[PATCH v4 6/6] arm64: Add HAVE_IOREMAP_PROT support

[Kefeng Wang]

With ioremap_prot() definition from generic ioremap, also move
pte_pgprot() from hugetlbpage.c into pgtable.h, then arm64 could
have HAVE_IOREMAP_PROT, which will enable generic_access_phys()
code, it is useful for debug, eg, gdb.

Acked-by: Catalin Marinas <catalin.marinas at arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual at arm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
---
 .../features/vm/ioremap_prot/arch-support.txt          |  2 +-
 arch/arm64/Kconfig                                     |  1 +
 arch/arm64/include/asm/pgtable.h                       | 10 ++++++++++
 arch/arm64/mm/hugetlbpage.c                            | 10 ----------
 4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/Documentation/features/vm/ioremap_prot/arch-support.txt b/Documentation/features/vm/ioremap_prot/arch-support.txt
index 205a90e82050..a710bd99c32e 100644
--- a/Documentation/features/vm/ioremap_prot/arch-support.txt
+++ b/Documentation/features/vm/ioremap_prot/arch-support.txt
@@ -9,7 +9,7 @@
     |       alpha: | TODO |
     |         arc: |  ok  |
     |         arm: | TODO |
-    |       arm64: | TODO |
+    |       arm64: |  ok  |
     |        csky: | TODO |
     |     hexagon: | TODO |
     |        ia64: | TODO |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index ac160aa26126..1267f325d32b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -189,6 +189,7 @@ config ARM64
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_GCC_PLUGINS
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
+	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_TIME_ACCOUNTING
 	select HAVE_KVM
 	select HAVE_NMI
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 0b6632f18364..5a2eb6232e69 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -427,6 +427,16 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
 	return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
 }
 
+/*
+ * Select all bits except the pfn
+ */
+static inline pgprot_t pte_pgprot(pte_t pte)
+{
+	unsigned long pfn = pte_pfn(pte);
+
+	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
+}
+
 #ifdef CONFIG_NUMA_BALANCING
 /*
  * See the comment in include/linux/pgtable.h
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index e2a5ec9fdc0d..8eab05367549 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -100,16 +100,6 @@ int pud_huge(pud_t pud)
 #endif
 }
 
-/*
- * Select all bits except the pfn
- */
-static inline pgprot_t pte_pgprot(pte_t pte)
-{
-	unsigned long pfn = pte_pfn(pte);
-
-	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
-}
-
 static int find_num_contig(struct mm_struct *mm, unsigned long addr,
 			   pte_t *ptep, size_t *pgsize)
 {
-- 
2.35.3