mm: use linear_page_[index, delta]() consistently

There are a number of places where we open code what linear_page_index()
and linear_page_delta() calculate.

Replace this code with the appropriate functions for consistency.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-21-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>	[DRM]
Acked-by: Kai Huang <kai.huang@intel.com> # for sgx
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Pedro Falcato <pfalcato@suse.de> # for mm
Reviewed-by: Ackerley Tng <ackerleytng@google.com>	[guest_memfd]
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: SJ Park <sj@kernel.org>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/arm/mm/fault-armv.c

@@ -132,7 +132,7 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
 	pgoff_t pgoff;
 	int aliases = 0;
 
-	pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT);
+	pgoff = linear_page_index(vma, addr);
 
 	/*
 	 * If we have any shared mappings that are in the same mm

arch/x86/kernel/cpu/sgx/virt.c

@@ -9,6 +9,7 @@
 #include <linux/miscdevice.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
+#include <linux/pagemap.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/slab.h>
@@ -41,7 +42,7 @@ static int __sgx_vepc_fault(struct sgx_vepc *vepc,
 	WARN_ON(!mutex_is_locked(&vepc->lock));
 
 	/* Calculate index of EPC page in virtual EPC's page_array */
-	index = vma->vm_pgoff + PFN_DOWN(addr - vma->vm_start);
+	index = linear_page_index(vma, addr);
 
 	epc_page = xa_load(&vepc->page_array, index);
 	if (epc_page)

drivers/gpu/drm/etnaviv/etnaviv_gem.c

@@ -6,6 +6,7 @@
 #include <drm/drm_prime.h>
 #include <drm/drm_print.h>
 #include <linux/dma-mapping.h>
+#include <linux/pagemap.h>
 #include <linux/shmem_fs.h>
 #include <linux/spinlock.h>
 #include <linux/vmalloc.h>
@@ -188,7 +189,7 @@ static vm_fault_t etnaviv_gem_fault(struct vm_fault *vmf)
 	}
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	pgoff = linear_page_delta(vma, vmf->address);
 
 	pfn = page_to_pfn(pages[pgoff]);
 

drivers/gpu/drm/gma500/gem.c

@@ -288,7 +288,7 @@ static vm_fault_t psb_gem_fault(struct vm_fault *vmf)
 
 	/* Page relative to the VMA start - we must calculate this ourselves
 	   because vmf->pgoff is the fake GEM offset */
-	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	page_offset = linear_page_delta(vma, vmf->address);
 
 	/* CPU view of the page, don't go via the GART for CPU writes */
 	if (pobj->stolen)

drivers/gpu/drm/msm/msm_gem.c

@@ -9,6 +9,7 @@
 #include <linux/spinlock.h>
 #include <linux/shmem_fs.h>
 #include <linux/dma-buf.h>
+#include <linux/pagemap.h>
 
 #include <drm/drm_dumb_buffers.h>
 #include <drm/drm_prime.h>
@@ -360,7 +361,7 @@ static vm_fault_t msm_gem_fault(struct vm_fault *vmf)
 	}
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	pgoff = linear_page_delta(vma, vmf->address);
 
 	pfn = page_to_pfn(pages[pgoff]);
 

drivers/gpu/drm/omapdrm/omap_gem.c

@@ -5,6 +5,7 @@
  */
 
 #include <linux/dma-mapping.h>
+#include <linux/pagemap.h>
 #include <linux/seq_file.h>
 #include <linux/shmem_fs.h>
 #include <linux/spinlock.h>
@@ -359,7 +360,7 @@ static vm_fault_t omap_gem_fault_1d(struct drm_gem_object *obj,
 	pgoff_t pgoff;
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	pgoff = linear_page_delta(vma, vmf->address);
 
 	if (omap_obj->pages) {
 		omap_gem_cpu_sync_page(obj, pgoff);
@@ -407,7 +408,7 @@ static vm_fault_t omap_gem_fault_2d(struct drm_gem_object *obj,
 	const int m = DIV_ROUND_UP(omap_obj->width << fmt, PAGE_SIZE);
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	pgoff = linear_page_delta(vma, vmf->address);
 
 	/*
 	 * Actual address we start mapping at is rounded down to previous slot

drivers/gpu/drm/tegra/gem.c

@@ -13,6 +13,7 @@
 #include <linux/dma-buf.h>
 #include <linux/iommu.h>
 #include <linux/module.h>
+#include <linux/pagemap.h>
 #include <linux/vmalloc.h>
 
 #include <drm/drm_drv.h>
@@ -564,7 +565,7 @@ static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
 	if (!bo->pages)
 		return VM_FAULT_SIGBUS;
 
-	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	offset = linear_page_delta(vma, vmf->address);
 	page = bo->pages[offset];
 
 	return vmf_insert_page(vma, vmf->address, page);

drivers/gpu/drm/ttm/ttm_bo_vm.c

@@ -32,6 +32,7 @@
 #define pr_fmt(fmt) "[TTM] " fmt
 
 #include <linux/export.h>
+#include <linux/pagemap.h>
 
 #include <drm/ttm/ttm_bo.h>
 #include <drm/ttm/ttm_placement.h>
@@ -208,9 +209,9 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 	if (unlikely(err != 0))
 		return VM_FAULT_SIGBUS;
 
-	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
-		vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
-	page_last = vma_pages(vma) + vma->vm_pgoff -
+	page_offset = linear_page_index(vma, address) -
+		drm_vma_node_start(&bo->base.vma_node);
+	page_last = vma_end_pgoff(vma) -
 		drm_vma_node_start(&bo->base.vma_node);
 
 	if (unlikely(page_offset >= PFN_UP(bo->base.size)))

drivers/vfio/pci/nvgrace-gpu/main.c

@@ -11,6 +11,7 @@
 #include <linux/jiffies.h>
 #include <linux/sched.h>
 #include <linux/pci-p2pdma.h>
+#include <linux/pagemap.h>
 #include <linux/pm_runtime.h>
 #include <linux/memory-failure.h>
 
@@ -385,7 +386,7 @@ static unsigned long addr_to_pgoff(struct vm_area_struct *vma,
 	u64 pgoff = vma->vm_pgoff &
 		((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 
-	return ((addr - vma->vm_start) >> PAGE_SHIFT) + pgoff;
+	return linear_page_delta(vma, addr) + pgoff;
 }
 
 static vm_fault_t nvgrace_gpu_vfio_pci_huge_fault(struct vm_fault *vmf,

drivers/vfio/pci/vfio_pci_core.c

@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/notifier.h>
+#include <linux/pagemap.h>
 #include <linux/pci.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
@@ -1780,7 +1781,7 @@ static vm_fault_t vfio_pci_mmap_huge_fault(struct vm_fault *vmf,
 	struct vm_area_struct *vma = vmf->vma;
 	struct vfio_pci_core_device *vdev = vma->vm_private_data;
 	unsigned long addr = vmf->address & ~((PAGE_SIZE << order) - 1);
-	unsigned long pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+	unsigned long pgoff = linear_page_delta(vma, addr);
 	unsigned long pfn = vma_to_pfn(vma) + pgoff;
 	vm_fault_t ret = VM_FAULT_FALLBACK;
 

mm/nommu.c

@@ -1355,7 +1355,7 @@ static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
 	*region = *vma->vm_region;
 	new->vm_region = region;
 
-	npages = (addr - vma->vm_start) >> PAGE_SHIFT;
+	npages = linear_page_delta(vma, addr);
 
 	if (new_below) {
 		region->vm_top = region->vm_end = new->vm_end = addr;

mm/vma.c

@@ -517,7 +517,7 @@ __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
 		new->vm_end = addr;
 	} else {
 		new->vm_start = addr;
-		new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT);
+		new->vm_pgoff += linear_page_delta(vma, addr);
 	}
 
 	err = -ENOMEM;

virt/kvm/guest_memfd.c

@@ -440,7 +440,7 @@ static int kvm_gmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpo
 static struct mempolicy *kvm_gmem_get_policy(struct vm_area_struct *vma,
 					     unsigned long addr, pgoff_t *ilx)
 {
-	pgoff_t pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT);
+	pgoff_t pgoff = linear_page_index(vma, addr);
 	struct inode *inode = file_inode(vma->vm_file);
 
 	*ilx = inode->i_ino;