Thread (14 messages) flat view 14 messages, 3 authors, 2011-06-10
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[PATCH v2 05/10] ARM: idmap: add header file for identity mapping functions

From: Frank Hofmann <hidden>
Date: 2011-06-10 09:13:18

Hi Will,

I'm wondering why identity_mapping_del() is restricted to SMP.

Yes have seen that the only current _user_ is SMP initialization, but does 
that mean it has to be restricted to that ?

I'd want to use it in hibernation resume code, to "cleanse" swapper_pg_dir 
of the identity mappings _after_ resume. That task doesn't depend on SMP 
or not.

Thanks,
FrankH.


On Thu, 9 Jun 2011, Will Deacon wrote:
quoted hunk ↗ jump to hunk
The identity mappings functions are useful outside of SMP booting, so
expose them through their own header file.

Signed-off-by: Will Deacon <redacted>
---
arch/arm/include/asm/idmap.h   |   16 ++++++++++++++++
arch/arm/include/asm/pgtable.h |    3 ---
arch/arm/kernel/process.c      |    3 +--
arch/arm/kernel/smp.c          |    1 +
arch/arm/mm/idmap.c            |    1 +
5 files changed, 19 insertions(+), 5 deletions(-)
create mode 100644 arch/arm/include/asm/idmap.h
diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h
new file mode 100644
index 0000000..ea9517e
--- /dev/null
+++ b/arch/arm/include/asm/idmap.h
@@ -0,0 +1,16 @@
+#ifndef _ARM_IDMAP_H
+#define _ARM_IDMAP_H
+
+#include <asm/page.h>
+
+void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end);
+
+#ifdef CONFIG_SMP
+void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end);
+#else
+void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end) {};
+#endif
+
+void setup_mm_for_reboot(char mode);
+
+#endif	/* _ARM_IDMAP_H */
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 5750704..9d559a8 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -474,9 +474,6 @@ 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/process.c b/arch/arm/kernel/process.c
index 5e1e541..8bd9d94 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -32,6 +32,7 @@
#include <linux/hw_breakpoint.h>

#include <asm/cacheflush.h>
+#include <asm/idmap.h>
#include <asm/leds.h>
#include <asm/processor.h>
#include <asm/system.h>
@@ -56,8 +57,6 @@ static const char *isa_modes[] = {
  "ARM" , "Thumb" , "Jazelle", "ThumbEE"
};

-extern void setup_mm_for_reboot(char mode);
-
static volatile int hlt_counter;

#include <mach/system.h>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 344e52b..dfc76aa 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -39,6 +39,7 @@
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
#include <asm/localtimer.h>
+#include <asm/idmap.h>

/*
 * as from 2.5, kernels no longer have an init_tasks structure
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 2be9139..4ae0f09 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -1,6 +1,7 @@
#include <linux/kernel.h>

#include <asm/cputype.h>
+#include <asm/idmap.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>

-- 
1.7.0.4
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