linux/arch/x86/mm/pageattr.c
John Ogness 459fbe0069 x86/mm/cpa: Avoid wbinvd() for PREEMPT
Although wbinvd() is faster than flushing many individual pages, it blocks
the memory bus for "long" periods of time (>100us), thus directly causing
unusually large latencies on all CPUs, regardless of any CPU isolation
features that may be active. This is an unpriviledged operatation as it is
exposed to user space via the graphics subsystem.

For 1024 pages, flushing those pages individually can take up to 2200us,
but the task remains fully preemptible during that time.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-30 15:33:52 +01:00

2006 lines
48 KiB
C

/*
* Copyright 2002 Andi Kleen, SuSE Labs.
* Thanks to Ben LaHaise for precious feedback.
*/
#include <linux/highmem.h>
#include <linux/bootmem.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 <linux/vmalloc.h>
#include <asm/e820.h>
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <linux/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;
unsigned long 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)
{
if (direct_pages_count[level] == 0)
return;
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
if (direct_gbpages)
seq_printf(m, "DirectMap1G: %8lu kB\n",
direct_pages_count[PG_LEVEL_1G] << 20);
}
#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)
{
/* Do not reference physical address outside the kernel. */
return __pa_symbol(roundup(_brk_end, PMD_SIZE) - 1) >> PAGE_SHIFT;
}
#endif
static inline int
within(unsigned long addr, unsigned long start, unsigned long end)
{
return addr >= start && addr < end;
}
static inline int
within_inclusive(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
*
* clflushopt is an unordered instruction which needs fencing with mfence or
* sfence to avoid ordering issues.
*/
void clflush_cache_range(void *vaddr, unsigned int size)
{
const unsigned long clflush_size = boot_cpu_data.x86_clflush_size;
void *p = (void *)((unsigned long)vaddr & ~(clflush_size - 1));
void *vend = vaddr + size;
if (p >= vend)
return;
mb();
for (; p < vend; p += clflush_size)
clflushopt(p);
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;
#ifdef CONFIG_PREEMPT
/*
* Avoid wbinvd() because it causes latencies on all CPUs,
* regardless of any CPU isolation that may be in effect.
*
* This should be extended for CAT enabled systems independent of
* PREEMPT because wbinvd() does not respect the CAT partitions and
* this is exposed to unpriviledged users through the graphics
* subsystem.
*/
unsigned long do_wbinvd = 0;
#else
unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */
#endif
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)
/*
* 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;
}
/*
* Lookup the page table entry for a virtual address in a specific pgd.
* Return a pointer to the entry and the level of the mapping.
*/
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);
}
/*
* Lookup the PMD entry for a virtual address. Return a pointer to the entry
* or NULL if not present.
*/
pmd_t *lookup_pmd_address(unsigned long address)
{
pgd_t *pgd;
pud_t *pud;
pgd = pgd_offset_k(address);
if (pgd_none(*pgd))
return NULL;
pud = pud_offset(pgd, address);
if (pud_none(*pud) || pud_large(*pud) || !pud_present(*pud))
return NULL;
return pmd_offset(pud, address);
}
/*
* 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;
pte_t *pte;
pte = lookup_address(virt_addr, &level);
BUG_ON(!pte);
/*
* pXX_pfn() returns unsigned long, which must be cast to phys_addr_t
* before being left-shifted PAGE_SHIFT bits -- this trick is to
* make 32-PAE kernel work correctly.
*/
switch (level) {
case PG_LEVEL_1G:
phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT;
offset = virt_addr & ~PUD_PAGE_MASK;
break;
case PG_LEVEL_2M:
phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT;
offset = virt_addr & ~PMD_PAGE_MASK;
break;
default:
phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
offset = virt_addr & ~PAGE_MASK;
}
return (phys_addr_t)(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, old_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_cpa(cpa, address, &level);
if (tmp != kpte)
goto out_unlock;
switch (level) {
case PG_LEVEL_2M:
old_prot = pmd_pgprot(*(pmd_t *)kpte);
old_pfn = pmd_pfn(*(pmd_t *)kpte);
break;
case PG_LEVEL_1G:
old_prot = pud_pgprot(*(pud_t *)kpte);
old_pfn = pud_pfn(*(pud_t *)kpte);
break;
default:
do_split = -EINVAL;
goto out_unlock;
}
psize = page_level_size(level);
pmask = page_level_mask(level);
/*
* 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:
* Convert protection attributes to 4k-format, as cpa->mask* are set
* up accordingly.
*/
old_pte = *kpte;
req_prot = pgprot_large_2_4k(old_prot);
pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr);
pgprot_val(req_prot) |= pgprot_val(cpa->mask_set);
/*
* req_prot is in format of 4k pages. It must be converted to large
* page format: the caching mode includes the PAT bit located at
* different bit positions in the two formats.
*/
req_prot = pgprot_4k_2_large(req_prot);
/*
* 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_pfn points to the large page base pfn. So we need
* to add the offset of the virtual address:
*/
pfn = old_pfn + ((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 = old_pfn;
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(old_pfn, 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(struct cpa_data *cpa, pte_t *kpte, unsigned long address,
struct page *base)
{
pte_t *pbase = (pte_t *)page_address(base);
unsigned long ref_pfn, 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_cpa(cpa, address, &level);
if (tmp != kpte) {
spin_unlock(&pgd_lock);
return 1;
}
paravirt_alloc_pte(&init_mm, page_to_pfn(base));
switch (level) {
case PG_LEVEL_2M:
ref_prot = pmd_pgprot(*(pmd_t *)kpte);
/* clear PSE and promote PAT bit to correct position */
ref_prot = pgprot_large_2_4k(ref_prot);
ref_pfn = pmd_pfn(*(pmd_t *)kpte);
break;
case PG_LEVEL_1G:
ref_prot = pud_pgprot(*(pud_t *)kpte);
ref_pfn = pud_pfn(*(pud_t *)kpte);
pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
/*
* Clear the PSE flags if the PRESENT flag is not 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;
break;
default:
spin_unlock(&pgd_lock);
return 1;
}
/*
* 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 = ref_pfn;
for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
set_pte(&pbase[i], pfn_pte(pfn, canon_pgprot(ref_prot)));
if (virt_addr_valid(address)) {
unsigned long pfn = PFN_DOWN(__pa(address));
if (pfn_range_is_mapped(pfn, pfn + 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(struct cpa_data *cpa, pte_t *kpte,
unsigned long address)
{
struct page *base;
if (!debug_pagealloc_enabled())
spin_unlock(&cpa_lock);
base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
if (!debug_pagealloc_enabled())
spin_lock(&cpa_lock);
if (!base)
return -ENOMEM;
if (__split_large_page(cpa, kpte, address, base))
__free_page(base);
return 0;
}
static bool try_to_free_pte_page(pte_t *pte)
{
int i;
for (i = 0; i < PTRS_PER_PTE; i++)
if (!pte_none(pte[i]))
return false;
free_page((unsigned long)pte);
return true;
}
static bool try_to_free_pmd_page(pmd_t *pmd)
{
int i;
for (i = 0; i < PTRS_PER_PMD; i++)
if (!pmd_none(pmd[i]))
return false;
free_page((unsigned long)pmd);
return true;
}
static bool unmap_pte_range(pmd_t *pmd, unsigned long start, unsigned long end)
{
pte_t *pte = pte_offset_kernel(pmd, start);
while (start < end) {
set_pte(pte, __pte(0));
start += PAGE_SIZE;
pte++;
}
if (try_to_free_pte_page((pte_t *)pmd_page_vaddr(*pmd))) {
pmd_clear(pmd);
return true;
}
return false;
}
static void __unmap_pmd_range(pud_t *pud, pmd_t *pmd,
unsigned long start, unsigned long end)
{
if (unmap_pte_range(pmd, start, end))
if (try_to_free_pmd_page((pmd_t *)pud_page_vaddr(*pud)))
pud_clear(pud);
}
static void unmap_pmd_range(pud_t *pud, unsigned long start, unsigned long end)
{
pmd_t *pmd = pmd_offset(pud, start);
/*
* Not on a 2MB page boundary?
*/
if (start & (PMD_SIZE - 1)) {
unsigned long next_page = (start + PMD_SIZE) & PMD_MASK;
unsigned long pre_end = min_t(unsigned long, end, next_page);
__unmap_pmd_range(pud, pmd, start, pre_end);
start = pre_end;
pmd++;
}
/*
* Try to unmap in 2M chunks.
*/
while (end - start >= PMD_SIZE) {
if (pmd_large(*pmd))
pmd_clear(pmd);
else
__unmap_pmd_range(pud, pmd, start, start + PMD_SIZE);
start += PMD_SIZE;
pmd++;
}
/*
* 4K leftovers?
*/
if (start < end)
return __unmap_pmd_range(pud, pmd, start, end);
/*
* Try again to free the PMD page if haven't succeeded above.
*/
if (!pud_none(*pud))
if (try_to_free_pmd_page((pmd_t *)pud_page_vaddr(*pud)))
pud_clear(pud);
}
static void unmap_pud_range(pgd_t *pgd, unsigned long start, unsigned long end)
{
pud_t *pud = pud_offset(pgd, start);
/*
* Not on a GB page boundary?
*/
if (start & (PUD_SIZE - 1)) {
unsigned long next_page = (start + PUD_SIZE) & PUD_MASK;
unsigned long pre_end = min_t(unsigned long, end, next_page);
unmap_pmd_range(pud, start, pre_end);
start = pre_end;
pud++;
}
/*
* Try to unmap in 1G chunks?
*/
while (end - start >= PUD_SIZE) {
if (pud_large(*pud))
pud_clear(pud);
else
unmap_pmd_range(pud, start, start + PUD_SIZE);
start += PUD_SIZE;
pud++;
}
/*
* 2M leftovers?
*/
if (start < end)
unmap_pmd_range(pud, start, end);
/*
* No need to try to free the PUD page because we'll free it in
* populate_pgd's error path
*/
}
static int alloc_pte_page(pmd_t *pmd)
{
pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
if (!pte)
return -1;
set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
return 0;
}
static int alloc_pmd_page(pud_t *pud)
{
pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
if (!pmd)
return -1;
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
return 0;
}
static void populate_pte(struct cpa_data *cpa,
unsigned long start, unsigned long end,
unsigned num_pages, pmd_t *pmd, pgprot_t pgprot)
{
pte_t *pte;
pte = pte_offset_kernel(pmd, start);
/*
* 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(pgprot) & _PAGE_PRESENT)
pgprot_val(pgprot) |= _PAGE_GLOBAL;
else
pgprot_val(pgprot) &= ~_PAGE_GLOBAL;
pgprot = canon_pgprot(pgprot);
while (num_pages-- && start < end) {
set_pte(pte, pfn_pte(cpa->pfn, pgprot));
start += PAGE_SIZE;
cpa->pfn++;
pte++;
}
}
static long populate_pmd(struct cpa_data *cpa,
unsigned long start, unsigned long end,
unsigned num_pages, pud_t *pud, pgprot_t pgprot)
{
long cur_pages = 0;
pmd_t *pmd;
pgprot_t pmd_pgprot;
/*
* Not on a 2M boundary?
*/
if (start & (PMD_SIZE - 1)) {
unsigned long pre_end = start + (num_pages << PAGE_SHIFT);
unsigned long next_page = (start + PMD_SIZE) & PMD_MASK;
pre_end = min_t(unsigned long, pre_end, next_page);
cur_pages = (pre_end - start) >> PAGE_SHIFT;
cur_pages = min_t(unsigned int, num_pages, cur_pages);
/*
* Need a PTE page?
*/
pmd = pmd_offset(pud, start);
if (pmd_none(*pmd))
if (alloc_pte_page(pmd))
return -1;
populate_pte(cpa, start, pre_end, cur_pages, pmd, pgprot);
start = pre_end;
}
/*
* We mapped them all?
*/
if (num_pages == cur_pages)
return cur_pages;
pmd_pgprot = pgprot_4k_2_large(pgprot);
while (end - start >= PMD_SIZE) {
/*
* We cannot use a 1G page so allocate a PMD page if needed.
*/
if (pud_none(*pud))
if (alloc_pmd_page(pud))
return -1;
pmd = pmd_offset(pud, start);
set_pmd(pmd, __pmd(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
massage_pgprot(pmd_pgprot)));
start += PMD_SIZE;
cpa->pfn += PMD_SIZE >> PAGE_SHIFT;
cur_pages += PMD_SIZE >> PAGE_SHIFT;
}
/*
* Map trailing 4K pages.
*/
if (start < end) {
pmd = pmd_offset(pud, start);
if (pmd_none(*pmd))
if (alloc_pte_page(pmd))
return -1;
populate_pte(cpa, start, end, num_pages - cur_pages,
pmd, pgprot);
}
return num_pages;
}
static long populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd,
pgprot_t pgprot)
{
pud_t *pud;
unsigned long end;
long cur_pages = 0;
pgprot_t pud_pgprot;
end = start + (cpa->numpages << PAGE_SHIFT);
/*
* Not on a Gb page boundary? => map everything up to it with
* smaller pages.
*/
if (start & (PUD_SIZE - 1)) {
unsigned long pre_end;
unsigned long next_page = (start + PUD_SIZE) & PUD_MASK;
pre_end = min_t(unsigned long, end, next_page);
cur_pages = (pre_end - start) >> PAGE_SHIFT;
cur_pages = min_t(int, (int)cpa->numpages, cur_pages);
pud = pud_offset(pgd, start);
/*
* Need a PMD page?
*/
if (pud_none(*pud))
if (alloc_pmd_page(pud))
return -1;
cur_pages = populate_pmd(cpa, start, pre_end, cur_pages,
pud, pgprot);
if (cur_pages < 0)
return cur_pages;
start = pre_end;
}
/* We mapped them all? */
if (cpa->numpages == cur_pages)
return cur_pages;
pud = pud_offset(pgd, start);
pud_pgprot = pgprot_4k_2_large(pgprot);
/*
* Map everything starting from the Gb boundary, possibly with 1G pages
*/
while (boot_cpu_has(X86_FEATURE_GBPAGES) && end - start >= PUD_SIZE) {
set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
massage_pgprot(pud_pgprot)));
start += PUD_SIZE;
cpa->pfn += PUD_SIZE >> PAGE_SHIFT;
cur_pages += PUD_SIZE >> PAGE_SHIFT;
pud++;
}
/* Map trailing leftover */
if (start < end) {
long tmp;
pud = pud_offset(pgd, start);
if (pud_none(*pud))
if (alloc_pmd_page(pud))
return -1;
tmp = populate_pmd(cpa, start, end, cpa->numpages - cur_pages,
pud, pgprot);
if (tmp < 0)
return cur_pages;
cur_pages += tmp;
}
return cur_pages;
}
/*
* 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);
pud_t *pud = NULL; /* shut up gcc */
pgd_t *pgd_entry;
long 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));
}
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) {
/*
* Leave the PUD page in place in case some other CPU or thread
* already found it, but remove any useless entries we just
* added to it.
*/
unmap_pud_range(pgd_entry, addr,
addr + (cpa->numpages << PAGE_SHIFT));
return ret;
}
cpa->numpages = ret;
return 0;
}
static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr,
int primary)
{
if (cpa->pgd) {
/*
* Right now, we only execute this code path when mapping
* the EFI virtual memory map regions, no other users
* provide a ->pgd value. This may change in the future.
*/
return populate_pgd(cpa, vaddr);
}
/*
* Ignore all non primary paths.
*/
if (!primary) {
cpa->numpages = 1;
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_cpa(cpa, address, &level);
if (!kpte)
return __cpa_process_fault(cpa, address, primary);
old_pte = *kpte;
if (pte_none(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(cpa, 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_inclusive(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)
{
unsigned long numpages = cpa->numpages;
int ret;
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_enabled())
spin_lock(&cpa_lock);
ret = __change_page_attr(cpa, checkalias);
if (!debug_pagealloc_enabled())
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 || !cpa->numpages);
numpages -= cpa->numpages;
if (cpa->flags & (CPA_PAGES_ARRAY | CPA_ARRAY))
cpa->curpage++;
else
*cpa->vaddr += cpa->numpages * PAGE_SIZE;
}
return 0;
}
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;
memset(&cpa, 0, sizeof(cpa));
/*
* 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 = !!pgprot2cachemode(mask_set);
/*
* On success we use CLFLUSH, when the CPU supports it to
* avoid the WBINVD. If the CPU does not support it and in the
* error case we fall back to cpa_flush_all (which uses
* WBINVD):
*/
if (!ret && boot_cpu_has(X86_FEATURE_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()
* If you really need strong UC use ioremap_uc(), but note
* that you cannot override IO areas with set_memory_*() as
* these helpers cannot work with IO memory.
*/
return change_page_attr_set(&addr, numpages,
cachemode2pgprot(_PAGE_CACHE_MODE_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_MODE_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,
enum page_cache_mode new_type)
{
enum page_cache_mode set_type;
int i, j;
int ret;
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;
}
/* If WC, set to UC- first and then WC */
set_type = (new_type == _PAGE_CACHE_MODE_WC) ?
_PAGE_CACHE_MODE_UC_MINUS : new_type;
ret = change_page_attr_set(addr, addrinarray,
cachemode2pgprot(set_type), 1);
if (!ret && new_type == _PAGE_CACHE_MODE_WC)
ret = change_page_attr_set_clr(addr, addrinarray,
cachemode2pgprot(
_PAGE_CACHE_MODE_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_MODE_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_MODE_WC);
}
EXPORT_SYMBOL(set_memory_array_wc);
int set_memory_array_wt(unsigned long *addr, int addrinarray)
{
return _set_memory_array(addr, addrinarray, _PAGE_CACHE_MODE_WT);
}
EXPORT_SYMBOL_GPL(set_memory_array_wt);
int _set_memory_wc(unsigned long addr, int numpages)
{
int ret;
unsigned long addr_copy = addr;
ret = change_page_attr_set(&addr, numpages,
cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS),
0);
if (!ret) {
ret = change_page_attr_set_clr(&addr_copy, numpages,
cachemode2pgprot(
_PAGE_CACHE_MODE_WC),
__pgprot(_PAGE_CACHE_MASK),
0, 0, NULL);
}
return ret;
}
int set_memory_wc(unsigned long addr, int numpages)
{
int ret;
ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
_PAGE_CACHE_MODE_WC, NULL);
if (ret)
return ret;
ret = _set_memory_wc(addr, numpages);
if (ret)
free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
return ret;
}
EXPORT_SYMBOL(set_memory_wc);
int _set_memory_wt(unsigned long addr, int numpages)
{
return change_page_attr_set(&addr, numpages,
cachemode2pgprot(_PAGE_CACHE_MODE_WT), 0);
}
int set_memory_wt(unsigned long addr, int numpages)
{
int ret;
ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
_PAGE_CACHE_MODE_WT, NULL);
if (ret)
return ret;
ret = _set_memory_wt(addr, numpages);
if (ret)
free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
return ret;
}
EXPORT_SYMBOL_GPL(set_memory_wt);
int _set_memory_wb(unsigned long addr, int numpages)
{
/* WB cache mode is hard wired to all cache attribute bits being 0 */
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;
/* WB cache mode is hard wired to all cache attribute bits being 0 */
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);
}
int set_memory_rw(unsigned long addr, int numpages)
{
return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
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,
enum page_cache_mode new_type)
{
unsigned long start;
unsigned long end;
enum page_cache_mode set_type;
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;
}
/* If WC, set to UC- first and then WC */
set_type = (new_type == _PAGE_CACHE_MODE_WC) ?
_PAGE_CACHE_MODE_UC_MINUS : new_type;
ret = cpa_set_pages_array(pages, addrinarray,
cachemode2pgprot(set_type));
if (!ret && new_type == _PAGE_CACHE_MODE_WC)
ret = change_page_attr_set_clr(NULL, addrinarray,
cachemode2pgprot(
_PAGE_CACHE_MODE_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_MODE_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_MODE_WC);
}
EXPORT_SYMBOL(set_pages_array_wc);
int set_pages_array_wt(struct page **pages, int addrinarray)
{
return _set_pages_array(pages, addrinarray, _PAGE_CACHE_MODE_WT);
}
EXPORT_SYMBOL_GPL(set_pages_array_wt);
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;
/* WB cache mode is hard wired to all cache attribute bits being 0 */
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,
.pgd = NULL,
.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,
.pgd = NULL,
.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 */
int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
unsigned numpages, unsigned long page_flags)
{
int retval = -EINVAL;
struct cpa_data cpa = {
.vaddr = &address,
.pfn = pfn,
.pgd = pgd,
.numpages = numpages,
.mask_set = __pgprot(0),
.mask_clr = __pgprot(0),
.flags = 0,
};
if (!(__supported_pte_mask & _PAGE_NX))
goto out;
if (!(page_flags & _PAGE_NX))
cpa.mask_clr = __pgprot(_PAGE_NX);
if (!(page_flags & _PAGE_RW))
cpa.mask_clr = __pgprot(_PAGE_RW);
cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags);
retval = __change_page_attr_set_clr(&cpa, 0);
__flush_tlb_all();
out:
return retval;
}
/*
* 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