[PATCH V4 23/26] arm/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Anshuman Khandual
2022-06-24T05:03:14Z

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: Russell King <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
arch/arm/Kconfig | 1 +
arch/arm/include/asm/pgtable.h | 17 -----------------
arch/arm/lib/uaccess_with_memcpy.c | 2 +-
arch/arm/mm/mmu.c | 20 ++++++++++++++++++++
4 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 7630ba9cb6cc..e153b6d4fc5b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -24,6 +24,7 @@ config ARM
select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB || !MMU
select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+ select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index cd1f84bb40ae..78a532068fec 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -137,23 +137,6 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
* 2) If we could do execute protection, then read is implied
* 3) write implies read permissions
*/
-#define __P000 __PAGE_NONE
-#define __P001 __PAGE_READONLY
-#define __P010 __PAGE_COPY
-#define __P011 __PAGE_COPY
-#define __P100 __PAGE_READONLY_EXEC
-#define __P101 __PAGE_READONLY_EXEC
-#define __P110 __PAGE_COPY_EXEC
-#define __P111 __PAGE_COPY_EXEC
-
-#define __S000 __PAGE_NONE
-#define __S001 __PAGE_READONLY
-#define __S010 __PAGE_SHARED
-#define __S011 __PAGE_SHARED
-#define __S100 __PAGE_READONLY_EXEC
-#define __S101 __PAGE_READONLY_EXEC
-#define __S110 __PAGE_SHARED_EXEC
-#define __S111 __PAGE_SHARED_EXEC

#ifndef __ASSEMBLY__
/*
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index c30b689bec2e..14eecaaf295f 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -237,7 +237,7 @@ static int __init test_size_treshold(void)
if (!dst_page)
goto no_dst;
kernel_ptr = page_address(src_page);
- user_ptr = vmap(&dst_page, 1, VM_IOREMAP, __pgprot(__P010));
+ user_ptr = vmap(&dst_page, 1, VM_IOREMAP, __pgprot(__PAGE_COPY));
if (!user_ptr)
goto no_vmap;

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 5e2be37a198e..2722abddd725 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -405,6 +405,26 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
}

+static pgprot_t protection_map[16] __ro_after_init = {
+ [VM_NONE] = __PAGE_NONE,
+ [VM_READ] = __PAGE_READONLY,
+ [VM_WRITE] = __PAGE_COPY,
+ [VM_WRITE | VM_READ] = __PAGE_COPY,
+ [VM_EXEC] = __PAGE_READONLY_EXEC,
+ [VM_EXEC | VM_READ] = __PAGE_READONLY_EXEC,
+ [VM_EXEC | VM_WRITE] = __PAGE_COPY_EXEC,
+ [VM_EXEC | VM_WRITE | VM_READ] = __PAGE_COPY_EXEC,
+ [VM_SHARED] = __PAGE_NONE,
+ [VM_SHARED | VM_READ] = __PAGE_READONLY,
+ [VM_SHARED | VM_WRITE] = __PAGE_SHARED,
+ [VM_SHARED | VM_WRITE | VM_READ] = __PAGE_SHARED,
+ [VM_SHARED | VM_EXEC] = __PAGE_READONLY_EXEC,
+ [VM_SHARED | VM_EXEC | VM_READ] = __PAGE_READONLY_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
+
/*
* Adjust the PMD section entries according to the CPU in use.
*/