From e10cd4b00904db127b178859d81f6b5d05d16c67 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@infradead.org>
Date: Thu, 28 Apr 2022 23:16:13 -0700
Subject: x86/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT.  This also unsubscribes from config
ARCH_HAS_FILTER_PGPROT, after dropping off arch_filter_pgprot() and
arch_vm_get_page_prot().

Link: https://lkml.kernel.org/r/20220414062125.609297-6-anshuman.khandual@arm.com
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 arch/x86/mm/Makefile |  2 +-
 arch/x86/mm/pgprot.c | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 arch/x86/mm/pgprot.c

(limited to 'arch/x86/mm')

diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index fe3d3061fc11..fb6b41a48ae5 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -20,7 +20,7 @@ CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
 endif
 
 obj-y				:=  init.o init_$(BITS).o fault.o ioremap.o extable.o mmap.o \
-				    pgtable.o physaddr.o setup_nx.o tlb.o cpu_entry_area.o maccess.o
+				    pgtable.o physaddr.o setup_nx.o tlb.o cpu_entry_area.o maccess.o pgprot.o
 
 obj-y				+= pat/
 
diff --git a/arch/x86/mm/pgprot.c b/arch/x86/mm/pgprot.c
new file mode 100644
index 000000000000..763742782286
--- /dev/null
+++ b/arch/x86/mm/pgprot.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <asm/pgtable.h>
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	unsigned long val = pgprot_val(protection_map[vm_flags &
+				      (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
+
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+	/*
+	 * Take the 4 protection key bits out of the vma->vm_flags value and
+	 * turn them in to the bits that we can put in to a pte.
+	 *
+	 * Only override these if Protection Keys are available (which is only
+	 * on 64-bit).
+	 */
+	if (vm_flags & VM_PKEY_BIT0)
+		val |= _PAGE_PKEY_BIT0;
+	if (vm_flags & VM_PKEY_BIT1)
+		val |= _PAGE_PKEY_BIT1;
+	if (vm_flags & VM_PKEY_BIT2)
+		val |= _PAGE_PKEY_BIT2;
+	if (vm_flags & VM_PKEY_BIT3)
+		val |= _PAGE_PKEY_BIT3;
+#endif
+
+	val = __sme_set(val);
+	if (val & _PAGE_PRESENT)
+		val &= __supported_pte_mask;
+	return __pgprot(val);
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
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