[cl] Permit sizes of 0 in clEnqueueXXXBuffer; mux; HAL

This is not explicitly forbidden by the current unified OpenCL
specification for clEnqueueReadBuffer, clEnqueueWriteBuffer, or
clEnqueueCopyBuffer; though it *was* forbidden up to and including
OpenCL 2.0.

Therefore, make the checks for size 0 dependent on the OpenCL version
being built.

A size of zero for clEnqueueFillBuffer has always been valid, so
explicitly test that. The muxCommandFillBuffer function forbids a size
of 0, so it was a bug to call that function when size was 0.

This requires updating the mux specification to allow sizes of 0 in all
of these functions. It also implicitly allows the same in the HAL,
though this is not as tightly specified.

Author: frasercrmck

doc/modules/mux/changes.rst

@@ -11,6 +11,13 @@ version increases mean backward compatible bug fixes have been applied.
    Versions prior to 1.0.0 may contain breaking changes in minor
    versions as the API is still under development.
 
+0.81.0
+------
+
+* ``muxCommandReadBuffer``, ``muxCommandWriteBuffer``,
+  ``muxCommandCopyBuffer``, and ``muxCommandFillBuffer`` now accept a ``size``
+  of zero.
+
 0.80.0
 ------
 

doc/specifications/mux-compiler-spec.rst

@@ -1,7 +1,7 @@
 ComputeMux Compiler Specification
 =================================
 
-   This is version 0.80.0 of the specification.
+   This is version 0.81.0 of the specification.
 
 ComputeMux is Codeplay’s proprietary API for executing compute workloads across
 heterogeneous devices. ComputeMux is an extremely lightweight,

doc/specifications/mux-runtime-spec.rst

@@ -1,7 +1,7 @@
 ComputeMux Runtime Specification
 ================================
 
-   This is version 0.80.0 of the specification.
+   This is version 0.81.0 of the specification.
 
 ComputeMux is Codeplay’s proprietary API for executing compute workloads across
 heterogeneous devices. ComputeMux is an extremely lightweight,

examples/refsi/hal_refsi/source/refsi_hal_g1.cpp

@@ -273,12 +273,14 @@ bool refsi_g1_hal_device::mem_copy(hal::hal_addr_t dst, hal::hal_addr_t src,
             dst, src, size);
   }
 
-  std::vector<uint8_t> temp(size);
-  if (!mem_read(temp.data(), src, size, locker)) {
-    return false;
-  }
-  if (!mem_write(dst, temp.data(), size, locker)) {
-    return false;
+  if (size) {
+    std::vector<uint8_t> temp(size);
+    if (!mem_read(temp.data(), src, size, locker)) {
+      return false;
+    }
+    if (!mem_write(dst, temp.data(), size, locker)) {
+      return false;
+    }
   }
 
   return true;

examples/refsi/hal_refsi/source/refsi_hal_m1.cpp

@@ -455,6 +455,10 @@ bool refsi_m1_hal_device::mem_copy(hal::hal_addr_t dst, hal::hal_addr_t src,
             dst, src, size);
   }
 
+  if (!size) {
+    return true;
+  }
+
   refsi_command_buffer cb;
 
   // Start a 1D DMA transfer to copy data from one buffer to another.

modules/mux/include/mux/mux.h

@@ -37,7 +37,7 @@ extern "C" {
 /// @brief Mux major version number.
 #define MUX_MAJOR_VERSION 0
 /// @brief Mux minor version number.
-#define MUX_MINOR_VERSION 80
+#define MUX_MINOR_VERSION 81
 /// @brief Mux patch version number.
 #define MUX_PATCH_VERSION 0
 /// @brief Mux combined version number.

modules/mux/source/command_buffer.cpp

@@ -160,10 +160,6 @@ mux_result_t muxCommandCopyBuffer(mux_command_buffer_t command_buffer,
     return mux_error_invalid_value;
   }
 
-  if (0 == size) {
-    return mux_error_invalid_value;
-  }
-
   if ((size + src_offset) > src_buffer->memory_requirements.size) {
     return mux_error_invalid_value;
   }
@@ -350,10 +346,6 @@ mux_result_t muxCommandFillBuffer(mux_command_buffer_t command_buffer,
     return mux_error_invalid_value;
   }
 
-  if (0 == size) {
-    return mux_error_invalid_value;
-  }
-
   if ((size + offset) > buffer->memory_requirements.size) {
     return mux_error_invalid_value;
   }
@@ -397,10 +389,6 @@ mux_result_t muxCommandReadBuffer(mux_command_buffer_t command_buffer,
     return mux_error_invalid_value;
   }
 
-  if (0 == size) {
-    return mux_error_invalid_value;
-  }
-
   if ((size + offset) > buffer->memory_requirements.size) {
     return mux_error_invalid_value;
   }
@@ -552,10 +540,6 @@ mux_result_t muxCommandWriteBuffer(mux_command_buffer_t command_buffer,
     return mux_error_invalid_value;
   }
 
-  if (0 == size) {
-    return mux_error_invalid_value;
-  }
-
   if ((size + offset) > buffer->memory_requirements.size) {
     return mux_error_invalid_value;
   }

modules/mux/targets/host/include/host/host.h

@@ -29,7 +29,7 @@ extern "C" {
 /// @brief Host major version number.
 #define HOST_MAJOR_VERSION 0
 /// @brief Host minor version number.
-#define HOST_MINOR_VERSION 80
+#define HOST_MINOR_VERSION 81
 /// @brief Host patch version number.
 #define HOST_PATCH_VERSION 0
 /// @brief Host combined version number.

modules/mux/targets/host/source/queue.cpp

@@ -94,6 +94,10 @@ void commandWriteBuffer(host::command_info_s *info) {
 void commandFillBuffer(host::command_info_s *info) {
   host::command_info_fill_buffer_s *const fill = &(info->fill_command);
 
+  if (!fill->size) {
+    return;
+  }
+
   auto buffer = static_cast<host::buffer_s *>(fill->buffer);
 
   size_t size = fill->pattern_size;

modules/mux/targets/riscv/include/riscv/riscv.h

@@ -29,7 +29,7 @@ extern "C" {
 /// @brief Riscv major version number.
 #define RISCV_MAJOR_VERSION 0
 /// @brief Riscv minor version number.
-#define RISCV_MINOR_VERSION 80
+#define RISCV_MINOR_VERSION 81
 /// @brief Riscv patch version number.
 #define RISCV_PATCH_VERSION 0
 /// @brief Riscv combined version number.