ARMv7-A isn't exactly the same as ARMv8-A32 (AArch32). This
function allows unit tests to make the distinction.
Signed-off-by: Andrew Jones <drjo...@redhat.com>
---
I'm actually unsure if there's a feature bit or not that I could
probe instead. It'd be nice if somebody can confirm. Thanks, drew
lib/arm/asm/processor.h | 20 ++++++++++++++++++++
lib/arm64/asm/processor.h | 5 +++++
2 files changed, 25 insertions(+)
diff --git a/lib/arm/asm/processor.h b/lib/arm/asm/processor.h
index f25e7eee3666..223e54beb72a 100644
--- a/lib/arm/asm/processor.h
+++ b/lib/arm/asm/processor.h
@@ -5,6 +5,7 @@
*
* This work is licensed under the terms of the GNU LGPL, version 2.
*/
+#include <bitops.h>
#include <asm/ptrace.h>
enum vector {
@@ -46,4 +47,23 @@ static inline unsigned int get_mpidr(void)
extern void start_usr(void (*func)(void *arg), void *arg, unsigned long
sp_usr);
extern bool is_user(void);
+/*
+ * ARMv7-A isn't exactly the same as ARMv8-A32 (AArch32). This
+ * function allows unit tests to make the distinction.
+ */
+static inline bool is_aarch32(void)
+{
+ /*
+ * XXX: Unfortunately there's no feature bit we can probe for
+ * this, so we do a hacky check for the processor type not being
+ * a Cortex-A15, which is the only v7 type we currently use.
+ */
+ unsigned long midr;
+
+ asm volatile("MRC p15, 0, %0, c0, c0, 0" : "=r" (midr));
+ midr &= GENMASK(31, 24) | GENMASK(15, 4);
+
+ return midr != ((0x41 << 24) | (0xc0f << 4));
+}
+
#endif /* _ASMARM_PROCESSOR_H_ */
diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h
index 84d5c7ce752b..b602e1fbbc2d 100644
--- a/lib/arm64/asm/processor.h
+++ b/lib/arm64/asm/processor.h
@@ -81,5 +81,10 @@ DEFINE_GET_SYSREG32(mpidr)
extern void start_usr(void (*func)(void *arg), void *arg, unsigned long
sp_usr);
extern bool is_user(void);
+static inline bool is_aarch32(void)
+{
+ return false;
+}
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASMARM64_PROCESSOR_H_ */
--
2.7.4
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
