Re: [Qemu-devel] [RESEND PATCH 05/23] hw/acpi/aml-build: Add aml_interrupt() term

[Igor Mammedov]

On Wed, 20 May 2015 19:28:26 +0800
Shannon Zhao <address@hidden> wrote:

> 
> 
> On 2015/5/20 19:05, Igor Mammedov wrote:
> > On Wed, 20 May 2015 12:23:02 +0800
> > Shannon Zhao <address@hidden> wrote:
> > 
> >> > From: Shannon Zhao <address@hidden>
> >> > 
> >> > Add aml_interrupt() for describing device interrupt in resource template.
> >> > These can be used to generating DSDT table for ACPI on ARM.
> >> > 
> >> > Signed-off-by: Shannon Zhao <address@hidden>
> >> > Signed-off-by: Shannon Zhao <address@hidden>
> >> > ---
> >> >  hw/acpi/aml-build.c         | 22 ++++++++++++++++++++++
> >> >  include/hw/acpi/aml-build.h | 42 
> >> > ++++++++++++++++++++++++++++++++++++++++++
> >> >  2 files changed, 64 insertions(+)
> >> > 
> >> > diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> >> > index 805a0ad..5f06367 100644
> >> > --- a/hw/acpi/aml-build.c
> >> > +++ b/hw/acpi/aml-build.c
> >> > @@ -531,6 +531,28 @@ Aml *aml_memory32_fixed(uint32_t addr, uint32_t 
> >> > size,
> >> >      return var;
> >> >  }
> >> >  
> >> > +/*
> >> > + * ACPI 5.0: 6.4.3.6 Extended Interrupt Descriptor
> >> > + * Type 1, Large Item Name 0x9
> >> > + */
> >> > +Aml *aml_interrupt(AmlConsumerAndProducer con_and_pro,
> >> > +                   AmlLevelAndEdge level_and_edge,
> >> > +                   AmlActiveHighAndLow high_and_low, AmlShared shared,
> >> > +                   uint32_t irq)
> >> > +{
> >> > +    Aml *var = aml_alloc();
> >> > +    uint8_t irq_flags = con_and_pro | (level_and_edge << 1)
> >> > +                        | (high_and_low << 2) | (shared << 3);
> >> > +
> >> > +    build_append_byte(var->buf, 0x89); /* Extended irq descriptor */
> >> > +    build_append_byte(var->buf, 6); /* Length, bits[7:0] minimum value 
> >> > = 6 */
> >> > +    build_append_byte(var->buf, 0); /* Length, bits[15:8] minimum value 
> >> > = 0 */
> >> > +    build_append_byte(var->buf, irq_flags); /* Interrupt Vector 
> >> > Information. */
> >> > +    build_append_byte(var->buf, 0x01); /* Interrupt table length = 1 */
> >> > +    build_append_4bytes(var->buf, irq); /* Interrupt Number */
> > Just looking at the patch I have no idea what above line does;
> > 
> > using 4 build_append_byte() is much clearer and matches the spec 1:1
> > when comparing.
> > 
> 
> I feel awkward and have no word to convince you. If you insist on this,
> I'll go back to 4 build_append_byte().
I've chatted with Michael about it, he doesn't insist on build_append_4bytes()
ans he is ok with using build_append_byte() 4 times.