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Subject[PATCH v2 05/22] ARM: LPAE: support 64-bit virt_to_phys patching
Date
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@ti.com>
---
arch/arm/include/asm/memory.h | 22 ++++++++++++++++++----
arch/arm/kernel/head.S | 4 ++++
arch/arm/kernel/setup.c | 2 +-
3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index 81e1714..dc5fbf3 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -154,14 +154,28 @@
#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;
- early_patch_imm8("add", t, x, __pv_offset, 0);
- return t;
+ unsigned long tlo, thi;
+
+ early_patch_imm8("add", tlo, x, __pv_offset, 0);
+
+#ifdef CONFIG_ARM_LPAE
+ /*
+ * On LPAE, we do not _need_ to do 64-bit arithmetic because the high
+ * order 32 bits are never changed by the phys-virt offset. We simply
+ * patch in the high order physical address bits instead.
+ */
+#ifdef __ARMEB__
+ early_patch_imm8_mov("mov", thi, __pv_phys_offset, 0);
+#else
+ early_patch_imm8_mov("mov", thi, __pv_phys_offset, 4);
+#endif
+#endif
+ return (u64)tlo | (u64)thi << 32;
}

static inline unsigned long __phys_to_virt(phys_addr_t x)
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 59e0f57..edb4f42 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -159,7 +159,7 @@ 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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