[PATCH v3 05/17] ARM: LPAE: support 64-bit virt_to_phys patching

From: Cyril Chemparathy
Date: Tue Sep 11 2012 - 13:42:45 EST


This patch adds support for 64-bit physical addresses in virt_to_phys()
patching. This does not do real 64-bit add/sub, but instead patches in the
upper 32-bits of the phys_offset directly into the output of virt_to_phys.

There is no corresponding change on the phys_to_virt() side, because
computations on the upper 32-bits would be discarded anyway.

Signed-off-by: Cyril Chemparathy <cyril@xxxxxx>
---
arch/arm/include/asm/memory.h | 38 ++++++++++++++++++++++++++++++++++++--
arch/arm/kernel/head.S | 4 ++++
arch/arm/kernel/setup.c | 2 +-
3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index a4fc01e..0643454 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -154,13 +154,47 @@
#ifdef CONFIG_ARM_PATCH_PHYS_VIRT

extern unsigned long __pv_offset;
-extern unsigned long __pv_phys_offset;
+extern phys_addr_t __pv_phys_offset;
#define PHYS_OFFSET __virt_to_phys(PAGE_OFFSET)

static inline phys_addr_t __virt_to_phys(unsigned long x)
{
- unsigned long t;
+ phys_addr_t t;
+
+#ifndef CONFIG_ARM_LPAE
early_patch_imm8("add", t, x, __pv_offset, 0);
+#else
+ unsigned long __tmp;
+
+#ifndef __ARMEB__
+#define PV_PHYS_HIGH "(__pv_phys_offset + 4)"
+#else
+#define PV_PHYS_HIGH "__pv_phys_offset"
+#endif
+
+ early_patch_stub(
+ /* type */ PATCH_IMM8,
+ /* code */
+ "ldr %[tmp], =__pv_offset\n"
+ "ldr %[tmp], [%[tmp]]\n"
+ "add %Q[to], %[from], %[tmp]\n"
+ "ldr %[tmp], =" PV_PHYS_HIGH "\n"
+ "ldr %[tmp], [%[tmp]]\n"
+ "mov %R[to], %[tmp]\n",
+ /* pad */ 4,
+ /* patch_data */
+ ".long __pv_offset\n"
+ "add %Q[to], %[from], %[imm]\n"
+ ".long " PV_PHYS_HIGH "\n"
+ "mov %R[to], %[imm]\n",
+ /* operands */
+ : [to] "=r" (t),
+ [tmp] "=&r" (__tmp)
+ : [from] "r" (x),
+ [imm] "I" (__IMM8),
+ "i" (&__pv_offset),
+ "i" (&__pv_phys_offset));
+#endif
return t;
}

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 69a3c09..61fb8df 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -530,7 +530,11 @@ ENDPROC(__fixup_pv_offsets)

.align
1: .long .
+#if defined(CONFIG_ARM_LPAE) && defined(__ARMEB__)
+ .long __pv_phys_offset + 4
+#else
.long __pv_phys_offset
+#endif
.long __pv_offset
.long PAGE_OFFSET
#endif
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index ba649ac..94d9853 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -150,7 +150,7 @@ DEFINE_PER_CPU(struct cpuinfo_arm, cpu_data);
* The initializers here prevent these from landing in the BSS section.
*/
unsigned long __pv_offset = 0xdeadbeef;
-unsigned long __pv_phys_offset = 0xdeadbeef;
+phys_addr_t __pv_phys_offset = 0xdeadbeef;
EXPORT_SYMBOL(__pv_phys_offset);

#endif
--
1.7.9.5

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