[for-6.2,16/43] target/xtensa: Implement do_unaligned_access for user-only

Message ID 20210729004647.282017-17-richard.henderson@linaro.org
State Superseded
Headers show
Series
  • Unaligned accesses for user-only
Related show

Commit Message

Richard Henderson July 29, 2021, 12:46 a.m.
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 target/xtensa/cpu.c    |  2 +-
 target/xtensa/helper.c | 30 +++++++++++++++---------------
 2 files changed, 16 insertions(+), 16 deletions(-)

-- 
2.25.1

Comments

Philippe Mathieu-Daudé July 29, 2021, 8:10 a.m. | #1
On 7/29/21 2:46 AM, Richard Henderson wrote:
> Cc: Max Filippov <jcmvbkbc@gmail.com>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  target/xtensa/cpu.c    |  2 +-

>  target/xtensa/helper.c | 30 +++++++++++++++---------------

>  2 files changed, 16 insertions(+), 16 deletions(-)


Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Peter Maydell July 29, 2021, 2:55 p.m. | #2
On Thu, 29 Jul 2021 at 02:03, Richard Henderson
<richard.henderson@linaro.org> wrote:
>

> Cc: Max Filippov <jcmvbkbc@gmail.com>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  target/xtensa/cpu.c    |  2 +-

>  target/xtensa/helper.c | 30 +++++++++++++++---------------

>  2 files changed, 16 insertions(+), 16 deletions(-)


The xtensa kernel has a CONFIG_XTENSA_UNALIGNED_USER option to
make the kernel silently fix up unaligned userspace accesses,
and most of the defconfigs for xtensa set it to 'y'.

-- PMM
Richard Henderson July 29, 2021, 6:22 p.m. | #3
On 7/29/21 4:55 AM, Peter Maydell wrote:
> On Thu, 29 Jul 2021 at 02:03, Richard Henderson

> <richard.henderson@linaro.org> wrote:

>>

>> Cc: Max Filippov <jcmvbkbc@gmail.com>

>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

>> ---

>>   target/xtensa/cpu.c    |  2 +-

>>   target/xtensa/helper.c | 30 +++++++++++++++---------------

>>   2 files changed, 16 insertions(+), 16 deletions(-)

> 

> The xtensa kernel has a CONFIG_XTENSA_UNALIGNED_USER option to

> make the kernel silently fix up unaligned userspace accesses,

> and most of the defconfigs for xtensa set it to 'y'.


I believe the load/store-exclusive instructions should still fault.


r~

Patch

diff --git a/target/xtensa/cpu.c b/target/xtensa/cpu.c
index 58ec3a0862..41816d91f6 100644
--- a/target/xtensa/cpu.c
+++ b/target/xtensa/cpu.c
@@ -195,11 +195,11 @@  static const struct TCGCPUOps xtensa_tcg_ops = {
     .cpu_exec_interrupt = xtensa_cpu_exec_interrupt,
     .tlb_fill = xtensa_cpu_tlb_fill,
     .debug_excp_handler = xtensa_breakpoint_handler,
+    .do_unaligned_access = xtensa_cpu_do_unaligned_access,
 
 #ifndef CONFIG_USER_ONLY
     .do_interrupt = xtensa_cpu_do_interrupt,
     .do_transaction_failed = xtensa_cpu_do_transaction_failed,
-    .do_unaligned_access = xtensa_cpu_do_unaligned_access,
 #endif /* !CONFIG_USER_ONLY */
 };
 
diff --git a/target/xtensa/helper.c b/target/xtensa/helper.c
index f18ab383fd..a5296399c5 100644
--- a/target/xtensa/helper.c
+++ b/target/xtensa/helper.c
@@ -242,6 +242,21 @@  void xtensa_cpu_list(void)
     }
 }
 
+void xtensa_cpu_do_unaligned_access(CPUState *cs,
+                                    vaddr addr, MMUAccessType access_type,
+                                    int mmu_idx, uintptr_t retaddr)
+{
+    XtensaCPU *cpu = XTENSA_CPU(cs);
+    CPUXtensaState *env = &cpu->env;
+
+    assert(xtensa_option_enabled(env->config,
+                                 XTENSA_OPTION_UNALIGNED_EXCEPTION));
+    cpu_restore_state(CPU(cpu), retaddr, true);
+    HELPER(exception_cause_vaddr)(env,
+                                  env->pc, LOAD_STORE_ALIGNMENT_CAUSE,
+                                  addr);
+}
+
 #ifdef CONFIG_USER_ONLY
 
 bool xtensa_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
@@ -263,21 +278,6 @@  bool xtensa_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
 
 #else /* !CONFIG_USER_ONLY */
 
-void xtensa_cpu_do_unaligned_access(CPUState *cs,
-                                    vaddr addr, MMUAccessType access_type,
-                                    int mmu_idx, uintptr_t retaddr)
-{
-    XtensaCPU *cpu = XTENSA_CPU(cs);
-    CPUXtensaState *env = &cpu->env;
-
-    assert(xtensa_option_enabled(env->config,
-                                 XTENSA_OPTION_UNALIGNED_EXCEPTION));
-    cpu_restore_state(CPU(cpu), retaddr, true);
-    HELPER(exception_cause_vaddr)(env,
-                                  env->pc, LOAD_STORE_ALIGNMENT_CAUSE,
-                                  addr);
-}
-
 bool xtensa_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
                          MMUAccessType access_type, int mmu_idx,
                          bool probe, uintptr_t retaddr)