Re: [Qemu-devel] [PATCH v6 3/5] acpi: add build_append_namestring() helper

[Igor Mammedov]

On Wed, 28 Jan 2015 17:16:17 +0200
"Michael S. Tsirkin" <address@hidden> wrote:

> On Wed, Jan 28, 2015 at 02:34:48PM +0000, Igor Mammedov wrote:
> > Use build_append_namestring() instead of build_append_nameseg()
> > So user won't have to care whether name is NameSeg, NamePath or
> > NameString.
> > 
> > See for refernce ACPI 5.0: 20.2.2 Name Objects Encoding
> > 
> 
> typo
will fix

> 
> > Signed-off-by: Igor Mammedov <address@hidden>
> > Reviewed-by: Claudio Fontana <address@hidden>
> > Acked-by: Marcel Apfelbaum <address@hidden>
> > ---
> > v4:
> >  * fix codding style of ACPI_DualNamePrefix & ACPI_MultiNamePrefix
> >    it's imposible to use literals as suggested due to
> >    g_array_append_val() requiring reference value
> > 
> > v3:
> >  assert on wrong Segcount earlier and extend condition to
> >   seg_count > 0 && seg_count <= 255
> >  as suggested by Claudio Fontana <address@hidden>
> > ---
> >  hw/acpi/aml-build.c         | 92 
> > ++++++++++++++++++++++++++++++++++++++++++++-
> >  hw/i386/acpi-build.c        | 35 ++++++++---------
> >  include/hw/acpi/aml-build.h |  2 +-
> >  3 files changed, 108 insertions(+), 21 deletions(-)
> > 
> > diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> > index b28c1f4..ed4ab56 100644
> > --- a/hw/acpi/aml-build.c
> > +++ b/hw/acpi/aml-build.c
> > @@ -52,7 +52,7 @@ void build_append_array(GArray *array, GArray *val)
> >  
> >  #define ACPI_NAMESEG_LEN 4
> >  
> > -void GCC_FMT_ATTR(2, 3)
> > +static void GCC_FMT_ATTR(2, 3)
> >  build_append_nameseg(GArray *array, const char *format, ...)
> >  {
> >      /* It would be nicer to use g_string_vprintf but it's only there in 
> > 2.22 */
> > @@ -71,6 +71,96 @@ build_append_nameseg(GArray *array, const char *format, 
> > ...)
> >      g_array_append_vals(array, "____", ACPI_NAMESEG_LEN - len);
> >  }
> >  
> > +static void
> > +build_append_namestringv(GArray *array, const char *format, va_list ap)
> > +{
> > +    /* It would be nicer to use g_string_vprintf but it's only there in 
> > 2.22 */
> > +    char *s;
> > +    int len;
> > +    va_list va_len;
> > +    char **segs;
> > +    char **segs_iter;
> > +    int seg_count = 0;
> > +
> > +    va_copy(va_len, ap);
> > +    len = vsnprintf(NULL, 0, format, va_len);
> > +    va_end(va_len);
> > +    len += 1;
> > +    s = g_new(typeof(*s), len);
> > +
> > +    len = vsnprintf(s, len, format, ap);
> > +
> > +    segs = g_strsplit(s, ".", 0);
> > +    g_free(s);
> > +
> > +    /* count segments */
> > +    segs_iter = segs;
> > +    while (*segs_iter) {
> > +        ++segs_iter;
> > +        ++seg_count;
> >
> How about we split out formatting?
> Make +build_append_namestringv acceptconst char **segs, int nsegs,
> put all code above to build_append_namestring.
ok

> 
> > +    /*
> > +     * ACPI 5.0 spec: 20.2.2 Name Objects Encoding:
> > +     * "SegCount can be from 1 to 255"
> > +     */
> > +    assert(seg_count > 0 && seg_count <= 255);
> > +
> > +    /* handle RootPath || PrefixPath */
> > +    s = *segs;
> > +    while (*s == '\\' || *s == '^') {
> > +        g_array_append_val(array, *s);
> > +        ++s;
> > +    }
> > +
> > +    switch (seg_count) {
> > +    case 1:
> > +        if (!*s) { /* NullName */
> > +            const uint8_t nullpath = 0;
> > +            g_array_append_val(array, nullpath);
> > +        } else {
> > +            build_append_nameseg(array, "%s", s);
> > +        }
> > +        break;
> > +
> > +    case 2: {
> > +        const uint8_t prefix_opcode  = 0x2E; /* DualNamePrefix */
> 
> const is pretty bogus here.
it's like in above block: const uint8_t nullpath = 0;

> 
> > +
> > +        g_array_append_val(array, prefix_opcode);
> > +        build_append_nameseg(array, "%s", s);
> 
> So nameseg only ever gets %s now?
> In that case, move varg parsing out of there,
> make it simply assept char*
ok

> 
> > +        build_append_nameseg(array, "%s", segs[1]);
> > +        break;
> > +    }
> > +    default: {
> > +        const uint8_t prefix_opcode = 0x2F; /* MultiNamePrefix */
> 
> And here.
> 
> > +        g_array_append_val(array, prefix_opcode);
> > +        g_array_append_val(array, seg_count);
> > +
> > +        /* handle the 1st segment manually due to prefix/root path */
> > +        build_append_nameseg(array, "%s", s);
> > +
> > +        /* add the rest of segments */
> > +        segs_iter = segs + 1;
> > +        while (*segs_iter) {
> > +            build_append_nameseg(array, "%s", *segs_iter);
> > +            ++segs_iter;
> > +        }
> > +        break;
> > +    } /* default */
> > +    } /* switch (seg_count) */
> 
> And the only reason for the extra {} is the local variable -
> just declare it at top of function and assign here, then you
> won't have these weird double }} things, and you won't need to
> add comments after } which is really confusing IMO.
> 
> Or drop the variable:
> 
>       g_array_append_val(array, 0x2F);  /* MultiNamePrefix */
g_array_append_val() doesn't work with literals, hence variable.


> 
> is just as clear.
> 
> 
> > +    g_strfreev(segs);
> > +}
> > +
> > +void GCC_FMT_ATTR(2, 3)
> > +build_append_namestring(GArray *array, const char *format, ...)
> > +{
> > +    va_list ap;
> > +
> > +    va_start(ap, format);
> > +    build_append_namestringv(array, format, ap);
> > +    va_end(ap);
> > +}
> > +
> >  /* 5.4 Definition Block Encoding */
> >  enum {
> >      PACKAGE_LENGTH_1BYTE_SHIFT = 6, /* Up to 63 - use extra 2 bits. */
> > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > index a92d008..380799b 100644
> > --- a/hw/i386/acpi-build.c
> > +++ b/hw/i386/acpi-build.c
> > @@ -282,7 +282,7 @@ static GArray *build_alloc_method(const char *name, 
> > uint8_t arg_count)
> >  {
> >      GArray *method = build_alloc_array();
> >  
> > -    build_append_nameseg(method, "%s", name);
> > +    build_append_namestring(method, "%s", name);
> >      build_append_byte(method, arg_count); /* MethodFlags: ArgCount */
> >  
> >      return method;
> > @@ -574,7 +574,7 @@ build_append_notify_method(GArray *device, const char 
> > *name,
> >  
> >      for (i = 0; i < count; i++) {
> >          GArray *target = build_alloc_array();
> > -        build_append_nameseg(target, format, i);
> > +        build_append_namestring(target, format, i);
> >          assert(i < 256); /* Fits in 1 byte */
> >          build_append_notify_target_ifequal(method, target, i, 1);
> >          build_free_array(target);
> > @@ -702,24 +702,24 @@ static void build_pci_bus_end(PCIBus *bus, void 
> > *bus_state)
> >  
> >      if (bus->parent_dev) {
> >          op = 0x82; /* DeviceOp */
> > -        build_append_nameseg(bus_table, "S%.02X",
> > +        build_append_namestring(bus_table, "S%.02X",
> >                               bus->parent_dev->devfn);
> >          build_append_byte(bus_table, 0x08); /* NameOp */
> > -        build_append_nameseg(bus_table, "_SUN");
> > +        build_append_namestring(bus_table, "_SUN");
> >          build_append_value(bus_table, PCI_SLOT(bus->parent_dev->devfn), 1);
> >          build_append_byte(bus_table, 0x08); /* NameOp */
> > -        build_append_nameseg(bus_table, "_ADR");
> > +        build_append_namestring(bus_table, "_ADR");
> >          build_append_value(bus_table, (PCI_SLOT(bus->parent_dev->devfn) << 
> > 16) |
> >                             PCI_FUNC(bus->parent_dev->devfn), 4);
> >      } else {
> >          op = 0x10; /* ScopeOp */;
> > -        build_append_nameseg(bus_table, "PCI0");
> > +        build_append_namestring(bus_table, "PCI0");
> >      }
> >  
> >      bsel = object_property_get_qobject(OBJECT(bus), ACPI_PCIHP_PROP_BSEL, 
> > NULL);
> >      if (bsel) {
> >          build_append_byte(bus_table, 0x08); /* NameOp */
> > -        build_append_nameseg(bus_table, "BSEL");
> > +        build_append_namestring(bus_table, "BSEL");
> >          build_append_int(bus_table, qint_get_int(qobject_to_qint(bsel)));
> >          memset(slot_hotplug_enable, 0xff, sizeof slot_hotplug_enable);
> >      } else {
> > @@ -822,7 +822,7 @@ static void build_pci_bus_end(PCIBus *bus, void 
> > *bus_state)
> >              build_append_int(notify, 0x1U << i);
> >              build_append_byte(notify, 0x00); /* NullName */
> >              build_append_byte(notify, 0x86); /* NotifyOp */
> > -            build_append_nameseg(notify, "S%.02X", PCI_DEVFN(i, 0));
> > +            build_append_namestring(notify, "S%.02X", PCI_DEVFN(i, 0));
> >              build_append_byte(notify, 0x69); /* Arg1Op */
> >  
> >              /* Pack it up */
> > @@ -846,12 +846,12 @@ static void build_pci_bus_end(PCIBus *bus, void 
> > *bus_state)
> >          if (bsel) {
> >              build_append_byte(method, 0x70); /* StoreOp */
> >              build_append_int(method, qint_get_int(qobject_to_qint(bsel)));
> > -            build_append_nameseg(method, "BNUM");
> > -            build_append_nameseg(method, "DVNT");
> > -            build_append_nameseg(method, "PCIU");
> > +            build_append_namestring(method, "BNUM");
> > +            build_append_namestring(method, "DVNT");
> > +            build_append_namestring(method, "PCIU");
> >              build_append_int(method, 1); /* Device Check */
> > -            build_append_nameseg(method, "DVNT");
> > -            build_append_nameseg(method, "PCID");
> > +            build_append_namestring(method, "DVNT");
> > +            build_append_namestring(method, "PCID");
> >              build_append_int(method, 3); /* Eject Request */
> >          }
> >  
> > @@ -877,11 +877,8 @@ static void build_pci_bus_end(PCIBus *bus, void 
> > *bus_state)
> >           * At the moment this is not needed for root as we have a single 
> > root.
> >           */
> >          if (bus->parent_dev) {
> > -            build_append_byte(parent->notify_table, '^'); /* 
> > ParentPrefixChar */
> > -            build_append_byte(parent->notify_table, 0x2E); /* 
> > DualNamePrefix */
> > -            build_append_nameseg(parent->notify_table, "S%.02X",
> > +            build_append_namestring(parent->notify_table, "^PCNT.S%.02X",
> >                                   bus->parent_dev->devfn);
> 
> Pls align continuation at opening (.
ok

> 
> > -            build_append_nameseg(parent->notify_table, "PCNT");
> >          }
> >      }
> >  
> > @@ -949,7 +946,7 @@ build_ssdt(GArray *table_data, GArray *linker,
> >          GArray *sb_scope = build_alloc_array();
> >          uint8_t op = 0x10; /* ScopeOp */
> >  
> > -        build_append_nameseg(sb_scope, "_SB");
> > +        build_append_namestring(sb_scope, "_SB");
> >  
> >          /* build Processor object for each processor */
> >          for (i = 0; i < acpi_cpus; i++) {
> > @@ -969,7 +966,7 @@ build_ssdt(GArray *table_data, GArray *linker,
> >  
> >          /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... 
> > })" */
> >          build_append_byte(sb_scope, 0x08); /* NameOp */
> > -        build_append_nameseg(sb_scope, "CPON");
> > +        build_append_namestring(sb_scope, "CPON");
> >  
> >          {
> >              GArray *package = build_alloc_array();
> > diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> > index e6a0b28..fd50625 100644
> > --- a/include/hw/acpi/aml-build.h
> > +++ b/include/hw/acpi/aml-build.h
> > @@ -12,7 +12,7 @@ void build_append_byte(GArray *array, uint8_t val);
> >  void build_append_array(GArray *array, GArray *val);
> >  
> >  void GCC_FMT_ATTR(2, 3)
> > -build_append_nameseg(GArray *array, const char *format, ...);
> > +build_append_namestring(GArray *array, const char *format, ...);
> >  
> >  void build_prepend_package_length(GArray *package, unsigned min_bytes);
> >  void build_package(GArray *package, uint8_t op, unsigned min_bytes);
> > -- 
> > 1.8.3.1
>