From ff0daca525dde796382b9ccd563f169df2571211 Mon Sep 17 00:00:00 2001
From: Russell King <rmk@dyn-67.arm.linux.org.uk>
Date: Thu, 29 Jun 2006 20:17:15 +0100
Subject: [ARM] Add section support to ioremap

Allow section mappings to be setup using ioremap() and torn down
with iounmap().  This requires additional support in the MM
context switch to ensure that mappings are properly synchronised
when mapped in.

Based an original implementation by Deepak Saxena, reworked and
ARMv6 support added by rmk.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 include/asm-arm/memory.h      |  5 +++++
 include/asm-arm/mmu.h         |  1 +
 include/asm-arm/mmu_context.h | 12 +++++++++++-
 3 files changed, 17 insertions(+), 1 deletion(-)

(limited to 'include/asm-arm')

diff --git a/include/asm-arm/memory.h b/include/asm-arm/memory.h
index 94f973b..176a4fb 100644
--- a/include/asm-arm/memory.h
+++ b/include/asm-arm/memory.h
@@ -68,6 +68,11 @@
  */
 #define XIP_VIRT_ADDR(physaddr)  (MODULE_START + ((physaddr) & 0x000fffff))
 
+/*
+ * Allow 2MB-aligned ioremap pages
+ */
+#define IOREMAP_MAX_ORDER	21
+
 #else /* CONFIG_MMU */
 
 /*
diff --git a/include/asm-arm/mmu.h b/include/asm-arm/mmu.h
index 23dde52..fe2a23b 100644
--- a/include/asm-arm/mmu.h
+++ b/include/asm-arm/mmu.h
@@ -7,6 +7,7 @@ typedef struct {
 #if __LINUX_ARM_ARCH__ >= 6
 	unsigned int id;
 #endif
+	unsigned int kvm_seq;
 } mm_context_t;
 
 #if __LINUX_ARM_ARCH__ >= 6
diff --git a/include/asm-arm/mmu_context.h b/include/asm-arm/mmu_context.h
index 9fadb01..d1a65b1 100644
--- a/include/asm-arm/mmu_context.h
+++ b/include/asm-arm/mmu_context.h
@@ -17,6 +17,8 @@
 #include <asm/cacheflush.h>
 #include <asm/proc-fns.h>
 
+void __check_kvm_seq(struct mm_struct *mm);
+
 #if __LINUX_ARM_ARCH__ >= 6
 
 /*
@@ -45,13 +47,21 @@ static inline void check_context(struct mm_struct *mm)
 {
 	if (unlikely((mm->context.id ^ cpu_last_asid) >> ASID_BITS))
 		__new_context(mm);
+
+	if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq))
+		__check_kvm_seq(mm);
 }
 
 #define init_new_context(tsk,mm)	(__init_new_context(tsk,mm),0)
 
 #else
 
-#define check_context(mm)		do { } while (0)
+static inline void check_context(struct mm_struct *mm)
+{
+	if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq))
+		__check_kvm_seq(mm);
+}
+
 #define init_new_context(tsk,mm)	0
 
 #endif
-- 
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