SYCL: implement memset ggml backend buffer interface (llama/12580)

* SYCL: implement memset ggml backend buffer interface

* use GGML_ABORT macro

* Do not wait for all queues to finish for memset operation

ggml/src/ggml-sycl/ggml-sycl.cpp

@@ -37,6 +37,7 @@
 #include "ggml-backend-impl.h"
 
 #include "ggml-sycl/backend.hpp"
+#include "ggml-sycl/common.hpp"
 #include "ggml-sycl/presets.hpp"
 #include "ggml-sycl/gemm.hpp"
 #include "ggml-sycl/sycl_hw.hpp"
@@ -490,6 +491,23 @@ catch (sycl::exception const &exc) {
   std::exit(1);
 }
 
+static void ggml_backend_sycl_buffer_memset_tensor(ggml_backend_buffer_t buffer, ggml_tensor * tensor, uint8_t value,
+                                                   size_t offset, size_t size) {
+    GGML_SYCL_DEBUG(" [SYCL] call %s\n", __func__);
+    ggml_backend_sycl_buffer_context * ctx = (ggml_backend_sycl_buffer_context *) buffer->context;
+    SYCL_CHECK(ggml_sycl_set_device(ctx->device));
+    auto stream = &(dpct::dev_mgr::instance().get_device(ctx->device).default_queue());
+    if (size == 0) {
+        return;  // Nothing to do
+    }
+    if (tensor->data == nullptr) {
+        GGML_ABORT("Error: Tensor data pointer is null.\n");
+    }
+    void * target_ptr = static_cast<char *>(tensor->data) + offset;
+    SYCL_CHECK(CHECK_TRY_ERROR((*stream).memset(target_ptr, value, size)));
+    SYCL_CHECK(CHECK_TRY_ERROR((*stream).wait()));
+}
+
 static void ggml_backend_sycl_buffer_reset(ggml_backend_buffer_t buffer) {
     GGML_SYCL_DEBUG("[SYCL] call %s\n", __func__);
     if (buffer == nullptr) {
@@ -510,7 +528,7 @@ static const ggml_backend_buffer_i ggml_backend_sycl_buffer_interface = {
     /* .free_buffer     = */ ggml_backend_sycl_buffer_free_buffer,
     /* .get_base        = */ ggml_backend_sycl_buffer_get_base,
     /* .init_tensor     = */ ggml_backend_sycl_buffer_init_tensor,
-    /* .memset_tensor   = */ NULL,
+    /* .memset_tensor   = */ ggml_backend_sycl_buffer_memset_tensor,
     /* .set_tensor      = */ ggml_backend_sycl_buffer_set_tensor,
     /* .get_tensor      = */ ggml_backend_sycl_buffer_get_tensor,
     /* .cpy_tensor      = */ ggml_backend_sycl_buffer_cpy_tensor,