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OpenCloudOS-Kernel/arch/powerpc/mm/pgtable_64.c

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/*
* This file contains ioremap and related functions for 64-bit machines.
*
* Derived from arch/ppc64/mm/init.c
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* Dave Engebretsen <engebret@us.ibm.com>
* Rework for PPC64 port.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
#include <asm/pgalloc.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/tlb.h>
#include <asm/processor.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/firmware.h>
#include "mmu_decl.h"
#define CREATE_TRACE_POINTS
#include <trace/events/thp.h>
/* Some sanity checking */
#if TASK_SIZE_USER64 > PGTABLE_RANGE
#error TASK_SIZE_USER64 exceeds pagetable range
#endif
#ifdef CONFIG_PPC_STD_MMU_64
#if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
#error TASK_SIZE_USER64 exceeds user VSID range
#endif
#endif
unsigned long ioremap_bot = IOREMAP_BASE;
#ifdef CONFIG_PPC_MMU_NOHASH
static __ref void *early_alloc_pgtable(unsigned long size)
{
void *pt;
if (init_bootmem_done)
pt = __alloc_bootmem(size, size, __pa(MAX_DMA_ADDRESS));
else
pt = __va(memblock_alloc_base(size, size,
__pa(MAX_DMA_ADDRESS)));
memset(pt, 0, size);
return pt;
}
#endif /* CONFIG_PPC_MMU_NOHASH */
/*
* map_kernel_page currently only called by __ioremap
* map_kernel_page adds an entry to the ioremap page table
* and adds an entry to the HPT, possibly bolting it
*/
int map_kernel_page(unsigned long ea, unsigned long pa, int flags)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
if (slab_is_available()) {
pgdp = pgd_offset_k(ea);
pudp = pud_alloc(&init_mm, pgdp, ea);
if (!pudp)
return -ENOMEM;
pmdp = pmd_alloc(&init_mm, pudp, ea);
if (!pmdp)
return -ENOMEM;
ptep = pte_alloc_kernel(pmdp, ea);
if (!ptep)
return -ENOMEM;
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
__pgprot(flags)));
} else {
#ifdef CONFIG_PPC_MMU_NOHASH
/* Warning ! This will blow up if bootmem is not initialized
* which our ppc64 code is keen to do that, we'll need to
* fix it and/or be more careful
*/
pgdp = pgd_offset_k(ea);
#ifdef PUD_TABLE_SIZE
if (pgd_none(*pgdp)) {
pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
BUG_ON(pudp == NULL);
pgd_populate(&init_mm, pgdp, pudp);
}
#endif /* PUD_TABLE_SIZE */
pudp = pud_offset(pgdp, ea);
if (pud_none(*pudp)) {
pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
BUG_ON(pmdp == NULL);
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, ea);
if (!pmd_present(*pmdp)) {
ptep = early_alloc_pgtable(PAGE_SIZE);
BUG_ON(ptep == NULL);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, ea);
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
__pgprot(flags)));
#else /* CONFIG_PPC_MMU_NOHASH */
/*
* If the mm subsystem is not fully up, we cannot create a
* linux page table entry for this mapping. Simply bolt an
* entry in the hardware page table.
*
*/
if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
mmu_io_psize, mmu_kernel_ssize)) {
printk(KERN_ERR "Failed to do bolted mapping IO "
"memory at %016lx !\n", pa);
return -ENOMEM;
}
#endif /* !CONFIG_PPC_MMU_NOHASH */
}
#ifdef CONFIG_PPC_BOOK3E_64
/*
* With hardware tablewalk, a sync is needed to ensure that
* subsequent accesses see the PTE we just wrote. Unlike userspace
* mappings, we can't tolerate spurious faults, so make sure
* the new PTE will be seen the first time.
*/
mb();
#else
smp_wmb();
#endif
return 0;
}
/**
* __ioremap_at - Low level function to establish the page tables
* for an IO mapping
*/
void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
unsigned long flags)
{
unsigned long i;
/* Make sure we have the base flags */
if ((flags & _PAGE_PRESENT) == 0)
flags |= pgprot_val(PAGE_KERNEL);
/* Non-cacheable page cannot be coherent */
if (flags & _PAGE_NO_CACHE)
flags &= ~_PAGE_COHERENT;
/* We don't support the 4K PFN hack with ioremap */
if (flags & _PAGE_4K_PFN)
return NULL;
WARN_ON(pa & ~PAGE_MASK);
WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
WARN_ON(size & ~PAGE_MASK);
for (i = 0; i < size; i += PAGE_SIZE)
if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
return NULL;
return (void __iomem *)ea;
}
/**
* __iounmap_from - Low level function to tear down the page tables
* for an IO mapping. This is used for mappings that
* are manipulated manually, like partial unmapping of
* PCI IOs or ISA space.
*/
void __iounmap_at(void *ea, unsigned long size)
{
WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
WARN_ON(size & ~PAGE_MASK);
unmap_kernel_range((unsigned long)ea, size);
}
void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
unsigned long flags, void *caller)
{
phys_addr_t paligned;
void __iomem *ret;
/*
* Choose an address to map it to.
* Once the imalloc system is running, we use it.
* Before that, we map using addresses going
* up from ioremap_bot. imalloc will use
* the addresses from ioremap_bot through
* IMALLOC_END
*
*/
paligned = addr & PAGE_MASK;
size = PAGE_ALIGN(addr + size) - paligned;
if ((size == 0) || (paligned == 0))
return NULL;
if (mem_init_done) {
struct vm_struct *area;
area = __get_vm_area_caller(size, VM_IOREMAP,
ioremap_bot, IOREMAP_END,
caller);
if (area == NULL)
return NULL;
area->phys_addr = paligned;
ret = __ioremap_at(paligned, area->addr, size, flags);
if (!ret)
vunmap(area->addr);
} else {
ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
if (ret)
ioremap_bot += size;
}
if (ret)
ret += addr & ~PAGE_MASK;
return ret;
}
void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
unsigned long flags)
{
return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
}
void __iomem * ioremap(phys_addr_t addr, unsigned long size)
{
unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
void *caller = __builtin_return_address(0);
if (ppc_md.ioremap)
return ppc_md.ioremap(addr, size, flags, caller);
return __ioremap_caller(addr, size, flags, caller);
}
void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
{
unsigned long flags = _PAGE_NO_CACHE;
void *caller = __builtin_return_address(0);
if (ppc_md.ioremap)
return ppc_md.ioremap(addr, size, flags, caller);
return __ioremap_caller(addr, size, flags, caller);
}
void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
unsigned long flags)
{
void *caller = __builtin_return_address(0);
/* writeable implies dirty for kernel addresses */
if (flags & _PAGE_RW)
flags |= _PAGE_DIRTY;
/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
flags &= ~(_PAGE_USER | _PAGE_EXEC);
#ifdef _PAGE_BAP_SR
/* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
* which means that we just cleared supervisor access... oops ;-) This
* restores it
*/
flags |= _PAGE_BAP_SR;
#endif
if (ppc_md.ioremap)
return ppc_md.ioremap(addr, size, flags, caller);
return __ioremap_caller(addr, size, flags, caller);
}
/*
* Unmap an IO region and remove it from imalloc'd list.
* Access to IO memory should be serialized by driver.
*/
void __iounmap(volatile void __iomem *token)
{
void *addr;
if (!mem_init_done)
return;
addr = (void *) ((unsigned long __force)
PCI_FIX_ADDR(token) & PAGE_MASK);
if ((unsigned long)addr < ioremap_bot) {
printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
" at 0x%p\n", addr);
return;
}
vunmap(addr);
}
void iounmap(volatile void __iomem *token)
{
if (ppc_md.iounmap)
ppc_md.iounmap(token);
else
__iounmap(token);
}
EXPORT_SYMBOL(ioremap);
EXPORT_SYMBOL(ioremap_wc);
EXPORT_SYMBOL(ioremap_prot);
EXPORT_SYMBOL(__ioremap);
EXPORT_SYMBOL(__ioremap_at);
EXPORT_SYMBOL(iounmap);
EXPORT_SYMBOL(__iounmap);
EXPORT_SYMBOL(__iounmap_at);
/*
* For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
* For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
*/
struct page *pmd_page(pmd_t pmd)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
if (pmd_trans_huge(pmd))
return pfn_to_page(pmd_pfn(pmd));
#endif
return virt_to_page(pmd_page_vaddr(pmd));
}
#ifdef CONFIG_PPC_64K_PAGES
static pte_t *get_from_cache(struct mm_struct *mm)
{
void *pte_frag, *ret;
spin_lock(&mm->page_table_lock);
ret = mm->context.pte_frag;
if (ret) {
pte_frag = ret + PTE_FRAG_SIZE;
/*
* If we have taken up all the fragments mark PTE page NULL
*/
if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
pte_frag = NULL;
mm->context.pte_frag = pte_frag;
}
spin_unlock(&mm->page_table_lock);
return (pte_t *)ret;
}
static pte_t *__alloc_for_cache(struct mm_struct *mm, int kernel)
{
void *ret = NULL;
struct page *page = alloc_page(GFP_KERNEL | __GFP_NOTRACK |
__GFP_REPEAT | __GFP_ZERO);
if (!page)
return NULL;
if (!kernel && !pgtable_page_ctor(page)) {
__free_page(page);
return NULL;
}
ret = page_address(page);
spin_lock(&mm->page_table_lock);
/*
* If we find pgtable_page set, we return
* the allocated page with single fragement
* count.
*/
if (likely(!mm->context.pte_frag)) {
atomic_set(&page->_count, PTE_FRAG_NR);
mm->context.pte_frag = ret + PTE_FRAG_SIZE;
}
spin_unlock(&mm->page_table_lock);
return (pte_t *)ret;
}
pte_t *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
{
pte_t *pte;
pte = get_from_cache(mm);
if (pte)
return pte;
return __alloc_for_cache(mm, kernel);
}
void page_table_free(struct mm_struct *mm, unsigned long *table, int kernel)
{
struct page *page = virt_to_page(table);
if (put_page_testzero(page)) {
if (!kernel)
pgtable_page_dtor(page);
free_hot_cold_page(page, 0);
}
}
#ifdef CONFIG_SMP
static void page_table_free_rcu(void *table)
{
struct page *page = virt_to_page(table);
if (put_page_testzero(page)) {
pgtable_page_dtor(page);
free_hot_cold_page(page, 0);
}
}
void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
{
unsigned long pgf = (unsigned long)table;
BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
pgf |= shift;
tlb_remove_table(tlb, (void *)pgf);
}
void __tlb_remove_table(void *_table)
{
void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
if (!shift)
/* PTE page needs special handling */
page_table_free_rcu(table);
else {
BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
kmem_cache_free(PGT_CACHE(shift), table);
}
}
#else
void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
{
if (!shift) {
/* PTE page needs special handling */
struct page *page = virt_to_page(table);
if (put_page_testzero(page)) {
pgtable_page_dtor(page);
free_hot_cold_page(page, 0);
}
} else {
BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
kmem_cache_free(PGT_CACHE(shift), table);
}
}
#endif
#endif /* CONFIG_PPC_64K_PAGES */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
* This is called when relaxing access to a hugepage. It's also called in the page
* fault path when we don't hit any of the major fault cases, ie, a minor
* update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
* handled those two for us, we additionally deal with missing execute
* permission here on some processors
*/
int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp, pmd_t entry, int dirty)
{
int changed;
#ifdef CONFIG_DEBUG_VM
WARN_ON(!pmd_trans_huge(*pmdp));
assert_spin_locked(&vma->vm_mm->page_table_lock);
#endif
changed = !pmd_same(*(pmdp), entry);
if (changed) {
__ptep_set_access_flags(pmdp_ptep(pmdp), pmd_pte(entry));
/*
* Since we are not supporting SW TLB systems, we don't
* have any thing similar to flush_tlb_page_nohash()
*/
}
return changed;
}
unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, unsigned long clr,
unsigned long set)
{
unsigned long old, tmp;
#ifdef CONFIG_DEBUG_VM
WARN_ON(!pmd_trans_huge(*pmdp));
assert_spin_locked(&mm->page_table_lock);
#endif
#ifdef PTE_ATOMIC_UPDATES
__asm__ __volatile__(
"1: ldarx %0,0,%3\n\
andi. %1,%0,%6\n\
bne- 1b \n\
andc %1,%0,%4 \n\
or %1,%1,%7\n\
stdcx. %1,0,%3 \n\
bne- 1b"
: "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
: "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (_PAGE_BUSY), "r" (set)
: "cc" );
#else
old = pmd_val(*pmdp);
*pmdp = __pmd((old & ~clr) | set);
#endif
trace_hugepage_update(addr, old, clr, set);
if (old & _PAGE_HASHPTE)
hpte_do_hugepage_flush(mm, addr, pmdp, old);
return old;
}
pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
if (pmd_trans_huge(*pmdp)) {
pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
} else {
/*
* khugepaged calls this for normal pmd
*/
pmd = *pmdp;
pmd_clear(pmdp);
/*
* Wait for all pending hash_page to finish. This is needed
* in case of subpage collapse. When we collapse normal pages
* to hugepage, we first clear the pmd, then invalidate all
* the PTE entries. The assumption here is that any low level
* page fault will see a none pmd and take the slow path that
* will wait on mmap_sem. But we could very well be in a
* hash_page with local ptep pointer value. Such a hash page
* can result in adding new HPTE entries for normal subpages.
* That means we could be modifying the page content as we
* copy them to a huge page. So wait for parallel hash_page
* to finish before invalidating HPTE entries. We can do this
* by sending an IPI to all the cpus and executing a dummy
* function there.
*/
kick_all_cpus_sync();
/*
* Now invalidate the hpte entries in the range
* covered by pmd. This make sure we take a
* fault and will find the pmd as none, which will
* result in a major fault which takes mmap_sem and
* hence wait for collapse to complete. Without this
* the __collapse_huge_page_copy can result in copying
* the old content.
*/
flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
}
return pmd;
}
int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
}
/*
* We currently remove entries from the hashtable regardless of whether
* the entry was young or dirty. The generic routines only flush if the
* entry was young or dirty which is not good enough.
*
* We should be more intelligent about this but for the moment we override
* these functions and force a tlb flush unconditionally
*/
int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
}
/*
* We mark the pmd splitting and invalidate all the hpte
* entries for this hugepage.
*/
void pmdp_splitting_flush(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
unsigned long old, tmp;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
#ifdef CONFIG_DEBUG_VM
WARN_ON(!pmd_trans_huge(*pmdp));
assert_spin_locked(&vma->vm_mm->page_table_lock);
#endif
#ifdef PTE_ATOMIC_UPDATES
__asm__ __volatile__(
"1: ldarx %0,0,%3\n\
andi. %1,%0,%6\n\
bne- 1b \n\
ori %1,%0,%4 \n\
stdcx. %1,0,%3 \n\
bne- 1b"
: "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
: "r" (pmdp), "i" (_PAGE_SPLITTING), "m" (*pmdp), "i" (_PAGE_BUSY)
: "cc" );
#else
old = pmd_val(*pmdp);
*pmdp = __pmd(old | _PAGE_SPLITTING);
#endif
/*
* If we didn't had the splitting flag set, go and flush the
* HPTE entries.
*/
trace_hugepage_splitting(address, old);
if (!(old & _PAGE_SPLITTING)) {
/* We need to flush the hpte */
if (old & _PAGE_HASHPTE)
hpte_do_hugepage_flush(vma->vm_mm, address, pmdp, old);
}
/*
* This ensures that generic code that rely on IRQ disabling
* to prevent a parallel THP split work as expected.
*/
kick_all_cpus_sync();
}
/*
* We want to put the pgtable in pmd and use pgtable for tracking
* the base page size hptes
*/
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable)
{
pgtable_t *pgtable_slot;
assert_spin_locked(&mm->page_table_lock);
/*
* we store the pgtable in the second half of PMD
*/
pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
*pgtable_slot = pgtable;
/*
* expose the deposited pgtable to other cpus.
* before we set the hugepage PTE at pmd level
* hash fault code looks at the deposted pgtable
* to store hash index values.
*/
smp_wmb();
}
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
{
pgtable_t pgtable;
pgtable_t *pgtable_slot;
assert_spin_locked(&mm->page_table_lock);
pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
pgtable = *pgtable_slot;
/*
* Once we withdraw, mark the entry NULL.
*/
*pgtable_slot = NULL;
/*
* We store HPTE information in the deposited PTE fragment.
* zero out the content on withdraw.
*/
memset(pgtable, 0, PTE_FRAG_SIZE);
return pgtable;
}
/*
* set a new huge pmd. We should not be called for updating
* an existing pmd entry. That should go via pmd_hugepage_update.
*/
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
WARN_ON(pmd_val(*pmdp) & _PAGE_PRESENT);
assert_spin_locked(&mm->page_table_lock);
WARN_ON(!pmd_trans_huge(pmd));
#endif
trace_hugepage_set_pmd(addr, pmd);
return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0);
}
/*
* A linux hugepage PMD was changed and the corresponding hash table entries
* neesd to be flushed.
*/
void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, unsigned long old_pmd)
{
int ssize, i;
unsigned long s_addr;
int max_hpte_count;
unsigned int psize, valid;
unsigned char *hpte_slot_array;
unsigned long hidx, vpn, vsid, hash, shift, slot;
/*
* Flush all the hptes mapping this hugepage
*/
s_addr = addr & HPAGE_PMD_MASK;
hpte_slot_array = get_hpte_slot_array(pmdp);
/*
* IF we try to do a HUGE PTE update after a withdraw is done.
* we will find the below NULL. This happens when we do
* split_huge_page_pmd
*/
if (!hpte_slot_array)
return;
/* get the base page size,vsid and segment size */
#ifdef CONFIG_DEBUG_VM
psize = get_slice_psize(mm, s_addr);
BUG_ON(psize == MMU_PAGE_16M);
#endif
if (old_pmd & _PAGE_COMBO)
psize = MMU_PAGE_4K;
else
psize = MMU_PAGE_64K;
if (!is_kernel_addr(s_addr)) {
ssize = user_segment_size(s_addr);
vsid = get_vsid(mm->context.id, s_addr, ssize);
WARN_ON(vsid == 0);
} else {
vsid = get_kernel_vsid(s_addr, mmu_kernel_ssize);
ssize = mmu_kernel_ssize;
}
if (ppc_md.hugepage_invalidate)
return ppc_md.hugepage_invalidate(vsid, s_addr,
hpte_slot_array,
psize, ssize);
/*
* No bluk hpte removal support, invalidate each entry
*/
shift = mmu_psize_defs[psize].shift;
max_hpte_count = HPAGE_PMD_SIZE >> shift;
for (i = 0; i < max_hpte_count; i++) {
/*
* 8 bits per each hpte entries
* 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
*/
valid = hpte_valid(hpte_slot_array, i);
if (!valid)
continue;
hidx = hpte_hash_index(hpte_slot_array, i);
/* get the vpn */
addr = s_addr + (i * (1ul << shift));
vpn = hpt_vpn(addr, vsid, ssize);
hash = hpt_hash(vpn, shift, ssize);
if (hidx & _PTEIDX_SECONDARY)
hash = ~hash;
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
slot += hidx & _PTEIDX_GROUP_IX;
ppc_md.hpte_invalidate(slot, vpn, psize,
MMU_PAGE_16M, ssize, 0);
}
}
static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
{
pmd_val(pmd) |= pgprot_val(pgprot);
return pmd;
}
pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
{
pmd_t pmd;
/*
* For a valid pte, we would have _PAGE_PRESENT or _PAGE_FILE always
* set. We use this to check THP page at pmd level.
* leaf pte for huge page, bottom two bits != 00
*/
pmd_val(pmd) = pfn << PTE_RPN_SHIFT;
pmd_val(pmd) |= _PAGE_THP_HUGE;
pmd = pmd_set_protbits(pmd, pgprot);
return pmd;
}
pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
{
return pfn_pmd(page_to_pfn(page), pgprot);
}
pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
pmd_val(pmd) &= _HPAGE_CHG_MASK;
pmd = pmd_set_protbits(pmd, newprot);
return pmd;
}
/*
* This is called at the end of handling a user page fault, when the
* fault has been handled by updating a HUGE PMD entry in the linux page tables.
* We use it to preload an HPTE into the hash table corresponding to
* the updated linux HUGE PMD entry.
*/
void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd)
{
return;
}
pmd_t pmdp_get_and_clear(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp)
{
pmd_t old_pmd;
pgtable_t pgtable;
unsigned long old;
pgtable_t *pgtable_slot;
old = pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
old_pmd = __pmd(old);
/*
* We have pmd == none and we are holding page_table_lock.
* So we can safely go and clear the pgtable hash
* index info.
*/
pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
pgtable = *pgtable_slot;
/*
* Let's zero out old valid and hash index details
* hash fault look at them.
*/
memset(pgtable, 0, PTE_FRAG_SIZE);
return old_pmd;
}
int has_transparent_hugepage(void)
{
if (!mmu_has_feature(MMU_FTR_16M_PAGE))
return 0;
/*
* We support THP only if PMD_SIZE is 16MB.
*/
if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT)
return 0;
/*
* We need to make sure that we support 16MB hugepage in a segement
* with base page size 64K or 4K. We only enable THP with a PAGE_SIZE
* of 64K.
*/
/*
* If we have 64K HPTE, we will be using that by default
*/
if (mmu_psize_defs[MMU_PAGE_64K].shift &&
(mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1))
return 0;
/*
* Ok we only have 4K HPTE
*/
if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1)
return 0;
return 1;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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