blob: 4b47ae0602e110b1e0039ed2b7e358299e3c3473 [file] [log] [blame]
/*
* Copyright 2002 Andi Kleen, SuSE Labs.
* Thanks to Ben LaHaise for precious feedback.
*/
#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/pfn.h>
#include <linux/percpu.h>
#include <linux/gfp.h>
#include <linux/pci.h>
#include <asm/e820.h>
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/proto.h>
#include <asm/pat.h>
/*
* The current flushing context - we pass it instead of 5 arguments:
*/
struct cpa_data {
unsigned long *vaddr;
pgd_t *pgd;
pgprot_t mask_set;
pgprot_t mask_clr;
int numpages;
int flags;
unsigned long pfn;
unsigned force_split : 1;
int curpage;
struct page **pages;
};
/*
* Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings)
* using cpa_lock. So that we don't allow any other cpu, with stale large tlb
* entries change the page attribute in parallel to some other cpu
* splitting a large page entry along with changing the attribute.
*/
static DEFINE_SPINLOCK(cpa_lock);
#define CPA_FLUSHTLB 1
#define CPA_ARRAY 2
#define CPA_PAGES_ARRAY 4
#ifdef CONFIG_PROC_FS
static unsigned long direct_pages_count[PG_LEVEL_NUM];
void update_page_count(int level, unsigned long pages)
{
/* Protect against CPA */
spin_lock(&pgd_lock);
direct_pages_count[level] += pages;
spin_unlock(&pgd_lock);
}
static void split_page_count(int level)
{
direct_pages_count[level]--;
direct_pages_count[level - 1] += PTRS_PER_PTE;
}
void arch_report_meminfo(struct seq_file *m)
{
seq_printf(m, "DirectMap4k: %8lu kB\n",
direct_pages_count[PG_LEVEL_4K] << 2);
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
seq_printf(m, "DirectMap2M: %8lu kB\n",
direct_pages_count[PG_LEVEL_2M] << 11);
#else
seq_printf(m, "DirectMap4M: %8lu kB\n",
direct_pages_count[PG_LEVEL_2M] << 12);
#endif
#ifdef CONFIG_X86_64
if (direct_gbpages)
seq_printf(m, "DirectMap1G: %8lu kB\n",
direct_pages_count[PG_LEVEL_1G] << 20);
#endif
}
#else
static inline void split_page_count(int level) { }
#endif
#ifdef CONFIG_X86_64
static inline unsigned long highmap_start_pfn(void)
{
return __pa_symbol(_text) >> PAGE_SHIFT;
}
static inline unsigned long highmap_end_pfn(void)
{
return __pa_symbol(roundup(_brk_end, PMD_SIZE)) >> PAGE_SHIFT;
}
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
# define debug_pagealloc 1
#else
# define debug_pagealloc 0
#endif
static inline int
within(unsigned long addr, unsigned long start, unsigned long end)
{
return addr >= start && addr < end;
}
/*
* Flushing functions
*/
/**
* clflush_cache_range - flush a cache range with clflush
* @vaddr: virtual start address
* @size: number of bytes to flush
*
* clflush is an unordered instruction which needs fencing with mfence
* to avoid ordering issues.
*/
void clflush_cache_range(void *vaddr, unsigned int size)
{
void *vend = vaddr + size - 1;
mb();
for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
clflush(vaddr);
/*
* Flush any possible final partial cacheline:
*/
clflush(vend);
mb();
}
EXPORT_SYMBOL_GPL(clflush_cache_range);
static void __cpa_flush_all(void *arg)
{
unsigned long cache = (unsigned long)arg;
/*
* Flush all to work around Errata in early athlons regarding
* large page flushing.
*/
__flush_tlb_all();
if (cache && boot_cpu_data.x86 >= 4)
wbinvd();
}
static void cpa_flush_all(unsigned long cache)
{
BUG_ON(irqs_disabled());
on_each_cpu(__cpa_flush_all, (void *) cache, 1);
}
static void __cpa_flush_range(void *arg)
{
/*
* We could optimize that further and do individual per page
* tlb invalidates for a low number of pages. Caveat: we must
* flush the high aliases on 64bit as well.
*/
__flush_tlb_all();
}
static void cpa_flush_range(unsigned long start, int numpages, int cache)
{
unsigned int i, level;
unsigned long addr;
BUG_ON(irqs_disabled());
WARN_ON(PAGE_ALIGN(start) != start);
on_each_cpu(__cpa_flush_range, NULL, 1);
if (!cache)
return;
/*
* We only need to flush on one CPU,
* clflush is a MESI-coherent instruction that
* will cause all other CPUs to flush the same
* cachelines:
*/
for (i = 0, addr = start; i < numpages; i++, addr += PAGE_SIZE) {
pte_t *pte = lookup_address(addr, &level);
/*
* Only flush present addresses:
*/
if (pte && (pte_val(*pte) & _PAGE_PRESENT))
clflush_cache_range((void *) addr, PAGE_SIZE);
}
}
static void cpa_flush_array(unsigned long *start, int numpages, int cache,
int in_flags, struct page **pages)
{
unsigned int i, level;
unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */
BUG_ON(irqs_disabled());
on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1);
if (!cache || do_wbinvd)
return;
/*
* We only need to flush on one CPU,
* clflush is a MESI-coherent instruction that
* will cause all other CPUs to flush the same
* cachelines:
*/
for (i = 0; i < numpages; i++) {
unsigned long addr;
pte_t *pte;
if (in_flags & CPA_PAGES_ARRAY)
addr = (unsigned long)page_address(pages[i]);
else
addr = start[i];
pte = lookup_address(addr, &level);
/*
* Only flush present addresses:
*/
if (pte && (pte_val(*pte) & _PAGE_PRESENT))
clflush_cache_range((void *)addr, PAGE_SIZE);
}
}
/*
* Certain areas of memory on x86 require very specific protection flags,
* for example the BIOS area or kernel text. Callers don't always get this
* right (again, ioremap() on BIOS memory is not uncommon) so this function
* checks and fixes these known static required protection bits.
*/
static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
unsigned long pfn)
{
pgprot_t forbidden = __pgprot(0);
/*
* The BIOS area between 640k and 1Mb needs to be executable for
* PCI BIOS based config access (CONFIG_PCI_GOBIOS) support.
*/
#ifdef CONFIG_PCI_BIOS
if (pcibios_enabled && within(pfn, BIOS_BEGIN >> PAGE_SHIFT, BIOS_END >> PAGE_SHIFT))
pgprot_val(forbidden) |= _PAGE_NX;
#endif
/*
* The kernel text needs to be executable for obvious reasons
* Does not cover __inittext since that is gone later on. On
* 64bit we do not enforce !NX on the low mapping
*/
if (within(address, (unsigned long)_text, (unsigned long)_etext))
pgprot_val(forbidden) |= _PAGE_NX;
/*
* The .rodata section needs to be read-only. Using the pfn
* catches all aliases.
*/
if (within(pfn, __pa_symbol(__start_rodata) >> PAGE_SHIFT,
__pa_symbol(__end_rodata) >> PAGE_SHIFT))
pgprot_val(forbidden) |= _PAGE_RW;
#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA)
/*
* Once the kernel maps the text as RO (kernel_set_to_readonly is set),
* kernel text mappings for the large page aligned text, rodata sections
* will be always read-only. For the kernel identity mappings covering
* the holes caused by this alignment can be anything that user asks.
*
* This will preserve the large page mappings for kernel text/data
* at no extra cost.
*/
if (kernel_set_to_readonly &&
within(address, (unsigned long)_text,
(unsigned long)__end_rodata_hpage_align)) {
unsigned int level;
/*
* Don't enforce the !RW mapping for the kernel text mapping,
* if the current mapping is already using small page mapping.
* No need to work hard to preserve large page mappings in this
* case.
*
* This also fixes the Linux Xen paravirt guest boot failure
* (because of unexpected read-only mappings for kernel identity
* mappings). In this paravirt guest case, the kernel text
* mapping and the kernel identity mapping share the same
* page-table pages. Thus we can't really use different
* protections for the kernel text and identity mappings. Also,
* these shared mappings are made of small page mappings.
* Thus this don't enforce !RW mapping for small page kernel
* text mapping logic will help Linux Xen parvirt guest boot
* as well.
*/
if (lookup_address(address, &level) && (level != PG_LEVEL_4K))
pgprot_val(forbidden) |= _PAGE_RW;
}
#endif
prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
return prot;
}
static pte_t *__lookup_address_in_pgd(pgd_t *pgd, unsigned long address,
unsigned int *level)
{
pud_t *pud;
pmd_t *pmd;
*level = PG_LEVEL_NONE;
if (pgd_none(*pgd))
return NULL;
pud = pud_offset(pgd, address);
if (pud_none(*pud))
return NULL;
*level = PG_LEVEL_1G;
if (pud_large(*pud) || !pud_present(*pud))
return (pte_t *)pud;
pmd = pmd_offset(pud, address);
if (pmd_none(*pmd))
return NULL;
*level = PG_LEVEL_2M;
if (pmd_large(*pmd) || !pmd_present(*pmd))
return (pte_t *)pmd;
*level = PG_LEVEL_4K;
return pte_offset_kernel(pmd, address);
}
/*
* Lookup the page table entry for a virtual address. Return a pointer
* to the entry and the level of the mapping.
*
* Note: We return pud and pmd either when the entry is marked large
* or when the present bit is not set. Otherwise we would return a
* pointer to a nonexisting mapping.
*/
pte_t *lookup_address(unsigned long address, unsigned int *level)
{
return __lookup_address_in_pgd(pgd_offset_k(address), address, level);
}
EXPORT_SYMBOL_GPL(lookup_address);
static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address,
unsigned int *level)
{
if (cpa->pgd)
return __lookup_address_in_pgd(cpa->pgd + pgd_index(address),
address, level);
return lookup_address(address, level);
}
/*
* This is necessary because __pa() does not work on some
* kinds of memory, like vmalloc() or the alloc_remap()
* areas on 32-bit NUMA systems. The percpu areas can
* end up in this kind of memory, for instance.
*
* This could be optimized, but it is only intended to be
* used at inititalization time, and keeping it
* unoptimized should increase the testing coverage for
* the more obscure platforms.
*/
phys_addr_t slow_virt_to_phys(void *__virt_addr)
{
unsigned long virt_addr = (unsigned long)__virt_addr;
phys_addr_t phys_addr;
unsigned long offset;
enum pg_level level;
unsigned long psize;
unsigned long pmask;
pte_t *pte;
pte = lookup_address(virt_addr, &level);
BUG_ON(!pte);
psize = page_level_size(level);
pmask = page_level_mask(level);
offset = virt_addr & ~pmask;
phys_addr = pte_pfn(*pte) << PAGE_SHIFT;
return (phys_addr | offset);
}
EXPORT_SYMBOL_GPL(slow_virt_to_phys);
/*
* Set the new pmd in all the pgds we know about:
*/
static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
{
/* change init_mm */
set_pte_atomic(kpte, pte);
#ifdef CONFIG_X86_32
if (!SHARED_KERNEL_PMD) {
struct page *page;
list_for_each_entry(page, &pgd_list, lru) {
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pgd = (pgd_t *)page_address(page) + pgd_index(address);
pud = pud_offset(pgd, address);
pmd = pmd_offset(pud, address);
set_pte_atomic((pte_t *)pmd, pte);
}
}
#endif
}
static int
try_preserve_large_page(pte_t *kpte, unsigned long address,
struct cpa_data *cpa)
{
unsigned long nextpage_addr, numpages, pmask, psize, addr, pfn;
pte_t new_pte, old_pte, *tmp;
pgprot_t old_prot, new_prot, req_prot;
int i, do_split = 1;
enum pg_level level;
if (cpa->force_split)
return 1;
spin_lock(&pgd_lock);
/*
* Check for races, another CPU might have split this page
* up already:
*/
tmp = lookup_address(address, &level);
if (tmp != kpte)
goto out_unlock;
switch (level) {
case PG_LEVEL_2M:
#ifdef CONFIG_X86_64
case PG_LEVEL_1G:
#endif
psize = page_level_size(level);
pmask = page_level_mask(level);
break;
default:
do_split = -EINVAL;
goto out_unlock;
}
/*
* Calculate the number of pages, which fit into this large
* page starting at address:
*/
nextpage_addr = (address + psize) & pmask;
numpages = (nextpage_addr - address) >> PAGE_SHIFT;
if (numpages < cpa->numpages)
cpa->numpages = numpages;
/*
* We are safe now. Check whether the new pgprot is the same:
*/
old_pte = *kpte;
old_prot = req_prot = pte_pgprot(old_pte);
pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr);
pgprot_val(req_prot) |= pgprot_val(cpa->mask_set);
/*
* Set the PSE and GLOBAL flags only if the PRESENT flag is
* set otherwise pmd_present/pmd_huge will return true even on
* a non present pmd. The canon_pgprot will clear _PAGE_GLOBAL
* for the ancient hardware that doesn't support it.
*/
if (pgprot_val(req_prot) & _PAGE_PRESENT)
pgprot_val(req_prot) |= _PAGE_PSE | _PAGE_GLOBAL;
else
pgprot_val(req_prot) &= ~(_PAGE_PSE | _PAGE_GLOBAL);
req_prot = canon_pgprot(req_prot);
/*
* old_pte points to the large page base address. So we need
* to add the offset of the virtual address:
*/
pfn = pte_pfn(old_pte) + ((address & (psize - 1)) >> PAGE_SHIFT);
cpa->pfn = pfn;
new_prot = static_protections(req_prot, address, pfn);
/*
* We need to check the full range, whether
* static_protection() requires a different pgprot for one of
* the pages in the range we try to preserve:
*/
addr = address & pmask;
pfn = pte_pfn(old_pte);
for (i = 0; i < (psize >> PAGE_SHIFT); i++, addr += PAGE_SIZE, pfn++) {
pgprot_t chk_prot = static_protections(req_prot, addr, pfn);
if (pgprot_val(chk_prot) != pgprot_val(new_prot))
goto out_unlock;
}
/*
* If there are no changes, return. maxpages has been updated
* above:
*/
if (pgprot_val(new_prot) == pgprot_val(old_prot)) {
do_split = 0;
goto out_unlock;
}
/*
* We need to change the attributes. Check, whether we can
* change the large page in one go. We request a split, when
* the address is not aligned and the number of pages is
* smaller than the number of pages in the large page. Note
* that we limited the number of possible pages already to
* the number of pages in the large page.
*/
if (address == (address & pmask) && cpa->numpages == (psize >> PAGE_SHIFT)) {
/*
* The address is aligned and the number of pages
* covers the full page.
*/
new_pte = pfn_pte(pte_pfn(old_pte), new_prot);
__set_pmd_pte(kpte, address, new_pte);
cpa->flags |= CPA_FLUSHTLB;
do_split = 0;
}
out_unlock:
spin_unlock(&pgd_lock);
return do_split;
}
static int
__split_large_page(pte_t *kpte, unsigned long address, struct page *base)
{
pte_t *pbase = (pte_t *)page_address(base);
unsigned long pfn, pfninc = 1;
unsigned int i, level;
pte_t *tmp;
pgprot_t ref_prot;
spin_lock(&pgd_lock);
/*
* Check for races, another CPU might have split this page
* up for us already:
*/
tmp = lookup_address(address, &level);
if (tmp != kpte) {
spin_unlock(&pgd_lock);
return 1;
}
paravirt_alloc_pte(&init_mm, page_to_pfn(base));
ref_prot = pte_pgprot(pte_clrhuge(*kpte));
/*
* If we ever want to utilize the PAT bit, we need to
* update this function to make sure it's converted from
* bit 12 to bit 7 when we cross from the 2MB level to
* the 4K level:
*/
WARN_ON_ONCE(pgprot_val(ref_prot) & _PAGE_PAT_LARGE);
#ifdef CONFIG_X86_64
if (level == PG_LEVEL_1G) {
pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
/*
* Set the PSE flags only if the PRESENT flag is set
* otherwise pmd_present/pmd_huge will return true
* even on a non present pmd.
*/
if (pgprot_val(ref_prot) & _PAGE_PRESENT)
pgprot_val(ref_prot) |= _PAGE_PSE;
else
pgprot_val(ref_prot) &= ~_PAGE_PSE;
}
#endif
/*
* Set the GLOBAL flags only if the PRESENT flag is set
* otherwise pmd/pte_present will return true even on a non
* present pmd/pte. The canon_pgprot will clear _PAGE_GLOBAL
* for the ancient hardware that doesn't support it.
*/
if (pgprot_val(ref_prot) & _PAGE_PRESENT)
pgprot_val(ref_prot) |= _PAGE_GLOBAL;
else
pgprot_val(ref_prot) &= ~_PAGE_GLOBAL;
/*
* Get the target pfn from the original entry:
*/
pfn = pte_pfn(*kpte);
for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
set_pte(&pbase[i], pfn_pte(pfn, canon_pgprot(ref_prot)));
if (pfn_range_is_mapped(PFN_DOWN(__pa(address)),
PFN_DOWN(__pa(address)) + 1))
split_page_count(level);
/*
* Install the new, split up pagetable.
*
* We use the standard kernel pagetable protections for the new
* pagetable protections, the actual ptes set above control the
* primary protection behavior:
*/
__set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
/*
* Intel Atom errata AAH41 workaround.
*
* The real fix should be in hw or in a microcode update, but
* we also probabilistically try to reduce the window of having
* a large TLB mixed with 4K TLBs while instruction fetches are
* going on.
*/
__flush_tlb_all();
spin_unlock(&pgd_lock);
return 0;
}
static int split_large_page(pte_t *kpte, unsigned long address)
{
struct page *base;
if (!debug_pagealloc)
spin_unlock(&cpa_lock);
base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
if (!debug_pagealloc)
spin_lock(&cpa_lock);
if (!base)
return -ENOMEM;
if (__split_large_page(kpte, address, base))
__free_page(base);
return 0;
}
#define populate_pud(cpa, addr, pgd, pgprot) (-1)
/*
* Restrictions for kernel page table do not necessarily apply when mapping in
* an alternate PGD.
*/
static int populate_pgd(struct cpa_data *cpa, unsigned long addr)
{
pgprot_t pgprot = __pgprot(_KERNPG_TABLE);
bool allocd_pgd = false;
pgd_t *pgd_entry;
pud_t *pud = NULL; /* shut up gcc */
int ret;
pgd_entry = cpa->pgd + pgd_index(addr);
/*
* Allocate a PUD page and hand it down for mapping.
*/
if (pgd_none(*pgd_entry)) {
pud = (pud_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
if (!pud)
return -1;
set_pgd(pgd_entry, __pgd(__pa(pud) | _KERNPG_TABLE));
allocd_pgd = true;
}
pgprot_val(pgprot) &= ~pgprot_val(cpa->mask_clr);
pgprot_val(pgprot) |= pgprot_val(cpa->mask_set);
ret = populate_pud(cpa, addr, pgd_entry, pgprot);
if (ret < 0)
return ret;
cpa->numpages = ret;
return 0;
}
static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr,
int primary)
{
/*
* Ignore all non primary paths.
*/
if (!primary)
return 0;
/*
* Ignore the NULL PTE for kernel identity mapping, as it is expected
* to have holes.
* Also set numpages to '1' indicating that we processed cpa req for
* one virtual address page and its pfn. TBD: numpages can be set based
* on the initial value and the level returned by lookup_address().
*/
if (within(vaddr, PAGE_OFFSET,
PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) {
cpa->numpages = 1;
cpa->pfn = __pa(vaddr) >> PAGE_SHIFT;
return 0;
} else {
WARN(1, KERN_WARNING "CPA: called for zero pte. "
"vaddr = %lx cpa->vaddr = %lx\n", vaddr,
*cpa->vaddr);
return -EFAULT;
}
}
static int __change_page_attr(struct cpa_data *cpa, int primary)
{
unsigned long address;
int do_split, err;
unsigned int level;
pte_t *kpte, old_pte;
if (cpa->flags & CPA_PAGES_ARRAY) {
struct page *page = cpa->pages[cpa->curpage];
if (unlikely(PageHighMem(page)))
return 0;
address = (unsigned long)page_address(page);
} else if (cpa->flags & CPA_ARRAY)
address = cpa->vaddr[cpa->curpage];
else
address = *cpa->vaddr;
repeat:
kpte = lookup_address(address, &level);
if (!kpte)
return __cpa_process_fault(cpa, address, primary);
old_pte = *kpte;
if (!pte_val(old_pte))
return __cpa_process_fault(cpa, address, primary);
if (level == PG_LEVEL_4K) {
pte_t new_pte;
pgprot_t new_prot = pte_pgprot(old_pte);
unsigned long pfn = pte_pfn(old_pte);
pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
new_prot = static_protections(new_prot, address, pfn);
/*
* Set the GLOBAL flags only if the PRESENT flag is
* set otherwise pte_present will return true even on
* a non present pte. The canon_pgprot will clear
* _PAGE_GLOBAL for the ancient hardware that doesn't
* support it.
*/
if (pgprot_val(new_prot) & _PAGE_PRESENT)
pgprot_val(new_prot) |= _PAGE_GLOBAL;
else
pgprot_val(new_prot) &= ~_PAGE_GLOBAL;
/*
* We need to keep the pfn from the existing PTE,
* after all we're only going to change it's attributes
* not the memory it points to
*/
new_pte = pfn_pte(pfn, canon_pgprot(new_prot));
cpa->pfn = pfn;
/*
* Do we really change anything ?
*/
if (pte_val(old_pte) != pte_val(new_pte)) {
set_pte_atomic(kpte, new_pte);
cpa->flags |= CPA_FLUSHTLB;
}
cpa->numpages = 1;
return 0;
}
/*
* Check, whether we can keep the large page intact
* and just change the pte:
*/
do_split = try_preserve_large_page(kpte, address, cpa);
/*
* When the range fits into the existing large page,
* return. cp->numpages and cpa->tlbflush have been updated in
* try_large_page:
*/
if (do_split <= 0)
return do_split;
/*
* We have to split the large page:
*/
err = split_large_page(kpte, address);
if (!err) {
/*
* Do a global flush tlb after splitting the large page
* and before we do the actual change page attribute in the PTE.
*
* With out this, we violate the TLB application note, that says
* "The TLBs may contain both ordinary and large-page
* translations for a 4-KByte range of linear addresses. This
* may occur if software modifies the paging structures so that
* the page size used for the address range changes. If the two
* translations differ with respect to page frame or attributes
* (e.g., permissions), processor behavior is undefined and may
* be implementation-specific."
*
* We do this global tlb flush inside the cpa_lock, so that we
* don't allow any other cpu, with stale tlb entries change the
* page attribute in parallel, that also falls into the
* just split large page entry.
*/
flush_tlb_all();
goto repeat;
}
return err;
}
static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias);
static int cpa_process_alias(struct cpa_data *cpa)
{
struct cpa_data alias_cpa;
unsigned long laddr = (unsigned long)__va(cpa->pfn << PAGE_SHIFT);
unsigned long vaddr;
int ret;
if (!pfn_range_is_mapped(cpa->pfn, cpa->pfn + 1))
return 0;
/*
* No need to redo, when the primary call touched the direct
* mapping already:
*/
if (cpa->flags & CPA_PAGES_ARRAY) {
struct page *page = cpa->pages[cpa->curpage];
if (unlikely(PageHighMem(page)))
return 0;
vaddr = (unsigned long)page_address(page);
} else if (cpa->flags & CPA_ARRAY)
vaddr = cpa->vaddr[cpa->curpage];
else
vaddr = *cpa->vaddr;
if (!(within(vaddr, PAGE_OFFSET,
PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)))) {
alias_cpa = *cpa;
alias_cpa.vaddr = &laddr;
alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
ret = __change_page_attr_set_clr(&alias_cpa, 0);
if (ret)
return ret;
}
#ifdef CONFIG_X86_64
/*
* If the primary call didn't touch the high mapping already
* and the physical address is inside the kernel map, we need
* to touch the high mapped kernel as well:
*/
if (!within(vaddr, (unsigned long)_text, _brk_end) &&
within(cpa->pfn, highmap_start_pfn(), highmap_end_pfn())) {
unsigned long temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) +
__START_KERNEL_map - phys_base;
alias_cpa = *cpa;
alias_cpa.vaddr = &temp_cpa_vaddr;
alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
/*
* The high mapping range is imprecise, so ignore the
* return value.
*/
__change_page_attr_set_clr(&alias_cpa, 0);
}
#endif
return 0;
}
static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
{
int ret, numpages = cpa->numpages;
while (numpages) {
/*
* Store the remaining nr of pages for the large page
* preservation check.
*/
cpa->numpages = numpages;
/* for array changes, we can't use large page */
if (cpa->flags & (CPA_ARRAY | CPA_PAGES_ARRAY))
cpa->numpages = 1;
if (!debug_pagealloc)
spin_lock(&cpa_lock);
ret = __change_page_attr(cpa, checkalias);
if (!debug_pagealloc)
spin_unlock(&cpa_lock);
if (ret)
return ret;
if (checkalias) {
ret = cpa_process_alias(cpa);
if (ret)
return ret;
}
/*
* Adjust the number of pages with the result of the
* CPA operation. Either a large page has been
* preserved or a single page update happened.
*/
BUG_ON(cpa->numpages > numpages);
numpages -= cpa->numpages;
if (cpa->flags & (CPA_PAGES_ARRAY | CPA_ARRAY))
cpa->curpage++;
else
*cpa->vaddr += cpa->numpages * PAGE_SIZE;
}
return 0;
}
static inline int cache_attr(pgprot_t attr)
{
return pgprot_val(attr) &
(_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
}
static int change_page_attr_set_clr(unsigned long *addr, int numpages,
pgprot_t mask_set, pgprot_t mask_clr,
int force_split, int in_flag,
struct page **pages)
{
struct cpa_data cpa;
int ret, cache, checkalias;
unsigned long baddr = 0;
/*
* Check, if we are requested to change a not supported
* feature:
*/
mask_set = canon_pgprot(mask_set);
mask_clr = canon_pgprot(mask_clr);
if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split)
return 0;
/* Ensure we are PAGE_SIZE aligned */
if (in_flag & CPA_ARRAY) {
int i;
for (i = 0; i < numpages; i++) {
if (addr[i] & ~PAGE_MASK) {
addr[i] &= PAGE_MASK;
WARN_ON_ONCE(1);
}
}
} else if (!(in_flag & CPA_PAGES_ARRAY)) {
/*
* in_flag of CPA_PAGES_ARRAY implies it is aligned.
* No need to cehck in that case
*/
if (*addr & ~PAGE_MASK) {
*addr &= PAGE_MASK;
/*
* People should not be passing in unaligned addresses:
*/
WARN_ON_ONCE(1);
}
/*
* Save address for cache flush. *addr is modified in the call
* to __change_page_attr_set_clr() below.
*/
baddr = *addr;
}
/* Must avoid aliasing mappings in the highmem code */
kmap_flush_unused();
vm_unmap_aliases();
cpa.vaddr = addr;
cpa.pages = pages;
cpa.numpages = numpages;
cpa.mask_set = mask_set;
cpa.mask_clr = mask_clr;
cpa.flags = 0;
cpa.curpage = 0;
cpa.force_split = force_split;
if (in_flag & (CPA_ARRAY | CPA_PAGES_ARRAY))
cpa.flags |= in_flag;
/* No alias checking for _NX bit modifications */
checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
ret = __change_page_attr_set_clr(&cpa, checkalias);
/*
* Check whether we really changed something:
*/
if (!(cpa.flags & CPA_FLUSHTLB))
goto out;
/*
* No need to flush, when we did not set any of the caching
* attributes:
*/
cache = cache_attr(mask_set);
/*
* On success we use clflush, when the CPU supports it to
* avoid the wbindv. If the CPU does not support it and in the
* error case we fall back to cpa_flush_all (which uses
* wbindv):
*/
if (!ret && cpu_has_clflush) {
if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
cpa_flush_array(addr, numpages, cache,
cpa.flags, pages);
} else
cpa_flush_range(baddr, numpages, cache);
} else
cpa_flush_all(cache);
out:
return ret;
}
static inline int change_page_attr_set(unsigned long *addr, int numpages,
pgprot_t mask, int array)
{
return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0,
(array ? CPA_ARRAY : 0), NULL);
}
static inline int change_page_attr_clear(unsigned long *addr, int numpages,
pgprot_t mask, int array)
{
return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0,
(array ? CPA_ARRAY : 0), NULL);
}
static inline int cpa_set_pages_array(struct page **pages, int numpages,
pgprot_t mask)
{
return change_page_attr_set_clr(NULL, numpages, mask, __pgprot(0), 0,
CPA_PAGES_ARRAY, pages);
}
static inline int cpa_clear_pages_array(struct page **pages, int numpages,
pgprot_t mask)
{
return change_page_attr_set_clr(NULL, numpages, __pgprot(0), mask, 0,
CPA_PAGES_ARRAY, pages);
}
int _set_memory_uc(unsigned long addr, int numpages)
{
/*
* for now UC MINUS. see comments in ioremap_nocache()
*/
return change_page_attr_set(&addr, numpages,
__pgprot(_PAGE_CACHE_UC_MINUS), 0);
}
int set_memory_uc(unsigned long addr, int numpages)
{
int ret;
/*
* for now UC MINUS. see comments in ioremap_nocache()
*/
ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
_PAGE_CACHE_UC_MINUS, NULL);
if (ret)
goto out_err;
ret = _set_memory_uc(addr, numpages);
if (ret)
goto out_free;
return 0;
out_free:
free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
out_err:
return ret;
}
EXPORT_SYMBOL(set_memory_uc);
static int _set_memory_array(unsigned long *addr, int addrinarray,
unsigned long new_type)
{
int i, j;
int ret;
/*
* for now UC MINUS. see comments in ioremap_nocache()
*/
for (i = 0; i < addrinarray; i++) {
ret = reserve_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE,
new_type, NULL);
if (ret)
goto out_free;
}
ret = change_page_attr_set(addr, addrinarray,
__pgprot(_PAGE_CACHE_UC_MINUS), 1);
if (!ret && new_type == _PAGE_CACHE_WC)
ret = change_page_attr_set_clr(addr, addrinarray,
__pgprot(_PAGE_CACHE_WC),
__pgprot(_PAGE_CACHE_MASK),
0, CPA_ARRAY, NULL);
if (ret)
goto out_free;
return 0;
out_free:
for (j = 0; j < i; j++)
free_memtype(__pa(addr[j]), __pa(addr[j]) + PAGE_SIZE);
return ret;
}
int set_memory_array_uc(unsigned long *addr, int addrinarray)
{
return _set_memory_array(addr, addrinarray, _PAGE_CACHE_UC_MINUS);
}
EXPORT_SYMBOL(set_memory_array_uc);
int set_memory_array_wc(unsigned long *addr, int addrinarray)
{
return _set_memory_array(addr, addrinarray, _PAGE_CACHE_WC);
}
EXPORT_SYMBOL(set_memory_array_wc);
int _set_memory_wc(unsigned long addr, int numpages)
{
int ret;
unsigned long addr_copy = addr;
ret = change_page_attr_set(&addr, numpages,
__pgprot(_PAGE_CACHE_UC_MINUS), 0);
if (!ret) {
ret = change_page_attr_set_clr(&addr_copy, numpages,
__pgprot(_PAGE_CACHE_WC),
__pgprot(_PAGE_CACHE_MASK),
0, 0, NULL);
}
return ret;
}
int set_memory_wc(unsigned long addr, int numpages)
{
int ret;
if (!pat_enabled)
return set_memory_uc(addr, numpages);
ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
_PAGE_CACHE_WC, NULL);
if (ret)
goto out_err;
ret = _set_memory_wc(addr, numpages);
if (ret)
goto out_free;
return 0;
out_free:
free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
out_err:
return ret;
}
EXPORT_SYMBOL(set_memory_wc);
int _set_memory_wb(unsigned long addr, int numpages)
{
return change_page_attr_clear(&addr, numpages,
__pgprot(_PAGE_CACHE_MASK), 0);
}
int set_memory_wb(unsigned long addr, int numpages)
{
int ret;
ret = _set_memory_wb(addr, numpages);
if (ret)
return ret;
free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
return 0;
}
EXPORT_SYMBOL(set_memory_wb);
int set_memory_array_wb(unsigned long *addr, int addrinarray)
{
int i;
int ret;
ret = change_page_attr_clear(addr, addrinarray,
__pgprot(_PAGE_CACHE_MASK), 1);
if (ret)
return ret;
for (i = 0; i < addrinarray; i++)
free_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE);
return 0;
}
EXPORT_SYMBOL(set_memory_array_wb);
int set_memory_x(unsigned long addr, int numpages)
{
if (!(__supported_pte_mask & _PAGE_NX))
return 0;
return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0);
}
EXPORT_SYMBOL(set_memory_x);
int set_memory_nx(unsigned long addr, int numpages)
{
if (!(__supported_pte_mask & _PAGE_NX))
return 0;
return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0);
}
EXPORT_SYMBOL(set_memory_nx);
int set_memory_ro(unsigned long addr, int numpages)
{
return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
EXPORT_SYMBOL_GPL(set_memory_ro);
int set_memory_rw(unsigned long addr, int numpages)
{
return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
EXPORT_SYMBOL_GPL(set_memory_rw);
int set_memory_np(unsigned long addr, int numpages)
{
return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_PRESENT), 0);
}
int set_memory_4k(unsigned long addr, int numpages)
{
return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
__pgprot(0), 1, 0, NULL);
}
int set_pages_uc(struct page *page, int numpages)
{
unsigned long addr = (unsigned long)page_address(page);
return set_memory_uc(addr, numpages);
}
EXPORT_SYMBOL(set_pages_uc);
static int _set_pages_array(struct page **pages, int addrinarray,
unsigned long new_type)
{
unsigned long start;
unsigned long end;
int i;
int free_idx;
int ret;
for (i = 0; i < addrinarray; i++) {
if (PageHighMem(pages[i]))
continue;
start = page_to_pfn(pages[i]) << PAGE_SHIFT;
end = start + PAGE_SIZE;
if (reserve_memtype(start, end, new_type, NULL))
goto err_out;
}
ret = cpa_set_pages_array(pages, addrinarray,
__pgprot(_PAGE_CACHE_UC_MINUS));
if (!ret && new_type == _PAGE_CACHE_WC)
ret = change_page_attr_set_clr(NULL, addrinarray,
__pgprot(_PAGE_CACHE_WC),
__pgprot(_PAGE_CACHE_MASK),
0, CPA_PAGES_ARRAY, pages);
if (ret)
goto err_out;
return 0; /* Success */
err_out:
free_idx = i;
for (i = 0; i < free_idx; i++) {
if (PageHighMem(pages[i]))
continue;
start = page_to_pfn(pages[i]) << PAGE_SHIFT;
end = start + PAGE_SIZE;
free_memtype(start, end);
}
return -EINVAL;
}
int set_pages_array_uc(struct page **pages, int addrinarray)
{
return _set_pages_array(pages, addrinarray, _PAGE_CACHE_UC_MINUS);
}
EXPORT_SYMBOL(set_pages_array_uc);
int set_pages_array_wc(struct page **pages, int addrinarray)
{
return _set_pages_array(pages, addrinarray, _PAGE_CACHE_WC);
}
EXPORT_SYMBOL(set_pages_array_wc);
int set_pages_wb(struct page *page, int numpages)
{
unsigned long addr = (unsigned long)page_address(page);
return set_memory_wb(addr, numpages);
}
EXPORT_SYMBOL(set_pages_wb);
int set_pages_array_wb(struct page **pages, int addrinarray)
{
int retval;
unsigned long start;
unsigned long end;
int i;
retval = cpa_clear_pages_array(pages, addrinarray,
__pgprot(_PAGE_CACHE_MASK));
if (retval)
return retval;
for (i = 0; i < addrinarray; i++) {
if (PageHighMem(pages[i]))
continue;
start = page_to_pfn(pages[i]) << PAGE_SHIFT;
end = start + PAGE_SIZE;
free_memtype(start, end);
}
return 0;
}
EXPORT_SYMBOL(set_pages_array_wb);
int set_pages_x(struct page *page, int numpages)
{
unsigned long addr = (unsigned long)page_address(page);
return set_memory_x(addr, numpages);
}
EXPORT_SYMBOL(set_pages_x);
int set_pages_nx(struct page *page, int numpages)
{
unsigned long addr = (unsigned long)page_address(page);
return set_memory_nx(addr, numpages);
}
EXPORT_SYMBOL(set_pages_nx);
int set_pages_ro(struct page *page, int numpages)
{
unsigned long addr = (unsigned long)page_address(page);
return set_memory_ro(addr, numpages);
}
int set_pages_rw(struct page *page, int numpages)
{
unsigned long addr = (unsigned long)page_address(page);
return set_memory_rw(addr, numpages);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
static int __set_pages_p(struct page *page, int numpages)
{
unsigned long tempaddr = (unsigned long) page_address(page);
struct cpa_data cpa = { .vaddr = &tempaddr,
.numpages = numpages,
.mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
.mask_clr = __pgprot(0),
.flags = 0};
/*
* No alias checking needed for setting present flag. otherwise,
* we may need to break large pages for 64-bit kernel text
* mappings (this adds to complexity if we want to do this from
* atomic context especially). Let's keep it simple!
*/
return __change_page_attr_set_clr(&cpa, 0);
}
static int __set_pages_np(struct page *page, int numpages)
{
unsigned long tempaddr = (unsigned long) page_address(page);
struct cpa_data cpa = { .vaddr = &tempaddr,
.numpages = numpages,
.mask_set = __pgprot(0),
.mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
.flags = 0};
/*
* No alias checking needed for setting not present flag. otherwise,
* we may need to break large pages for 64-bit kernel text
* mappings (this adds to complexity if we want to do this from
* atomic context especially). Let's keep it simple!
*/
return __change_page_attr_set_clr(&cpa, 0);
}
void kernel_map_pages(struct page *page, int numpages, int enable)
{
if (PageHighMem(page))
return;
if (!enable) {
debug_check_no_locks_freed(page_address(page),
numpages * PAGE_SIZE);
}
/*
* The return value is ignored as the calls cannot fail.
* Large pages for identity mappings are not used at boot time
* and hence no memory allocations during large page split.
*/
if (enable)
__set_pages_p(page, numpages);
else
__set_pages_np(page, numpages);
/*
* We should perform an IPI and flush all tlbs,
* but that can deadlock->flush only current cpu:
*/
__flush_tlb_all();
arch_flush_lazy_mmu_mode();
}
#ifdef CONFIG_HIBERNATION
bool kernel_page_present(struct page *page)
{
unsigned int level;
pte_t *pte;
if (PageHighMem(page))
return false;
pte = lookup_address((unsigned long)page_address(page), &level);
return (pte_val(*pte) & _PAGE_PRESENT);
}
#endif /* CONFIG_HIBERNATION */
#endif /* CONFIG_DEBUG_PAGEALLOC */
/*
* The testcases use internal knowledge of the implementation that shouldn't
* be exposed to the rest of the kernel. Include these directly here.
*/
#ifdef CONFIG_CPA_DEBUG
#include "pageattr-test.c"
#endif