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-rw-r--r--arch/arm/include/asm/assembler.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 5c8b3bf4d825..683a1e6b6020 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -22,6 +22,7 @@
#include <asm/ptrace.h>
#include <asm/domain.h>
+#include <asm/opcodes-virt.h>
#define IOMEM(x) (x)
@@ -240,6 +241,33 @@
#endif
/*
+ * Helper macro to enter SVC mode cleanly and mask interrupts. reg is
+ * a scratch register for the macro to overwrite.
+ *
+ * This macro is intended for forcing the CPU into SVC mode at boot time.
+ * you cannot return to the original mode.
+ *
+ * Beware, it also clobers LR.
+ */
+.macro safe_svcmode_maskall reg:req
+ mrs \reg , cpsr
+ mov lr , \reg
+ and lr , lr , #MODE_MASK
+ cmp lr , #HYP_MODE
+ orr \reg , \reg , #PSR_A_BIT | PSR_I_BIT | PSR_F_BIT
+ bic \reg , \reg , #MODE_MASK
+ orr \reg , \reg , #SVC_MODE
+THUMB( orr \reg , \reg , #PSR_T_BIT )
+ msr spsr_cxsf, \reg
+ adr lr, BSYM(2f)
+ bne 1f
+ __MSR_ELR_HYP(14)
+ __ERET
+1: movs pc, lr
+2:
+.endm
+
+/*
* STRT/LDRT access macros with ARM and Thumb-2 variants
*/
#ifdef CONFIG_THUMB2_KERNEL
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