Re: [Qemu-devel] [PATCH v3 16/16] target-arm: Add support for VIRQ and VFIQ

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Fri, Aug 01, 2014 at 03:32:59PM +0100, Peter Maydell wrote:
> On 17 June 2014 09:45, Edgar E. Iglesias <edgar.iglesias@gmail.com> wrote:
> > From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
> >
> > Acked-by: Greg Bellows <greg.bellows@linaro.org>
> > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
> > ---
> >  cpu-exec.c              | 12 ++++++++++++
> >  target-arm/cpu.c        | 20 ++++++++++++++++++--
> >  target-arm/cpu.h        | 24 ++++++++++++++++++++++--
> >  target-arm/helper-a64.c |  2 ++
> >  target-arm/helper.c     |  4 ++++
> >  target-arm/internals.h  |  2 ++
> >  6 files changed, 60 insertions(+), 4 deletions(-)
> >
> > diff --git a/cpu-exec.c b/cpu-exec.c
> > index a579ffc..baf5643 100644
> > --- a/cpu-exec.c
> > +++ b/cpu-exec.c
> > @@ -498,6 +498,18 @@ int cpu_exec(CPUArchState *env)
> >                          cc->do_interrupt(cpu);
> >                          next_tb = 0;
> >                      }
> > +                    if (interrupt_request & CPU_INTERRUPT_VIRQ
> > +                        && arm_excp_unmasked(cpu, EXCP_VIRQ)) {
> > +                        cpu->exception_index = EXCP_VIRQ;
> > +                        cc->do_interrupt(cpu);
> > +                        next_tb = 0;
> > +                    }
> > +                    if (interrupt_request & CPU_INTERRUPT_VFIQ
> > +                        && arm_excp_unmasked(cpu, EXCP_VFIQ)) {
> > +                        cpu->exception_index = EXCP_VFIQ;
> > +                        cc->do_interrupt(cpu);
> > +                        next_tb = 0;
> > +                    }
> >  #elif defined(TARGET_UNICORE32)
> >                      if (interrupt_request & CPU_INTERRUPT_HARD
> >                          && !(env->uncached_asr & ASR_I)) {
> > diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> > index 8e64c5a..cd7a5df 100644
> > --- a/target-arm/cpu.c
> > +++ b/target-arm/cpu.c
> > @@ -195,6 +195,20 @@ static void arm_cpu_set_irq(void *opaque, int irq, int level)
> >              cpu_reset_interrupt(cs, CPU_INTERRUPT_FIQ);
> >          }
> >          break;
> > +    case ARM_CPU_VIRQ:
> > +        if (level) {
> > +            cpu_interrupt(cs, CPU_INTERRUPT_VIRQ);
> > +        } else {
> > +            cpu_reset_interrupt(cs, CPU_INTERRUPT_VIRQ);
> > +        }
> > +        break;
> > +    case ARM_CPU_VFIQ:
> > +        if (level) {
> > +            cpu_interrupt(cs, CPU_INTERRUPT_VFIQ);
> > +        } else {
> > +            cpu_reset_interrupt(cs, CPU_INTERRUPT_VFIQ);
> > +        }
> > +        break;
> 
> With four cases this kind of wants a lookup of irq to CPU_INTERRUPT_
> value I think, rather than the code duplication.

Added a table lookup, thanks.

> 
> >      default:
> >          hw_error("arm_cpu_set_irq: Bad interrupt line %d\n", irq);
> >      }
> > @@ -242,9 +256,11 @@ static void arm_cpu_initfn(Object *obj)
> >  #ifndef CONFIG_USER_ONLY
> >      /* Our inbound IRQ and FIQ lines */
> >      if (kvm_enabled()) {
> > -        qdev_init_gpio_in(DEVICE(cpu), arm_cpu_kvm_set_irq, 2);
> > +        /* VIRQ and VFIQ are unused with KVM but we add them to maintain
> > +           the same interface as non-KVM CPUs.  */
> 
>     /* Multiline comments
>      * should look like this.
>      */


Fixed

> 
> > +        qdev_init_gpio_in(DEVICE(cpu), arm_cpu_kvm_set_irq, 4);
> >      } else {
> > -        qdev_init_gpio_in(DEVICE(cpu), arm_cpu_set_irq, 2);
> > +        qdev_init_gpio_in(DEVICE(cpu), arm_cpu_set_irq, 4);
> >      }
> >
> >      cpu->gt_timer[GTIMER_PHYS] = timer_new(QEMU_CLOCK_VIRTUAL, GTIMER_SCALE,
> > diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> > index bb123bd..df61bbd 100644
> > --- a/target-arm/cpu.h
> > +++ b/target-arm/cpu.h
> > @@ -53,6 +53,8 @@
> >  #define EXCP_STREX          10
> >  #define EXCP_HVC            11   /* HyperVisor Call */
> >  #define EXCP_SMC            12   /* Secure Monitor Call */
> > +#define EXCP_VIRQ           13
> > +#define EXCP_VFIQ           14
> >
> >  #define ARMV7M_EXCP_RESET   1
> >  #define ARMV7M_EXCP_NMI     2
> > @@ -67,6 +69,8 @@
> >
> >  /* ARM-specific interrupt pending bits.  */
> >  #define CPU_INTERRUPT_FIQ   CPU_INTERRUPT_TGT_EXT_1
> > +#define CPU_INTERRUPT_VIRQ  CPU_INTERRUPT_TGT_EXT_2
> > +#define CPU_INTERRUPT_VFIQ  CPU_INTERRUPT_TGT_EXT_3
> >
> >  /* The usual mapping for an AArch64 system register to its AArch32
> >   * counterpart is for the 32 bit world to have access to the lower
> > @@ -85,6 +89,9 @@
> >  /* Meanings of the ARMCPU object's two inbound GPIO lines */
> 
> You forgot to update this comment ^^^

Done


> 
> >  #define ARM_CPU_IRQ 0
> >  #define ARM_CPU_FIQ 1
> > +#define ARM_CPU_VIRQ 2
> > +#define ARM_CPU_VFIQ 3
> 
> >
> >  typedef void ARMWriteCPFunc(void *opaque, int cp_info,
> >                              int srcreg, int operand, uint32_t value);
> > @@ -1142,6 +1149,8 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx)
> >       * EL2 if we are in NS EL0/1.
> >       */
> >      bool irq_can_hyp = !secure && cur_el < 2 && target_el == 2;
> > +    bool irq_unmasked = ((IS_M(env) && env->regs[15] < 0xfffffff0)
> > +                          || !(env->daif & PSTATE_I));
> 
> The M profile stuff is starting to look increasingly weird here.

Yes, not sure what to do about it though. I forgot to move the
comment in cpu-exec to here, will do that.

Cheers,
Edgar