[PATCH v1 06/11] x86/mm/pat: remove old pfnmap tracking interface

[David Hildenbrand <david@redhat.com>]

We can now get rid of the old interface along with get_pat_info() and
follow_phys().

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/x86/mm/pat/memtype.c | 147 --------------------------------------
 include/linux/pgtable.h   |  66 -----------------
 2 files changed, 213 deletions(-)

diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c
index c011d8dd8f441..668ebf0065157 100644
--- a/arch/x86/mm/pat/memtype.c
+++ b/arch/x86/mm/pat/memtype.c
@@ -933,119 +933,6 @@ static void free_pfn_range(u64 paddr, unsigned long size)
 		memtype_free(paddr, paddr + size);
 }
 
-static int follow_phys(struct vm_area_struct *vma, unsigned long *prot,
-		resource_size_t *phys)
-{
-	struct follow_pfnmap_args args = { .vma = vma, .address = vma->vm_start };
-
-	if (follow_pfnmap_start(&args))
-		return -EINVAL;
-
-	/* Never return PFNs of anon folios in COW mappings. */
-	if (!args.special) {
-		follow_pfnmap_end(&args);
-		return -EINVAL;
-	}
-
-	*prot = pgprot_val(args.pgprot);
-	*phys = (resource_size_t)args.pfn << PAGE_SHIFT;
-	follow_pfnmap_end(&args);
-	return 0;
-}
-
-static int get_pat_info(struct vm_area_struct *vma, resource_size_t *paddr,
-		pgprot_t *pgprot)
-{
-	unsigned long prot;
-
-	VM_WARN_ON_ONCE(!(vma->vm_flags & VM_PAT));
-
-	/*
-	 * We need the starting PFN and cachemode used for track_pfn_remap()
-	 * that covered the whole VMA. For most mappings, we can obtain that
-	 * information from the page tables. For COW mappings, we might now
-	 * suddenly have anon folios mapped and follow_phys() will fail.
-	 *
-	 * Fallback to using vma->vm_pgoff, see remap_pfn_range_notrack(), to
-	 * detect the PFN. If we need the cachemode as well, we're out of luck
-	 * for now and have to fail fork().
-	 */
-	if (!follow_phys(vma, &prot, paddr)) {
-		if (pgprot)
-			*pgprot = __pgprot(prot);
-		return 0;
-	}
-	if (is_cow_mapping(vma->vm_flags)) {
-		if (pgprot)
-			return -EINVAL;
-		*paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
-		return 0;
-	}
-	WARN_ON_ONCE(1);
-	return -EINVAL;
-}
-
-int track_pfn_copy(struct vm_area_struct *dst_vma,
-		struct vm_area_struct *src_vma, unsigned long *pfn)
-{
-	const unsigned long vma_size = src_vma->vm_end - src_vma->vm_start;
-	resource_size_t paddr;
-	pgprot_t pgprot;
-	int rc;
-
-	if (!(src_vma->vm_flags & VM_PAT))
-		return 0;
-
-	/*
-	 * Duplicate the PAT information for the dst VMA based on the src
-	 * VMA.
-	 */
-	if (get_pat_info(src_vma, &paddr, &pgprot))
-		return -EINVAL;
-	rc = reserve_pfn_range(paddr, vma_size, &pgprot, 1);
-	if (rc)
-		return rc;
-
-	/* Reservation for the destination VMA succeeded. */
-	vm_flags_set(dst_vma, VM_PAT);
-	*pfn = PHYS_PFN(paddr);
-	return 0;
-}
-
-void untrack_pfn_copy(struct vm_area_struct *dst_vma, unsigned long pfn)
-{
-	untrack_pfn(dst_vma, pfn, dst_vma->vm_end - dst_vma->vm_start, true);
-	/*
-	 * Reservation was freed, any copied page tables will get cleaned
-	 * up later, but without getting PAT involved again.
-	 */
-}
-
-/*
- * prot is passed in as a parameter for the new mapping. If the vma has
- * a linear pfn mapping for the entire range, or no vma is provided,
- * reserve the entire pfn + size range with single reserve_pfn_range
- * call.
- */
-int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
-		    unsigned long pfn, unsigned long addr, unsigned long size)
-{
-	resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT;
-
-	/* reserve the whole chunk starting from paddr */
-	if (!vma || (addr == vma->vm_start
-				&& size == (vma->vm_end - vma->vm_start))) {
-		int ret;
-
-		ret = reserve_pfn_range(paddr, size, prot, 0);
-		if (ret == 0 && vma)
-			vm_flags_set(vma, VM_PAT);
-		return ret;
-	}
-
-	return pfnmap_sanitize_pgprot(pfn, size, prot);
-}
-
 int pfnmap_sanitize_pgprot(unsigned long pfn, unsigned long size, pgprot_t *prot)
 {
 	resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT;
@@ -1082,40 +969,6 @@ void pfnmap_untrack(unsigned long pfn, unsigned long size)
 	free_pfn_range(paddr, size);
 }
 
-/*
- * untrack_pfn is called while unmapping a pfnmap for a region.
- * untrack can be called for a specific region indicated by pfn and size or
- * can be for the entire vma (in which case pfn, size are zero).
- */
-void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
-		 unsigned long size, bool mm_wr_locked)
-{
-	resource_size_t paddr;
-
-	if (vma && !(vma->vm_flags & VM_PAT))
-		return;
-
-	/* free the chunk starting from pfn or the whole chunk */
-	paddr = (resource_size_t)pfn << PAGE_SHIFT;
-	if (!paddr && !size) {
-		if (get_pat_info(vma, &paddr, NULL))
-			return;
-		size = vma->vm_end - vma->vm_start;
-	}
-	free_pfn_range(paddr, size);
-	if (vma) {
-		if (mm_wr_locked)
-			vm_flags_clear(vma, VM_PAT);
-		else
-			__vm_flags_mod(vma, 0, VM_PAT);
-	}
-}
-
-void untrack_pfn_clear(struct vm_area_struct *vma)
-{
-	vm_flags_clear(vma, VM_PAT);
-}
-
 pgprot_t pgprot_writecombine(pgprot_t prot)
 {
 	pgprot_set_cachemode(&prot, _PAGE_CACHE_MODE_WC);
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 898a3ab195578..0ffc6b9339182 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1489,17 +1489,6 @@ static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
  * vmf_insert_pfn.
  */
 
-/*
- * track_pfn_remap is called when a _new_ pfn mapping is being established
- * by remap_pfn_range() for physical range indicated by pfn and size.
- */
-static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
-				  unsigned long pfn, unsigned long addr,
-				  unsigned long size)
-{
-	return 0;
-}
-
 static inline int pfnmap_sanitize_pgprot(unsigned long pfn, unsigned long size,
 		pgprot_t *prot)
 {
@@ -1515,55 +1504,7 @@ static inline int pfnmap_track(unsigned long pfn, unsigned long size,
 static inline void pfnmap_untrack(unsigned long pfn, unsigned long size)
 {
 }
-
-/*
- * track_pfn_copy is called when a VM_PFNMAP VMA is about to get the page
- * tables copied during copy_page_range(). Will store the pfn to be
- * passed to untrack_pfn_copy() only if there is something to be untracked.
- * Callers should initialize the pfn to 0.
- */
-static inline int track_pfn_copy(struct vm_area_struct *dst_vma,
-		struct vm_area_struct *src_vma, unsigned long *pfn)
-{
-	return 0;
-}
-
-/*
- * untrack_pfn_copy is called when a VM_PFNMAP VMA failed to copy during
- * copy_page_range(), but after track_pfn_copy() was already called. Can
- * be called even if track_pfn_copy() did not actually track anything:
- * handled internally.
- */
-static inline void untrack_pfn_copy(struct vm_area_struct *dst_vma,
-		unsigned long pfn)
-{
-}
-
-/*
- * untrack_pfn is called while unmapping a pfnmap for a region.
- * untrack can be called for a specific region indicated by pfn and size or
- * can be for the entire vma (in which case pfn, size are zero).
- */
-static inline void untrack_pfn(struct vm_area_struct *vma,
-			       unsigned long pfn, unsigned long size,
-			       bool mm_wr_locked)
-{
-}
-
-/*
- * untrack_pfn_clear is called in the following cases on a VM_PFNMAP VMA:
- *
- * 1) During mremap() on the src VMA after the page tables were moved.
- * 2) During fork() on the dst VMA, immediately after duplicating the src VMA.
- */
-static inline void untrack_pfn_clear(struct vm_area_struct *vma)
-{
-}
 #else
-extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
-			   unsigned long pfn, unsigned long addr,
-			   unsigned long size);
-
 /**
  * pfnmap_sanitize_pgprot - sanitize the pgprot for a pfn range
  * @pfn: the start of the pfn range
@@ -1603,13 +1544,6 @@ int pfnmap_track(unsigned long pfn, unsigned long size, pgprot_t *prot);
  * un-doing any reservation.
  */
 void pfnmap_untrack(unsigned long pfn, unsigned long size);
-extern int track_pfn_copy(struct vm_area_struct *dst_vma,
-		struct vm_area_struct *src_vma, unsigned long *pfn);
-extern void untrack_pfn_copy(struct vm_area_struct *dst_vma,
-		unsigned long pfn);
-extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
-			unsigned long size, bool mm_wr_locked);
-extern void untrack_pfn_clear(struct vm_area_struct *vma);
 #endif
 
 #ifdef CONFIG_MMU
-- 
2.49.0