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authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2019-03-05 15:46:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-05 21:07:18 -0800
commit8ef5cbde6dafce8f30edb53f87cb485ceace63df (patch)
tree1bbcf16c5471e067062943d506a932ff0e203527 /arch/powerpc
parentmm/hugetlb: add prot_modify_start/commit sequence for hugetlb update (diff)
downloadlinux-dev-8ef5cbde6dafce8f30edb53f87cb485ceace63df.tar.xz
linux-dev-8ef5cbde6dafce8f30edb53f87cb485ceace63df.zip
arch/powerpc/mm/hugetlb: NestMMU workaround for hugetlb mprotect RW upgrade
NestMMU requires us to mark the pte invalid and flush the tlb when we do a RW upgrade of pte. We fixed a variant of this in the fault path in bd5050e38aec ("powerpc/mm/radix: Change pte relax sequence to handle nest MMU hang"). Link: http://lkml.kernel.org/r/20190116085035.29729-6-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rw-r--r--arch/powerpc/include/asm/book3s/64/hugetlb.h12
-rw-r--r--arch/powerpc/mm/hugetlbpage-hash64.c25
-rw-r--r--arch/powerpc/mm/hugetlbpage-radix.c17
3 files changed, 54 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index 5b0177733994..66c1e4f88d65 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -13,6 +13,10 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff,
unsigned long flags);
+extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t old_pte, pte_t pte);
+
static inline int hstate_get_psize(struct hstate *hstate)
{
unsigned long shift;
@@ -42,4 +46,12 @@ static inline bool gigantic_page_supported(void)
/* hugepd entry valid bit */
#define HUGEPD_VAL_BITS (0x8000000000000000UL)
+#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
+extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep);
+
+#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
+extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t old_pte, pte_t new_pte);
#endif
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index 2e6a8f9345d3..367ce3a4a503 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -121,3 +121,28 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
*ptep = __pte(new_pte & ~H_PAGE_BUSY);
return 0;
}
+
+pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ unsigned long pte_val;
+ /*
+ * Clear the _PAGE_PRESENT so that no hardware parallel update is
+ * possible. Also keep the pte_present true so that we don't take
+ * wrong fault.
+ */
+ pte_val = pte_update(vma->vm_mm, addr, ptep,
+ _PAGE_PRESENT, _PAGE_INVALID, 1);
+
+ return __pte(pte_val);
+}
+
+void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *ptep, pte_t old_pte, pte_t pte)
+{
+
+ if (radix_enabled())
+ return radix__huge_ptep_modify_prot_commit(vma, addr, ptep,
+ old_pte, pte);
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+}
diff --git a/arch/powerpc/mm/hugetlbpage-radix.c b/arch/powerpc/mm/hugetlbpage-radix.c
index 2486bee0f93e..11d9ea28a816 100644
--- a/arch/powerpc/mm/hugetlbpage-radix.c
+++ b/arch/powerpc/mm/hugetlbpage-radix.c
@@ -90,3 +90,20 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
return vm_unmapped_area(&info);
}
+
+void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t old_pte, pte_t pte)
+{
+ struct mm_struct *mm = vma->vm_mm;
+
+ /*
+ * To avoid NMMU hang while relaxing access we need to flush the tlb before
+ * we set the new value.
+ */
+ if (is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) &&
+ (atomic_read(&mm->context.copros) > 0))
+ radix__flush_hugetlb_page(vma, addr);
+
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+}