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authorPeter Maydell <peter.maydell@linaro.org>2017-10-09 14:48:39 +0100
committerPeter Maydell <peter.maydell@linaro.org>2017-10-12 13:23:14 +0100
commit76eff04d166b8fe747adbe82de8b7e060e668ff9 (patch)
treeed744634fa6e695f1595ab8beec13568f0af6bfb
parentdcf14dfb704519846f396a376339ebdb93eaf049 (diff)
target/arm: Implement SG instruction corner cases
The common situation of the SG instruction is that it is executed from S&NSC memory by a CPU in NS state. That case is handled by v7m_handle_execute_nsc(). However the instruction also has defined behaviour in a couple of other cases: * SG instruction in NS memory (behaves as a NOP) * SG in S memory but CPU already secure (clears IT bits and does nothing else) * SG instruction in v8M without Security Extension (NOP) These can be implemented in translate.c. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 1507556919-24992-10-git-send-email-peter.maydell@linaro.org
-rw-r--r--target/arm/translate.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c
index 6634badb5a..4da1a4cbc6 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -9778,7 +9778,28 @@ static int disas_thumb2_insn(DisasContext *s, uint32_t insn)
* - load/store doubleword, load/store exclusive, ldacq/strel,
* table branch.
*/
- if (insn & 0x01200000) {
+ if (insn == 0xe97fe97f && arm_dc_feature(s, ARM_FEATURE_M) &&
+ arm_dc_feature(s, ARM_FEATURE_V8)) {
+ /* 0b1110_1001_0111_1111_1110_1001_0111_111
+ * - SG (v8M only)
+ * The bulk of the behaviour for this instruction is implemented
+ * in v7m_handle_execute_nsc(), which deals with the insn when
+ * it is executed by a CPU in non-secure state from memory
+ * which is Secure & NonSecure-Callable.
+ * Here we only need to handle the remaining cases:
+ * * in NS memory (including the "security extension not
+ * implemented" case) : NOP
+ * * in S memory but CPU already secure (clear IT bits)
+ * We know that the attribute for the memory this insn is
+ * in must match the current CPU state, because otherwise
+ * get_phys_addr_pmsav8 would have generated an exception.
+ */
+ if (s->v8m_secure) {
+ /* Like the IT insn, we don't need to generate any code */
+ s->condexec_cond = 0;
+ s->condexec_mask = 0;
+ }
+ } else if (insn & 0x01200000) {
/* 0b1110_1000_x11x_xxxx_xxxx_xxxx_xxxx_xxxx
* - load/store dual (post-indexed)
* 0b1111_1001_x10x_xxxx_xxxx_xxxx_xxxx_xxxx