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-rw-r--r--arch/arm/include/asm/idmap.h17
-rw-r--r--arch/arm/include/asm/pgtable.h3
-rw-r--r--arch/arm/kernel/smp.c1
-rw-r--r--arch/arm/kernel/vmlinux.lds.S7
-rw-r--r--arch/arm/mm/idmap.c26
5 files changed, 51 insertions, 3 deletions
diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h
new file mode 100644
index 000000000000..62e3d19c9ad7
--- /dev/null
+++ b/arch/arm/include/asm/idmap.h
@@ -0,0 +1,17 @@
+#ifndef __ASM_IDMAP_H
+#define __ASM_IDMAP_H
+
+#include <linux/compiler.h>
+#include <asm/pgtable.h>
+
+/* Tag a function as requiring to be executed via an identity mapping. */
+#define __idmap __section(.idmap.text) noinline notrace
+
+extern pgd_t *idmap_pgd;
+
+void identity_mapping_add(pgd_t *, unsigned long, unsigned long);
+void identity_mapping_del(pgd_t *, unsigned long, unsigned long);
+
+void setup_mm_for_reboot(void);
+
+#endif /* __ASM_IDMAP_H */
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 9451dce3a553..03893a55e680 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -346,9 +346,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
#define pgtable_cache_init() do { } while (0)
-void identity_mapping_add(pgd_t *, unsigned long, unsigned long);
-void identity_mapping_del(pgd_t *, unsigned long, unsigned long);
-
#endif /* !__ASSEMBLY__ */
#endif /* CONFIG_MMU */
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index ef5640b9e218..8afadda37459 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -31,6 +31,7 @@
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/exception.h>
+#include <asm/idmap.h>
#include <asm/topology.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 20b3041e0860..f76e75548670 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -13,6 +13,12 @@
*(.proc.info.init) \
VMLINUX_SYMBOL(__proc_info_end) = .;
+#define IDMAP_TEXT \
+ ALIGN_FUNCTION(); \
+ VMLINUX_SYMBOL(__idmap_text_start) = .; \
+ *(.idmap.text) \
+ VMLINUX_SYMBOL(__idmap_text_end) = .;
+
#ifdef CONFIG_HOTPLUG_CPU
#define ARM_CPU_DISCARD(x)
#define ARM_CPU_KEEP(x) x
@@ -92,6 +98,7 @@ SECTIONS
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
+ IDMAP_TEXT
#ifdef CONFIG_MMU
*(.fixup)
#endif
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 296ad2eaddb0..cda5ea3157a7 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -1,8 +1,12 @@
#include <linux/kernel.h>
#include <asm/cputype.h>
+#include <asm/idmap.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
+#include <asm/sections.h>
+
+pgd_t *idmap_pgd;
static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
unsigned long prot)
@@ -73,6 +77,28 @@ void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end)
}
#endif
+extern char __idmap_text_start[], __idmap_text_end[];
+
+static int __init init_static_idmap(void)
+{
+ phys_addr_t idmap_start, idmap_end;
+
+ idmap_pgd = pgd_alloc(&init_mm);
+ if (!idmap_pgd)
+ return -ENOMEM;
+
+ /* Add an identity mapping for the physical address of the section. */
+ idmap_start = virt_to_phys((void *)__idmap_text_start);
+ idmap_end = virt_to_phys((void *)__idmap_text_end);
+
+ pr_info("Setting up static identity map for 0x%llx - 0x%llx\n",
+ (long long)idmap_start, (long long)idmap_end);
+ identity_mapping_add(idmap_pgd, idmap_start, idmap_end);
+
+ return 0;
+}
+arch_initcall(init_static_idmap);
+
/*
* In order to soft-boot, we need to insert a 1:1 mapping in place of
* the user-mode pages. This will then ensure that we have predictable