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提交 6a1ea362 编写于 作者: A Aneesh Kumar K.V 提交者： Michael Ellerman
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powerpc/mm: THP is only available on hash64 as of now 

Only code movement in this patch. No functionality change.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
上级 c0a6c719
隐藏空白更改
内联 并排
Showing with 369 addition and 372 deletion
arch/powerpc/include/asm/book3s/64/pgtable.h
浏览文件 @ 6a1ea362
...@@ -777,18 +777,6 @@ static inline void vmemmap_remove_mapping(unsigned long start, ...@@ -777,18 +777,6 @@ static inline void vmemmap_remove_mapping(unsigned long start,
#endif #endif
struct page *realmode_pfn_to_page(unsigned long pfn); struct page *realmode_pfn_to_page(unsigned long pfn);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
extern pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot);
extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd);
extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd);
extern int has_transparent_hugepage(void);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
static inline pte_t pmd_pte(pmd_t pmd) static inline pte_t pmd_pte(pmd_t pmd)
{ {
return __pte(pmd_val(pmd)); return __pte(pmd_val(pmd));
...@@ -803,7 +791,6 @@ static inline pte_t *pmdp_ptep(pmd_t *pmd) ...@@ -803,7 +791,6 @@ static inline pte_t *pmdp_ptep(pmd_t *pmd)
{ {
return (pte_t *)pmd; return (pte_t *)pmd;
} }
#define pmd_pfn(pmd) pte_pfn(pmd_pte(pmd)) #define pmd_pfn(pmd) pte_pfn(pmd_pte(pmd))
#define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) #define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd))
#define pmd_young(pmd) pte_young(pmd_pte(pmd)) #define pmd_young(pmd) pte_young(pmd_pte(pmd))
...@@ -830,6 +817,16 @@ static inline int pmd_protnone(pmd_t pmd) ...@@ -830,6 +817,16 @@ static inline int pmd_protnone(pmd_t pmd)
#define __HAVE_ARCH_PMD_WRITE #define __HAVE_ARCH_PMD_WRITE
#define pmd_write(pmd) pte_write(pmd_pte(pmd)) #define pmd_write(pmd) pte_write(pmd_pte(pmd))
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
extern pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot);
extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd);
extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd);
extern int has_transparent_hugepage(void);
static inline pmd_t pmd_mkhuge(pmd_t pmd) static inline pmd_t pmd_mkhuge(pmd_t pmd)
{ {
return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE)); return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE));
...@@ -878,5 +875,6 @@ static inline int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl, ...@@ -878,5 +875,6 @@ static inline int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
*/ */
return true; return true;
} }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif /* __ASSEMBLY__ */ #endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_BOOK3S_64_PGTABLE_H_ */ #endif /* _ASM_POWERPC_BOOK3S_64_PGTABLE_H_ */
arch/powerpc/mm/pgtable-hash64.c
浏览文件 @ 6a1ea362
...@@ -15,6 +15,9 @@ ...@@ -15,6 +15,9 @@
#include "mmu_decl.h" #include "mmu_decl.h"
#define CREATE_TRACE_POINTS
#include <trace/events/thp.h>
#ifdef CONFIG_SPARSEMEM_VMEMMAP #ifdef CONFIG_SPARSEMEM_VMEMMAP
/* /*
* On hash-based CPUs, the vmemmap is bolted in the hash table. * On hash-based CPUs, the vmemmap is bolted in the hash table.
...@@ -93,3 +96,358 @@ int hash__map_kernel_page(unsigned long ea, unsigned long pa, unsigned long flag ...@@ -93,3 +96,358 @@ int hash__map_kernel_page(unsigned long ea, unsigned long pa, unsigned long flag
smp_wmb(); smp_wmb();
return 0; return 0;
} }
#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)
{
__be64 old_be, tmp;
unsigned long old;
#ifdef CONFIG_DEBUG_VM
WARN_ON(!pmd_trans_huge(*pmdp));
assert_spin_locked(&mm->page_table_lock);
#endif
__asm__ __volatile__(
"1: ldarx %0,0,%3\n\
and. %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_be), "=&r" (tmp), "=m" (*pmdp)
: "r" (pmdp), "r" (cpu_to_be64(clr)), "m" (*pmdp),
"r" (cpu_to_be64(H_PAGE_BUSY)), "r" (cpu_to_be64(set))
: "cc" );
old = be64_to_cpu(old_be);
trace_hugepage_update(addr, old, clr, set);
if (old & H_PAGE_HASHPTE)
hpte_do_hugepage_flush(mm, addr, pmdp, old);
return old;
}
pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
VM_BUG_ON(pmd_trans_huge(*pmdp));
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;
}
/*
* We currently remove entries from the hashtable regardless of whether
* the entry was young or dirty.
*
* We should be more intelligent about this but for the moment we override
* these functions and force a tlb flush unconditionally
*/
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 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;
}
void pmdp_huge_split_prepare(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
VM_BUG_ON(REGION_ID(address) != USER_REGION_ID);
/*
* We can't mark the pmd none here, because that will cause a race
* against exit_mmap. We need to continue mark pmd TRANS HUGE, while
* we spilt, but at the same time we wan't rest of the ppc64 code
* not to insert hash pte on this, because we will be modifying
* the deposited pgtable in the caller of this function. Hence
* clear the _PAGE_USER so that we move the fault handling to
* higher level function and that will serialize against ptl.
* We need to flush existing hash pte entries here even though,
* the translation is still valid, because we will withdraw
* pgtable_t after this.
*/
pmd_hugepage_update(vma->vm_mm, address, pmdp, 0, _PAGE_PRIVILEGED);
}
/*
* 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(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
assert_spin_locked(&mm->page_table_lock);
WARN_ON(!pmd_trans_huge(pmd));
#endif
trace_hugepage_set_pmd(addr, pmd_val(pmd));
return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
/*
* We use this to invalidate a pmdp entry before switching from a
* hugepte to regular pmd entry.
*/
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);
/*
* This ensures that generic code that rely on IRQ disabling
* to prevent a parallel THP split work as expected.
*/
kick_all_cpus_sync();
}
/*
* 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;
unsigned int psize;
unsigned long vsid;
unsigned long flags = 0;
const struct cpumask *tmp;
/* get the base page size,vsid and segment size */
#ifdef CONFIG_DEBUG_VM
psize = get_slice_psize(mm, addr);
BUG_ON(psize == MMU_PAGE_16M);
#endif
if (old_pmd & H_PAGE_COMBO)
psize = MMU_PAGE_4K;
else
psize = MMU_PAGE_64K;
if (!is_kernel_addr(addr)) {
ssize = user_segment_size(addr);
vsid = get_vsid(mm->context.id, addr, ssize);
WARN_ON(vsid == 0);
} else {
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
ssize = mmu_kernel_ssize;
}
tmp = cpumask_of(smp_processor_id());
if (cpumask_equal(mm_cpumask(mm), tmp))
flags |= HPTE_LOCAL_UPDATE;
return flush_hash_hugepage(vsid, addr, pmdp, psize, ssize, flags);
}
static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
{
return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
}
pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
{
unsigned long pmdv;
pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
return pmd_set_protbits(__pmd(pmdv), pgprot);
}
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)
{
unsigned long pmdv;
pmdv = pmd_val(pmd);
pmdv &= _HPAGE_CHG_MASK;
return pmd_set_protbits(__pmd(pmdv), newprot);
}
/*
* 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_huge_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);
/*
* Serialize against find_linux_pte_or_hugepte which does lock-less
* lookup in page tables with local interrupts disabled. For huge pages
* it casts pmd_t to pte_t. Since format of pte_t is different from
* pmd_t we want to prevent transit from pmd pointing to page table
* to pmd pointing to huge page (and back) while interrupts are disabled.
* We clear pmd to possibly replace it with page table pointer in
* different code paths. So make sure we wait for the parallel
* find_linux_pte_or_hugepage to finish.
*/
kick_all_cpus_sync();
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 */
arch/powerpc/mm/pgtable_64.c
浏览文件 @ 6a1ea362
...@@ -55,9 +55,6 @@ ...@@ -55,9 +55,6 @@
#include "mmu_decl.h" #include "mmu_decl.h"
#define CREATE_TRACE_POINTS
#include <trace/events/thp.h>
#ifdef CONFIG_PPC_STD_MMU_64 #ifdef CONFIG_PPC_STD_MMU_64
#if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT)) #if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
#error TASK_SIZE_USER64 exceeds user VSID range #error TASK_SIZE_USER64 exceeds user VSID range
...@@ -435,359 +432,3 @@ void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift) ...@@ -435,359 +432,3 @@ void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
} }
} }
#endif #endif
#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)
{
__be64 old_be, tmp;
unsigned long old;
#ifdef CONFIG_DEBUG_VM
WARN_ON(!pmd_trans_huge(*pmdp));
assert_spin_locked(&mm->page_table_lock);
#endif
__asm__ __volatile__(
"1: ldarx %0,0,%3\n\
and. %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_be), "=&r" (tmp), "=m" (*pmdp)
: "r" (pmdp), "r" (cpu_to_be64(clr)), "m" (*pmdp),
"r" (cpu_to_be64(H_PAGE_BUSY)), "r" (cpu_to_be64(set))
: "cc" );
old = be64_to_cpu(old_be);
trace_hugepage_update(addr, old, clr, set);
if (old & H_PAGE_HASHPTE)
hpte_do_hugepage_flush(mm, addr, pmdp, old);
return old;
}
pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
VM_BUG_ON(pmd_trans_huge(*pmdp));
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;
}
/*
* We currently remove entries from the hashtable regardless of whether
* the entry was young or dirty.
*
* We should be more intelligent about this but for the moment we override
* these functions and force a tlb flush unconditionally
*/
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 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;
}
void pmdp_huge_split_prepare(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
VM_BUG_ON(REGION_ID(address) != USER_REGION_ID);
/*
* We can't mark the pmd none here, because that will cause a race
* against exit_mmap. We need to continue mark pmd TRANS HUGE, while
* we spilt, but at the same time we wan't rest of the ppc64 code
* not to insert hash pte on this, because we will be modifying
* the deposited pgtable in the caller of this function. Hence
* clear the _PAGE_USER so that we move the fault handling to
* higher level function and that will serialize against ptl.
* We need to flush existing hash pte entries here even though,
* the translation is still valid, because we will withdraw
* pgtable_t after this.
*/
pmd_hugepage_update(vma->vm_mm, address, pmdp, 0, _PAGE_PRIVILEGED);
}
/*
* 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(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
assert_spin_locked(&mm->page_table_lock);
WARN_ON(!pmd_trans_huge(pmd));
#endif
trace_hugepage_set_pmd(addr, pmd_val(pmd));
return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
/*
* We use this to invalidate a pmdp entry before switching from a
* hugepte to regular pmd entry.
*/
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);
/*
* This ensures that generic code that rely on IRQ disabling
* to prevent a parallel THP split work as expected.
*/
kick_all_cpus_sync();
}
/*
* 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;
unsigned int psize;
unsigned long vsid;
unsigned long flags = 0;
const struct cpumask *tmp;
/* get the base page size,vsid and segment size */
#ifdef CONFIG_DEBUG_VM
psize = get_slice_psize(mm, addr);
BUG_ON(psize == MMU_PAGE_16M);
#endif
if (old_pmd & H_PAGE_COMBO)
psize = MMU_PAGE_4K;
else
psize = MMU_PAGE_64K;
if (!is_kernel_addr(addr)) {
ssize = user_segment_size(addr);
vsid = get_vsid(mm->context.id, addr, ssize);
WARN_ON(vsid == 0);
} else {
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
ssize = mmu_kernel_ssize;
}
tmp = cpumask_of(smp_processor_id());
if (cpumask_equal(mm_cpumask(mm), tmp))
flags |= HPTE_LOCAL_UPDATE;
return flush_hash_hugepage(vsid, addr, pmdp, psize, ssize, flags);
}
static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
{
return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
}
pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
{
unsigned long pmdv;
pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
return pmd_set_protbits(__pmd(pmdv), pgprot);
}
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)
{
unsigned long pmdv;
pmdv = pmd_val(pmd);
pmdv &= _HPAGE_CHG_MASK;
return pmd_set_protbits(__pmd(pmdv), newprot);
}
/*
* 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_huge_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);
/*
* Serialize against find_linux_pte_or_hugepte which does lock-less
* lookup in page tables with local interrupts disabled. For huge pages
* it casts pmd_t to pte_t. Since format of pte_t is different from
* pmd_t we want to prevent transit from pmd pointing to page table
* to pmd pointing to huge page (and back) while interrupts are disabled.
* We clear pmd to possibly replace it with page table pointer in
* different code paths. So make sure we wait for the parallel
* find_linux_pte_or_hugepage to finish.
*/
kick_all_cpus_sync();
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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