| Name |
| |
| ARM_shared_virtual_memory |
| |
| Name Strings |
| |
| cl_arm_shared_virtual_memory |
| |
| Contributors |
| |
| Robert Elliott, ARM |
| Mats Petersson, ARM |
| |
| Contact |
| |
| Robert Elliott, ARM (robert.elliott 'at' ARM.com) |
| |
| IP Status |
| |
| No claims or disclosures are known to exist. |
| |
| Version |
| |
| Revision: #2, Mar 14th, 2018 |
| |
| Number |
| |
| OpenCL Extension #40 |
| |
| Status |
| |
| Deprecated in favour of the equivalent OpenCL 2.0 feature. |
| |
| Extension Type |
| |
| OpenCL device extension |
| |
| Dependencies |
| |
| Requires OpenCL version 1.2 or later. |
| |
| Overview |
| |
| This extension enables the shared virtual memory features in |
| versions prior to 2.0 as described in OpenCL version 2.0 section |
| 3. |
| |
| The C11 style atomics provided in OpenCL C version 2.0 is also |
| supported, with the exception that generic address space is not |
| supported. For these functions, address space specific variants |
| have been provided. |
| |
| Memory allocated through clSVMAllocARM can be used as host_ptr |
| passed to clCreateImage and clCreateBuffer, as per 5.6.1 in the |
| OpenCL 2.0 specification. |
| |
| Header File |
| |
| cl_ext.h |
| |
| New Types |
| |
| Atomic types according to OpenCL C version 2.0 section: |
| Memory order 6.13.11.3 |
| Memory scope 6.13.11.4 |
| Atomic integer and floating-point types 6.13.11.6 |
| |
| New host types |
| |
| The following types are added to allow the arguments to the |
| functions described below. Bitfield types are using the same |
| bit values as their CL 2.0 counterparts. The cl_kernel_exec_info_arm |
| type uses the new tokens CL_KERNEL_EXEC_INFO_SVM_PTRS_ARM and |
| CL_KERNEL_EXEC_INFO_SVM_FINE_GRAIN_SYSTEM_ARM. |
| |
| typedef cl_bitfield cl_svm_mem_flags_arm; |
| typedef cl_uint cl_kernel_exec_info_arm; |
| typedef cl_bitfield cl_device_svm_capabilities_arm; |
| |
| New Procedures and Functions |
| |
| Built-in Function |
| |
| Atomic C11 functions as per OpenCL C version 2.0 section 6.13.11. |
| Program scope variables and generic address space are not |
| supported. |
| |
| Examples that should work: |
| |
| kernel nuclear_reactor() |
| { |
| local volatile atomic_int destMemory; |
| int value = 42; |
| int old_value = atomic_fetch_max( &destMemory, value ); |
| } |
| |
| kernel nuclear_reactor(global atomic_int *destMemory) |
| { |
| int value = 42; |
| int oldValue = atomic_fetch_max( destMemory, value ); |
| } |
| |
| The following is not expected to work: |
| |
| global atomic_int globalAtomic; |
| |
| kernel nuclear_reactor() |
| { |
| int value = 42; |
| int old_value = atomic_fetch_max( &globalAtomic, value ); |
| } |
| |
| /* This is an example showing exolicit need for generic |
| addresss space by mixing local and global in the same atomic |
| call. */ |
| kernel nuclear_reactor(global atomic_int *destMemory, int choice) |
| { |
| local atomic_int localMemory; |
| int value = 42; |
| int oldValue = atomic_fetch_max( (choice) ? destMemory : &localMemory, |
| value ); |
| } |
| |
| To make this example work: |
| |
| /* This is an example showing exolicit need for generic |
| addresss space by mixing local and global in the same atomic |
| call. */ |
| kernel nuclear_reactor(global atomic_int *destMemory, int choice) |
| { |
| local atomic_int localMemory; |
| int value = 42; |
| |
| int oldValue; |
| |
| if (choice) |
| oldValue = atomic_fetch_max( destMemory, value ); |
| else |
| oldValue = atomic_fetch_max( &localMemory, value ); |
| } |
| |
| |
| Description |
| |
| See OpenCL C version 2.0 section 6.13.11. Note however that |
| generic address space is not supported, so the are supported for |
| the private, local and global address spaces. |
| |
| To enable this functionality, the compiler option '-cl-arm-svm' |
| should be passed as an option to the relevant clBuildProgram |
| or clCompileProgram call. |
| |
| Driver functions |
| |
| The following new functions are added to allow shared virtual |
| memory to be allocated, deallocated and accessed. For |
| description see OpenCL 2.0 section 5.6. |
| |
| clEnqueueSVMMapARM |
| clEnqueueSVMUnmapARM |
| clSVMAllocARM |
| clSVMFreeARM |
| clEnqueueSVMFreeARM |
| clEnqueueSVMMemcpyARM |
| clEnqueueSVMMemFillARM |
| |
| Functions for kernels and their arguments are added, as per OpenCL |
| version 2.0 section 5.9.2. |
| |
| clSetKernelArgSVMPointerARM |
| clSetKernelExecInfoARM |
| |
| Changes to existing functions: |
| The clGetDeviceInfo function now accepts an additional enumeration |
| to get the SVM capabilities: CL_DEVICE_SVM_CAPABILITIES_ARM, see |
| section 4.2 of OpenCL version 2.0. |
| |
| The clGetMemObjectInfo will accept a param_name of |
| CL_MEM_USES_SVM_POINTER_ARM, as per section 5.5.5 of OpenCL |
| version 2.0. |
| |
| The clGetEventInfo function to respond to CL_EVENT_COMMAND_TYPE |
| with a CL_COMMAND_SVM_xxx_ARM as per section 5.11 of OpenCL version |
| 2.0. Note that if the driver is built as a CL2.0 driver, the value |
| returned by clGetEventInfo will be the one described in te CL2.0 |
| specification even when using the extension calls. |
| |
| New Tokens |
| |
| The following new attributes and properties are added: |
| |
| To be used by clGetDeviceInfo |
| #define CL_DEVICE_SVM_CAPABILITIES_ARM 0x40B6 |
| |
| #define CL_MEM_USES_SVM_POINTER_ARM 0x40B7 |
| |
| To be used by clSetKernelExecInfoARM: |
| #define CL_KERNEL_EXEC_INFO_SVM_PTRS_ARM 0x40B8 |
| #define CL_KERNEL_EXEC_INFO_SVM_FINE_GRAIN_SYSTEM_ARM 0x40B9 |
| |
| To be used by clGetEventInfo: |
| #define CL_COMMAND_SVM_FREE_ARM 0x40BA |
| #define CL_COMMAND_SVM_MEMCPY_ARM 0x40BB |
| #define CL_COMMAND_SVM_MEMFILL_ARM 0x40BC |
| #define CL_COMMAND_SVM_MAP_ARM 0x40BD |
| #define CL_COMMAND_SVM_UNMAP_ARM 0x40BE |
| |
| Flag values returned by clGetDeviceInfo with |
| CL_DEVICE_SVM_CAPABILITIES_ARM as the param_name. |
| |
| #define CL_DEVICE_SVM_COARSE_GRAIN_BUFFER_ARM (1 << 0) |
| #define CL_DEVICE_SVM_FINE_GRAIN_BUFFER_ARM (1 << 1) |
| #define CL_DEVICE_SVM_FINE_GRAIN_SYSTEM_ARM (1 << 2) |
| #define CL_DEVICE_SVM_ATOMICS_ARM (1 << 3) |
| |
| Flag values used by clSVMAllocARM: |
| #define CL_MEM_SVM_FINE_GRAIN_BUFFER_ARM (1 << 10) |
| #define CL_MEM_SVM_ATOMICS_ARM (1 << 11) |
| |
| Revision History |
| |
| Revision: #1, Mar 15th, 2016 - Initial revision |
| Revision: #2, Mar 14th, 2018 - Deprecate the extension |
