[v4,09/12] target/arm: Make m_helper.c optional via CONFIG_ARM_V7M

Commit Message

Philippe Mathieu-Daudé Sept. 29, 2020, 10:43 p.m. UTC

From: Thomas Huth <[e-mail]>

We've already got the CONFIG_ARM_V7M switch, but it currently can
not be disabled yet. The m_helper.c code should not be compiled
into the binary if the switch is not enabled. We also have to
provide some stubs in a separate file to make sure that we still
can link the other code without CONFIG_ARM_V7M.

Signed-off-by: Thomas Huth <[e-mail]>
Message-Id: <[e-mail]>
[PMD: Keep m_helper-stub.c but extend it, rewrite the rest]
Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
Rewrite since v3, therefore removed Richard R-b tag.
---
 target/arm/cpu.h           | 12 -------
 target/arm/cpu_tcg.c       |  4 ++-
 target/arm/helper.c        |  7 ----
 target/arm/m_helper-stub.c | 73 ++++++++++++++++++++++++++++++++++++++
 target/arm/meson.build     |  4 ++-
 5 files changed, 79 insertions(+), 21 deletions(-)
 create mode 100644 target/arm/m_helper-stub.c

Comments

Richard Henderson Oct. 3, 2020, 9:48 a.m. UTC | #1

On 9/29/20 5:43 PM, Philippe Mathieu-Daudé wrote:
> +arm_ss.add(when: 'CONFIG_ARM_V7M', if_true: files('m_helper.c'), if_false: files('m_helper-stub.c'))
> +
>  arm_ss.add(zlib)
>  
>  arm_ss.add(when: 'CONFIG_TCG', if_true: files('arm-semi.c'))
> +arm_ss.add(when: 'CONFIG_TCG', if_false: files('m_helper-stub.c'))

I'm a bit surprised about adding the file twice.
Since ARM_V7M depends on TCG, isn't the second line redundant?


r~

Philippe Mathieu-Daudé Jan. 29, 2021, 6:53 p.m. UTC | #2

On 10/3/20 11:48 AM, Richard Henderson wrote:
> On 9/29/20 5:43 PM, Philippe Mathieu-Daudé wrote:
>> +arm_ss.add(when: 'CONFIG_ARM_V7M', if_true: files('m_helper.c'), if_false: files('m_helper-stub.c'))
>> +
>>  arm_ss.add(zlib)
>>  
>>  arm_ss.add(when: 'CONFIG_TCG', if_true: files('arm-semi.c'))
>> +arm_ss.add(when: 'CONFIG_TCG', if_false: files('m_helper-stub.c'))
> 
> I'm a bit surprised about adding the file twice.
> Since ARM_V7M depends on TCG, isn't the second line redundant?

This does:

if TCG
    if CONFIG_ARM_V7M
        files('m_helper.c')
    else #!V7M
        files('m_helper-stub.c'))
    endif
else #!TCG
    files('m_helper-stub.c'))
endif

So:

if !TCG or !V7M
    files('m_helper-stub.c'))
else
    files('m_helper.c')
endif

There might be a better way to express that in Meson...
I only understood how to do AND with arrays, but not OR.

Paolo/Marc-André, is it possible?

Thanks,

Phil.

Patch

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 6036f61d60..c5f4c1b181 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -2117,12 +2117,6 @@  uint32_t arm_phys_excp_target_el(CPUState *cs, uint32_t excp_idx,
 /* Interface between CPU and Interrupt controller.  */
 #ifndef CONFIG_USER_ONLY
 bool armv7m_nvic_can_take_pending_exception(void *opaque);
-#else
-static inline bool armv7m_nvic_can_take_pending_exception(void *opaque)
-{
-    return true;
-}
-#endif
 /**
  * armv7m_nvic_set_pending: mark the specified exception as pending
  * @opaque: the NVIC
@@ -2228,13 +2222,7 @@  int armv7m_nvic_raw_execution_priority(void *opaque);
  * @secure: the security state to test
  * This corresponds to the pseudocode IsReqExecPriNeg().
  */
-#ifndef CONFIG_USER_ONLY
 bool armv7m_nvic_neg_prio_requested(void *opaque, bool secure);
-#else
-static inline bool armv7m_nvic_neg_prio_requested(void *opaque, bool secure)
-{
-    return false;
-}
 #endif
 
 /* Interface for defining coprocessor registers.
diff --git a/target/arm/cpu_tcg.c b/target/arm/cpu_tcg.c
index 00b0e08f33..563b0e82bc 100644
--- a/target/arm/cpu_tcg.c
+++ b/target/arm/cpu_tcg.c
@@ -15,6 +15,7 @@ 
 /* CPU models. These are not needed for the AArch64 linux-user build. */
 #if !defined(CONFIG_USER_ONLY) || !defined(TARGET_AARCH64)
 
+#ifndef CONFIG_USER_ONLY
 static bool arm_v7m_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
 {
     CPUClass *cc = CPU_GET_CLASS(cs);
@@ -38,6 +39,7 @@  static bool arm_v7m_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
     }
     return ret;
 }
+#endif /* CONFIG_USER_ONLY */
 
 static void arm926_initfn(Object *obj)
 {
@@ -602,9 +604,9 @@  static void arm_v7m_class_init(ObjectClass *oc, void *data)
     acc->info = data;
 #ifndef CONFIG_USER_ONLY
     cc->do_interrupt = arm_v7m_cpu_do_interrupt;
+    cc->cpu_exec_interrupt = arm_v7m_cpu_exec_interrupt;
 #endif
 
-    cc->cpu_exec_interrupt = arm_v7m_cpu_exec_interrupt;
     cc->gdb_core_xml_file = "arm-m-profile.xml";
 }
 
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 88bd9dd35d..5196a17bdb 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -12653,13 +12653,6 @@  int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx)
     }
 }
 
-#ifndef CONFIG_TCG
-ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate)
-{
-    g_assert_not_reached();
-}
-#endif
-
 ARMMMUIdx arm_mmu_idx_el(CPUARMState *env, int el)
 {
     if (arm_feature(env, ARM_FEATURE_M)) {
diff --git a/target/arm/m_helper-stub.c b/target/arm/m_helper-stub.c
new file mode 100644
index 0000000000..6d751424e8
--- /dev/null
+++ b/target/arm/m_helper-stub.c
@@ -0,0 +1,73 @@ 
+/*
+ * ARM V7M related stubs.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/helper-proto.h"
+#include "internals.h"
+
+void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest)
+{
+    g_assert_not_reached();
+}
+
+void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest)
+{
+    g_assert_not_reached();
+}
+
+uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
+{
+    g_assert_not_reached();
+}
+
+void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val)
+{
+    g_assert_not_reached();
+}
+
+uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op)
+{
+    g_assert_not_reached();
+}
+
+void HELPER(v7m_preserve_fp_state)(CPUARMState *env)
+{
+    g_assert_not_reached();
+}
+
+void write_v7m_exception(CPUARMState *env, uint32_t new_exc)
+{
+    g_assert_not_reached();
+}
+
+void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr)
+{
+    g_assert_not_reached();
+}
+
+void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr)
+{
+    g_assert_not_reached();
+}
+
+ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate)
+{
+    g_assert_not_reached();
+}
+
+#ifndef CONFIG_USER_ONLY
+
+bool armv7m_nvic_can_take_pending_exception(void *opaque)
+{
+    g_assert_not_reached();
+}
+
+void arm_v7m_cpu_do_interrupt(CPUState *cs)
+{
+    g_assert_not_reached();
+}
+
+#endif /* CONFIG_USER_ONLY */
diff --git a/target/arm/meson.build b/target/arm/meson.build
index f5de2a77b8..f6a88297a8 100644
--- a/target/arm/meson.build
+++ b/target/arm/meson.build
@@ -21,7 +21,6 @@  arm_ss.add(files(
   'gdbstub.c',
   'helper.c',
   'iwmmxt_helper.c',
-  'm_helper.c',
   'neon_helper.c',
   'op_helper.c',
   'tlb_helper.c',
@@ -30,9 +29,12 @@  arm_ss.add(files(
   'vfp_helper.c',
   'cpu_tcg.c',
 ))
+arm_ss.add(when: 'CONFIG_ARM_V7M', if_true: files('m_helper.c'), if_false: files('m_helper-stub.c'))
+
 arm_ss.add(zlib)
 
 arm_ss.add(when: 'CONFIG_TCG', if_true: files('arm-semi.c'))
+arm_ss.add(when: 'CONFIG_TCG', if_false: files('m_helper-stub.c'))
 
 arm_ss.add(when: 'CONFIG_KVM', if_true: files('kvm.c', 'kvm64.c'), if_false: files('kvm-stub.c'))