Re: [Qemu-devel] [PATCH v4 12/17] hw/intc/arm_gic: Change behavior of EOIR writes

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

On Fri, May 01, 2015 at 06:50:38PM +0100, Peter Maydell wrote:
> From: Fabian Aggeler <aggelerf@ethz.ch>
> 
> Grouping (GICv2) and Security Extensions change the behavior of EOIR
> writes. Completing Group0 interrupts is only allowed from Secure state.
> 
> Signed-off-by: Fabian Aggeler <aggelerf@ethz.ch>
> Signed-off-by: Greg Bellows <greg.bellows@linaro.org>
> Message-id: 1429113742-8371-13-git-send-email-greg.bellows@linaro.org
> [PMM: Rather than go to great lengths to ignore the UNPREDICTABLE case
>  of a Secure EOI of a Group1 (NS) irq with AckCtl == 0, we just let
>  it fall through; add a comment about it.]
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>


> ---
>  hw/intc/arm_gic.c      | 14 ++++++++++++--
>  hw/intc/armv7m_nvic.c  |  2 +-
>  hw/intc/gic_internal.h |  2 +-
>  3 files changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
> index 75c69b3..4ad80e7 100644
> --- a/hw/intc/arm_gic.c
> +++ b/hw/intc/arm_gic.c
> @@ -382,7 +382,7 @@ static uint8_t gic_get_running_priority(GICState *s, int cpu, MemTxAttrs attrs)
>      }
>  }
>  
> -void gic_complete_irq(GICState *s, int cpu, int irq)
> +void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs)
>  {
>      int update = 0;
>      int cm = 1 << cpu;
> @@ -412,6 +412,16 @@ void gic_complete_irq(GICState *s, int cpu, int irq)
>          }
>      }
>  
> +    if (s->security_extn && !attrs.secure && !GIC_TEST_GROUP(irq, cm)) {
> +        DPRINTF("Non-secure EOI for Group0 interrupt %d ignored\n", irq);
> +        return;
> +    }
> +
> +    /* Secure EOI with GICC_CTLR.AckCtl == 0 when the IRQ is a Group 1
> +     * interrupt is UNPREDICTABLE. We choose to handle it as if AckCtl == 1,
> +     * i.e. go ahead and complete the irq anyway.
> +     */
> +
>      if (irq != s->running_irq[cpu]) {
>          /* Complete an IRQ that is not currently running.  */
>          int tmp = s->running_irq[cpu];
> @@ -959,7 +969,7 @@ static MemTxResult gic_cpu_write(GICState *s, int cpu, int offset,
>          }
>          break;
>      case 0x10: /* End Of Interrupt */
> -        gic_complete_irq(s, cpu, value & 0x3ff);
> +        gic_complete_irq(s, cpu, value & 0x3ff, attrs);
>          return MEMTX_OK;
>      case 0x1c: /* Aliased Binary Point */
>          if (!gic_has_groups(s) || (s->security_extn && !attrs.secure)) {
> diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
> index c226daf..dd06ceb 100644
> --- a/hw/intc/armv7m_nvic.c
> +++ b/hw/intc/armv7m_nvic.c
> @@ -135,7 +135,7 @@ void armv7m_nvic_complete_irq(void *opaque, int irq)
>      nvic_state *s = (nvic_state *)opaque;
>      if (irq >= 16)
>          irq += 16;
> -    gic_complete_irq(&s->gic, 0, irq);
> +    gic_complete_irq(&s->gic, 0, irq, MEMTXATTRS_UNSPECIFIED);
>  }
>  
>  static uint32_t nvic_readl(nvic_state *s, uint32_t offset)
> diff --git a/hw/intc/gic_internal.h b/hw/intc/gic_internal.h
> index 119fb81..d3cebef 100644
> --- a/hw/intc/gic_internal.h
> +++ b/hw/intc/gic_internal.h
> @@ -79,7 +79,7 @@
>  
>  void gic_set_pending_private(GICState *s, int cpu, int irq);
>  uint32_t gic_acknowledge_irq(GICState *s, int cpu);
> -void gic_complete_irq(GICState *s, int cpu, int irq);
> +void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs);
>  void gic_update(GICState *s);
>  void gic_init_irqs_and_distributor(GICState *s);
>  void gic_set_priority(GICState *s, int cpu, int irq, uint8_t val,
> -- 
> 1.9.1
>