Re: [Qemu-devel] [PATCH V2 6/8] acpi: add build_append_namestring() helper

[Claudio Fontana <claudio.fontana@huawei.com>]

On 16.12.2014 11:58, 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
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  hw/acpi/acpi_gen_utils.c         | 86 +++++++++++++++++++++++++++++++++++++++-
>  hw/i386/acpi-build.c             | 35 ++++++++--------
>  include/hw/acpi/acpi_gen_utils.h |  2 +-
>  3 files changed, 102 insertions(+), 21 deletions(-)
> 
> diff --git a/hw/acpi/acpi_gen_utils.c b/hw/acpi/acpi_gen_utils.c
> index 82d9cb7..2e52690 100644
> --- a/hw/acpi/acpi_gen_utils.c
> +++ b/hw/acpi/acpi_gen_utils.c
> @@ -31,7 +31,7 @@ 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 */
> @@ -50,6 +50,90 @@ build_append_nameseg(GArray *array, const char *format, ...)
>      g_array_append_vals(array, "____", ACPI_NAMESEG_LEN - len);
>  }
>  
> +static const uint8_t ACPI_DualNamePrefix  = 0x2E;
> +static const uint8_t ACPI_MultiNamePrefix = 0x2F;
> +
> +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;
> +    }

since SegCount is explicitly mentioned in 20.2.2 as being between 1 and 255,
why don't we assert right here (instead of below), and add an assert for seg_count != 0 as well while we're at it?

Thanks,

Claudio

> +
> +    /* 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:
> +        g_array_append_val(array, ACPI_DualNamePrefix);
> +        build_append_nameseg(array, "%s", s);
> +        build_append_nameseg(array, "%s", segs[1]);
> +        break;
> +
> +    default:
> +        g_array_append_val(array, ACPI_MultiNamePrefix);
> +        assert(seg_count <= 0xFF); /* ByteData Max */
> +        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;
> +    }
> +    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 870e4a0..0f6202d 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -273,7 +273,7 @@ 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;
> @@ -565,7 +565,7 @@ 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);
> @@ -693,24 +693,24 @@ 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 {
> @@ -813,7 +813,7 @@ 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 */
> @@ -837,12 +837,12 @@ 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 */
>          }
>  
> @@ -868,11 +868,8 @@ 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);
> -            build_append_nameseg(parent->notify_table, "PCNT");
>          }
>      }
>  
> @@ -940,7 +937,7 @@ 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++) {
> @@ -960,7 +957,7 @@ 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/acpi_gen_utils.h b/include/hw/acpi/acpi_gen_utils.h
> index e6a0b28..fd50625 100644
> --- a/include/hw/acpi/acpi_gen_utils.h
> +++ b/include/hw/acpi/acpi_gen_utils.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);
>