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From:   Anshuman Khandual <anshuman.khandual@arm.com>
To:     linux-mm@kvack.org, akpm@linux-foundation.org
Cc:     linux-kernel@vger.kernel.org,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Christoph Hellwig <hch@infradead.org>,
        linux-arch@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: [PATCH V2 28/30] ia64/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT
Date:   Mon, 21 Feb 2022 12:08:37 +0530
Message-Id: <1645425519-9034-29-git-send-email-anshuman.khandual@arm.com>
In-Reply-To: <1645425519-9034-1-git-send-email-anshuman.khandual@arm.com>
References: <1645425519-9034-1-git-send-email-anshuman.khandual@arm.com>
Precedence: bulk

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX
macros can be dropped which are no longer needed.

Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/ia64/Kconfig               |  1 +
 arch/ia64/include/asm/pgtable.h | 17 --------------
 arch/ia64/mm/init.c             | 41 ++++++++++++++++++++++++++++++++-
 3 files changed, 41 insertions(+), 18 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index a7e01573abd8..0ab15e8d5783 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -11,6 +11,7 @@ config IA64
 	select ARCH_HAS_DMA_MARK_CLEAN
 	select ARCH_HAS_STRNCPY_FROM_USER
 	select ARCH_HAS_STRNLEN_USER
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select ACPI
diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
index 9584b2c5f394..8154c78bba56 100644
--- a/arch/ia64/include/asm/pgtable.h
+++ b/arch/ia64/include/asm/pgtable.h
@@ -161,23 +161,6 @@
  * attempts to write to the page.
  */
 	/* xwr */
-#define __P000	PAGE_NONE
-#define __P001	PAGE_READONLY
-#define __P010	PAGE_READONLY	/* write to priv pg -> copy & make writable */
-#define __P011	PAGE_READONLY	/* ditto */
-#define __P100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
-#define __P101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
-#define __P110	PAGE_COPY_EXEC
-#define __P111	PAGE_COPY_EXEC
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_READONLY
-#define __S010	PAGE_SHARED	/* we don't have (and don't need) write-only */
-#define __S011	PAGE_SHARED
-#define __S100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
-#define __S101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
-#define __S110	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
-#define __S111	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
 
 #define pgd_ERROR(e)	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
 #if CONFIG_PGTABLE_LEVELS == 4
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 5d165607bf35..2a922883e30f 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -273,7 +273,7 @@ static int __init gate_vma_init(void)
 	gate_vma.vm_start = FIXADDR_USER_START;
 	gate_vma.vm_end = FIXADDR_USER_END;
 	gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
-	gate_vma.vm_page_prot = __P101;
+	gate_vma.vm_page_prot = __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX);
 
 	return 0;
 }
@@ -492,3 +492,42 @@ void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
 	__remove_pages(start_pfn, nr_pages, altmap);
 }
 #endif
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) {
+	case VM_NONE:
+		return PAGE_NONE;
+	case VM_READ:
+	/* write to priv pg -> copy & make writable */
+	case VM_WRITE:
+	/* write to priv pg -> copy & make writable */
+	case VM_WRITE | VM_READ:
+		return PAGE_READONLY;
+	case VM_EXEC:
+		return __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX);
+	case VM_EXEC | VM_READ:
+		return __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX);
+	case VM_EXEC | VM_WRITE:
+	case VM_EXEC | VM_WRITE | VM_READ:
+		return PAGE_COPY_EXEC;
+	case VM_SHARED:
+		return PAGE_NONE;
+	case VM_SHARED | VM_READ:
+		return PAGE_READONLY;
+	/* we don't have (and don't need) write-only */
+	case VM_SHARED | VM_WRITE:
+	case VM_SHARED | VM_WRITE | VM_READ:
+		return PAGE_SHARED;
+	case VM_SHARED | VM_EXEC:
+		return __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX);
+	case VM_SHARED | VM_EXEC | VM_READ:
+		return __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX);
+	case VM_SHARED | VM_EXEC | VM_WRITE:
+	case VM_SHARED | VM_EXEC | VM_WRITE | VM_READ:
+		return __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX);
+	default:
+		BUILD_BUG();
+	}
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1