diff mbox series

[v4,2/5] xen/riscv: introduce trap_init()

Message ID b1b2252d3105eeaf0cee10ae2be253c8526d0e5c.1677237653.git.oleksii.kurochko@gmail.com (mailing list archive)
State Superseded
Headers show
Series RISCV basic exception handling implementation | expand

Commit Message

Oleksii Kurochko Feb. 24, 2023, 11:35 a.m. UTC 
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
Changes in V4:
  - Nothing changed
---
Changes in V3:
  - Nothing changed
---
Changes in V2:
  - Rename setup_trap_handler() to trap_init().
  - Add Reviewed-by to the commit message.
---
 xen/arch/riscv/include/asm/traps.h | 1 +
 xen/arch/riscv/setup.c             | 4 ++++
 xen/arch/riscv/traps.c             | 7 +++++++
 3 files changed, 12 insertions(+)

Comments

Jan Beulich Feb. 27, 2023, 12:50 p.m. UTC | #1 
On 24.02.2023 12:35, Oleksii Kurochko wrote:
> @@ -11,6 +13,8 @@ void __init noreturn start_xen(void)
>  {
>      early_printk("Hello from C env\n");
>  
> +    trap_init();
> +
>      for ( ;; )
>          asm volatile ("wfi");

Along the lines of what Andrew has said there - it's hard to see
how this can come (both code flow and patch ordering wise) ahead
of clearing .bss.

Jan
Oleksii Kurochko March 1, 2023, 10:34 a.m. UTC | #2 
On Mon, 2023-02-27 at 13:50 +0100, Jan Beulich wrote:
> On 24.02.2023 12:35, Oleksii Kurochko wrote:
> > @@ -11,6 +13,8 @@ void __init noreturn start_xen(void)
> >  {
> >      early_printk("Hello from C env\n");
> >  
> > +    trap_init();
> > +
> >      for ( ;; )
> >          asm volatile ("wfi");
> 
> Along the lines of what Andrew has said there - it's hard to see
> how this can come (both code flow and patch ordering wise) ahead
> of clearing .bss.
So should I add the patch with initializatin of bss as a part of this
patch series?

~ Oleksii
Jan Beulich March 1, 2023, 10:44 a.m. UTC | #3 
On 01.03.2023 11:34, Oleksii wrote:
> On Mon, 2023-02-27 at 13:50 +0100, Jan Beulich wrote:
>> On 24.02.2023 12:35, Oleksii Kurochko wrote:
>>> @@ -11,6 +13,8 @@ void __init noreturn start_xen(void)
>>>  {
>>>      early_printk("Hello from C env\n");
>>>  
>>> +    trap_init();
>>> +
>>>      for ( ;; )
>>>          asm volatile ("wfi");
>>
>> Along the lines of what Andrew has said there - it's hard to see
>> how this can come (both code flow and patch ordering wise) ahead
>> of clearing .bss.
> So should I add the patch with initializatin of bss as a part of this
> patch series?

That or make clear in the cover letter that there is a dependency.

Jan
diff mbox series

Patch

diff --git a/xen/arch/riscv/include/asm/traps.h b/xen/arch/riscv/include/asm/traps.h
index f3fb6b25d1..f1879294ef 100644
--- a/xen/arch/riscv/include/asm/traps.h
+++ b/xen/arch/riscv/include/asm/traps.h
@@ -7,6 +7,7 @@ 
 
 void do_trap(struct cpu_user_regs *cpu_regs);
 void handle_trap(void);
+void trap_init(void);
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/xen/arch/riscv/setup.c b/xen/arch/riscv/setup.c
index d09ffe1454..c8513ca4f8 100644
--- a/xen/arch/riscv/setup.c
+++ b/xen/arch/riscv/setup.c
@@ -1,7 +1,9 @@ 
 #include <xen/compile.h>
 #include <xen/init.h>
 
+#include <asm/csr.h>
 #include <asm/early_printk.h>
+#include <asm/traps.h>
 
 /* Xen stack for bringing up the first CPU. */
 unsigned char __initdata cpu0_boot_stack[STACK_SIZE]
@@ -11,6 +13,8 @@  void __init noreturn start_xen(void)
 {
     early_printk("Hello from C env\n");
 
+    trap_init();
+
     for ( ;; )
         asm volatile ("wfi");
 
diff --git a/xen/arch/riscv/traps.c b/xen/arch/riscv/traps.c
index 29b1a0dfae..ad7311f269 100644
--- a/xen/arch/riscv/traps.c
+++ b/xen/arch/riscv/traps.c
@@ -13,6 +13,13 @@ 
 #include <asm/processor.h>
 #include <asm/traps.h>
 
+void trap_init(void)
+{
+    unsigned long addr = (unsigned long)&handle_trap;
+
+    csr_write(CSR_STVEC, addr);
+}
+
 static const char *decode_trap_cause(unsigned long cause)
 {
     static const char *const trap_causes[] = {