linux/arch/powerpc/mm/hugetlbpage.c
Becky Bruce 41151e77a4 powerpc: Hugetlb for BookE
Enable hugepages on Freescale BookE processors.  This allows the kernel to
use huge TLB entries to map pages, which can greatly reduce the number of
TLB misses and the amount of TLB thrashing experienced by applications with
large memory footprints.  Care should be taken when using this on FSL
processors, as the number of large TLB entries supported by the core is low
(16-64) on current processors.

The supported set of hugepage sizes include 4m, 16m, 64m, 256m, and 1g.
Page sizes larger than the max zone size are called "gigantic" pages and
must be allocated on the command line (and cannot be deallocated).

This is currently only fully implemented for Freescale 32-bit BookE
processors, but there is some infrastructure in the code for
64-bit BooKE.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-09-20 09:19:40 +10:00

876 lines
21 KiB
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/of_fdt.h>
#include <linux/memblock.h>
#include <linux/bootmem.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/setup.h>
#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 64-bit implementations, this is
* just used to track 16G pages and so is a single array. 32-bit
* implementations may have more than one gpage size due to limitations
* of the memory allocators, so we need multiple arrays
*/
#ifdef CONFIG_PPC64
#define MAX_NUMBER_GPAGES 1024
static u64 gpage_freearray[MAX_NUMBER_GPAGES];
static unsigned nr_gpages;
#else
#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];
#endif
static inline int shift_to_mmu_psize(unsigned int shift)
{
int psize;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize)
if (mmu_psize_defs[psize].shift == shift)
return psize;
return -1;
}
static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
{
if (mmu_psize_defs[mmu_psize].shift)
return mmu_psize_defs[mmu_psize].shift;
BUG();
}
#define hugepd_none(hpd) ((hpd).pd == 0)
pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
{
pgd_t *pg;
pud_t *pu;
pmd_t *pm;
hugepd_t *hpdp = NULL;
unsigned pdshift = PGDIR_SHIFT;
if (shift)
*shift = 0;
pg = pgdir + pgd_index(ea);
if (is_hugepd(pg)) {
hpdp = (hugepd_t *)pg;
} else if (!pgd_none(*pg)) {
pdshift = PUD_SHIFT;
pu = pud_offset(pg, ea);
if (is_hugepd(pu))
hpdp = (hugepd_t *)pu;
else if (!pud_none(*pu)) {
pdshift = PMD_SHIFT;
pm = pmd_offset(pu, ea);
if (is_hugepd(pm))
hpdp = (hugepd_t *)pm;
else if (!pmd_none(*pm)) {
return pte_offset_kernel(pm, ea);
}
}
}
if (!hpdp)
return NULL;
if (shift)
*shift = hugepd_shift(*hpdp);
return hugepte_offset(hpdp, ea, pdshift);
}
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
return find_linux_pte_or_hugepte(mm->pgd, addr, 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_PPC64
cachep = PGT_CACHE(pdshift - pshift);
#else
int i;
int num_hugepd = 1 << (pshift - pdshift);
cachep = hugepte_cache;
#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_PPC64
if (!hugepd_none(*hpdp))
kmem_cache_free(cachep, new);
else
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
#else
/*
* 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
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);
}
#endif
spin_unlock(&mm->page_table_lock);
return 0;
}
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 >= PUD_SHIFT) {
hpdp = (hugepd_t *)pg;
} else {
pdshift = PUD_SHIFT;
pu = pud_alloc(mm, pg, addr);
if (pshift >= PMD_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);
}
#ifdef CONFIG_PPC32
/* Build list of addresses of gigantic pages. This function is used in early
* boot before the buddy or bootmem 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(hstate->order + PAGE_SHIFT);
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 = alloc_bootmem(sizeof(struct huge_bootmem_page));
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)
{
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;
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, &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 /* PPC64 */
/* Build list of addresses of gigantic pages. This function is used in early
* boot before the buddy or bootmem 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
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
return 0;
}
#ifdef CONFIG_PPC32
#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 = &__get_cpu_var(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);
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;
}
}
#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_PPC64
unsigned int shift = hugepd_shift(*hpdp);
#else
/* Note: On 32-bit the hpdp may be the first of several */
num_hugepd = (1 << (hugepd_shift(*hpdp) - pdshift));
#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;
tlb->need_flush = 1;
#ifdef CONFIG_PPC64
pgtable_free_tlb(tlb, hugepte, pdshift - shift);
#else
hugepd_free(tlb, hugepte);
#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;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none(*pmd))
continue;
free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,
addr, next, floor, ceiling);
} while (pmd++, 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);
}
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;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (!is_hugepd(pud)) {
if (pud_none_or_clear_bad(pud))
continue;
hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
ceiling);
} else {
free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,
addr, next, floor, ceiling);
}
} while (pud++, 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.
*
* Must be called with pagetable lock held.
*/
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(pgd)) {
if (pgd_none_or_clear_bad(pgd))
continue;
hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
} else {
#ifdef CONFIG_PPC32
/*
* Increment next by the size of the huge mapping since
* on 32-bit 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);
}
struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
{
pte_t *ptep;
struct page *page;
unsigned shift;
unsigned long mask;
ptep = find_linux_pte_or_hugepte(mm->pgd, address, &shift);
/* Verify it is a huge page else bail. */
if (!ptep || !shift)
return ERR_PTR(-EINVAL);
mask = (1UL << shift) - 1;
page = pte_page(*ptep);
if (page)
page += (address & mask) / PAGE_SIZE;
return page;
}
int pmd_huge(pmd_t pmd)
{
return 0;
}
int pud_huge(pud_t pud)
{
return 0;
}
struct page *
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
pmd_t *pmd, int write)
{
BUG();
return NULL;
}
static noinline 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;
pte_t pte;
int refs;
pte_end = (addr + sz) & ~(sz-1);
if (pte_end < end)
end = pte_end;
pte = *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);
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 */
while (*nr) {
put_page(page);
(*nr)--;
}
}
return 1;
}
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_hugepd(hugepd_t *hugepd, unsigned pdshift,
unsigned long addr, 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;
}
unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff,
unsigned long flags)
{
#ifdef CONFIG_MM_SLICES
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, 0);
#else
return get_unmapped_area(file, addr, len, pgoff, flags);
#endif
}
unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
{
#ifdef CONFIG_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;
#ifdef CONFIG_SPU_FS_64K_LS
/* Disable support for 64K huge pages when 64K SPU local store
* support is enabled as the current implementation conflicts.
*/
if (shift == PAGE_SHIFT_64K)
return -EINVAL;
#endif /* CONFIG_SPU_FS_64K_LS */
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_FSL_BOOKE
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;
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
module_init(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, KM_PPC_SYNC_ICACHE);
__flush_dcache_icache(start);
kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
}
}
}