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Message-ID: <20240809160909.1023470-16-peterx@redhat.com>
Date: Fri, 9 Aug 2024 12:09:05 -0400
From: Peter Xu <peterx@...hat.com>
To: linux-mm@...ck.org,
linux-kernel@...r.kernel.org
Cc: Sean Christopherson <seanjc@...gle.com>,
Oscar Salvador <osalvador@...e.de>,
Jason Gunthorpe <jgg@...dia.com>,
Axel Rasmussen <axelrasmussen@...gle.com>,
linux-arm-kernel@...ts.infradead.org,
x86@...nel.org,
peterx@...hat.com,
Will Deacon <will@...nel.org>,
Gavin Shan <gshan@...hat.com>,
Paolo Bonzini <pbonzini@...hat.com>,
Zi Yan <ziy@...dia.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Catalin Marinas <catalin.marinas@....com>,
Ingo Molnar <mingo@...hat.com>,
Alistair Popple <apopple@...dia.com>,
Borislav Petkov <bp@...en8.de>,
David Hildenbrand <david@...hat.com>,
Thomas Gleixner <tglx@...utronix.de>,
kvm@...r.kernel.org,
Dave Hansen <dave.hansen@...ux.intel.com>,
Alex Williamson <alex.williamson@...hat.com>,
Yan Zhao <yan.y.zhao@...el.com>
Subject: [PATCH 15/19] mm/access_process_vm: Use the new follow_pfnmap API
Use the new API that can understand huge pfn mappings.
Signed-off-by: Peter Xu <peterx@...hat.com>
---
mm/memory.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 2194e0f9f541..313c17eedf56 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -6504,34 +6504,34 @@ 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;
}
@@ -6540,7 +6540,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
else
memcpy_fromio(buf, maddr + offset, len);
ret = len;
- pte_unmap_unlock(ptep, ptl);
+ follow_pfnmap_end(&args);
out_unmap:
iounmap(maddr);
--
2.45.0
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