Update code object V3 kernarg queries

Code object V2 had the ability to support the following queries:

- HSA_CODE_SYMBOL_INFO_KERNEL_KERNARG_SEGMENT_SIZE
- HSA_EXECUTABLE_SYMBOL_INFO_KERNEL_KERNARG_SEGMENT_SIZE
- HSA_CODE_SYMBOL_INFO_KERNEL_KERNARG_SEGMENT_ALIGNMENT
- HSA_EXECUTABLE_SYMBOL_INFO_KERNEL_KERNARG_SEGMENT_ALIGNMENT

However code object V3 onwards cannot support these as the kernel
descriptor changed. These queries need to be deprecated.

Until then return more reasonable values:

- For kernarg alignment return 16 which is the minimum alignment
  required by the HSA standard.

- For kernarg size return the field from the kernel descriptor which
  is a hint. If it is 0 then the compiler is not specifying the kernarg
  size, or the kernel has no kernarg.

Change-Id: I19ce6cd0f3658a2bf62277492f39100ea5ab4256


[ROCm/ROCR-Runtime commit: ef755e4c82]

projects/rocr-runtime/runtime/hsa-runtime/loader/AMDHSAKernelDescriptor.h

@@ -167,7 +167,8 @@ enum : int32_t {
 struct kernel_descriptor_t {
   uint32_t group_segment_fixed_size;
   uint32_t private_segment_fixed_size;
-  uint8_t reserved0[8];
+  uint32_t kernarg_size;
+  uint8_t reserved0[4];
   int64_t kernel_code_entry_byte_offset;
   uint8_t reserved1[24];
   uint32_t compute_pgm_rsrc1;
@@ -185,8 +186,11 @@ static_assert(
 static_assert(
     offsetof(kernel_descriptor_t, private_segment_fixed_size) == 4,
     "invalid offset for private_segment_fixed_size");
+static_assert(
+      offsetof(kernel_descriptor_t, kernarg_size) == 8,
+      "invalid offset for kernarg_size");
 static_assert(
-    offsetof(kernel_descriptor_t, reserved0) == 8,
+    offsetof(kernel_descriptor_t, reserved0) == 12,
     "invalid offset for reserved0");
 static_assert(
     offsetof(kernel_descriptor_t, kernel_code_entry_byte_offset) == 16,

projects/rocr-runtime/runtime/hsa-runtime/loader/executable.cpp

@@ -1422,8 +1422,8 @@ hsa_status_t ExecutableImpl::LoadDefinitionSymbol(hsa_agent_t agent,
     llvm::amdhsa::kernel_descriptor_t kd;
     sym->GetSection()->getData(sym->SectionOffset(), &kd, sizeof(kd));
 
-    uint32_t kernarg_segment_size = 0;      // FIXME.
-    uint32_t kernarg_segment_alignment = 0; // FIXME.
+    uint32_t kernarg_segment_size = kd.kernarg_size; // FIXME: If 0 then the compiler is not specifying the size.
+    uint32_t kernarg_segment_alignment = 16;         // FIXME: Use the minumum HSA required alignment.
     uint32_t group_segment_size = kd.group_segment_fixed_size;
     uint32_t private_segment_size = kd.private_segment_fixed_size;
     bool is_dynamic_callstack = false;