target-arm: Provide correct syndrome information for cpreg access traps

For exceptions taken to AArch64, if a coprocessor/system register
access fails due to a trap or enable bit then the syndrome information
must include details of the failing instruction (crn/crm/opc1/opc2
fields, etc). Make the decoder construct the syndrome information
at translate time so it can be passed at runtime to the access-check
helper function and used as required.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

1 files changed, 128 insertions, 0 deletions

diff --git a/target-arm/internals.h b/target-arm/internals.h
index a38a57f4d4..cc3fbf9e88 100644
--- a/target-arm/internals.h
+++ b/target-arm/internals.h
@@ -46,4 +46,132 @@ enum arm_fprounding {
 
 int arm_rmode_to_sf(int rmode);
 
+/* Valid Syndrome Register EC field values */
+enum arm_exception_class {
+    EC_UNCATEGORIZED          = 0x00,
+    EC_WFX_TRAP               = 0x01,
+    EC_CP15RTTRAP             = 0x03,
+    EC_CP15RRTTRAP            = 0x04,
+    EC_CP14RTTRAP             = 0x05,
+    EC_CP14DTTRAP             = 0x06,
+    EC_ADVSIMDFPACCESSTRAP    = 0x07,
+    EC_FPIDTRAP               = 0x08,
+    EC_CP14RRTTRAP            = 0x0c,
+    EC_ILLEGALSTATE           = 0x0e,
+    EC_AA32_SVC               = 0x11,
+    EC_AA32_HVC               = 0x12,
+    EC_AA32_SMC               = 0x13,
+    EC_AA64_SVC               = 0x15,
+    EC_AA64_HVC               = 0x16,
+    EC_AA64_SMC               = 0x17,
+    EC_SYSTEMREGISTERTRAP     = 0x18,
+    EC_INSNABORT              = 0x20,
+    EC_INSNABORT_SAME_EL      = 0x21,
+    EC_PCALIGNMENT            = 0x22,
+    EC_DATAABORT              = 0x24,
+    EC_DATAABORT_SAME_EL      = 0x25,
+    EC_SPALIGNMENT            = 0x26,
+    EC_AA32_FPTRAP            = 0x28,
+    EC_AA64_FPTRAP            = 0x2c,
+    EC_SERROR                 = 0x2f,
+    EC_BREAKPOINT             = 0x30,
+    EC_BREAKPOINT_SAME_EL     = 0x31,
+    EC_SOFTWARESTEP           = 0x32,
+    EC_SOFTWARESTEP_SAME_EL   = 0x33,
+    EC_WATCHPOINT             = 0x34,
+    EC_WATCHPOINT_SAME_EL     = 0x35,
+    EC_AA32_BKPT              = 0x38,
+    EC_VECTORCATCH            = 0x3a,
+    EC_AA64_BKPT              = 0x3c,
+};
+
+#define ARM_EL_EC_SHIFT 26
+#define ARM_EL_IL_SHIFT 25
+#define ARM_EL_IL (1 << ARM_EL_IL_SHIFT)
+
+/* Utility functions for constructing various kinds of syndrome value.
+ * Note that in general we follow the AArch64 syndrome values; in a
+ * few cases the value in HSR for exceptions taken to AArch32 Hyp
+ * mode differs slightly, so if we ever implemented Hyp mode then the
+ * syndrome value would need some massaging on exception entry.
+ * (One example of this is that AArch64 defaults to IL bit set for
+ * exceptions which don't specifically indicate information about the
+ * trapping instruction, whereas AArch32 defaults to IL bit clear.)
+ */
+static inline uint32_t syn_uncategorized(void)
+{
+    return (EC_UNCATEGORIZED << ARM_EL_EC_SHIFT) | ARM_EL_IL;
+}
+
+static inline uint32_t syn_aa64_svc(uint32_t imm16)
+{
+    return (EC_AA64_SVC << ARM_EL_EC_SHIFT) | ARM_EL_IL | (imm16 & 0xffff);
+}
+
+static inline uint32_t syn_aa32_svc(uint32_t imm16, bool is_thumb)
+{
+    return (EC_AA32_SVC << ARM_EL_EC_SHIFT) | (imm16 & 0xffff)
+        | (is_thumb ? 0 : ARM_EL_IL);
+}
+
+static inline uint32_t syn_aa64_bkpt(uint32_t imm16)
+{
+    return (EC_AA64_BKPT << ARM_EL_EC_SHIFT) | ARM_EL_IL | (imm16 & 0xffff);
+}
+
+static inline uint32_t syn_aa32_bkpt(uint32_t imm16, bool is_thumb)
+{
+    return (EC_AA32_BKPT << ARM_EL_EC_SHIFT) | (imm16 & 0xffff)
+        | (is_thumb ? 0 : ARM_EL_IL);
+}
+
+static inline uint32_t syn_aa64_sysregtrap(int op0, int op1, int op2,
+                                           int crn, int crm, int rt,
+                                           int isread)
+{
+    return (EC_SYSTEMREGISTERTRAP << ARM_EL_EC_SHIFT) | ARM_EL_IL
+        | (op0 << 20) | (op2 << 17) | (op1 << 14) | (crn << 10) | (rt << 5)
+        | (crm << 1) | isread;
+}
+
+static inline uint32_t syn_cp14_rt_trap(int cv, int cond, int opc1, int opc2,
+                                        int crn, int crm, int rt, int isread,
+                                        bool is_thumb)
+{
+    return (EC_CP14RTTRAP << ARM_EL_EC_SHIFT)
+        | (is_thumb ? 0 : ARM_EL_IL)
+        | (cv << 24) | (cond << 20) | (opc2 << 17) | (opc1 << 14)
+        | (crn << 10) | (rt << 5) | (crm << 1) | isread;
+}
+
+static inline uint32_t syn_cp15_rt_trap(int cv, int cond, int opc1, int opc2,
+                                        int crn, int crm, int rt, int isread,
+                                        bool is_thumb)
+{
+    return (EC_CP15RTTRAP << ARM_EL_EC_SHIFT)
+        | (is_thumb ? 0 : ARM_EL_IL)
+        | (cv << 24) | (cond << 20) | (opc2 << 17) | (opc1 << 14)
+        | (crn << 10) | (rt << 5) | (crm << 1) | isread;
+}
+
+static inline uint32_t syn_cp14_rrt_trap(int cv, int cond, int opc1, int crm,
+                                         int rt, int rt2, int isread,
+                                         bool is_thumb)
+{
+    return (EC_CP14RRTTRAP << ARM_EL_EC_SHIFT)
+        | (is_thumb ? 0 : ARM_EL_IL)
+        | (cv << 24) | (cond << 20) | (opc1 << 16)
+        | (rt2 << 10) | (rt << 5) | (crm << 1) | isread;
+}
+
+static inline uint32_t syn_cp15_rrt_trap(int cv, int cond, int opc1, int crm,
+                                         int rt, int rt2, int isread,
+                                         bool is_thumb)
+{
+    return (EC_CP15RRTTRAP << ARM_EL_EC_SHIFT)
+        | (is_thumb ? 0 : ARM_EL_IL)
+        | (cv << 24) | (cond << 20) | (opc1 << 16)
+        | (rt2 << 10) | (rt << 5) | (crm << 1) | isread;
+}
+
 #endif