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>
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index ebdaaf7..51fc9b3 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__
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 1595fb2..0f8963a 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -487,7 +487,7 @@
.align 2
__v7_setup_stack_ptr:
- .word __v7_setup_stack - . + PHYS_OFFSET_FIXUP
+ .word PHYS_RELATIVE(__v7_setup_stack, .)
ENDPROC(__v7_setup)
.bss