From b17269a51cc7f046a6f2cf9a6c314a0de885e5a5 Mon Sep 17 00:00:00 2001
From: Peter Xu <peterx@redhat.com>
Date: Mon, 26 Aug 2024 16:43:49 -0400
Subject: [PATCH] mm/access_process_vm: use the new follow_pfnmap API
Use the new API that can understand huge pfn mappings.
Link: https://lkml.kernel.org/r/20240826204353.2228736-16-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/memory.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 3878bf69bc14c..cfc278691466f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -6341,34 +6341,34 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
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 };
retry:
- if (follow_pte(vma, addr, &ptep, &ptl))
+ if (follow_pfnmap_start(&args))
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;
- if (follow_pte(vma, addr, &ptep, &ptl))
+ if (follow_pfnmap_start(&args))
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;
}
@@ -6377,7 +6377,7 @@ retry:
else
memcpy_fromio(buf, maddr + offset, len);
ret = len;
- pte_unmap_unlock(ptep, ptl);
+ follow_pfnmap_end(&args);
out_unmap:
iounmap(maddr);
--
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