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Re: [Qemu-devel] [PATCH v2 06/47] acpi: add acpi_name() & acpi_name_decl
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v2 06/47] acpi: add acpi_name() & acpi_name_decl() term |
Date: |
Fri, 23 Jan 2015 15:42:30 +0200 |
On Fri, Jan 23, 2015 at 02:32:45PM +0100, Igor Mammedov wrote:
> On Fri, 23 Jan 2015 10:59:48 +0200
> "Michael S. Tsirkin" <address@hidden> wrote:
>
> > On Thu, Jan 22, 2015 at 02:49:50PM +0000, Igor Mammedov wrote:
> > > Signed-off-by: Igor Mammedov <address@hidden>
> > > ---
> > > hw/acpi/acpi-build-utils.c | 24 ++++++++++++++++++++++++
> > > include/hw/acpi/acpi-build-utils.h | 3 +++
> > > 2 files changed, 27 insertions(+)
> > >
> > > diff --git a/hw/acpi/acpi-build-utils.c b/hw/acpi/acpi-build-utils.c
> > > index 40a1769..1bda2ec 100644
> > > --- a/hw/acpi/acpi-build-utils.c
> > > +++ b/hw/acpi/acpi-build-utils.c
> > > @@ -314,6 +314,30 @@ static AcpiAml aml_allocate_internal(uint8_t op,
> > > AcpiBlockFlags flags)
> > > return var;
> > > }
> > >
> > > +/*
> > > + * help to construct NameString, which return AcpiAml object
> > > + * for using with other aml_append or other acpi_* terms
> >
> > Here and elsewhere: I can't parse this header text.
> > I'm guessing you just mean "construct NameString",
> > and that's it?
> yes
>
> >
> > Also, most other places use build_append_namestring -
> > so when should acpi_name be used instead?
> > This should be made clear here in the comment.
> acpi_name() is a replacement/wrapper around build_append_namestring()
> which returns AcpiAml object. build_append_namestring() is a nonpublic
> lowlevel helper that deals with GArray,
> while acpi_name() follows semantic of AML API.
>
> >
> > > + */
> > > +AcpiAml GCC_FMT_ATTR(1, 2) acpi_name(const char *name_format, ...)
> > > +{
> >
> > This isn't really a name. It just appends a string. So rename this
> > acpi_string and then the below one adding a name can be named acpi_name?
> acpi_string is introduced in 27/47, which is a prefixed string
> as described in spec.
>
> > Also, in many places one must use only one nameseg.
> Where is it exactly?
> Perhaps we could build in acpi_name() a check if we know in
> what context enforce it. Better to have single/uniform API
> for names than a several which is confusing.
I agree here.
> > I think a separate api that actually validates
> > that it's one segment is better than silently failing.
> > Do we ever use it for more than 1 segment?
> Yes we use names with more than one segment.
Interesting. where exactly?
> > If not, maybe the right thing to do is
> > to use build_append_nameseg and call this one acpi_nameseg.
> acpi_name() is used only for passing name as arguments to methods,
> in spec there isn't a limitation to only one segment when it comes
> to names, in ASL part of it. namesegment however only AML construct
> which helps to build name, I prefer not expose lowlevel AML
> unless we have to.
OK, I agree.
> >
> >
> > > + va_list ap;
> > > + AcpiAml var = aml_allocate_internal(0, NON_BLOCK);
> >
> > 0 hard coded? What does it mean?
> 1st arg for NON_BLOCK context doesn't mean anything/ignored.
> alternatively I can make aml_allocate_nonblock() wrapper
> around generic allocator.
0 isn't a valid opcode either, it can really be anything.
> > Same elsewhere.
> >
> > > + va_start(ap, name_format);
> > > + build_append_namestringv(var.buf, name_format, ap);
> > > + va_end(ap);
> > > + return var;
> > > +
> > > +/* ACPI 5.0: 20.2.5.1 Namespace Modifier Objects Encoding: DefName */
> >
> > Let's quote the earliest spec which documents each object:
> > one year from now 5.0 will not be the latest.
> > Applies here and elsewhere.
> > In most places this will be 1.0b.
> > Where the construct is newer, this will automatically
> > document which guests support it.
> I'll try to do it.
>
> >
> > > +AcpiAml acpi_name_decl(const char *name, AcpiAml val)
> > > +{
> > > + AcpiAml var = aml_allocate_internal(0, NON_BLOCK);
> > > + build_append_byte(var.buf, 0x08);
> >
> > Pls add comment documenting what 0x08 is here.
> sure
>
> >
> > > + build_append_namestring(var.buf, "%s", name);
> > > + aml_append(&var, val);
> > > + return var;
> > > +}
> > > +
> > > /* ACPI 5.0: 20.2.5.3 Type 1 Opcodes Encoding: DefIfElse */
> > > AcpiAml acpi_if(AcpiAml predicate)
> > > {
> > > diff --git a/include/hw/acpi/acpi-build-utils.h
> > > b/include/hw/acpi/acpi-build-utils.h
> > > index 177f9ed..868cfa5 100644
> > > --- a/include/hw/acpi/acpi-build-utils.h
> > > +++ b/include/hw/acpi/acpi-build-utils.h
> > > @@ -21,6 +21,9 @@ typedef struct AcpiAml {
> > >
> > > void aml_append(AcpiAml *parent_ctx, AcpiAml child);
> > >
> > > +/* non block ASL object primitives */
> >
> > what does it mean that it's a "non block primitive"?
> > I didn't find this concept in the spec.
> As for a question what is NON_BLOCK, it's for simple inline ASL
> construct that doesn't have to be packaged in special way
> examles:
> Store(A,B)
> Name(FOO, VAL)
> IO(...)
> while there are different block elements differing in how
> they are created see 1/47 aml_append():
>
> ResourceTemplate {
> /* block of other ASL items */
> }
>
> Package() {
> /* block of other ASL items */
> }
>
> if ... else ...
>
> Scope() {
> /* block of other ASL items */
> }
>
> and so on.
"special way" is kind of vague.
Maybe add a comment explaining when it's used.
Is it when length isn't used as a prefix?
AML_NO_PREFIX?
> >
> > > +AcpiAml GCC_FMT_ATTR(1, 2) acpi_name(const char *name_format, ...);
> > > +AcpiAml acpi_name_decl(const char *name, AcpiAml val);
> > > /* Block ASL object primitives */
> > > AcpiAml acpi_if(AcpiAml predicate);
> > > AcpiAml acpi_method(const char *name, int arg_count);
> > > --
> > > 1.8.3.1
- [Qemu-devel] [PATCH v2 41/47] pc: acpi-build: create PCI0._CRS dynamically, (continued)
- [Qemu-devel] [PATCH v2 41/47] pc: acpi-build: create PCI0._CRS dynamically, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 44/47] pc: acpi-build: drop remaining ssdt_misc template and use acpi_def_block(), Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 45/47] acpi: add acpi_iqr_no_flags() term, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 46/47] pc: export applesmc IO port/len, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 43/47] pc: acpi-build: prepare to make ACPI tables blob opaque for table building functions, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 47/47] pc: acpi-build: drop template patching and create Device(SMC) dynamically, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 17/47] acpi: add acpi_package() term, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 06/47] acpi: add acpi_name() & acpi_name_decl() term, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 11/47] acpi: add acpi_arg0(), acpi_arg1(), acpi_arg2(), acpi_arg3() terms, Igor Mammedov, 2015/01/22
- Re: [Qemu-devel] [PATCH v2 11/47] acpi: add acpi_arg0(), acpi_arg1(), acpi_arg2(), acpi_arg3() terms, Marcel Apfelbaum, 2015/01/23
- Re: [Qemu-devel] [PATCH v2 11/47] acpi: add acpi_arg0(), acpi_arg1(), acpi_arg2(), acpi_arg3() terms, Michael S. Tsirkin, 2015/01/23
- Re: [Qemu-devel] [PATCH v2 11/47] acpi: add acpi_arg0(), acpi_arg1(), acpi_arg2(), acpi_arg3() terms, Igor Mammedov, 2015/01/23
- [Qemu-devel] [PATCH v2 10/47] acpi: add acpi_return() term, Igor Mammedov, 2015/01/22
- [Qemu-devel] [PATCH v2 01/47] acpi: introduce AML composer aml_append(), Igor Mammedov, 2015/01/22
- Re: [Qemu-devel] [PATCH v2 01/47] acpi: introduce AML composer aml_append(), Michael S. Tsirkin, 2015/01/23