mm/access_process_vm: use the new follow_pfnmap API

jira LE-3557
Rebuild_History Non-Buildable kernel-5.14.0-570.26.1.el9_6
commit-author Peter Xu <[email protected]>
commit b17269a
Empty-Commit: Cherry-Pick Conflicts during history rebuild.
Will be included in final tarball splat. Ref for failed cherry-pick at:
ciq/ciq_backports/kernel-5.14.0-570.26.1.el9_6/b17269a5.failed

Use the new API that can understand huge pfn mappings.

Link: https://lkml.kernel.org/r/[email protected]
	Signed-off-by: Peter Xu <[email protected]>
	Cc: Alexander Gordeev <[email protected]>
	Cc: Alex Williamson <[email protected]>
	Cc: Aneesh Kumar K.V <[email protected]>
	Cc: Borislav Petkov <[email protected]>
	Cc: Catalin Marinas <[email protected]>
	Cc: Christian Borntraeger <[email protected]>
	Cc: Dave Hansen <[email protected]>
	Cc: David Hildenbrand <[email protected]>
	Cc: Gavin Shan <[email protected]>
	Cc: Gerald Schaefer <[email protected]>
	Cc: Heiko Carstens <[email protected]>
	Cc: Ingo Molnar <[email protected]>
	Cc: Jason Gunthorpe <[email protected]>
	Cc: Matthew Wilcox <[email protected]>
	Cc: Niklas Schnelle <[email protected]>
	Cc: Paolo Bonzini <[email protected]>
	Cc: Ryan Roberts <[email protected]>
	Cc: Sean Christopherson <[email protected]>
	Cc: Sven Schnelle <[email protected]>
	Cc: Thomas Gleixner <[email protected]>
	Cc: Vasily Gorbik <[email protected]>
	Cc: Will Deacon <[email protected]>
	Cc: Zi Yan <[email protected]>
	Signed-off-by: Andrew Morton <[email protected]>
(cherry picked from commit b17269a)
	Signed-off-by: Jonathan Maple <[email protected]>

# Conflicts:
#	mm/memory.c

Author: PlaidCat

ciq/ciq_backports/kernel-5.14.0-570.26.1.el9_6/b17269a5.failed

@@ -0,0 +1,105 @@
+mm/access_process_vm: use the new follow_pfnmap API
+
+jira LE-3557
+Rebuild_History Non-Buildable kernel-5.14.0-570.26.1.el9_6
+commit-author Peter Xu <[email protected]>
+commit b17269a51cc7f046a6f2cf9a6c314a0de885e5a5
+Empty-Commit: Cherry-Pick Conflicts during history rebuild.
+Will be included in final tarball splat. Ref for failed cherry-pick at:
+ciq/ciq_backports/kernel-5.14.0-570.26.1.el9_6/b17269a5.failed
+
+Use the new API that can understand huge pfn mappings.
+
+Link: https://lkml.kernel.org/r/[email protected]
+	Signed-off-by: Peter Xu <[email protected]>
+	Cc: Alexander Gordeev <[email protected]>
+	Cc: Alex Williamson <[email protected]>
+	Cc: Aneesh Kumar K.V <[email protected]>
+	Cc: Borislav Petkov <[email protected]>
+	Cc: Catalin Marinas <[email protected]>
+	Cc: Christian Borntraeger <[email protected]>
+	Cc: Dave Hansen <[email protected]>
+	Cc: David Hildenbrand <[email protected]>
+	Cc: Gavin Shan <[email protected]>
+	Cc: Gerald Schaefer <[email protected]>
+	Cc: Heiko Carstens <[email protected]>
+	Cc: Ingo Molnar <[email protected]>
+	Cc: Jason Gunthorpe <[email protected]>
+	Cc: Matthew Wilcox <[email protected]>
+	Cc: Niklas Schnelle <[email protected]>
+	Cc: Paolo Bonzini <[email protected]>
+	Cc: Ryan Roberts <[email protected]>
+	Cc: Sean Christopherson <[email protected]>
+	Cc: Sven Schnelle <[email protected]>
+	Cc: Thomas Gleixner <[email protected]>
+	Cc: Vasily Gorbik <[email protected]>
+	Cc: Will Deacon <[email protected]>
+	Cc: Zi Yan <[email protected]>
+	Signed-off-by: Andrew Morton <[email protected]>
+(cherry picked from commit b17269a51cc7f046a6f2cf9a6c314a0de885e5a5)
+	Signed-off-by: Jonathan Maple <[email protected]>
+
+# Conflicts:
+#	mm/memory.c
+diff --cc mm/memory.c
+index e2794e3b8919,cfc278691466..000000000000
+--- a/mm/memory.c
++++ b/mm/memory.c
+@@@ -5749,37 -6341,34 +5749,45 @@@ int generic_access_phys(struct vm_area_
+  	resource_size_t phys_addr;
+  	unsigned long prot = 0;
+  	void __iomem *maddr;
+- 	pte_t *ptep, pte;
+- 	spinlock_t *ptl;
+  	int offset = offset_in_page(addr);
+  	int ret = -EINVAL;
++ 	bool writable;
++ 	struct follow_pfnmap_args args = { .vma = vma, .address = addr };
+  
+ +	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+ +		return -EINVAL;
+ +
+  retry:
+++<<<<<<< HEAD
+ +	if (follow_pte(vma->vm_mm, addr, &ptep, &ptl))
+++=======
++ 	if (follow_pfnmap_start(&args))
+++>>>>>>> b17269a51cc7 (mm/access_process_vm: use the new follow_pfnmap API)
+  		return -EINVAL;
+- 	pte = ptep_get(ptep);
+- 	pte_unmap_unlock(ptep, ptl);
++ 	prot = pgprot_val(args.pgprot);
++ 	phys_addr = (resource_size_t)args.pfn << PAGE_SHIFT;
++ 	writable = args.writable;
++ 	follow_pfnmap_end(&args);
+  
+- 	prot = pgprot_val(pte_pgprot(pte));
+- 	phys_addr = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT;
+- 
+- 	if ((write & FOLL_WRITE) && !pte_write(pte))
++ 	if ((write & FOLL_WRITE) && !writable)
+  		return -EINVAL;
+  
+  	maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot);
+  	if (!maddr)
+  		return -ENOMEM;
+  
+++<<<<<<< HEAD
+ +	if (follow_pte(vma->vm_mm, addr, &ptep, &ptl))
+++=======
++ 	if (follow_pfnmap_start(&args))
+++>>>>>>> b17269a51cc7 (mm/access_process_vm: use the new follow_pfnmap API)
+  		goto out_unmap;
+  
+- 	if (!pte_same(pte, ptep_get(ptep))) {
+- 		pte_unmap_unlock(ptep, ptl);
++ 	if ((prot != pgprot_val(args.pgprot)) ||
++ 	    (phys_addr != (args.pfn << PAGE_SHIFT)) ||
++ 	    (writable != args.writable)) {
++ 		follow_pfnmap_end(&args);
+  		iounmap(maddr);
+- 
+  		goto retry;
+  	}
+  
+* Unmerged path mm/memory.c