[PATCH v2 9/9] target/arm: Implement TCGCPUOps for plugin register reads

[Richard Henderson <richard.henderson@linaro.org>]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/internals.h   |  7 +++++--
 target/arm/cpu.c         | 38 ++++++++++++++++++++++++++++++++++++++
 target/arm/cpu64.c       | 25 +++++++++++++++++++++++++
 target/arm/tcg/cpu-v7m.c |  2 ++
 4 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/target/arm/internals.h b/target/arm/internals.h
index dc53d86249..fe28937515 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -358,11 +358,14 @@ void init_cpreg_list(ARMCPU *cpu);
 void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu);
 void arm_translate_init(void);
 
+#ifdef CONFIG_TCG
 void arm_restore_state_to_opc(CPUState *cs,
                               const TranslationBlock *tb,
                               const uint64_t *data);
-
-#ifdef CONFIG_TCG
+bool arm_plugin_need_unwind_for_reg(CPUState *cs, int reg);
+int arm_plugin_unwind_read_reg(CPUState *cs, GByteArray *buf, int reg,
+                               const TranslationBlock *tb,
+                               const uint64_t *data);
 void arm_cpu_synchronize_from_tb(CPUState *cs, const TranslationBlock *tb);
 bool arm_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
 #endif /* CONFIG_TCG */
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 3cd4711064..e8ac3da351 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -29,6 +29,7 @@
 #include "cpu.h"
 #ifdef CONFIG_TCG
 #include "hw/core/tcg-cpu-ops.h"
+#include "gdbstub/helpers.h"
 #endif /* CONFIG_TCG */
 #include "internals.h"
 #include "cpu-features.h"
@@ -120,6 +121,41 @@ void arm_restore_state_to_opc(CPUState *cs,
         env->exception.syndrome = data[2] << ARM_INSN_START_WORD2_SHIFT;
     }
 }
+
+bool arm_plugin_need_unwind_for_reg(CPUState *cs, int reg)
+{
+    return reg == 15 || reg == 25; /* pc (r15) or cpsr */
+}
+
+int arm_plugin_unwind_read_reg(CPUState *cs, GByteArray *buf, int reg,
+                               const TranslationBlock *tb,
+                               const uint64_t *data)
+{
+    CPUARMState *env = cpu_env(cs);
+    uint32_t val, condexec;
+
+    switch (reg) {
+    case 15: /* PC */
+        val = data[0];
+        if (tb_cflags(tb) & CF_PCREL) {
+            val |= env->regs[15] & TARGET_PAGE_MASK;
+        }
+        break;
+    case 25: /* CPSR, or XPSR for M-profile */
+        if (arm_feature(env, ARM_FEATURE_M)) {
+            val = xpsr_read(env);
+        } else {
+            val = cpsr_read(env);
+        }
+        condexec = data[1] & 0xff;
+        val = (val & ~(3 << 25)) | ((condexec & 3) << 25);
+        val = (val & ~(0xfc << 8)) | ((condexec & 0xfc) << 8);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+    return gdb_get_reg32(buf, val);
+}
 #endif /* CONFIG_TCG */
 
 /*
@@ -2657,6 +2693,8 @@ static const TCGCPUOps arm_tcg_ops = {
     .synchronize_from_tb = arm_cpu_synchronize_from_tb,
     .debug_excp_handler = arm_debug_excp_handler,
     .restore_state_to_opc = arm_restore_state_to_opc,
+    .plugin_need_unwind_for_reg = arm_plugin_need_unwind_for_reg,
+    .plugin_unwind_read_reg = arm_plugin_unwind_read_reg,
 
 #ifdef CONFIG_USER_ONLY
     .record_sigsegv = arm_cpu_record_sigsegv,
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 7ba80099af..1595be5d8f 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -33,6 +33,8 @@
 #include "hw/qdev-properties.h"
 #ifdef CONFIG_TCG
 #include "hw/core/tcg-cpu-ops.h"
+#include "exec/translation-block.h"
+#include "gdbstub/helpers.h"
 #endif
 #include "internals.h"
 #include "cpu-features.h"
@@ -797,11 +799,34 @@ static const gchar *aarch64_gdb_arch_name(CPUState *cs)
 }
 
 #ifdef CONFIG_TCG
+static bool aarch64_plugin_need_unwind_for_reg(CPUState *cs, int reg)
+{
+    return reg == 32; /* pc */
+}
+
+static int aarch64_plugin_unwind_read_reg(CPUState *cs, GByteArray *buf,
+                                          int reg, const TranslationBlock *tb,
+                                          const uint64_t *data)
+{
+    CPUARMState *env = cpu_env(cs);
+    uint64_t val;
+
+    assert(reg == 32);
+
+    val = data[0];
+    if (tb_cflags(tb) & CF_PCREL) {
+        val |= env->pc & TARGET_PAGE_MASK;
+    }
+    return gdb_get_reg64(buf, val);
+}
+
 static const TCGCPUOps aarch64_tcg_ops = {
     .initialize = arm_translate_init,
     .synchronize_from_tb = arm_cpu_synchronize_from_tb,
     .debug_excp_handler = arm_debug_excp_handler,
     .restore_state_to_opc = arm_restore_state_to_opc,
+    .plugin_need_unwind_for_reg = aarch64_plugin_need_unwind_for_reg,
+    .plugin_unwind_read_reg = aarch64_plugin_unwind_read_reg,
 
 #ifdef CONFIG_USER_ONLY
     .record_sigsegv = arm_cpu_record_sigsegv,
diff --git a/target/arm/tcg/cpu-v7m.c b/target/arm/tcg/cpu-v7m.c
index c059c681e9..47e44f70c7 100644
--- a/target/arm/tcg/cpu-v7m.c
+++ b/target/arm/tcg/cpu-v7m.c
@@ -237,6 +237,8 @@ static const TCGCPUOps arm_v7m_tcg_ops = {
     .synchronize_from_tb = arm_cpu_synchronize_from_tb,
     .debug_excp_handler = arm_debug_excp_handler,
     .restore_state_to_opc = arm_restore_state_to_opc,
+    .plugin_need_unwind_for_reg = arm_plugin_need_unwind_for_reg,
+    .plugin_unwind_read_reg = arm_plugin_unwind_read_reg,
 
 #ifdef CONFIG_USER_ONLY
     .record_sigsegv = arm_cpu_record_sigsegv,
-- 
2.34.1