From 3df33f12be2f6fa88dff12564ab1d069482e3224 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 29 Apr 2016 23:26:29 +1000 Subject: [PATCH] powerpc/mm/thp: Abstraction for THP functions Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/book3s/64/hash-64k.h | 23 ++- .../include/asm/book3s/64/pgtable-64k.h | 42 +----- arch/powerpc/include/asm/book3s/64/pgtable.h | 83 +++++++++-- arch/powerpc/mm/Makefile | 2 +- arch/powerpc/mm/pgtable-book3s64.c | 118 +++++++++++++++ arch/powerpc/mm/pgtable-hash64.c | 137 ++---------------- 6 files changed, 226 insertions(+), 179 deletions(-) create mode 100644 arch/powerpc/mm/pgtable-book3s64.c diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h index 80d2abe25280..5aae4f530c21 100644 --- a/arch/powerpc/include/asm/book3s/64/hash-64k.h +++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h @@ -119,11 +119,6 @@ static inline int hash__remap_4k_pfn(struct vm_area_struct *vma, unsigned long a #define H_PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE) #ifdef CONFIG_TRANSPARENT_HUGEPAGE -extern unsigned long pmd_hugepage_update(struct mm_struct *mm, - unsigned long addr, - pmd_t *pmdp, - unsigned long clr, - unsigned long set); static inline char *get_hpte_slot_array(pmd_t *pmdp) { /* @@ -193,6 +188,24 @@ static inline int hash__pmd_same(pmd_t pmd_a, pmd_t pmd_b) return (((pmd_raw(pmd_a) ^ pmd_raw(pmd_b)) & ~cpu_to_be64(_PAGE_HPTEFLAGS)) == 0); } +static inline pmd_t hash__pmd_mkhuge(pmd_t pmd) +{ + return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE)); +} + +extern unsigned long hash__pmd_hugepage_update(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp, + unsigned long clr, unsigned long set); +extern pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp); +extern void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, + pgtable_t pgtable); +extern pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); +extern void hash__pmdp_huge_split_prepare(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp); +extern pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp); +extern int hash__has_transparent_hugepage(void); #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif /* __ASSEMBLY__ */ diff --git a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h index 27b5e34abe24..79331cf77613 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h @@ -54,41 +54,6 @@ static inline int hugepd_ok(hugepd_t hpd) #endif /* CONFIG_HUGETLB_PAGE */ #ifdef CONFIG_TRANSPARENT_HUGEPAGE -static inline int pmd_large(pmd_t pmd) -{ - return !!(pmd_val(pmd) & _PAGE_PTE); -} - -static inline pmd_t pmd_mknotpresent(pmd_t pmd) -{ - return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT); -} -/* - * For radix we should always find H_PAGE_HASHPTE zero. Hence - * the below will work for radix too - */ -static inline int __pmdp_test_and_clear_young(struct mm_struct *mm, - unsigned long addr, pmd_t *pmdp) -{ - unsigned long old; - - if ((pmd_val(*pmdp) & (_PAGE_ACCESSED | H_PAGE_HASHPTE)) == 0) - return 0; - old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED, 0); - return ((old & _PAGE_ACCESSED) != 0); -} - -#define __HAVE_ARCH_PMDP_SET_WRPROTECT -static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr, - pmd_t *pmdp) -{ - - if ((pmd_val(*pmdp) & _PAGE_WRITE) == 0) - return; - - pmd_hugepage_update(mm, addr, pmdp, _PAGE_WRITE, 0); -} - static inline int pmd_trans_huge(pmd_t pmd) { if (radix_enabled()) @@ -103,6 +68,12 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) return radix__pmd_same(pmd_a, pmd_b); return hash__pmd_same(pmd_a, pmd_b); } + +static inline pmd_t pmd_mkhuge(pmd_t pmd) +{ + return hash__pmd_mkhuge(pmd); +} + #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ static inline int remap_4k_pfn(struct vm_area_struct *vma, unsigned long addr, @@ -111,7 +82,6 @@ static inline int remap_4k_pfn(struct vm_area_struct *vma, unsigned long addr, if (radix_enabled()) BUG(); return hash__remap_4k_pfn(vma, addr, pfn, prot); - } #endif /* __ASSEMBLY__ */ #endif /*_ASM_POWERPC_BOOK3S_64_PGTABLE_64K_H */ diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index dfdd1f4e4cf0..5f290d39e563 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -769,7 +769,6 @@ static inline int __meminit vmemmap_create_mapping(unsigned long start, static inline void vmemmap_remove_mapping(unsigned long start, unsigned long page_size) { - if (radix_enabled()) return radix__vmemmap_remove_mapping(start, page_size); return hash__vmemmap_remove_mapping(start, page_size); @@ -825,11 +824,52 @@ 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); +extern int hash__has_transparent_hugepage(void); +static inline int has_transparent_hugepage(void) +{ + return hash__has_transparent_hugepage(); +} -static inline pmd_t pmd_mkhuge(pmd_t pmd) +static inline unsigned long +pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, + unsigned long clr, unsigned long set) { - return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE)); + return hash__pmd_hugepage_update(mm, addr, pmdp, clr, set); +} + +static inline int pmd_large(pmd_t pmd) +{ + return !!(pmd_val(pmd) & _PAGE_PTE); +} + +static inline pmd_t pmd_mknotpresent(pmd_t pmd) +{ + return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT); +} +/* + * For radix we should always find H_PAGE_HASHPTE zero. Hence + * the below will work for radix too + */ +static inline int __pmdp_test_and_clear_young(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) +{ + unsigned long old; + + if ((pmd_val(*pmdp) & (_PAGE_ACCESSED | H_PAGE_HASHPTE)) == 0) + return 0; + old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED, 0); + return ((old & _PAGE_ACCESSED) != 0); +} + +#define __HAVE_ARCH_PMDP_SET_WRPROTECT +static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp) +{ + + if ((pmd_val(*pmdp) & _PAGE_WRITE) == 0) + return; + + pmd_hugepage_update(mm, addr, pmdp, _PAGE_WRITE, 0); } #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS @@ -842,26 +882,43 @@ extern int pmdp_test_and_clear_young(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp); #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR -extern pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, - unsigned long addr, pmd_t *pmdp); +static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) +{ + return hash__pmdp_huge_get_and_clear(mm, addr, pmdp); +} -extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, - unsigned long address, pmd_t *pmdp); +static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp) +{ + return hash__pmdp_collapse_flush(vma, address, pmdp); +} #define pmdp_collapse_flush pmdp_collapse_flush #define __HAVE_ARCH_PGTABLE_DEPOSIT -extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, - pgtable_t pgtable); +static inline void pgtable_trans_huge_deposit(struct mm_struct *mm, + pmd_t *pmdp, pgtable_t pgtable) +{ + return hash__pgtable_trans_huge_deposit(mm, pmdp, pgtable); +} + #define __HAVE_ARCH_PGTABLE_WITHDRAW -extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); +static inline pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, + pmd_t *pmdp) +{ + return hash__pgtable_trans_huge_withdraw(mm, pmdp); +} #define __HAVE_ARCH_PMDP_INVALIDATE extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp); #define __HAVE_ARCH_PMDP_HUGE_SPLIT_PREPARE -extern void pmdp_huge_split_prepare(struct vm_area_struct *vma, - unsigned long address, pmd_t *pmdp); +static inline void pmdp_huge_split_prepare(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp) +{ + return hash__pmdp_huge_split_prepare(vma, address, pmdp); +} #define pmd_move_must_withdraw pmd_move_must_withdraw struct spinlock; diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile index 47511dd00599..f2cea6d5e764 100644 --- a/arch/powerpc/mm/Makefile +++ b/arch/powerpc/mm/Makefile @@ -14,7 +14,7 @@ obj-$(CONFIG_PPC_MMU_NOHASH) += mmu_context_nohash.o tlb_nohash.o \ obj-$(CONFIG_PPC_BOOK3E) += tlb_low_$(CONFIG_WORD_SIZE)e.o hash64-$(CONFIG_PPC_NATIVE) := hash_native_64.o obj-$(CONFIG_PPC_BOOK3E_64) += pgtable-book3e.o -obj-$(CONFIG_PPC_STD_MMU_64) += pgtable-hash64.o hash_utils_64.o slb_low.o slb.o $(hash64-y) mmu_context_book3s64.o +obj-$(CONFIG_PPC_STD_MMU_64) += pgtable-hash64.o hash_utils_64.o slb_low.o slb.o $(hash64-y) mmu_context_book3s64.o pgtable-book3s64.o obj-$(CONFIG_PPC_RADIX_MMU) += pgtable-radix.o tlb-radix.o obj-$(CONFIG_PPC_STD_MMU_32) += ppc_mmu_32.o hash_low_32.o mmu_context_hash32.o obj-$(CONFIG_PPC_STD_MMU) += tlb_hash$(CONFIG_WORD_SIZE).o diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c new file mode 100644 index 000000000000..d566a250164d --- /dev/null +++ b/arch/powerpc/mm/pgtable-book3s64.c @@ -0,0 +1,118 @@ +/* + * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation. + * + * 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 +#include +#include + +#include "mmu_decl.h" +#include + +#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; +} + +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); +} +/* + * 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(); +} + +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; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ diff --git a/arch/powerpc/mm/pgtable-hash64.c b/arch/powerpc/mm/pgtable-hash64.c index 9699a1ccedb5..c23e286a6b8f 100644 --- a/arch/powerpc/mm/pgtable-hash64.c +++ b/arch/powerpc/mm/pgtable-hash64.c @@ -99,35 +99,9 @@ int hash__map_kernel_page(unsigned long ea, unsigned long pa, unsigned long flag #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 hash__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; @@ -158,8 +132,8 @@ unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, return old; } -pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, - pmd_t *pmdp) +pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) { pmd_t pmd; @@ -197,25 +171,12 @@ pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long 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) +void hash__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); @@ -233,7 +194,7 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, smp_wmb(); } -pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) +pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) { pgtable_t pgtable; pgtable_t *pgtable_slot; @@ -253,8 +214,8 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) return pgtable; } -void pmdp_huge_split_prepare(struct vm_area_struct *vma, - unsigned long address, pmd_t *pmdp) +void hash__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); @@ -274,39 +235,6 @@ void pmdp_huge_split_prepare(struct vm_area_struct *vma, 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. @@ -346,47 +274,8 @@ void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr, 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 hash__pmdp_huge_get_and_clear(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) { pmd_t old_pmd; pgtable_t pgtable; @@ -421,7 +310,7 @@ pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, return old_pmd; } -int has_transparent_hugepage(void) +int hash__has_transparent_hugepage(void) { if (!mmu_has_feature(MMU_FTR_16M_PAGE)) -- 2.20.1