target/riscv: Add textra matching condition for the triggers

According to RISC-V Debug specification, the optional textra32 and
textra64 trigger CSRs can be used to configure additional matching
conditions for the triggers. For example, if the textra.MHSELECT field
is set to 4 (mcontext), this trigger will only match or fire if the low
bits of mcontext/hcontext equal textra.MHVALUE field.

This commit adds the aforementioned matching condition as common trigger
matching conditions. Currently, the only legal values of textra.MHSELECT
are 0 (ignore) and 4 (mcontext). When textra.MHSELECT is 0, we pass the
checking. When textra.MHSELECT is 4, we compare textra.MHVALUE with
mcontext CSR. The remaining fields, such as textra.SBYTEMASK,
textra.SVALUE, and textra.SSELECT, are hardwired to zero for now. Thus,
we skip checking them here.

Signed-off-by: Alvin Chang <alvinga@andestech.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240826024657.262553-3-alvinga@andestech.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/debug.c b/target/riscv/debug.c
index d6b4a061447fa1f7c6524a21d74a647f24ab9669..c79b51af3072bcef99bccd94c3d5183df3c07226 100644 (file)
--- a/target/riscv/debug.c
+++ b/target/riscv/debug.c
@@ -364,11 +364,54 @@ static bool trigger_priv_match(CPURISCVState *env, trigger_type_t type,
     return false;
 }
 
+static bool trigger_textra_match(CPURISCVState *env, trigger_type_t type,
+                                 int trigger_index)
+{
+    target_ulong textra = env->tdata3[trigger_index];
+    target_ulong mhvalue, mhselect;
+
+    if (type < TRIGGER_TYPE_AD_MATCH || type > TRIGGER_TYPE_AD_MATCH6) {
+        /* textra checking is only applicable when type is 2, 3, 4, 5, or 6 */
+        return true;
+    }
+
+    switch (riscv_cpu_mxl(env)) {
+    case MXL_RV32:
+        mhvalue  = get_field(textra, TEXTRA32_MHVALUE);
+        mhselect = get_field(textra, TEXTRA32_MHSELECT);
+        break;
+    case MXL_RV64:
+    case MXL_RV128:
+        mhvalue  = get_field(textra, TEXTRA64_MHVALUE);
+        mhselect = get_field(textra, TEXTRA64_MHSELECT);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    /* Check mhvalue and mhselect. */
+    switch (mhselect) {
+    case MHSELECT_IGNORE:
+        break;
+    case MHSELECT_MCONTEXT:
+        /* Match if the low bits of mcontext/hcontext equal mhvalue. */
+        if (mhvalue != env->mcontext) {
+            return false;
+        }
+        break;
+    default:
+        break;
+    }
+
+    return true;
+}
+
 /* Common matching conditions for all types of the triggers. */
 static bool trigger_common_match(CPURISCVState *env, trigger_type_t type,
                                  int trigger_index)
 {
-    return trigger_priv_match(env, type, trigger_index);
+    return trigger_priv_match(env, type, trigger_index) &&
+           trigger_textra_match(env, type, trigger_index);
 }
 
 /* type 2 trigger */

diff --git a/target/riscv/debug.h b/target/riscv/debug.h
index c34786357898fd8eb7e8379e0a94c9eb0da91ac0..f76b8f944a2efa1d9b355583da6a333f50955e83 100644 (file)
--- a/target/riscv/debug.h
+++ b/target/riscv/debug.h
@@ -131,6 +131,9 @@ enum {
 #define ITRIGGER_VU           BIT(25)
 #define ITRIGGER_VS           BIT(26)
 
+#define MHSELECT_IGNORE       0
+#define MHSELECT_MCONTEXT     4
+
 bool tdata_available(CPURISCVState *env, int tdata_index);
 
 target_ulong tselect_csr_read(CPURISCVState *env);