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

[Anshuman Khandual <anshuman.khandual@xxxxxxx>]

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@xxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
 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.
  */
-- 
2.25.1