From cb10c28ac82c9b7a5e9b3b1dc7157036c20c36dd Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 25 Mar 2024 07:45:41 +0800 Subject: [PATCH] mm: remove follow_pfn Remove follow_pfn now that the last user is gone. Link: https://lkml.kernel.org/r/20240324234542.2038726-3-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: David Hildenbrand Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fei Li Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Nathan Chancellor Signed-off-by: Andrew Morton --- include/linux/mm.h | 2 -- mm/memory.c | 36 ++---------------------------------- mm/nommu.c | 21 --------------------- 3 files changed, 2 insertions(+), 57 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index dd47ba7a1c04..cb8e6158b577 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2424,8 +2424,6 @@ int copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma); int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp, spinlock_t **ptlp); -int follow_pfn(struct vm_area_struct *vma, unsigned long address, - unsigned long *pfn); int follow_phys(struct vm_area_struct *vma, unsigned long address, unsigned int flags, unsigned long *prot, resource_size_t *phys); int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, diff --git a/mm/memory.c b/mm/memory.c index bcd29104f5ea..652370703e41 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5884,8 +5884,8 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore * should be taken for read. * - * KVM uses this function. While it is arguably less bad than ``follow_pfn``, - * it is not a good general-purpose API. + * KVM uses this function. While it is arguably less bad than the historic + * ``follow_pfn``, it is not a good general-purpose API. * * Return: zero on success, -ve otherwise. */ @@ -5927,38 +5927,6 @@ out: } EXPORT_SYMBOL_GPL(follow_pte); -/** - * follow_pfn - look up PFN at a user virtual address - * @vma: memory mapping - * @address: user virtual address - * @pfn: location to store found PFN - * - * Only IO mappings and raw PFN mappings are allowed. - * - * This function does not allow the caller to read the permissions - * of the PTE. Do not use it. - * - * Return: zero and the pfn at @pfn on success, -ve otherwise. - */ -int follow_pfn(struct vm_area_struct *vma, unsigned long address, - unsigned long *pfn) -{ - int ret = -EINVAL; - spinlock_t *ptl; - pte_t *ptep; - - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) - return ret; - - ret = follow_pte(vma->vm_mm, address, &ptep, &ptl); - if (ret) - return ret; - *pfn = pte_pfn(ptep_get(ptep)); - pte_unmap_unlock(ptep, ptl); - return 0; -} -EXPORT_SYMBOL(follow_pfn); - #ifdef CONFIG_HAVE_IOREMAP_PROT int follow_phys(struct vm_area_struct *vma, unsigned long address, unsigned int flags, diff --git a/mm/nommu.c b/mm/nommu.c index 88b646ea6d30..331d2f778695 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -110,27 +110,6 @@ unsigned int kobjsize(const void *objp) return page_size(page); } -/** - * follow_pfn - look up PFN at a user virtual address - * @vma: memory mapping - * @address: user virtual address - * @pfn: location to store found PFN - * - * Only IO mappings and raw PFN mappings are allowed. - * - * Returns zero and the pfn at @pfn on success, -ve otherwise. - */ -int follow_pfn(struct vm_area_struct *vma, unsigned long address, - unsigned long *pfn) -{ - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) - return -EINVAL; - - *pfn = address >> PAGE_SHIFT; - return 0; -} -EXPORT_SYMBOL(follow_pfn); - void vfree(const void *addr) { kfree(addr);