_ERR "iounmap: bad address %p\n", addr); dump_stack(); return; } free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p)); /* Finally remove it */ o = remove_vm_area((void __force *)addr); BUG_ON(p != o || o == NULL); kfree(p); }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen11169.38%637.50%
Thomas Gleixner2314.38%425.00%
Venkatesh Pallipadi1610.00%16.25%
Pekka Paalanen53.12%16.25%
Al Viro31.88%318.75%
JoonSoo Kim21.25%16.25%
Total160100.00%16100.00%

EXPORT_SYMBOL(iounmap);
int __init arch_ioremap_pud_supported(void) { #ifdef CONFIG_X86_64 return boot_cpu_has(X86_FEATURE_GBPAGES); #else return 0; #endif }

Contributors

PersonTokensPropCommitsCommitProp
Toshi Kani1979.17%133.33%
Borislav Petkov416.67%133.33%
Jan Beulich14.17%133.33%
Total24100.00%3100.00%


int __init arch_ioremap_pmd_supported(void) { return boot_cpu_has(X86_FEATURE_PSE); }

Contributors

PersonTokensPropCommitsCommitProp
Toshi Kani964.29%133.33%
Borislav Petkov428.57%133.33%
Jan Beulich17.14%133.33%
Total14100.00%3100.00%

/* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access */
void *xlate_dev_mem_ptr(phys_addr_t phys) { unsigned long start = phys & PAGE_MASK; unsigned long offset = phys & ~PAGE_MASK; void *vaddr; /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */ if (page_is_ram(start >> PAGE_SHIFT)) return __va(phys); vaddr = ioremap_cache(start, PAGE_SIZE); /* Only add the offset on success and return NULL if the ioremap() failed: */ if (vaddr) vaddr += offset; return vaddr; }

Contributors

PersonTokensPropCommitsCommitProp
Venkatesh Pallipadi4364.18%120.00%
Ingo Molnar2232.84%240.00%
Thierry Reding11.49%120.00%
Xiaotian Feng11.49%120.00%
Total67100.00%5100.00%


void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) { if (page_is_ram(phys >> PAGE_SHIFT)) return; iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK)); }

Contributors

PersonTokensPropCommitsCommitProp
Venkatesh Pallipadi3997.50%150.00%
Thierry Reding12.50%150.00%
Total40100.00%2100.00%

static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) { /* Don't assume we're using swapper_pg_dir at this point */ pgd_t *base = __va(read_cr3()); pgd_t *pgd = &base[pgd_index(addr)]; pud_t *pud = pud_offset(pgd, addr); pmd_t *pmd = pmd_offset(pud, addr); return pmd; }

Contributors

PersonTokensPropCommitsCommitProp
Ian Campbell3759.68%133.33%
Thomas Gleixner1320.97%133.33%
Jeremy Fitzhardinge1219.35%133.33%
Total62100.00%3100.00%


static inline pte_t * __init early_ioremap_pte(unsigned long addr) { return &bm_pte[pte_index(addr)]; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner1669.57%150.00%
Ian Campbell730.43%150.00%
Total23100.00%2100.00%


bool __init is_early_ioremap_ptep(pte_t *ptep) { return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)]; }

Contributors

PersonTokensPropCommitsCommitProp
Jeremy Fitzhardinge32100.00%1100.00%
Total32100.00%1100.00%


void __init early_ioremap_init(void) { pmd_t *pmd; #ifdef CONFIG_X86_64 BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); #else WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); #endif early_ioremap_setup(); pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); memset(bm_pte, 0, sizeof(bm_pte)); pmd_populate_kernel(&init_mm, pmd, bm_pte); /* * The boot-ioremap range spans multiple pmds, for which * we are not prepared: */ #define __FIXADDR_TOP (-PAGE_SIZE) BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); #undef __FIXADDR_TOP if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { WARN_ON(1); printk(KERN_WARNING "pmd %p != %p\n", pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", fix_to_virt(FIX_BTMAP_BEGIN)); printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n", fix_to_virt(FIX_BTMAP_END)); printk(KERN_WARNING "FIX_BTMAP_END: %d\n", FIX_BTMAP_END); printk(KERN_WARNING "FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); } }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner9849.00%114.29%
Andrew Lutomirski5125.50%114.29%
Jan Beulich2814.00%114.29%
Ian Campbell2010.00%228.57%
Mark Salter21.00%114.29%
Wang Chen10.50%114.29%
Total200100.00%7100.00%


void __init __early_set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) { unsigned long addr = __fix_to_virt(idx); pte_t *pte; if (idx >= __end_of_fixed_addresses) { BUG(); return; } pte = early_ioremap_pte(addr); if (pgprot_val(flags)) set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); else pte_clear(&init_mm, addr, pte); __flush_tlb_one(addr); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner6374.12%125.00%
Ian Campbell1922.35%125.00%
Jeremy Fitzhardinge22.35%125.00%
Masami Hiramatsu11.18%125.00%
Total85100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner33619.92%1213.79%
Andi Kleen30918.32%1213.79%
Venkatesh Pallipadi24314.40%89.20%
Toshi Kani955.63%44.60%
Ian Campbell905.33%22.30%
Juergen Gross834.92%22.30%
Roland Dreier784.62%11.15%
Jeremy Fitzhardinge533.14%66.90%
Andrew Lutomirski513.02%11.15%
Luis R. Rodriguez422.49%22.30%
Pekka Paalanen402.37%22.30%
Rik Van Riel382.25%11.15%
Xiaotian Feng342.02%22.30%
Ingo Molnar331.96%66.90%
Jan Beulich301.78%22.30%
Christoph Lameter261.54%11.15%
Randy Dunlap171.01%11.15%
Suresh B. Siddha160.95%22.30%
Al Viro120.71%33.45%
Tim Gardner100.59%11.15%
Kenji Kaneshige90.53%11.15%
Borislav Petkov80.47%22.30%
Laura Abbott70.41%11.15%
H. Peter Anvin40.24%11.15%
Andreas Herrmann40.24%11.15%
Linus Torvalds30.18%11.15%
Harvey Harrison30.18%11.15%
Wanpeng Li20.12%11.15%
Mark Salter20.12%11.15%
JoonSoo Kim20.12%11.15%
Thierry Reding20.12%11.15%
Håvard Skinnemoen20.12%11.15%
Mike Travis10.06%11.15%
Masami Hiramatsu10.06%11.15%
Wang Chen10.06%11.15%
Total1687100.00%87100.00%
Directory: arch/x86/mm
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