Commit d6379159 authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

mm: remove unused savedwrite infrastructure 

NUMA hinting no longer uses savedwrite, let's rip it out.

... and while at it, drop __pte_write() and __pmd_write() on ppc64.

Link: https://lkml.kernel.org/r/20221108174652.198904-7-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6a56ccbc

arch/powerpc/include/asm/book3s/64/pgtable.h

+4 −76
Original line number Diff line number Diff line
@@ -401,35 +401,9 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm, 
#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH

#define pmdp_clear_flush_young pmdp_test_and_clear_young



static inline int __pte_write(pte_t pte)

{

	return !!(pte_raw(pte) & cpu_to_be64(_PAGE_WRITE));

}



#ifdef CONFIG_NUMA_BALANCING

#define pte_savedwrite pte_savedwrite

static inline bool pte_savedwrite(pte_t pte)

{

	/*

	 * Saved write ptes are prot none ptes that doesn't have

	 * privileged bit sit. We mark prot none as one which has

	 * present and pviliged bit set and RWX cleared. To mark

	 * protnone which used to have _PAGE_WRITE set we clear

	 * the privileged bit.

	 */

	return !(pte_raw(pte) & cpu_to_be64(_PAGE_RWX | _PAGE_PRIVILEGED));

}

#else

#define pte_savedwrite pte_savedwrite

static inline bool pte_savedwrite(pte_t pte)

{

	return false;

}

#endif



static inline int pte_write(pte_t pte)

{

	return __pte_write(pte) || pte_savedwrite(pte);

	return !!(pte_raw(pte) & cpu_to_be64(_PAGE_WRITE));

}



static inline int pte_read(pte_t pte)
@@ -441,24 +415,16 @@ static inline int pte_read(pte_t pte) 
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,

				      pte_t *ptep)

{

	if (__pte_write(*ptep))

	if (pte_write(*ptep))

		pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 0);

	else if (unlikely(pte_savedwrite(*ptep)))

		pte_update(mm, addr, ptep, 0, _PAGE_PRIVILEGED, 0);

}



#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT

static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,

					   unsigned long addr, pte_t *ptep)

{

	/*

	 * We should not find protnone for hugetlb, but this complete the

	 * interface.

	 */

	if (__pte_write(*ptep))

	if (pte_write(*ptep))

		pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 1);

	else if (unlikely(pte_savedwrite(*ptep)))

		pte_update(mm, addr, ptep, 0, _PAGE_PRIVILEGED, 1);

}



#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
@@ -535,36 +501,6 @@ static inline int pte_protnone(pte_t pte) 
	return (pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT | _PAGE_PTE | _PAGE_RWX)) ==

		cpu_to_be64(_PAGE_PRESENT | _PAGE_PTE);

}



#define pte_mk_savedwrite pte_mk_savedwrite

static inline pte_t pte_mk_savedwrite(pte_t pte)

{

	/*

	 * Used by Autonuma subsystem to preserve the write bit

	 * while marking the pte PROT_NONE. Only allow this

	 * on PROT_NONE pte

	 */

	VM_BUG_ON((pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT | _PAGE_RWX | _PAGE_PRIVILEGED)) !=

		  cpu_to_be64(_PAGE_PRESENT | _PAGE_PRIVILEGED));

	return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_PRIVILEGED));

}



#define pte_clear_savedwrite pte_clear_savedwrite

static inline pte_t pte_clear_savedwrite(pte_t pte)

{

	/*

	 * Used by KSM subsystem to make a protnone pte readonly.

	 */

	VM_BUG_ON(!pte_protnone(pte));

	return __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_PRIVILEGED));

}

#else

#define pte_clear_savedwrite pte_clear_savedwrite

static inline pte_t pte_clear_savedwrite(pte_t pte)

{

	VM_WARN_ON(1);

	return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_WRITE));

}

#endif /* CONFIG_NUMA_BALANCING */



static inline bool pte_hw_valid(pte_t pte)
@@ -641,8 +577,6 @@ static inline unsigned long pte_pfn(pte_t pte) 
/* Generic modifiers for PTE bits */

static inline pte_t pte_wrprotect(pte_t pte)

{

	if (unlikely(pte_savedwrite(pte)))

		return pte_clear_savedwrite(pte);

	return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_WRITE));

}
@@ -1139,8 +1073,6 @@ static inline pte_t *pmdp_ptep(pmd_t *pmd) 
#define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))

#define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))

#define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))

#define pmd_mk_savedwrite(pmd)	pte_pmd(pte_mk_savedwrite(pmd_pte(pmd)))

#define pmd_clear_savedwrite(pmd)	pte_pmd(pte_clear_savedwrite(pmd_pte(pmd)))



#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY

#define pmd_soft_dirty(pmd)    pte_soft_dirty(pmd_pte(pmd))
@@ -1162,8 +1094,6 @@ static inline int pmd_protnone(pmd_t pmd) 
#endif /* CONFIG_NUMA_BALANCING */



#define pmd_write(pmd)		pte_write(pmd_pte(pmd))

#define __pmd_write(pmd)	__pte_write(pmd_pte(pmd))

#define pmd_savedwrite(pmd)	pte_savedwrite(pmd_pte(pmd))



#define pmd_access_permitted pmd_access_permitted

static inline bool pmd_access_permitted(pmd_t pmd, bool write)
@@ -1241,10 +1171,8 @@ static inline int __pmdp_test_and_clear_young(struct mm_struct *mm, 
static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,

				      pmd_t *pmdp)

{

	if (__pmd_write((*pmdp)))

	if (pmd_write(*pmdp))

		pmd_hugepage_update(mm, addr, pmdp, _PAGE_WRITE, 0);

	else if (unlikely(pmd_savedwrite(*pmdp)))

		pmd_hugepage_update(mm, addr, pmdp, 0, _PAGE_PRIVILEGED);

}



/*

arch/powerpc/kvm/book3s_hv_rm_mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -265,7 +265,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags, 
		}

		pte = kvmppc_read_update_linux_pte(ptep, writing);

		if (pte_present(pte) && !pte_protnone(pte)) {

			if (writing && !__pte_write(pte))

			if (writing && !pte_write(pte))

				/* make the actual HPTE be read-only */

				ptel = hpte_make_readonly(ptel);

			is_ci = pte_ci(pte);

include/linux/pgtable.h

+0 −24
Original line number Diff line number Diff line
@@ -503,30 +503,6 @@ static inline pte_t pte_sw_mkyoung(pte_t pte) 
#define pte_sw_mkyoung	pte_sw_mkyoung

#endif



#ifndef pte_savedwrite

#define pte_savedwrite pte_write

#endif



#ifndef pte_mk_savedwrite

#define pte_mk_savedwrite pte_mkwrite

#endif



#ifndef pte_clear_savedwrite

#define pte_clear_savedwrite pte_wrprotect

#endif



#ifndef pmd_savedwrite

#define pmd_savedwrite pmd_write

#endif



#ifndef pmd_mk_savedwrite

#define pmd_mk_savedwrite pmd_mkwrite

#endif



#ifndef pmd_clear_savedwrite

#define pmd_clear_savedwrite pmd_wrprotect

#endif



#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

static inline void pmdp_set_wrprotect(struct mm_struct *mm,

mm/debug_vm_pgtable.c

+0 −32
Original line number Diff line number Diff line
@@ -171,18 +171,6 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args) 
	ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);

}



static void __init pte_savedwrite_tests(struct pgtable_debug_args *args)

{

	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);



	if (!IS_ENABLED(CONFIG_NUMA_BALANCING))

		return;



	pr_debug("Validating PTE saved write\n");

	WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));

	WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));

}



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)

{
@@ -302,22 +290,6 @@ static void __init pmd_leaf_tests(struct pgtable_debug_args *args) 
	WARN_ON(!pmd_leaf(pmd));

}



static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args)

{

	pmd_t pmd;



	if (!IS_ENABLED(CONFIG_NUMA_BALANCING))

		return;



	if (!has_transparent_hugepage())

		return;



	pr_debug("Validating PMD saved write\n");

	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none);

	WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));

	WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));

}



#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD

static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)

{
@@ -451,7 +423,6 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { } 
static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }

static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { }

static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }

static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args) { }

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */



#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
@@ -1288,9 +1259,6 @@ static int __init debug_vm_pgtable(void) 
	pmd_leaf_tests(&args);

	pud_leaf_tests(&args);



	pte_savedwrite_tests(&args);

	pmd_savedwrite_tests(&args);



	pte_special_tests(&args);

	pte_protnone_tests(&args);

	pmd_protnone_tests(&args);