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

From: Kefeng Wang
Date: Mon Jun 06 2022 - 03:39:15 EST


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@xxxxxxx>
Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
.../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