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authorRussell King <rmk+kernel@arm.linux.org.uk>2016-02-16 17:33:56 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2016-02-17 00:28:39 +0000
commit8ff97fa31333e8d0f4f7029798d9c7d59359b05c (patch)
tree23903431f74033ab44908b48b16fb2380478aa10 /arch/arm/include/asm/memory.h
parentd78114554939aec0344b494e759d0679224562db (diff)
downloadlinux-8ff97fa31333e8d0f4f7029798d9c7d59359b05c.tar.bz2
ARM: make the physical-relative calculation more obvious
The physical-relative calculation between the XIP text and data sections introduced by the previous patch was far from obvious. Let's simplify it by turning it into a macro which takes the two (virtual) addresses. This allows us to arrange the calculation in a more obvious manner - we can make it two sub-expressions which calculate the physical address for each symbol, and then takes the difference of those physical addresses. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/memory.h')
-rw-r--r--arch/arm/include/asm/memory.h15
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index ebdaaf7dd19f..51fc9b3b52ea 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -135,11 +135,18 @@
#define PLAT_PHYS_OFFSET UL(CONFIG_PHYS_OFFSET)
#ifdef CONFIG_XIP_KERNEL
-#define PHYS_OFFSET_FIXUP \
- ( XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) - PAGE_OFFSET + \
- PLAT_PHYS_OFFSET - CONFIG_XIP_PHYS_ADDR )
+/*
+ * When referencing data in RAM from the XIP region in a relative manner
+ * with the MMU off, we need the relative offset between the two physical
+ * addresses. The macro below achieves this, which is:
+ * __pa(v_data) - __xip_pa(v_text)
+ */
+#define PHYS_RELATIVE(v_data, v_text) \
+ (((v_data) - PAGE_OFFSET + PLAT_PHYS_OFFSET) - \
+ ((v_text) - XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) + \
+ CONFIG_XIP_PHYS_ADDR))
#else
-#define PHYS_OFFSET_FIXUP 0
+#define PHYS_RELATIVE(v_data, v_text) ((v_data) - (v_text))
#endif
#ifndef __ASSEMBLY__