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authorPeter Maydell <peter.maydell@linaro.org>2021-01-08 19:51:57 +0000
committerPeter Maydell <peter.maydell@linaro.org>2021-01-12 21:19:02 +0000
commite4d51ac6921dc861bfb3d20e4c7dcf345840a9da (patch)
treec6ddb6d408f8eb89d697ce5a6b03b6b52a848902
parentfa56cf7e86f99d5557a4fb730e375777b89d8b50 (diff)
target/arm: Don't decode insns in the XScale/iWMMXt space as cp insns
In commit cd8be50e58f63413c0 we converted the A32 coprocessor insns to decodetree. This accidentally broke XScale/iWMMXt insns, because it moved the handling of "cp insns which are handled by looking up the cp register in the hashtable" from after the call to the legacy disas_xscale_insn() decode to before it, with the result that all XScale/iWMMXt insns now UNDEF. Update valid_cp() so that it knows that on XScale cp 0 and 1 are not standard coprocessor instructions; this will cause the decodetree trans_ functions to ignore them, so that execution will correctly get through to the legacy decode again. Cc: qemu-stable@nongnu.org Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Message-id: 20210108195157.32067-1-peter.maydell@linaro.org
-rw-r--r--target/arm/translate.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c
index f5acd32e76..528b93dffa 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -5282,7 +5282,14 @@ static bool valid_cp(DisasContext *s, int cp)
* only cp14 and cp15 are valid, and other values aren't considered
* to be in the coprocessor-instruction space at all. v8M still
* permits coprocessors 0..7.
+ * For XScale, we must not decode the XScale cp0, cp1 space as
+ * a standard coprocessor insn, because we want to fall through to
+ * the legacy disas_xscale_insn() decoder after decodetree is done.
*/
+ if (arm_dc_feature(s, ARM_FEATURE_XSCALE) && (cp == 0 || cp == 1)) {
+ return false;
+ }
+
if (arm_dc_feature(s, ARM_FEATURE_V8) &&
!arm_dc_feature(s, ARM_FEATURE_M)) {
return cp >= 14;