Re: [patch V4 part 3 18/29] x86/entry: Convert Device not available exception to IDTENTRY

2020-05-13 Thread Andy Lutomirski
On Tue, May 5, 2020 at 7:15 AM Thomas Gleixner  wrote:
>
> From: Thomas Gleixner 
>
> Convert #NM to IDTENTRY:
>   - Implement the C entry point with DEFINE_IDTENTRY
>   - Emit the ASM stub with DECLARE_IDTENTRY
>   - Remove the ASM idtentry in 64bit
>   - Remove the open coded ASM entry code in 32bit
>   - Fixup the XEN/PV code
>   - Remove the old prototyoes
>   - Remove the RCU warning as the new entry macro ensures correctness
>
> No functional change.


Acked-by: Andy Lutomirski 


[patch V4 part 3 18/29] x86/entry: Convert Device not available exception to IDTENTRY

2020-05-05 Thread Thomas Gleixner
From: Thomas Gleixner 

Convert #NM to IDTENTRY:
  - Implement the C entry point with DEFINE_IDTENTRY
  - Emit the ASM stub with DECLARE_IDTENTRY
  - Remove the ASM idtentry in 64bit
  - Remove the open coded ASM entry code in 32bit
  - Fixup the XEN/PV code
  - Remove the old prototyoes
  - Remove the RCU warning as the new entry macro ensures correctness

No functional change.

Signed-off-by: Thomas Gleixner 

---
 arch/x86/entry/entry_32.S   |7 ---
 arch/x86/entry/entry_64.S   |1 -
 arch/x86/include/asm/idtentry.h |1 +
 arch/x86/include/asm/traps.h|3 ---
 arch/x86/kernel/idt.c   |2 +-
 arch/x86/kernel/traps.c |8 ++--
 arch/x86/xen/enlighten_pv.c |2 +-
 arch/x86/xen/xen-asm_64.S   |2 +-
 8 files changed, 6 insertions(+), 20 deletions(-)

--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1311,13 +1311,6 @@ SYM_CODE_START(simd_coprocessor_error)
jmp common_exception
 SYM_CODE_END(simd_coprocessor_error)
 
-SYM_CODE_START(device_not_available)
-   ASM_CLAC
-   pushl   $0
-   pushl   $do_device_not_available
-   jmp common_exception
-SYM_CODE_END(device_not_available)
-
 #ifdef CONFIG_PARAVIRT
 SYM_CODE_START(native_iret)
iret
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1074,7 +1074,6 @@ apicinterrupt IRQ_WORK_VECTOR irq_work
  */
 
 idtentry   X86_TRAP_BP int3do_int3 
has_error_code=0
-idtentry   X86_TRAP_NM device_not_available
do_device_not_available has_error_code=0
 idtentry   X86_TRAP_OLD_MF coprocessor_segment_overrun 
do_coprocessor_segment_overrun  has_error_code=0
 idtentry   X86_TRAP_TS invalid_TSS do_invalid_TSS  
has_error_code=1
 idtentry   X86_TRAP_NP segment_not_present 
do_segment_not_present  has_error_code=1
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -81,5 +81,6 @@ DECLARE_IDTENTRY(X86_TRAP_DE, exc_divid
 DECLARE_IDTENTRY(X86_TRAP_OF,  exc_overflow);
 DECLARE_IDTENTRY(X86_TRAP_BR,  exc_bounds);
 DECLARE_IDTENTRY(X86_TRAP_UD,  exc_invalid_op);
+DECLARE_IDTENTRY(X86_TRAP_NM,  exc_device_not_available);
 
 #endif
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -14,7 +14,6 @@
 asmlinkage void debug(void);
 asmlinkage void nmi(void);
 asmlinkage void int3(void);
-asmlinkage void device_not_available(void);
 #ifdef CONFIG_X86_64
 asmlinkage void double_fault(void);
 #endif
@@ -37,7 +36,6 @@ asmlinkage void simd_coprocessor_error(v
 asmlinkage void xen_xennmi(void);
 asmlinkage void xen_xendebug(void);
 asmlinkage void xen_int3(void);
-asmlinkage void xen_device_not_available(void);
 asmlinkage void xen_double_fault(void);
 asmlinkage void xen_coprocessor_segment_overrun(void);
 asmlinkage void xen_invalid_TSS(void);
@@ -57,7 +55,6 @@ asmlinkage void xen_simd_coprocessor_err
 dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
 dotraplinkage void do_nmi(struct pt_regs *regs, long error_code);
 dotraplinkage void do_int3(struct pt_regs *regs, long error_code);
-dotraplinkage void do_device_not_available(struct pt_regs *regs, long 
error_code);
 #if defined(CONFIG_X86_64) || defined(CONFIG_DOUBLEFAULT)
 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, 
unsigned long cr2);
 #endif
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -74,7 +74,7 @@ static const __initconst struct idt_data
INTG(X86_TRAP_NMI,  nmi),
INTG(X86_TRAP_BR,   asm_exc_bounds),
INTG(X86_TRAP_UD,   asm_exc_invalid_op),
-   INTG(X86_TRAP_NM,   device_not_available),
+   INTG(X86_TRAP_NM,   asm_exc_device_not_available),
INTG(X86_TRAP_OLD_MF,   coprocessor_segment_overrun),
INTG(X86_TRAP_TS,   invalid_TSS),
INTG(X86_TRAP_NP,   segment_not_present),
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -874,13 +874,10 @@ do_spurious_interrupt_bug(struct pt_regs
 */
 }
 
-dotraplinkage void
-do_device_not_available(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY(exc_device_not_available)
 {
unsigned long cr0 = read_cr0();
 
-   RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
-
 #ifdef CONFIG_MATH_EMULATION
if (!boot_cpu_has(X86_FEATURE_FPU) && (cr0 & X86_CR0_EM)) {
struct math_emu_info info = { };
@@ -905,10 +902,9 @@ do_device_not_available(struct pt_regs *
 * to kill the task than getting stuck in a never-ending
 * loop of #NM faults.
 */
-   die("unexpected #NM exception", regs, error_code);
+   die("unexpected #NM exception", regs, 0);