Commit 7b806d22 authored Mar 12, 2023 by Lorenzo Stoakes Committed by Andrew Morton Apr 05, 2023

mm: remove vmf_insert_pfn_xxx_prot() for huge page-table entries

This functionality's sole user, the drm ttm module, removed support for it
in commit 0d979509 ("drm/ttm: remove ttm_bo_vm_insert_huge()") as the
whole approach is currently unworkable without a PMD/PUD special bit and
updates to GUP.

Link: https://lkml.kernel.org/r/604c2ad79659d4b8a6e3e1611c6219d5d3233988.1678661628.git.lstoakes@gmail.com


Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent 28d8b812

include/linux/huge_mm.h

+2 −37

Original line number	Diff line number	Diff line
		@@ -39,44 +39,9 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
		int change_huge_pmd(struct mmu_gather tlb, struct vm_area_struct vma,
		pmd_t *pmd, unsigned long addr, pgprot_t newprot,
		unsigned long cp_flags);
		vm_fault_t vmf_insert_pfn_pmd_prot(struct vm_fault *vmf, pfn_t pfn,
		pgprot_t pgprot, bool write);

		/**
		* vmf_insert_pfn_pmd - insert a pmd size pfn
		* @vmf: Structure describing the fault
		* @pfn: pfn to insert
		* @pgprot: page protection to use
		* @write: whether it's a write fault
		*
		* Insert a pmd size pfn. See vmf_insert_pfn() for additional info.
		*
		* Return: vm_fault_t value.
		*/
		static inline vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn,
		bool write)
		{
		return vmf_insert_pfn_pmd_prot(vmf, pfn, vmf->vma->vm_page_prot, write);
		}
		vm_fault_t vmf_insert_pfn_pud_prot(struct vm_fault *vmf, pfn_t pfn,
		pgprot_t pgprot, bool write);

		/**
		* vmf_insert_pfn_pud - insert a pud size pfn
		* @vmf: Structure describing the fault
		* @pfn: pfn to insert
		* @pgprot: page protection to use
		* @write: whether it's a write fault
		*
		* Insert a pud size pfn. See vmf_insert_pfn() for additional info.
		*
		* Return: vm_fault_t value.
		*/
		static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
		bool write)
		{
		return vmf_insert_pfn_pud_prot(vmf, pfn, vmf->vma->vm_page_prot, write);
		}
		vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write);
		vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write);

		enum transparent_hugepage_flag {
		TRANSPARENT_HUGEPAGE_UNSUPPORTED,

mm/huge_memory.c

+13 −18

Original line number	Diff line number	Diff line
		@@ -885,23 +885,20 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
		}

		/**
		* vmf_insert_pfn_pmd_prot - insert a pmd size pfn
		* vmf_insert_pfn_pmd - insert a pmd size pfn
		* @vmf: Structure describing the fault
		* @pfn: pfn to insert
		* @pgprot: page protection to use
		* @write: whether it's a write fault
		*
		* Insert a pmd size pfn. See vmf_insert_pfn() for additional info and
		* also consult the vmf_insert_mixed_prot() documentation when
		* @pgprot != @vmf->vma->vm_page_prot.
		* Insert a pmd size pfn. See vmf_insert_pfn() for additional info.
		*
		* Return: vm_fault_t value.
		*/
		vm_fault_t vmf_insert_pfn_pmd_prot(struct vm_fault *vmf, pfn_t pfn,
		pgprot_t pgprot, bool write)
		vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write)
		{
		unsigned long addr = vmf->address & PMD_MASK;
		struct vm_area_struct *vma = vmf->vma;
		pgprot_t pgprot = vma->vm_page_prot;
		pgtable_t pgtable = NULL;

		/*
		@@ -929,7 +926,7 @@ vm_fault_t vmf_insert_pfn_pmd_prot(struct vm_fault *vmf, pfn_t pfn,
		insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, pgtable);
		return VM_FAULT_NOPAGE;
		}
		EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd_prot);
		EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd);

		#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
		static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma)
		@@ -940,9 +937,10 @@ static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma)
		}

		static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
		pud_t *pud, pfn_t pfn, pgprot_t prot, bool write)
		pud_t *pud, pfn_t pfn, bool write)
		{
		struct mm_struct *mm = vma->vm_mm;
		pgprot_t prot = vma->vm_page_prot;
		pud_t entry;
		spinlock_t *ptl;

		@@ -976,23 +974,20 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
		}

		/**
		* vmf_insert_pfn_pud_prot - insert a pud size pfn
		* vmf_insert_pfn_pud - insert a pud size pfn
		* @vmf: Structure describing the fault
		* @pfn: pfn to insert
		* @pgprot: page protection to use
		* @write: whether it's a write fault
		*
		* Insert a pud size pfn. See vmf_insert_pfn() for additional info and
		* also consult the vmf_insert_mixed_prot() documentation when
		* @pgprot != @vmf->vma->vm_page_prot.
		* Insert a pud size pfn. See vmf_insert_pfn() for additional info.
		*
		* Return: vm_fault_t value.
		*/
		vm_fault_t vmf_insert_pfn_pud_prot(struct vm_fault *vmf, pfn_t pfn,
		pgprot_t pgprot, bool write)
		vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write)
		{
		unsigned long addr = vmf->address & PUD_MASK;
		struct vm_area_struct *vma = vmf->vma;
		pgprot_t pgprot = vma->vm_page_prot;

		/*
		* If we had pud_special, we could avoid all these restrictions,
		@@ -1010,10 +1005,10 @@ vm_fault_t vmf_insert_pfn_pud_prot(struct vm_fault *vmf, pfn_t pfn,

		track_pfn_insert(vma, &pgprot, pfn);

		insert_pfn_pud(vma, addr, vmf->pud, pfn, pgprot, write);
		insert_pfn_pud(vma, addr, vmf->pud, pfn, write);
		return VM_FAULT_NOPAGE;
		}
		EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud_prot);
		EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud);
		#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */

		static void touch_pmd(struct vm_area_struct *vma, unsigned long addr,