[PATCH V4 16/26] riscv/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Anshuman Khandual
2022-06-24T04:48:19Z

This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports standard
vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT, which looks
up a private and static protection_map[] array. Subsequently all __SXXX and
__PXXX macros can be dropped which are no longer needed.

Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: linux-riscv@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/pgtable.h | 20 --------------------
arch/riscv/mm/init.c | 20 ++++++++++++++++++++
3 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 32ffef9f6e5b..583389d4e43a 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -32,6 +32,7 @@ config RISCV
select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
select ARCH_STACKWALK
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 1d1be9d9419c..23e643db6575 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -186,26 +186,6 @@ extern struct pt_alloc_ops pt_ops __initdata;

extern pgd_t swapper_pg_dir[];

-/* MAP_PRIVATE permissions: xwr (copy-on-write) */
-#define __P000 PAGE_NONE
-#define __P001 PAGE_READ
-#define __P010 PAGE_COPY
-#define __P011 PAGE_COPY
-#define __P100 PAGE_EXEC
-#define __P101 PAGE_READ_EXEC
-#define __P110 PAGE_COPY_EXEC
-#define __P111 PAGE_COPY_READ_EXEC
-
-/* MAP_SHARED permissions: xwr */
-#define __S000 PAGE_NONE
-#define __S001 PAGE_READ
-#define __S010 PAGE_SHARED
-#define __S011 PAGE_SHARED
-#define __S100 PAGE_EXEC
-#define __S101 PAGE_READ_EXEC
-#define __S110 PAGE_SHARED_EXEC
-#define __S111 PAGE_SHARED_EXEC
-
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_present(pmd_t pmd)
{
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index d466ec670e1f..f976580500b1 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -288,6 +288,26 @@ static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAG
#define early_pg_dir ((pgd_t *)XIP_FIXUP(early_pg_dir))
#endif /* CONFIG_XIP_KERNEL */

+static pgprot_t protection_map[16] __ro_after_init = {
+ [VM_NONE] = PAGE_NONE,
+ [VM_READ] = PAGE_READ,
+ [VM_WRITE] = PAGE_COPY,
+ [VM_WRITE | VM_READ] = PAGE_COPY,
+ [VM_EXEC] = PAGE_EXEC,
+ [VM_EXEC | VM_READ] = PAGE_READ_EXEC,
+ [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC,
+ [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_READ_EXEC,
+ [VM_SHARED] = PAGE_NONE,
+ [VM_SHARED | VM_READ] = PAGE_READ,
+ [VM_SHARED | VM_WRITE] = PAGE_SHARED,
+ [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
+ [VM_SHARED | VM_EXEC] = PAGE_EXEC,
+ [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READ_EXEC,
+ [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC,
+ [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC
+};
+DECLARE_VM_GET_PAGE_PROT
+
void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
{
unsigned long addr = __fix_to_virt(idx);
--
2.25.1