Commit 53273655 authored by Ryan Roberts's avatar Ryan Roberts Committed by Andrew Morton
Browse files

arm64/mm: convert READ_ONCE(*ptep) to ptep_get(ptep) 

There are a number of places in the arch code that read a pte by using the
READ_ONCE() macro.  Refactor these call sites to instead use the
ptep_get() helper, which itself is a READ_ONCE().  Generated code should
be the same.

This will benefit us when we shortly introduce the transparent contpte
support.  In this case, ptep_get() will become more complex so we now have
all the code abstracted through it.

Link: https://lkml.kernel.org/r/20240215103205.2607016-8-ryan.roberts@arm.com


Signed-off-by: default avatarRyan Roberts <ryan.roberts@arm.com>
Tested-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent fb23bf6b

arch/arm64/include/asm/pgtable.h

+9 −3
Original line number Diff line number Diff line
@@ -275,6 +275,12 @@ static inline void set_pte(pte_t *ptep, pte_t pte) 
	}

}



#define ptep_get ptep_get

static inline pte_t ptep_get(pte_t *ptep)

{

	return READ_ONCE(*ptep);

}



extern void __sync_icache_dcache(pte_t pteval);

bool pgattr_change_is_safe(u64 old, u64 new);
@@ -302,7 +308,7 @@ static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, 
	if (!IS_ENABLED(CONFIG_DEBUG_VM))

		return;



	old_pte = READ_ONCE(*ptep);

	old_pte = ptep_get(ptep);



	if (!pte_valid(old_pte) || !pte_valid(pte))

		return;
@@ -904,7 +910,7 @@ static inline int __ptep_test_and_clear_young(pte_t *ptep) 
{

	pte_t old_pte, pte;



	pte = READ_ONCE(*ptep);

	pte = ptep_get(ptep);

	do {

		old_pte = pte;

		pte = pte_mkold(pte);
@@ -986,7 +992,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres 
{

	pte_t old_pte, pte;



	pte = READ_ONCE(*ptep);

	pte = ptep_get(ptep);

	do {

		old_pte = pte;

		pte = pte_wrprotect(pte);

arch/arm64/kernel/efi.c

+1 −1
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) 
{

	struct set_perm_data *spd = data;

	const efi_memory_desc_t *md = spd->md;

	pte_t pte = READ_ONCE(*ptep);

	pte_t pte = ptep_get(ptep);



	if (md->attribute & EFI_MEMORY_RO)

		pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));

arch/arm64/mm/fault.c

+2 −2
Original line number Diff line number Diff line
@@ -191,7 +191,7 @@ static void show_pte(unsigned long addr) 
		if (!ptep)

			break;



		pte = READ_ONCE(*ptep);

		pte = ptep_get(ptep);

		pr_cont(", pte=%016llx", pte_val(pte));

		pte_unmap(ptep);

	} while(0);
@@ -214,7 +214,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, 
			  pte_t entry, int dirty)

{

	pteval_t old_pteval, pteval;

	pte_t pte = READ_ONCE(*ptep);

	pte_t pte = ptep_get(ptep);



	if (pte_same(pte, entry))

		return 0;

arch/arm64/mm/hugetlbpage.c

+3 −3
Original line number Diff line number Diff line
@@ -485,7 +485,7 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm, 
	size_t pgsize;

	pte_t pte;



	if (!pte_cont(READ_ONCE(*ptep))) {

	if (!pte_cont(ptep_get(ptep))) {

		ptep_set_wrprotect(mm, addr, ptep);

		return;

	}
@@ -510,7 +510,7 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, 
	size_t pgsize;

	int ncontig;



	if (!pte_cont(READ_ONCE(*ptep)))

	if (!pte_cont(ptep_get(ptep)))

		return ptep_clear_flush(vma, addr, ptep);



	ncontig = find_num_contig(mm, addr, ptep, &pgsize);
@@ -543,7 +543,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr 
		 * when the permission changes from executable to non-executable

		 * in cases where cpu is affected with errata #2645198.

		 */

		if (pte_user_exec(READ_ONCE(*ptep)))

		if (pte_user_exec(ptep_get(ptep)))

			return huge_ptep_clear_flush(vma, addr, ptep);

	}

	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);

arch/arm64/mm/kasan_init.c

+1 −1
Original line number Diff line number Diff line
@@ -113,7 +113,7 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, 
			memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE);

		next = addr + PAGE_SIZE;

		set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL));

	} while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep)));

	} while (ptep++, addr = next, addr != end && pte_none(ptep_get(ptep)));

}



static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr,