[PATCH v2 00/25] AMDKFD kernel driver

From: Oded Gabbay
Date: Thu Jul 17 2014 - 09:57:51 EST


Forgot to cc mailing list on cover letter. Sorry.

As a continuation to the existing discussion, here is a v2 patch series restructured with a cleaner history and no totally-different-early-versions of the code.

Instead of 83 patches, there are now a total of 25 patches, where 5 of them
are modifications to radeon driver and 18 of them include only amdkfd code.
There is no code going away or even modified between patches, only added.

The driver was renamed from radeon_kfd to amdkfd and moved to reside under
drm/radeon/amdkfd. This move was done to emphasize the fact that this driver is an AMD-only driver at this point. Having said that, we do foresee a generic hsa framework being implemented in the future and in that case, we will adjust amdkfd to work within that framework.

As the amdkfd driver should support multiple AMD gfx drivers, we want to keep it as a seperate driver from radeon. Therefore, the amdkfd code is contained in its own folder. The amdkfd folder was put under the radeon folder because the only AMD gfx driver in the Linux kernel at this point
is the radeon driver. Having said that, we will probably need to move it (maybe to be directly under drm) after we integrate with additional AMD gfx drivers.

For people who like to review using git, the v2 patch set is located at:
http://cgit.freedesktop.org/~gabbayo/linux/log/?h=kfd-next-3.17-v2

Written by Oded Gabbayh <oded.gabbay@xxxxxxx>

Original Cover Letter:

This patch set implements a Heterogeneous System Architecture (HSA) driver for radeon-family GPUs.
HSA allows different processor types (CPUs, DSPs, GPUs, etc..) to share system resources more effectively via HW features including shared pageable memory, userspace-accessible work queues, and platform-level atomics. In addition to the memory protection mechanisms in GPUVM and IOMMUv2, the Sea Islands family of GPUs also performs HW-level validation of commands passed in through the queues (aka rings).

The code in this patch set is intended to serve both as a sample driver for other HSA-compatible hardware devices and as a production driver for radeon-family processors. The code is architected to support multiple CPUs each with connected GPUs, although the current implementation focuses on a single Kaveri/Berlin APU, and works alongside the existing radeon kernel graphics driver (kgd).
AMD GPUs designed for use with HSA (Sea Islands and up) share some hardware functionality between HSA compute and regular gfx/compute (memory, interrupts, registers), while other functionality has been added specifically for HSA compute (hw scheduler for virtualized compute rings). All shared hardware is owned by the radeon graphics driver, and an interface between kfd and kgd allows the kfd to make use of those shared resources, while HSA-specific functionality is managed directly by kfd by submitting packets into an HSA-specific command queue (the "HIQ").

During kfd module initialization a char device node (/dev/kfd) is created (surviving until module exit), with ioctls for queue creation & management, and data structures are initialized for managing HSA device topology.
The rest of the initialization is driven by calls from the radeon kgd at the following points :

- radeon_init (kfd_init)
- radeon_exit (kfd_fini)
- radeon_driver_load_kms (kfd_device_probe, kfd_device_init)
- radeon_driver_unload_kms (kfd_device_fini)

During the probe and init processing per-device data structures are established which connect to the associated graphics kernel driver. This information is exposed to userspace via sysfs, along with a version number allowing userspace to determine if a topology change has occurred while it was reading from sysfs.
The interface between kfd and kgd also allows the kfd to request buffer management services from kgd, and allows kgd to route interrupt requests to kfd code since the interrupt block is shared between regular graphics/compute and HSA compute subsystems in the GPU.

The kfd code works with an open source usermode library ("libhsakmt") which is in the final stages of IP review and should be published in a separate repo over the next few days.
The code operates in one of three modes, selectable via the sched_policy module parameter :

- sched_policy=0 uses a hardware scheduler running in the MEC block within CP, and allows oversubscription (more queues than HW slots)
- sched_policy=1 also uses HW scheduling but does not allow oversubscription, so create_queue requests fail when we run out of HW slots
- sched_policy=2 does not use HW scheduling, so the driver manually assigns queues to HW slots by programming registers

The "no HW scheduling" option is for debug & new hardware bringup only, so has less test coverage than the other options. Default in the current code is "HW scheduling without oversubscription" since that is where we have the most test coverage but we expect to change the default to "HW scheduling with oversubscription" after further testing. This effectively removes the HW limit on the number of work queues available to applications.

Programs running on the GPU are associated with an address space through the VMID field, which is translated to a unique PASID at access time via a set of 16 VMID-to-PASID mapping registers. The available VMIDs (currently 16) are partitioned (under control of the radeon kgd) between current gfx/compute and HSA compute, with each getting 8 in the current code. The VMID-to-PASID mapping registers are updated by the HW scheduler when used, and by driver code if HW scheduling is not being used.
The Sea Islands compute queues use a new "doorbell" mechanism instead of the earlier kernel-managed write pointer registers. Doorbells use a separate BAR dedicated for this purpose, and pages within the doorbell aperture are mapped to userspace (each page mapped to only one user address space). Writes to the doorbell aperture are intercepted by GPU hardware, allowing userspace code to safely manage work queues (rings) without requiring a kernel call for every ring update.
First step for an application process is to open the kfd device. Calls to open create a kfd "process" structure only for the first thread of the process. Subsequent open calls are checked to see if they are from processes using the same mm_struct and, if so, don't do anything. The kfd per-process data lives as long as the mm_struct exists. Each mm_struct is associated with a unique PASID, allowing the IOMMUv2 to make userspace process memory accessible to the GPU.
Next step is for the application to collect topology information via sysfs. This gives userspace enough information to be able to identify specific nodes (processors) in subsequent queue management calls. Application processes can create queues on multiple processors, and processors support queues from multiple processes.
At this point the application can create work queues in userspace memory and pass them through the usermode library to kfd to have them mapped onto HW queue slots so that commands written to the queues can be executed by the GPU. Queue operations specify a processor node, and so the bulk of this code is device-specific.
Written by John Bridgman <John.Bridgman@xxxxxxx>


Alexey Skidanov (1):
amdkfd: Implement the Get Process Aperture IOCTL

Andrew Lewycky (3):
amdkfd: Add basic modules to amdkfd
amdkfd: Add interrupt handling module
amdkfd: Implement the Set Memory Policy IOCTL

Ben Goz (8):
amdkfd: Add queue module
amdkfd: Add mqd_manager module
amdkfd: Add kernel queue module
amdkfd: Add module parameter of scheduling policy
amdkfd: Add packet manager module
amdkfd: Add process queue manager module
amdkfd: Add device queue manager module
amdkfd: Implement the create/destroy/update queue IOCTLs

Evgeny Pinchuk (3):
amdkfd: Add topology module to amdkfd
amdkfd: Implement the Get Clock Counters IOCTL
amdkfd: Implement the PMC Acquire/Release IOCTLs

Oded Gabbay (10):
mm: Add kfd_process pointer to mm_struct
drm/radeon: reduce number of free VMIDs and pipes in KV
drm/radeon/cik: Don't touch int of pipes 1-7
drm/radeon: Report doorbell configuration to amdkfd
drm/radeon: adding synchronization for GRBM GFX
drm/radeon: Add radeon <--> amdkfd interface
Update MAINTAINERS and CREDITS files with amdkfd info
amdkfd: Add IOCTL set definitions of amdkfd
amdkfd: Add amdkfd skeleton driver
amdkfd: Add binding/unbinding calls to amd_iommu driver

CREDITS | 7 +
MAINTAINERS | 10 +
drivers/gpu/drm/radeon/Kconfig | 2 +
drivers/gpu/drm/radeon/Makefile | 3 +
drivers/gpu/drm/radeon/amdkfd/Kconfig | 10 +
drivers/gpu/drm/radeon/amdkfd/Makefile | 14 +
drivers/gpu/drm/radeon/amdkfd/cik_mqds.h | 185 +++
drivers/gpu/drm/radeon/amdkfd/cik_regs.h | 220 ++++
drivers/gpu/drm/radeon/amdkfd/kfd_aperture.c | 123 ++
drivers/gpu/drm/radeon/amdkfd/kfd_chardev.c | 518 +++++++++
drivers/gpu/drm/radeon/amdkfd/kfd_crat.h | 294 +++++
drivers/gpu/drm/radeon/amdkfd/kfd_device.c | 254 ++++
.../drm/radeon/amdkfd/kfd_device_queue_manager.c | 985 ++++++++++++++++
.../drm/radeon/amdkfd/kfd_device_queue_manager.h | 101 ++
drivers/gpu/drm/radeon/amdkfd/kfd_doorbell.c | 264 +++++
drivers/gpu/drm/radeon/amdkfd/kfd_interrupt.c | 161 +++
drivers/gpu/drm/radeon/amdkfd/kfd_kernel_queue.c | 305 +++++
drivers/gpu/drm/radeon/amdkfd/kfd_kernel_queue.h | 66 ++
drivers/gpu/drm/radeon/amdkfd/kfd_module.c | 131 +++
drivers/gpu/drm/radeon/amdkfd/kfd_mqd_manager.c | 291 +++++
drivers/gpu/drm/radeon/amdkfd/kfd_mqd_manager.h | 54 +
drivers/gpu/drm/radeon/amdkfd/kfd_packet_manager.c | 488 ++++++++
drivers/gpu/drm/radeon/amdkfd/kfd_pasid.c | 97 ++
drivers/gpu/drm/radeon/amdkfd/kfd_pm4_headers.h | 682 +++++++++++
drivers/gpu/drm/radeon/amdkfd/kfd_pm4_opcodes.h | 107 ++
drivers/gpu/drm/radeon/amdkfd/kfd_priv.h | 466 ++++++++
drivers/gpu/drm/radeon/amdkfd/kfd_process.c | 405 +++++++
.../drm/radeon/amdkfd/kfd_process_queue_manager.c | 343 ++++++
drivers/gpu/drm/radeon/amdkfd/kfd_queue.c | 109 ++
drivers/gpu/drm/radeon/amdkfd/kfd_topology.c | 1207 ++++++++++++++++++++
drivers/gpu/drm/radeon/amdkfd/kfd_topology.h | 168 +++
drivers/gpu/drm/radeon/amdkfd/kfd_vidmem.c | 96 ++
drivers/gpu/drm/radeon/cik.c | 154 +--
drivers/gpu/drm/radeon/cik_reg.h | 65 ++
drivers/gpu/drm/radeon/cikd.h | 51 +-
drivers/gpu/drm/radeon/radeon.h | 9 +
drivers/gpu/drm/radeon/radeon_device.c | 32 +
drivers/gpu/drm/radeon/radeon_drv.c | 5 +
drivers/gpu/drm/radeon/radeon_kfd.c | 566 +++++++++
drivers/gpu/drm/radeon/radeon_kfd.h | 119 ++
drivers/gpu/drm/radeon/radeon_kms.c | 7 +
include/linux/mm_types.h | 14 +
include/uapi/linux/kfd_ioctl.h | 133 +++
43 files changed, 9226 insertions(+), 95 deletions(-)
create mode 100644 drivers/gpu/drm/radeon/amdkfd/Kconfig
create mode 100644 drivers/gpu/drm/radeon/amdkfd/Makefile
create mode 100644 drivers/gpu/drm/radeon/amdkfd/cik_mqds.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/cik_regs.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_aperture.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_chardev.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_crat.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_device.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_device_queue_manager.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_device_queue_manager.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_doorbell.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_interrupt.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_kernel_queue.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_kernel_queue.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_module.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_mqd_manager.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_mqd_manager.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_packet_manager.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_pasid.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_pm4_headers.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_pm4_opcodes.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_priv.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_process.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_process_queue_manager.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_queue.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_topology.c
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_topology.h
create mode 100644 drivers/gpu/drm/radeon/amdkfd/kfd_vidmem.c
create mode 100644 drivers/gpu/drm/radeon/radeon_kfd.c
create mode 100644 drivers/gpu/drm/radeon/radeon_kfd.h
create mode 100644 include/uapi/linux/kfd_ioctl.h

--
1.9.1

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