[Mesa-dev] [PATCH 1/2] intel: gen-decoder: rework how we handle groups

Rafael Antognolli rafael.antognolli at intel.com
Tue May 30 21:39:42 UTC 2017


On Tue, May 30, 2017 at 08:59:06PM +0100, Lionel Landwerlin wrote:
> The current way of handling groups doesn't seem to be able to handle
> MI_LOAD_REGISTER_* with more than one register.

Hi Lionel, I don't think this is entirely true. I have added support to read
variable length structs on commit
1ea41163eb0657e7c6cd46c45bdbc3fd4e8e72f8. Maybe it doesn't work for every
case, but at least partial support is there.

I also tested this patch on arb_gpu_shader5-xfb-streams on hsw, because I
wanted to see the behavior when reading the MI_LOAD_REGISTER_IMM from
hsw_begin_transform_feedback, and it seems that aubinator gets into some kind
of infinite loop if I don't apply patch #2. But if I do apply it, then
aubinator crashes.

> the way we handle groups by building a traversal list on load the
> GENXML files.
> 
> Let's say you have
> 
> Instruction {
>   Field0
>   Field1
>   Field2
>   Group0 (count=2) {
>     Field0-0
>     Field0-1
>   }
>   Group1 (count=4) {
>     Field1-0
>     Field1-1
>   }
> }
> 
> We build of linked on load that goes :
> 
> Instruction -> Group0 -> Group1
> 
> All of those are gen_group structures, making the traversal trivial.
> We just need to iterate groups for the right number of times (count
> field in genxml).
> 
> The more fancy case is when you have only a single group of unknown
> size (count=0). In that case we keep on reading that group for as long
> as we're within the DWordLength of that instruction.

If I understood correctly, the main change is that the groups are organized in
a linked list instead of an array, and that makes the traversal of the whole
thing easier, right? Is there any other functional change?

Rafael

> 
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> ---
>  src/intel/common/gen_decoder.c | 208 +++++++++++++++++++++++++++--------------
>  src/intel/common/gen_decoder.h |  19 ++--
>  src/intel/tools/aubinator.c    |   4 +-
>  3 files changed, 151 insertions(+), 80 deletions(-)
> 
> diff --git a/src/intel/common/gen_decoder.c b/src/intel/common/gen_decoder.c
> index 3ea2eaf8dbf..6db02c854ff 100644
> --- a/src/intel/common/gen_decoder.c
> +++ b/src/intel/common/gen_decoder.c
> @@ -38,6 +38,8 @@
> 
>  #define XML_BUFFER_SIZE 4096
> 
> +#define MAX(a, b) ((a) < (b) ? (b) : (a))
> +
>  #define MAKE_GEN(major, minor) ( ((major) << 8) | (minor) )
> 
>  struct gen_spec {
> @@ -67,9 +69,6 @@ struct parser_context {
>     struct gen_group *group;
>     struct gen_enum *enoom;
> 
> -   int nfields;
> -   struct gen_field *fields[128];
> -
>     int nvalues;
>     struct gen_value *values[256];
> 
> @@ -178,8 +177,32 @@ xzalloc(size_t s)
>     return fail_on_null(zalloc(s));
>  }
> 
> +static void
> +get_group_offset_count(const char **atts, uint32_t *offset, uint32_t *count,
> +                       uint32_t *size, bool *variable)
> +{
> +   char *p;
> +   int i;
> +
> +   for (i = 0; atts[i]; i += 2) {
> +      if (strcmp(atts[i], "count") == 0) {
> +         *count = strtoul(atts[i + 1], &p, 0);
> +         if (*count == 0)
> +            *variable = true;
> +      } else if (strcmp(atts[i], "start") == 0) {
> +         *offset = strtoul(atts[i + 1], &p, 0);
> +      } else if (strcmp(atts[i], "size") == 0) {
> +         *size = strtoul(atts[i + 1], &p, 0);
> +      }
> +   }
> +   return;
> +}
> +
>  static struct gen_group *
> -create_group(struct parser_context *ctx, const char *name, const char **atts)
> +create_group(struct parser_context *ctx,
> +             const char *name,
> +             const char **atts,
> +             struct gen_group *parent)
>  {
>     struct gen_group *group;
> 
> @@ -190,9 +213,17 @@ create_group(struct parser_context *ctx, const char *name, const char **atts)
>     group->spec = ctx->spec;
>     group->group_offset = 0;
>     group->group_count = 0;
> -   group->variable_offset = 0;
>     group->variable = false;
> 
> +   if (parent) {
> +      group->parent = parent;
> +      get_group_offset_count(atts,
> +                             &group->group_offset,
> +                             &group->group_count,
> +                             &group->group_size,
> +                             &group->variable);
> +   }
> +
>     return group;
>  }
> 
> @@ -211,28 +242,6 @@ create_enum(struct parser_context *ctx, const char *name, const char **atts)
>  }
> 
>  static void
> -get_group_offset_count(struct parser_context *ctx, const char *name,
> -                       const char **atts, uint32_t *offset, uint32_t *count,
> -                       uint32_t *elem_size, bool *variable)
> -{
> -   char *p;
> -   int i;
> -
> -   for (i = 0; atts[i]; i += 2) {
> -      if (strcmp(atts[i], "count") == 0) {
> -         *count = strtoul(atts[i + 1], &p, 0);
> -         if (*count == 0)
> -            *variable = true;
> -      } else if (strcmp(atts[i], "start") == 0) {
> -         *offset = strtoul(atts[i + 1], &p, 0);
> -      } else if (strcmp(atts[i], "size") == 0) {
> -         *elem_size = strtoul(atts[i + 1], &p, 0);
> -      }
> -   }
> -   return;
> -}
> -
> -static void
>  get_register_offset(const char **atts, uint32_t *offset)
>  {
>     char *p;
> @@ -336,14 +345,9 @@ create_field(struct parser_context *ctx, const char **atts)
>        if (strcmp(atts[i], "name") == 0)
>           field->name = xstrdup(atts[i + 1]);
>        else if (strcmp(atts[i], "start") == 0)
> -         field->start = ctx->group->group_offset+strtoul(atts[i + 1], &p, 0);
> +         field->start = strtoul(atts[i + 1], &p, 0);
>        else if (strcmp(atts[i], "end") == 0) {
> -         field->end = ctx->group->group_offset+strtoul(atts[i + 1], &p, 0);
> -         if (ctx->group->group_offset) {
> -            ctx->group->group_offset = field->end+1;
> -            if (ctx->group->variable)
> -               ctx->group->variable_offset = ctx->group->group_offset;
> -         }
> +         field->end = strtoul(atts[i + 1], &p, 0);
>        } else if (strcmp(atts[i], "type") == 0)
>           field->type = string_to_type(ctx, atts[i + 1]);
>        else if (strcmp(atts[i], "default") == 0 &&
> @@ -372,9 +376,31 @@ create_value(struct parser_context *ctx, const char **atts)
>  }
> 
>  static void
> +create_and_append_field(struct parser_context *ctx,
> +                        const char **atts)
> +{
> +   if (ctx->group->nfields == ctx->group->fields_size) {
> +      ctx->group->fields_size = MAX(ctx->group->fields_size * 2, 2);
> +
> +      if (!ctx->group->fields) {
> +         ctx->group->fields =
> +            (struct gen_field **) calloc(ctx->group->fields_size,
> +                                         sizeof(ctx->group->fields[0]));
> +      } else {
> +         ctx->group->fields =
> +            (struct gen_field **) realloc(ctx->group->fields,
> +                                          sizeof(ctx->group->fields[0]) * ctx->group->fields_size);
> +      }
> +   }
> +
> +   ctx->group->fields[ctx->group->nfields++] = create_field(ctx, atts);
> +}
> +
> +static void
>  start_element(void *data, const char *element_name, const char **atts)
>  {
>     struct parser_context *ctx = data;
> +   struct gen_spec *prev_spec = ctx->spec;
>     int i;
>     const char *name = NULL;
>     const char *gen = NULL;
> @@ -405,25 +431,30 @@ start_element(void *data, const char *element_name, const char **atts)
>        ctx->spec->gen = MAKE_GEN(major, minor);
>     } else if (strcmp(element_name, "instruction") == 0 ||
>                strcmp(element_name, "struct") == 0) {
> -      ctx->group = create_group(ctx, name, atts);
> +      ctx->group = create_group(ctx, name, atts, NULL);
>     } else if (strcmp(element_name, "register") == 0) {
> -      ctx->group = create_group(ctx, name, atts);
> +      ctx->group = create_group(ctx, name, atts, NULL);
>        get_register_offset(atts, &ctx->group->register_offset);
>     } else if (strcmp(element_name, "group") == 0) {
> -      get_group_offset_count(ctx, name, atts, &ctx->group->group_offset,
> -                             &ctx->group->group_count, &ctx->group->elem_size,
> -                             &ctx->group->variable);
> +      struct gen_group *previous_group = ctx->group;
> +      while (previous_group->next)
> +         previous_group = previous_group->next;
> +
> +      struct gen_group *group = create_group(ctx, "", atts, ctx->group);
> +      previous_group->next = group;
> +      ctx->group = group;
>     } else if (strcmp(element_name, "field") == 0) {
> -      do {
> -         ctx->fields[ctx->nfields++] = create_field(ctx, atts);
> -         if (ctx->group->group_count)
> -            ctx->group->group_count--;
> -      } while (ctx->group->group_count > 0);
> +      create_and_append_field(ctx, atts);
>     } else if (strcmp(element_name, "enum") == 0) {
>        ctx->enoom = create_enum(ctx, name, atts);
>     } else if (strcmp(element_name, "value") == 0) {
>        ctx->values[ctx->nvalues++] = create_value(ctx, atts);
> +      assert(ctx->nvalues < ARRAY_SIZE(ctx->values));
>     }
> +
> +   assert(prev_spec == ctx->spec);
> +
> +
>  }
> 
>  static void
> @@ -435,14 +466,9 @@ end_element(void *data, const char *name)
>     if (strcmp(name, "instruction") == 0 ||
>         strcmp(name, "struct") == 0 ||
>         strcmp(name, "register") == 0) {
> -      size_t size = ctx->nfields * sizeof(ctx->fields[0]);
>        struct gen_group *group = ctx->group;
> 
> -      group->fields = xzalloc(size);
> -      group->nfields = ctx->nfields;
> -      memcpy(group->fields, ctx->fields, size);
> -      ctx->nfields = 0;
> -      ctx->group = NULL;
> +      ctx->group = ctx->group->parent;
> 
>        for (int i = 0; i < group->nfields; i++) {
>           if (group->fields[i]->start >= 16 &&
> @@ -461,12 +487,15 @@ end_element(void *data, const char *name)
>           spec->structs[spec->nstructs++] = group;
>        else if (strcmp(name, "register") == 0)
>           spec->registers[spec->nregisters++] = group;
> +
> +      assert(spec->ncommands < ARRAY_SIZE(spec->commands));
> +      assert(spec->nstructs < ARRAY_SIZE(spec->structs));
> +      assert(spec->nregisters < ARRAY_SIZE(spec->registers));
>     } else if (strcmp(name, "group") == 0) {
> -      ctx->group->group_offset = 0;
> -      ctx->group->group_count = 0;
> +      ctx->group = ctx->group->parent;
>     } else if (strcmp(name, "field") == 0) {
> -      assert(ctx->nfields > 0);
> -      struct gen_field *field = ctx->fields[ctx->nfields - 1];
> +      assert(ctx->group->nfields > 0);
> +      struct gen_field *field = ctx->group->fields[ctx->group->nfields - 1];
>        size_t size = ctx->nvalues * sizeof(ctx->values[0]);
>        field->inline_enum.values = xzalloc(size);
>        field->inline_enum.nvalues = ctx->nvalues;
> @@ -752,12 +781,11 @@ gen_field_iterator_init(struct gen_field_iterator *iter,
>                          const uint32_t *p,
>                          bool print_colors)
>  {
> +   memset(iter, 0, sizeof(*iter));
> +
>     iter->group = group;
>     iter->p = p;
> -   iter->i = 0;
>     iter->print_colors = print_colors;
> -   iter->repeat = false;
> -   iter->addr_inc = 0;
>  }
> 
>  static const char *
> @@ -771,6 +799,56 @@ gen_get_enum_name(struct gen_enum *e, uint64_t value)
>     return NULL;
>  }
> 
> +static bool iter_more_fields(const struct gen_field_iterator *iter)
> +{
> +   return iter->field_iter < iter->group->nfields;
> +}
> +
> +static uint32_t iter_group_offset_bits(const struct gen_field_iterator *iter,
> +                                       uint32_t group_iter)
> +{
> +   return iter->group->group_offset + (group_iter * iter->group->group_size);
> +}
> +
> +static bool iter_more_groups(const struct gen_field_iterator *iter)
> +{
> +   if (iter->group->variable) {
> +      return iter_group_offset_bits(iter, iter->group_iter + 1) <
> +              (gen_group_get_length(iter->group, iter->p) * 32);
> +   } else {
> +      return (iter->group_iter + 1) < iter->group->group_count ||
> +         iter->group->next != NULL;
> +   }
> +}
> +
> +static void iter_advance_group(struct gen_field_iterator *iter)
> +{
> +   if (iter->group->variable)
> +      iter->group_iter++;
> +   else {
> +      if ((iter->group_iter + 1) < iter->group->group_count) {
> +         iter->group_iter++;
> +      } else {
> +         iter->group = iter->group->next;
> +         iter->group_iter = 0;
> +      }
> +   }
> +
> +   iter->field_iter = 0;
> +}
> +
> +static void iter_advance_field(struct gen_field_iterator *iter)
> +{
> +   if (iter->field_iter == iter->group->nfields)
> +      iter_advance_group(iter);
> +
> +   iter->field = iter->group->fields[iter->field_iter++];
> +   iter->name = iter->field->name;
> +   iter->dword = iter_group_offset_bits(iter, iter->group_iter) / 32 +
> +      iter->field->start / 32;
> +   iter->struct_desc = NULL;
> +}
> +
>  bool
>  gen_field_iterator_next(struct gen_field_iterator *iter)
>  {
> @@ -779,22 +857,10 @@ gen_field_iterator_next(struct gen_field_iterator *iter)
>        float f;
>     } v;
> 
> -   if (iter->i == iter->group->nfields) {
> -      if (iter->group->group_size > 0) {
> -         int iter_length = iter->group->elem_size;
> -
> -         iter->group->group_size -= iter_length / 32;
> -         iter->addr_inc += iter_length;
> -         iter->dword = (iter->field->start + iter->addr_inc) / 32;
> -         return true;
> -      }
> +   if (!iter_more_fields(iter) && !iter_more_groups(iter))
>        return false;
> -   }
> 
> -   iter->field = iter->group->fields[iter->i++];
> -   iter->name = iter->field->name;
> -   iter->dword = iter->field->start / 32;
> -   iter->struct_desc = NULL;
> +   iter_advance_field(iter);
> 
>     if ((iter->field->end - iter->field->start) > 32)
>        v.qw = ((uint64_t) iter->p[iter->dword+1] << 32) | iter->p[iter->dword];
> diff --git a/src/intel/common/gen_decoder.h b/src/intel/common/gen_decoder.h
> index 4f4295ff95a..0a4de6bc8f9 100644
> --- a/src/intel/common/gen_decoder.h
> +++ b/src/intel/common/gen_decoder.h
> @@ -58,23 +58,28 @@ struct gen_field_iterator {
>     struct gen_group *struct_desc;
>     const uint32_t *p;
>     int dword; /**< current field starts at &p[dword] */
> -   int i;
> +
> +   int field_iter;
> +   int group_iter;
> +
>     struct gen_field *field;
>     bool print_colors;
> -   bool repeat;
> -   uint32_t addr_inc;
>  };
> 
>  struct gen_group {
>     struct gen_spec *spec;
>     char *name;
> -   int nfields;
> +
>     struct gen_field **fields;
> +   uint32_t nfields;
> +   uint32_t fields_size;
> +
>     uint32_t group_offset, group_count;
> -   uint32_t elem_size;
> -   uint32_t variable_offset;
> -   bool variable;
>     uint32_t group_size;
> +   bool variable;
> +
> +   struct gen_group *parent;
> +   struct gen_group *next;
> 
>     uint32_t opcode_mask;
>     uint32_t opcode;
> diff --git a/src/intel/tools/aubinator.c b/src/intel/tools/aubinator.c
> index 53b2a27fa90..5ad884c9e61 100644
> --- a/src/intel/tools/aubinator.c
> +++ b/src/intel/tools/aubinator.c
> @@ -108,8 +108,8 @@ valid_offset(uint32_t offset)
>  static void
>  group_set_size(struct gen_group *strct, uint32_t size)
>  {
> -   if (strct->variable && strct->elem_size)
> -      strct->group_size = size - (strct->variable_offset / 32);
> +   if (strct->variable && strct->group_size)
> +      strct->group_size = size - (strct->group_offset / 32);
>  }
> 
>  static void
> --
> 2.11.0
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