- 根目录:
- arch
- powerpc
- mm
- hugetlbpage.c
/*
* PPC Huge TLB Page Support for Kernel.
*
* Copyright (C) 2003 David Gibson, IBM Corporation.
* Copyright (C) 2011 Becky Bruce, Freescale Semiconductor
*
* Based on the IA-32 version:
* Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
*/
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
#include <linux/export.h>
#include <linux/of_fdt.h>
#include <linux/memblock.h>
#include <linux/bootmem.h>
#include <linux/moduleparam.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/setup.h>
#include <asm/hugetlb.h>
#ifdef CONFIG_HUGETLB_PAGE
#define PAGE_SHIFT_64K 16
#define PAGE_SHIFT_16M 24
#define PAGE_SHIFT_16G 34
unsigned int HPAGE_SHIFT;
/*
* Tracks gpages after the device tree is scanned and before the
* huge_boot_pages list is ready. On non-Freescale implementations, this is
* just used to track 16G pages and so is a single array. FSL-based
* implementations may have more than one gpage size, so we need multiple
* arrays
*/
#ifdef CONFIG_PPC_FSL_BOOK3E
#define MAX_NUMBER_GPAGES 128
struct psize_gpages {
u64 gpage_list[MAX_NUMBER_GPAGES];
unsigned int nr_gpages;
};
static struct psize_gpages gpage_freearray[MMU_PAGE_COUNT];
#else
#define MAX_NUMBER_GPAGES 1024
static u64 gpage_freearray[MAX_NUMBER_GPAGES];
static unsigned nr_gpages;
#endif
#define hugepd_none(hpd) ((hpd).pd == 0)
#ifdef CONFIG_PPC_BOOK3S_64
/*
* At this point we do the placement change only for BOOK3S 64. This would
* possibly work on other subarchs.
*/
/*
* We have PGD_INDEX_SIZ = 12 and PTE_INDEX_SIZE = 8, so that we can have
* 16GB hugepage pte in PGD and 16MB hugepage pte at PMD;
*
* Defined in such a way that we can optimize away code block at build time
* if CONFIG_HUGETLB_PAGE=n.
*/
int pmd_huge(pmd_t pmd)
{
/*
* leaf pte for huge page, bottom two bits != 00
*/
return ((pmd_val(pmd) & 0x3) != 0x0);
}
int pud_huge(pud_t pud)
{
/*
* leaf pte for huge page, bottom two bits != 00
*/
return ((pud_val(pud) & 0x3) != 0x0);
}
int pgd_huge(pgd_t pgd)
{
/*
* leaf pte for huge page, bottom two bits != 00
*/
return ((pgd_val(pgd) & 0x3) != 0x0);
}
#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_DEBUG_VM)
/*
* This enables us to catch the wrong page directory format
* Moved here so that we can use WARN() in the call.
*/
int hugepd_ok(hugepd_t hpd)
{
bool is_hugepd;
/*
* We should not find this format in page directory, warn otherwise.
*/
is_hugepd = (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
WARN(is_hugepd, "Found wrong page directory format\n");
return 0;
}
#endif
#else
int pmd_huge(pmd_t pmd)
{
return 0;
}
int pud_huge(pud_t pud)
{
return 0;
}
int pgd_huge(pgd_t pgd)
{
return 0;
}
#endif
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
/* Only called for hugetlbfs pages, hence can ignore THP */
return __find_linux_pte_or_hugepte(mm->pgd, addr, NULL, NULL);
}
static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
unsigned long address, unsigned pdshift, unsigned pshift)
{
struct kmem_cache *cachep;
pte_t *new;
#ifdef CONFIG_PPC_FSL_BOOK3E
int i;
int num_hugepd = 1 << (pshift - pdshift);
cachep = hugepte_cache;
#else
cachep = PGT_CACHE(pdshift - pshift);
#endif
new = kmem_cache_zalloc(cachep, GFP_KERNEL|__GFP_REPEAT);
BUG_ON(pshift > HUGEPD_SHIFT_MASK);
BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK);
if (! new)
return -ENOMEM;
spin_lock(&mm->page_table_lock);
#ifdef CONFIG_PPC_FSL_BOOK3E
/*
* We have multiple higher-level entries that point to the same
* actual pte location. Fill in each as we go and backtrack on error.
* We need all of these so the DTLB pgtable walk code can find the
* right higher-level entry without knowing if it's a hugepage or not.
*/
for (i = 0; i < num_hugepd; i++, hpdp++) {
if (unlikely(!hugepd_none(*hpdp)))
break;
else
/* We use the old format for PPC_FSL_BOOK3E */
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
}
/* If we bailed from the for loop early, an error occurred, clean up */
if (i < num_hugepd) {
for (i = i - 1 ; i >= 0; i--, hpdp--)
hpdp->pd = 0;
kmem_cache_free(cachep, new);
}
#else
if (!hugepd_none(*hpdp))
kmem_cache_free(cachep, new);
else {
#ifdef CONFIG_PPC_BOOK3S_64
hpdp->pd = (unsigned long)new |
(shift_to_mmu_psize(pshift) << 2);
#else
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
#endif
}
#endif
spin_unlock(&mm->page_table_lock);
return 0;
}
/*
* These macros define how to determine which level of the page table holds
* the hpdp.
*/
#ifdef CONFIG_PPC_FSL_BOOK3E
#define HUGEPD_PGD_SHIFT PGDIR_SHIFT
#define HUGEPD_PUD_SHIFT PUD_SHIFT
#else
#define HUGEPD_PGD_SHIFT PUD_SHIFT
#define HUGEPD_PUD_SHIFT PMD_SHIFT
#endif
#ifdef CONFIG_PPC_BOOK3S_64
/*
* At this point we do the placement change only for BOOK3S 64. This would
* possibly work on other subarchs.
*/
pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
{
pgd_t *pg;
pud_t *pu;
pmd_t *pm;
hugepd_t *hpdp = NULL;
unsigned pshift = __ffs(sz);
unsigned pdshift = PGDIR_SHIFT;
addr &= ~(sz-1);
pg = pgd_offset(mm, addr);
if (pshift == PGDIR_SHIFT)
/* 16GB huge page */
return (pte_t *) pg;
else if (pshift > PUD_SHIFT)
/*
* We need to use hugepd table
*/
hpdp = (hugepd_t *)pg;
else {
pdshift = PUD_SHIFT;
pu = pud_alloc(mm, pg, addr);
if (pshift == PUD_SHIFT)
return (pte_t *)pu;
else if (pshift > PMD_SHIFT)
hpdp = (hugepd_t *)pu;
else {
pdshift = PMD_SHIFT;
pm = pmd_alloc(mm, pu, addr);
if (pshift == PMD_SHIFT)
/* 16MB hugepage */
return (pte_t *)pm;
else
hpdp = (hugepd_t *)pm;
}
}
if (!hpdp)
return NULL;
BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift))
return NULL;
return hugepte_offset(*hpdp, addr, pdshift);
}
#else
pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
{
pgd_t *pg;
pud_t *pu;
pmd_t *pm;
hugepd_t *hpdp = NULL;
unsigned pshift = __ffs(sz);
unsigned pdshift = PGDIR_SHIFT;
addr &= ~(sz-1);
pg = pgd_offset(mm, addr);
if (pshift >= HUGEPD_PGD_SHIFT) {
hpdp = (hugepd_t *)pg;
} else {
pdshift = PUD_SHIFT;
pu = pud_alloc(mm, pg, addr);
if (pshift >= HUGEPD_PUD_SHIFT) {
hpdp = (hugepd_t *)pu;
} else {
pdshift = PMD_SHIFT;
pm = pmd_alloc(mm, pu, addr);
hpdp = (hugepd_t *)pm;
}
}
if (!hpdp)
return NULL;
BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift))
return NULL;
return hugepte_offset(*hpdp, addr, pdshift);
}
#endif
#ifdef CONFIG_PPC_FSL_BOOK3E
/* Build list of addresses of gigantic pages. This function is used in early
* boot before the buddy allocator is setup.
*/
void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages)
{
unsigned int idx = shift_to_mmu_psize(__ffs(page_size));
int i;
if (addr == 0)
return;
gpage_freearray[idx].nr_gpages = number_of_pages;
for (i = 0; i < number_of_pages; i++) {
gpage_freearray[idx].gpage_list[i] = addr;
addr += page_size;
}
}
/*
* Moves the gigantic page addresses from the temporary list to the
* huge_boot_pages list.
*/
int alloc_bootmem_huge_page(struct hstate *hstate)
{
struct huge_bootmem_page *m;
int idx = shift_to_mmu_psize(huge_page_shift(hstate));
int nr_gpages = gpage_freearray[idx].nr_gpages;
if (nr_gpages == 0)
return 0;
#ifdef CONFIG_HIGHMEM
/*
* If gpages can be in highmem we can't use the trick of storing the
* data structure in the page; allocate space for this
*/
m = memblock_virt_alloc(sizeof(struct huge_bootmem_page), 0);
m->phys = gpage_freearray[idx].gpage_list[--nr_gpages];
#else
m = phys_to_virt(gpage_freearray[idx].gpage_list[--nr_gpages]);
#endif
list_add(&m->list, &huge_boot_pages);
gpage_freearray[idx].nr_gpages = nr_gpages;
gpage_freearray[idx].gpage_list[nr_gpages] = 0;
m->hstate = hstate;
return 1;
}
/*
* Scan the command line hugepagesz= options for gigantic pages; store those in
* a list that we use to allocate the memory once all options are parsed.
*/
unsigned long gpage_npages[MMU_PAGE_COUNT];
static int __init do_gpage_early_setup(char *param, char *val,
const char *unused, void *arg)
{
static phys_addr_t size;
unsigned long npages;
/*
* The hugepagesz and hugepages cmdline options are interleaved. We
* use the size variable to keep track of whether or not this was done
* properly and skip over instances where it is incorrect. Other
* command-line parsing code will issue warnings, so we don't need to.
*
*/
if ((strcmp(param, "default_hugepagesz") == 0) ||
(strcmp(param, "hugepagesz") == 0)) {
size = memparse(val, NULL);
} else if (strcmp(param, "hugepages") == 0) {
if (size != 0) {
if (sscanf(val, "%lu", &npages) <= 0)
npages = 0;
if (npages > MAX_NUMBER_GPAGES) {
pr_warn("MMU: %lu pages requested for page "
"size %llu KB, limiting to "
__stringify(MAX_NUMBER_GPAGES) "\n",
npages, size / 1024);
npages = MAX_NUMBER_GPAGES;
}
gpage_npages[shift_to_mmu_psize(__ffs(size))] = npages;
size = 0;
}
}
return 0;
}
/*
* This function allocates physical space for pages that are larger than the
* buddy allocator can handle. We want to allocate these in highmem because
* the amount of lowmem is limited. This means that this function MUST be
* called before lowmem_end_addr is set up in MMU_init() in order for the lmb
* allocate to grab highmem.
*/
void __init reserve_hugetlb_gpages(void)
{
static __initdata char cmdline[COMMAND_LINE_SIZE];
phys_addr_t size, base;
int i;
strlcpy(cmdline, boot_command_line, COMMAND_LINE_SIZE);
parse_args("hugetlb gpages", cmdline, NULL, 0, 0, 0,
NULL, &do_gpage_early_setup);
/*
* Walk gpage list in reverse, allocating larger page sizes first.
* Skip over unsupported sizes, or sizes that have 0 gpages allocated.
* When we reach the point in the list where pages are no longer
* considered gpages, we're done.
*/
for (i = MMU_PAGE_COUNT-1; i >= 0; i--) {
if (mmu_psize_defs[i].shift == 0 || gpage_npages[i] == 0)
continue;
else if (mmu_psize_to_shift(i) < (MAX_ORDER + PAGE_SHIFT))
break;
size = (phys_addr_t)(1ULL << mmu_psize_to_shift(i));
base = memblock_alloc_base(size * gpage_npages[i], size,
MEMBLOCK_ALLOC_ANYWHERE);
add_gpage(base, size, gpage_npages[i]);
}
}
#else /* !PPC_FSL_BOOK3E */
/* Build list of addresses of gigantic pages. This function is used in early
* boot before the buddy allocator is setup.
*/
void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages)
{
if (!addr)
return;
while (number_of_pages > 0) {
gpage_freearray[nr_gpages] = addr;
nr_gpages++;
number_of_pages--;
addr += page_size;
}
}
/* Moves the gigantic page addresses from the temporary list to the
* huge_boot_pages list.
*/
int alloc_bootmem_huge_page(struct hstate *hstate)
{
struct huge_bootmem_page *m;
if (nr_gpages == 0)
return 0;
m = phys_to_virt(gpage_freearray[--nr_gpages]);
gpage_freearray[nr_gpages] = 0;
list_add(&m->list, &huge_boot_pages);
m->hstate = hstate;
return 1;
}
#endif
#ifdef CONFIG_PPC_FSL_BOOK3E
#define HUGEPD_FREELIST_SIZE \
((PAGE_SIZE - sizeof(struct hugepd_freelist)) / sizeof(pte_t))
struct hugepd_freelist {
struct rcu_head rcu;
unsigned int index;
void *ptes[0];
};
static DEFINE_PER_CPU(struct hugepd_freelist *, hugepd_freelist_cur);
static void hugepd_free_rcu_callback(struct rcu_head *head)
{
struct hugepd_freelist *batch =
container_of(head, struct hugepd_freelist, rcu);
unsigned int i;
for (i = 0; i < batch->index; i++)
kmem_cache_free(hugepte_cache, batch->ptes[i]);
free_page((unsigned long)batch);
}
static void hugepd_free(struct mmu_gather *tlb, void *hugepte)
{
struct hugepd_freelist **batchp;
batchp = this_cpu_ptr(&hugepd_freelist_cur);
if (atomic_read(&tlb->mm->mm_users) < 2 ||
cpumask_equal(mm_cpumask(tlb->mm),
cpumask_of(smp_processor_id()))) {
kmem_cache_free(hugepte_cache, hugepte);
put_cpu_var(hugepd_freelist_cur);
return;
}
if (*batchp == NULL) {
*batchp = (struct hugepd_freelist *)__get_free_page(GFP_ATOMIC);
(*batchp)->index = 0;
}
(*batchp)->ptes[(*batchp)->index++] = hugepte;
if ((*batchp)->index == HUGEPD_FREELIST_SIZE) {
call_rcu_sched(&(*batchp)->rcu, hugepd_free_rcu_callback);
*batchp = NULL;
}
put_cpu_var(hugepd_freelist_cur);
}
#endif
static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift,
unsigned long start, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pte_t *hugepte = hugepd_page(*hpdp);
int i;
unsigned long pdmask = ~((1UL << pdshift) - 1);
unsigned int num_hugepd = 1;
#ifdef CONFIG_PPC_FSL_BOOK3E
/* Note: On fsl the hpdp may be the first of several */
num_hugepd = (1 << (hugepd_shift(*hpdp) - pdshift));
#else
unsigned int shift = hugepd_shift(*hpdp);
#endif
start &= pdmask;
if (start < floor)
return;
if (ceiling) {
ceiling &= pdmask;
if (! ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
for (i = 0; i < num_hugepd; i++, hpdp++)
hpdp->pd = 0;
#ifdef CONFIG_PPC_FSL_BOOK3E
hugepd_free(tlb, hugepte);
#else
pgtable_free_tlb(tlb, hugepte, pdshift - shift);
#endif
}
static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pmd_t *pmd;
unsigned long next;
unsigned long start;
start = addr;
do {
pmd = pmd_offset(pud, addr);
next = pmd_addr_end(addr, end);
if (!is_hugepd(__hugepd(pmd_val(*pmd)))) {
/*
* if it is not hugepd pointer, we should already find
* it cleared.
*/
WARN_ON(!pmd_none_or_clear_bad(pmd));
continue;
}
#ifdef CONFIG_PPC_FSL_BOOK3E
/*
* Increment next by the size of the huge mapping since
* there may be more than one entry at this level for a
* single hugepage, but all of them point to
* the same kmem cache that holds the hugepte.
*/
next = addr + (1 << hugepd_shift(*(hugepd_t *)pmd));
#endif
free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,
addr, next, floor, ceiling);
} while (addr = next, addr != end);
start &= PUD_MASK;
if (start < floor)
return;
if (ceiling) {
ceiling &= PUD_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
pmd = pmd_offset(pud, start);
pud_clear(pud);
pmd_free_tlb(tlb, pmd, start);
mm_dec_nr_pmds(tlb->mm);
}
static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pud_t *pud;
unsigned long next;
unsigned long start;
start = addr;
do {
pud = pud_offset(pgd, addr);
next = pud_addr_end(addr, end);
if (!is_hugepd(__hugepd(pud_val(*pud)))) {
if (pud_none_or_clear_bad(pud))
continue;
hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
ceiling);
} else {
#ifdef CONFIG_PPC_FSL_BOOK3E
/*
* Increment next by the size of the huge mapping since
* there may be more than one entry at this level for a
* single hugepage, but all of them point to
* the same kmem cache that holds the hugepte.
*/
next = addr + (1 << hugepd_shift(*(hugepd_t *)pud));
#endif
free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,
addr, next, floor, ceiling);
}
} while (addr = next, addr != end);
start &= PGDIR_MASK;
if (start < floor)
return;
if (ceiling) {
ceiling &= PGDIR_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
pud = pud_offset(pgd, start);
pgd_clear(pgd);
pud_free_tlb(tlb, pud, start);
}
/*
* This function frees user-level page tables of a process.
*/
void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pgd_t *pgd;
unsigned long next;
/*
* Because there are a number of different possible pagetable
* layouts for hugepage ranges, we limit knowledge of how
* things should be laid out to the allocation path
* (huge_pte_alloc(), above). Everything else works out the
* structure as it goes from information in the hugepd
* pointers. That means that we can't here use the
* optimization used in the normal page free_pgd_range(), of
* checking whether we're actually covering a large enough
* range to have to do anything at the top level of the walk
* instead of at the bottom.
*
* To make sense of this, you should probably go read the big
* block comment at the top of the normal free_pgd_range(),
* too.
*/
do {
next = pgd_addr_end(addr, end);
pgd = pgd_offset(tlb->mm, addr);
if (!is_hugepd(__hugepd(pgd_val(*pgd)))) {
if (pgd_none_or_clear_bad(pgd))
continue;
hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
} else {
#ifdef CONFIG_PPC_FSL_BOOK3E
/*
* Increment next by the size of the huge mapping since
* there may be more than one entry at the pgd level
* for a single hugepage, but all of them point to the
* same kmem cache that holds the hugepte.
*/
next = addr + (1 << hugepd_shift(*(hugepd_t *)pgd));
#endif
free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT,
addr, next, floor, ceiling);
}
} while (addr = next, addr != end);
}
/*
* We are holding mmap_sem, so a parallel huge page collapse cannot run.
* To prevent hugepage split, disable irq.
*/
struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
{
bool is_thp;
pte_t *ptep, pte;
unsigned shift;
unsigned long mask, flags;
struct page *page = ERR_PTR(-EINVAL);
local_irq_save(flags);
ptep = find_linux_pte_or_hugepte(mm->pgd, address, &is_thp, &shift);
if (!ptep)
goto no_page;
pte = READ_ONCE(*ptep);
/*
* Verify it is a huge page else bail.
* Transparent hugepages are handled by generic code. We can skip them
* here.
*/
if (!shift || is_thp)
goto no_page;
if (!pte_present(pte)) {
page = NULL;
goto no_page;
}
mask = (1UL << shift) - 1;
page = pte_page(pte);
if (page)
page += (address & mask) / PAGE_SIZE;
no_page:
local_irq_restore(flags);
return page;
}
struct page *
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
pmd_t *pmd, int write)
{
BUG();
return NULL;
}
struct page *
follow_huge_pud(struct mm_struct *mm, unsigned long address,
pud_t *pud, int write)
{
BUG();
return NULL;
}
static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
unsigned long sz)
{
unsigned long __boundary = (addr + sz) & ~(sz-1);
return (__boundary - 1 < end - 1) ? __boundary : end;
}
int gup_huge_pd(hugepd_t hugepd, unsigned long addr, unsigned pdshift,
unsigned long end, int write, struct page **pages, int *nr)
{
pte_t *ptep;
unsigned long sz = 1UL << hugepd_shift(hugepd);
unsigned long next;
ptep = hugepte_offset(hugepd, addr, pdshift);
do {
next = hugepte_addr_end(addr, end, sz);
if (!gup_hugepte(ptep, sz, addr, end, write, pages, nr))
return 0;
} while (ptep++, addr = next, addr != end);
return 1;
}
#ifdef CONFIG_PPC_MM_SLICES
unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff,
unsigned long flags)
{
struct hstate *hstate = hstate_file(file);
int mmu_psize = shift_to_mmu_psize(huge_page_shift(hstate));
return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1);
}
#endif
unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
{
#ifdef CONFIG_PPC_MM_SLICES
unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
return 1UL << mmu_psize_to_shift(psize);
#else
if (!is_vm_hugetlb_page(vma))
return PAGE_SIZE;
return huge_page_size(hstate_vma(vma));
#endif
}
static inline bool is_power_of_4(unsigned long x)
{
if (is_power_of_2(x))
return (__ilog2(x) % 2) ? false : true;
return false;
}
static int __init add_huge_page_size(unsigned long long size)
{
int shift = __ffs(size);
int mmu_psize;
/* Check that it is a page size supported by the hardware and
* that it fits within pagetable and slice limits. */
#ifdef CONFIG_PPC_FSL_BOOK3E
if ((size < PAGE_SIZE) || !is_power_of_4(size))
return -EINVAL;
#else
if (!is_power_of_2(size)
|| (shift > SLICE_HIGH_SHIFT) || (shift <= PAGE_SHIFT))
return -EINVAL;
#endif
if ((mmu_psize = shift_to_mmu_psize(shift)) < 0)
return -EINVAL;
BUG_ON(mmu_psize_defs[mmu_psize].shift != shift);
/* Return if huge page size has already been setup */
if (size_to_hstate(size))
return 0;
hugetlb_add_hstate(shift - PAGE_SHIFT);
return 0;
}
static int __init hugepage_setup_sz(char *str)
{
unsigned long long size;
size = memparse(str, &str);
if (add_huge_page_size(size) != 0)
printk(KERN_WARNING "Invalid huge page size specified(%llu)\n", size);
return 1;
}
__setup("hugepagesz=", hugepage_setup_sz);
#ifdef CONFIG_PPC_FSL_BOOK3E
struct kmem_cache *hugepte_cache;
static int __init hugetlbpage_init(void)
{
int psize;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
unsigned shift;
if (!mmu_psize_defs[psize].shift)
continue;
shift = mmu_psize_to_shift(psize);
/* Don't treat normal page sizes as huge... */
if (shift != PAGE_SHIFT)
if (add_huge_page_size(1ULL << shift) < 0)
continue;
}
/*
* Create a kmem cache for hugeptes. The bottom bits in the pte have
* size information encoded in them, so align them to allow this
*/
hugepte_cache = kmem_cache_create("hugepte-cache", sizeof(pte_t),
HUGEPD_SHIFT_MASK + 1, 0, NULL);
if (hugepte_cache == NULL)
panic("%s: Unable to create kmem cache for hugeptes\n",
__func__);
/* Default hpage size = 4M */
if (mmu_psize_defs[MMU_PAGE_4M].shift)
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift;
else
panic("%s: Unable to set default huge page size\n", __func__);
return 0;
}
#else
static int __init hugetlbpage_init(void)
{
int psize;
if (!mmu_has_feature(MMU_FTR_16M_PAGE))
return -ENODEV;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
unsigned shift;
unsigned pdshift;
if (!mmu_psize_defs[psize].shift)
continue;
shift = mmu_psize_to_shift(psize);
if (add_huge_page_size(1ULL << shift) < 0)
continue;
if (shift < PMD_SHIFT)
pdshift = PMD_SHIFT;
else if (shift < PUD_SHIFT)
pdshift = PUD_SHIFT;
else
pdshift = PGDIR_SHIFT;
/*
* if we have pdshift and shift value same, we don't
* use pgt cache for hugepd.
*/
if (pdshift != shift) {
pgtable_cache_add(pdshift - shift, NULL);
if (!PGT_CACHE(pdshift - shift))
panic("hugetlbpage_init(): could not create "
"pgtable cache for %d bit pagesize\n", shift);
}
}
/* Set default large page size. Currently, we pick 16M or 1M
* depending on what is available
*/
if (mmu_psize_defs[MMU_PAGE_16M].shift)
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_16M].shift;
else if (mmu_psize_defs[MMU_PAGE_1M].shift)
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_1M].shift;
return 0;
}
#endif
arch_initcall(hugetlbpage_init);
void flush_dcache_icache_hugepage(struct page *page)
{
int i;
void *start;
BUG_ON(!PageCompound(page));
for (i = 0; i < (1UL << compound_order(page)); i++) {
if (!PageHighMem(page)) {
__flush_dcache_icache(page_address(page+i));
} else {
start = kmap_atomic(page+i);
__flush_dcache_icache(start);
kunmap_atomic(start);
}
}
}
#endif /* CONFIG_HUGETLB_PAGE */
/*
* We have 4 cases for pgds and pmds:
* (1) invalid (all zeroes)
* (2) pointer to next table, as normal; bottom 6 bits == 0
* (3) leaf pte for huge page, bottom two bits != 00
* (4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table
*
* So long as we atomically load page table pointers we are safe against teardown,
* we can follow the address down to the the page and take a ref on it.
* This function need to be called with interrupts disabled. We use this variant
* when we have MSR[EE] = 0 but the paca->soft_enabled = 1
*/
pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
bool *is_thp, unsigned *shift)
{
pgd_t pgd, *pgdp;
pud_t pud, *pudp;
pmd_t pmd, *pmdp;
pte_t *ret_pte;
hugepd_t *hpdp = NULL;
unsigned pdshift = PGDIR_SHIFT;
if (shift)
*shift = 0;
if (is_thp)
*is_thp = false;
pgdp = pgdir + pgd_index(ea);
pgd = READ_ONCE(*pgdp);
/*
* Always operate on the local stack value. This make sure the
* value don't get updated by a parallel THP split/collapse,
* page fault or a page unmap. The return pte_t * is still not
* stable. So should be checked there for above conditions.
*/
if (pgd_none(pgd))
return NULL;
else if (pgd_huge(pgd)) {
ret_pte = (pte_t *) pgdp;
goto out;
} else if (is_hugepd(__hugepd(pgd_val(pgd))))
hpdp = (hugepd_t *)&pgd;
else {
/*
* Even if we end up with an unmap, the pgtable will not
* be freed, because we do an rcu free and here we are
* irq disabled
*/
pdshift = PUD_SHIFT;
pudp = pud_offset(&pgd, ea);
pud = READ_ONCE(*pudp);
if (pud_none(pud))
return NULL;
else if (pud_huge(pud)) {
ret_pte = (pte_t *) pudp;
goto out;
} else if (is_hugepd(__hugepd(pud_val(pud))))
hpdp = (hugepd_t *)&pud;
else {
pdshift = PMD_SHIFT;
pmdp = pmd_offset(&pud, ea);
pmd = READ_ONCE(*pmdp);
/*
* A hugepage collapse is captured by pmd_none, because
* it mark the pmd none and do a hpte invalidate.
*
* We don't worry about pmd_trans_splitting here, The
* caller if it needs to handle the splitting case
* should check for that.
*/
if (pmd_none(pmd))
return NULL;
if (pmd_trans_huge(pmd)) {
if (is_thp)
*is_thp = true;
ret_pte = (pte_t *) pmdp;
goto out;
}
if (pmd_huge(pmd)) {
ret_pte = (pte_t *) pmdp;
goto out;
} else if (is_hugepd(__hugepd(pmd_val(pmd))))
hpdp = (hugepd_t *)&pmd;
else
return pte_offset_kernel(&pmd, ea);
}
}
if (!hpdp)
return NULL;
ret_pte = hugepte_offset(*hpdp, ea, pdshift);
pdshift = hugepd_shift(*hpdp);
out:
if (shift)
*shift = pdshift;
return ret_pte;
}
EXPORT_SYMBOL_GPL(__find_linux_pte_or_hugepte);
int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
unsigned long mask;
unsigned long pte_end;
struct page *head, *page, *tail;
pte_t pte;
int refs;
pte_end = (addr + sz) & ~(sz-1);
if (pte_end < end)
end = pte_end;
pte = READ_ONCE(*ptep);
mask = _PAGE_PRESENT | _PAGE_USER;
if (write)
mask |= _PAGE_RW;
if ((pte_val(pte) & mask) != mask)
return 0;
/* hugepages are never "special" */
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
refs = 0;
head = pte_page(pte);
page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
tail = page;
do {
VM_BUG_ON(compound_head(page) != head);
pages[*nr] = page;
(*nr)++;
page++;
refs++;
} while (addr += PAGE_SIZE, addr != end);
if (!page_cache_add_speculative(head, refs)) {
*nr -= refs;
return 0;
}
if (unlikely(pte_val(pte) != pte_val(*ptep))) {
/* Could be optimized better */
*nr -= refs;
while (refs--)
put_page(head);
return 0;
}
/*
* Any tail page need their mapcount reference taken before we
* return.
*/
while (refs--) {
if (PageTail(tail))
get_huge_page_tail(tail);
tail++;
}
return 1;
}