target-arm: Add support for AArch32 ARMv8 CRC32 instructions

Add support for AArch32 CRC32 and CRC32C instructions added in ARMv8
and add a CPU feature flag to enable these instructions.

The CRC32-C implementation used is the built-in qemu implementation
and The CRC-32 implementation is from zlib. This requires adding zlib
to LIBS to ensure it is linked for the linux-user binary.

Signed-off-by: Will Newton <will.newton@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1393411566-24104-3-git-send-email-will.newton@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 56219527ca..90f85f1899 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -5,6 +5,8 @@
 #include "sysemu/arch_init.h"
 #include "sysemu/sysemu.h"
 #include "qemu/bitops.h"
+#include "qemu/crc32c.h"
+#include <zlib.h> /* For crc32 */
 
 #ifndef CONFIG_USER_ONLY
 static inline int get_phys_addr(CPUARMState *env, uint32_t address,
@@ -4703,3 +4705,40 @@ int arm_rmode_to_sf(int rmode)
     }
     return rmode;
 }
+
+static void crc_init_buffer(uint8_t *buf, uint32_t val, uint32_t bytes)
+{
+    memset(buf, 0, 4);
+
+    if (bytes == 1) {
+        buf[0] = val & 0xff;
+    } else if (bytes == 2) {
+        buf[0] = val & 0xff;
+        buf[1] = (val >> 8) & 0xff;
+    } else {
+        buf[0] = val & 0xff;
+        buf[1] = (val >> 8) & 0xff;
+        buf[2] = (val >> 16) & 0xff;
+        buf[3] = (val >> 24) & 0xff;
+    }
+}
+
+uint32_t HELPER(crc32)(uint32_t acc, uint32_t val, uint32_t bytes)
+{
+    uint8_t buf[4];
+
+    crc_init_buffer(buf, val, bytes);
+
+    /* zlib crc32 converts the accumulator and output to one's complement.  */
+    return crc32(acc ^ 0xffffffff, buf, bytes) ^ 0xffffffff;
+}
+
+uint32_t HELPER(crc32c)(uint32_t acc, uint32_t val, uint32_t bytes)
+{
+    uint8_t buf[4];
+
+    crc_init_buffer(buf, val, bytes);
+
+    /* Linux crc32c converts the output to one's complement.  */
+    return crc32c(acc, buf, bytes) ^ 0xffffffff;
+}