[cuda] Port over allocator and buffer implementation (#13985)

This commit ports over existing CUDA driver allocator and buffer
implementation. The main logic is kept as-is, with one noticeable
changes--context wrapper is dropped and fields in it are directly
put in various API calls. This is to make supporting multiple
device and stream easier later. Other changes are just polishing
on comments and errors.

Progress towards #13245

experimental/cuda2/CMakeLists.txt

@@ -17,7 +17,13 @@ iree_cc_library(
     "api.h"
   SRCS
     "api.h"
+    "cuda_allocator.c"
+    "cuda_allocator.h"
+    "cuda_buffer.c"
+    "cuda_buffer.h"
     "cuda_driver.c"
+    "memory_pools.c"
+    "memory_pools.h"
   DEPS
     ::dynamic_symbols
     iree::base

experimental/cuda2/api.h

@@ -16,6 +16,30 @@
 extern "C" {
 #endif  // __cplusplus
 
+//===----------------------------------------------------------------------===//
+// iree_hal_cuda_device_t
+//===----------------------------------------------------------------------===//
+
+// Parameters defining a CUmemoryPool.
+typedef struct iree_hal_cuda2_memory_pool_params_t {
+  // Minimum number of bytes to keep in the pool when trimming with
+  // iree_hal_device_trim.
+  uint64_t minimum_capacity;
+  // Soft maximum number of bytes to keep in the pool.
+  // When more than this is allocated the extra will be freed at the next
+  // device synchronization in order to remain under the threshold.
+  uint64_t release_threshold;
+  // TODO: per-device access permissions array.
+} iree_hal_cuda2_memory_pool_params_t;
+
+// Parameters for each CUmemoryPool used for queue-ordered allocations.
+typedef struct iree_hal_cuda2_memory_pooling_params_t {
+  // Used exclusively for DEVICE_LOCAL allocations.
+  iree_hal_cuda2_memory_pool_params_t device_local;
+  // Used for any host-visible/host-local memory types.
+  iree_hal_cuda2_memory_pool_params_t other;
+} iree_hal_cuda2_memory_pooling_params_t;
+
 //===----------------------------------------------------------------------===//
 // iree_hal_cuda2_driver_t
 //===----------------------------------------------------------------------===//