[PATCH v2 2/3] include/exec: Provide the cpu_internal_tswap() functions

Martin Kröning via qemu development posted 3 patches 2 days, 19 hours ago
Maintainers: Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Zhao Liu <zhao1.liu@intel.com>, "Michael S. Tsirkin" <mst@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>, Peter Maydell <peter.maydell@linaro.org>, Nicholas Piggin <npiggin@gmail.com>, Chinmay Rath <rathc@linux.ibm.com>
[PATCH v2 2/3] include/exec: Provide the cpu_internal_tswap() functions
Posted by Martin Kröning via qemu development 2 days, 19 hours ago
These functions are needed to support semihosting on CPUs that support
runtime-configurable endianness. They should not be used in other contexts.

Signed-off-by: Martin Kröning <martin.kroening@eonerc.rwth-aachen.de>
---
 include/exec/tswap.h | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/include/exec/tswap.h b/include/exec/tswap.h
index 9e94fa0021..6d9301129d 100644
--- a/include/exec/tswap.h
+++ b/include/exec/tswap.h
@@ -10,6 +10,7 @@
 
 #include "qemu/bswap.h"
 #include "qemu/target-info.h"
+#include "hw/core/cpu.h"
 
 /*
  * If we're in target-specific code, we can hard-code the swapping
@@ -72,4 +73,39 @@ static inline void tswap64s(uint64_t *s)
 }
 #endif
 
+/*
+ * If we're in semihosting code, have to swap depending on the currently
+ * configured endianness of the CPU. These functions should not be used in
+ * other contexts.
+ */
+#define cpu_internal_needs_bswap(cpu) \
+    (HOST_BIG_ENDIAN != cpu_internal_is_big_endian(cpu))
+
+static inline uint16_t cpu_internal_tswap16(CPUState *cpu, uint16_t s)
+{
+    if (target_needs_bswap() || cpu_internal_needs_bswap(cpu)) {
+        return bswap16(s);
+    } else {
+        return s;
+    }
+}
+
+static inline uint32_t cpu_internal_tswap32(CPUState *cpu, uint32_t s)
+{
+    if (target_needs_bswap() || cpu_internal_needs_bswap(cpu)) {
+        return bswap32(s);
+    } else {
+        return s;
+    }
+}
+
+static inline uint64_t cpu_internal_tswap64(CPUState *cpu, uint64_t s)
+{
+    if (target_needs_bswap() || cpu_internal_needs_bswap(cpu)) {
+        return bswap64(s);
+    } else {
+        return s;
+    }
+}
+
 #endif  /* TSWAP_H */

-- 
Git-155)