linux/arch/x86/mm/ioremap.c
Linus Torvalds d70b3ef54c Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Ingo Molnar:
 "There were so many changes in the x86/asm, x86/apic and x86/mm topics
  in this cycle that the topical separation of -tip broke down somewhat -
  so the result is a more traditional architecture pull request,
  collected into the 'x86/core' topic.

  The topics were still maintained separately as far as possible, so
  bisectability and conceptual separation should still be pretty good -
  but there were a handful of merge points to avoid excessive
  dependencies (and conflicts) that would have been poorly tested in the
  end.

  The next cycle will hopefully be much more quiet (or at least will
  have fewer dependencies).

  The main changes in this cycle were:

   * x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
     Gleixner)

     - This is the second and most intrusive part of changes to the x86
       interrupt handling - full conversion to hierarchical interrupt
       domains:

          [IOAPIC domain]   -----
                                 |
          [MSI domain]      --------[Remapping domain] ----- [ Vector domain ]
                                 |   (optional)          |
          [HPET MSI domain] -----                        |
                                                         |
          [DMAR domain]     -----------------------------
                                                         |
          [Legacy domain]   -----------------------------

       This now reflects the actual hardware and allowed us to distangle
       the domain specific code from the underlying parent domain, which
       can be optional in the case of interrupt remapping.  It's a clear
       separation of functionality and removes quite some duct tape
       constructs which plugged the remap code between ioapic/msi/hpet
       and the vector management.

     - Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
       injection into guests (Feng Wu)

   * x86/asm changes:

     - Tons of cleanups and small speedups, micro-optimizations.  This
       is in preparation to move a good chunk of the low level entry
       code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
       Brian Gerst)

     - Moved all system entry related code to a new home under
       arch/x86/entry/ (Ingo Molnar)

     - Removal of the fragile and ugly CFI dwarf debuginfo annotations.
       Conversion to C will reintroduce many of them - but meanwhile
       they are only getting in the way, and the upstream kernel does
       not rely on them (Ingo Molnar)

     - NOP handling refinements. (Borislav Petkov)

   * x86/mm changes:

     - Big PAT and MTRR rework: making the code more robust and
       preparing to phase out exposing direct MTRR interfaces to drivers -
       in favor of using PAT driven interfaces (Toshi Kani, Luis R
       Rodriguez, Borislav Petkov)

     - New ioremap_wt()/set_memory_wt() interfaces to support
       Write-Through cached memory mappings.  This is especially
       important for good performance on NVDIMM hardware (Toshi Kani)

   * x86/ras changes:

     - Add support for deferred errors on AMD (Aravind Gopalakrishnan)

       This is an important RAS feature which adds hardware support for
       poisoned data.  That means roughly that the hardware marks data
       which it has detected as corrupted but wasn't able to correct, as
       poisoned data and raises an APIC interrupt to signal that in the
       form of a deferred error.  It is the OS's responsibility then to
       take proper recovery action and thus prolonge system lifetime as
       far as possible.

     - Add support for Intel "Local MCE"s: upcoming CPUs will support
       CPU-local MCE interrupts, as opposed to the traditional system-
       wide broadcasted MCE interrupts (Ashok Raj)

     - Misc cleanups (Borislav Petkov)

   * x86/platform changes:

     - Intel Atom SoC updates

  ... and lots of other cleanups, fixlets and other changes - see the
  shortlog and the Git log for details"

* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
  x86/hpet: Use proper hpet device number for MSI allocation
  x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
  x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
  x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
  x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
  genirq: Prevent crash in irq_move_irq()
  genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
  iommu, x86: Properly handle posted interrupts for IOMMU hotplug
  iommu, x86: Provide irq_remapping_cap() interface
  iommu, x86: Setup Posted-Interrupts capability for Intel iommu
  iommu, x86: Add cap_pi_support() to detect VT-d PI capability
  iommu, x86: Avoid migrating VT-d posted interrupts
  iommu, x86: Save the mode (posted or remapped) of an IRTE
  iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
  iommu: dmar: Provide helper to copy shared irte fields
  iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
  iommu: Add new member capability to struct irq_remap_ops
  x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
  x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
  x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
  ...
2015-06-22 17:59:09 -07:00

513 lines
14 KiB
C

/*
* 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/module.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;
}
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;
WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn);
return 0;
}
/*
* 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;
int ram_region;
/* 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..
*/
/* First check if whole region can be identified as RAM or not */
ram_region = region_is_ram(phys_addr, size);
if (ram_region > 0) {
WARN_ONCE(1, "ioremap on RAM at 0x%lx - 0x%lx\n",
(unsigned long int)phys_addr,
(unsigned long int)last_addr);
return NULL;
}
/* If could not be identified(-1), check page by page */
if (ram_region < 0) {
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)
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.
*/
WARN_ONCE(iomem_map_sanity_check(unaligned_phys_addr, unaligned_size),
KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
return ret_addr;
err_free_area:
free_vm_area(area);
err_free_memtype:
free_memtype(phys_addr, phys_addr + size);
return NULL;
}
/**
* 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));
}
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));
}
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));
}
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));
}
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));
}
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));
}
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);
}
EXPORT_SYMBOL(iounmap);
int __init arch_ioremap_pud_supported(void)
{
#ifdef CONFIG_X86_64
return cpu_has_gbpages;
#else
return 0;
#endif
}
int __init arch_ioremap_pmd_supported(void)
{
return cpu_has_pse;
}
/*
* 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;
}
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));
}
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;
}
static inline pte_t * __init early_ioremap_pte(unsigned long addr)
{
return &bm_pte[pte_index(addr)];
}
bool __init is_early_ioremap_ptep(pte_t *ptep)
{
return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)];
}
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);
}
}
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);
}