Commit b7298e41 authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

mm/huge_memory: move more common code into insert_pmd() 

Patch series "mm: vm_normal_page*() improvements", v3.

Cleanup and unify vm_normal_page_*() handling, also marking the huge
zerofolio as special in the PMD.  Add+use vm_normal_page_pud() and cleanup
that XEN vm_ops->find_special_page thingy.

There are plans of using vm_normal_page_*() more widely soon.


This patch (of 11):

Let's clean it all further up.

No functional change intended.

Link: https://lkml.kernel.org/r/20250811112631.759341-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250811112631.759341-2-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Reviewed-by: default avatarAlistair Popple <apopple@nvidia.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: default avatarWei Yang <richard.weiyang@gmail.com>
Reviewed-by: default avatarLance Yang <lance.yang@linux.dev>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Juegren Gross <jgross@suse.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent fb49a442

mm/huge_memory.c

+24 −48
Original line number Diff line number Diff line
@@ -1379,15 +1379,25 @@ struct folio_or_pfn { 
	bool is_folio;

};



static int insert_pmd(struct vm_area_struct *vma, unsigned long addr,

static vm_fault_t insert_pmd(struct vm_area_struct *vma, unsigned long addr,

		pmd_t *pmd, struct folio_or_pfn fop, pgprot_t prot,

		bool write, pgtable_t pgtable)

		bool write)

{

	struct mm_struct *mm = vma->vm_mm;

	pgtable_t pgtable = NULL;

	spinlock_t *ptl;

	pmd_t entry;



	lockdep_assert_held(pmd_lockptr(mm, pmd));

	if (addr < vma->vm_start || addr >= vma->vm_end)

		return VM_FAULT_SIGBUS;



	if (arch_needs_pgtable_deposit()) {

		pgtable = pte_alloc_one(vma->vm_mm);

		if (!pgtable)

			return VM_FAULT_OOM;

	}



	ptl = pmd_lock(mm, pmd);

	if (!pmd_none(*pmd)) {

		const unsigned long pfn = fop.is_folio ? folio_pfn(fop.folio) :

					  fop.pfn;
@@ -1395,15 +1405,14 @@ static int insert_pmd(struct vm_area_struct *vma, unsigned long addr, 
		if (write) {

			if (pmd_pfn(*pmd) != pfn) {

				WARN_ON_ONCE(!is_huge_zero_pmd(*pmd));

				return -EEXIST;

				goto out_unlock;

			}

			entry = pmd_mkyoung(*pmd);

			entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);

			if (pmdp_set_access_flags(vma, addr, pmd, entry, 1))

				update_mmu_cache_pmd(vma, addr, pmd);

		}



		return -EEXIST;

		goto out_unlock;

	}



	if (fop.is_folio) {
@@ -1424,11 +1433,17 @@ static int insert_pmd(struct vm_area_struct *vma, unsigned long addr, 
	if (pgtable) {

		pgtable_trans_huge_deposit(mm, pmd, pgtable);

		mm_inc_nr_ptes(mm);

		pgtable = NULL;

	}



	set_pmd_at(mm, addr, pmd, entry);

	update_mmu_cache_pmd(vma, addr, pmd);

	return 0;



out_unlock:

	spin_unlock(ptl);

	if (pgtable)

		pte_free(mm, pgtable);

	return VM_FAULT_NOPAGE;

}



/**
@@ -1450,9 +1465,6 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, unsigned long pfn, 
	struct folio_or_pfn fop = {

		.pfn = pfn,

	};

	pgtable_t pgtable = NULL;

	spinlock_t *ptl;

	int error;



	/*

	 * If we had pmd_special, we could avoid all these restrictions,
@@ -1464,25 +1476,9 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, unsigned long pfn, 
						(VM_PFNMAP|VM_MIXEDMAP));

	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));



	if (addr < vma->vm_start || addr >= vma->vm_end)

		return VM_FAULT_SIGBUS;



	if (arch_needs_pgtable_deposit()) {

		pgtable = pte_alloc_one(vma->vm_mm);

		if (!pgtable)

			return VM_FAULT_OOM;

	}



	pfnmap_setup_cachemode_pfn(pfn, &pgprot);



	ptl = pmd_lock(vma->vm_mm, vmf->pmd);

	error = insert_pmd(vma, addr, vmf->pmd, fop, pgprot, write,

			   pgtable);

	spin_unlock(ptl);

	if (error && pgtable)

		pte_free(vma->vm_mm, pgtable);



	return VM_FAULT_NOPAGE;

	return insert_pmd(vma, addr, vmf->pmd, fop, pgprot, write);

}

EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd);
@@ -1491,35 +1487,15 @@ vm_fault_t vmf_insert_folio_pmd(struct vm_fault *vmf, struct folio *folio, 
{

	struct vm_area_struct *vma = vmf->vma;

	unsigned long addr = vmf->address & PMD_MASK;

	struct mm_struct *mm = vma->vm_mm;

	struct folio_or_pfn fop = {

		.folio = folio,

		.is_folio = true,

	};

	spinlock_t *ptl;

	pgtable_t pgtable = NULL;

	int error;



	if (addr < vma->vm_start || addr >= vma->vm_end)

		return VM_FAULT_SIGBUS;



	if (WARN_ON_ONCE(folio_order(folio) != PMD_ORDER))

		return VM_FAULT_SIGBUS;



	if (arch_needs_pgtable_deposit()) {

		pgtable = pte_alloc_one(vma->vm_mm);

		if (!pgtable)

			return VM_FAULT_OOM;

	}



	ptl = pmd_lock(mm, vmf->pmd);

	error = insert_pmd(vma, addr, vmf->pmd, fop, vma->vm_page_prot,

			   write, pgtable);

	spin_unlock(ptl);

	if (error && pgtable)

		pte_free(mm, pgtable);



	return VM_FAULT_NOPAGE;

	return insert_pmd(vma, addr, vmf->pmd, fop, vma->vm_page_prot, write);

}

EXPORT_SYMBOL_GPL(vmf_insert_folio_pmd);