[PATCH 4/4] drm/amdkfd: Add support for user-mode trap handlers

Oded Gabbay oded.gabbay at gmail.com
Tue Nov 21 11:50:13 UTC 2017


Hi Felix,
I added all 4 patches to -next.
Oded

On Tue, Nov 14, 2017 at 11:41 PM, Felix Kuehling <Felix.Kuehling at amd.com> wrote:
> A second-level user mode trap handler can be installed. The CWSR trap
> handler jumps to the secondary trap handler conditionally for any
> conditions not handled by it. This can be used e.g. for debugging or
> catching math exceptions.
>
> When CWSR is disabled, the user mode trap handler is installed as
> first level trap handler.
>
> Signed-off-by: Shaoyun.liu <shaoyun.liu at amd.com>
> Signed-off-by: Jay Cornwall <Jay.Cornwall at amd.com>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_chardev.c           | 37 +++++++++++++++++++++-
>  .../gpu/drm/amd/amdkfd/kfd_device_queue_manager.c  | 22 +++++++++++++
>  .../gpu/drm/amd/amdkfd/kfd_device_queue_manager.h  |  5 +++
>  include/uapi/linux/kfd_ioctl.h                     | 12 ++++++-
>  4 files changed, 74 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> index 2a4612d..cc61ec2 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> @@ -432,6 +432,38 @@ static int kfd_ioctl_set_memory_policy(struct file *filep,
>         return err;
>  }
>
> +static int kfd_ioctl_set_trap_handler(struct file *filep,
> +                                       struct kfd_process *p, void *data)
> +{
> +       struct kfd_ioctl_set_trap_handler_args *args = data;
> +       struct kfd_dev *dev;
> +       int err = 0;
> +       struct kfd_process_device *pdd;
> +
> +       dev = kfd_device_by_id(args->gpu_id);
> +       if (dev == NULL)
> +               return -EINVAL;
> +
> +       mutex_lock(&p->mutex);
> +
> +       pdd = kfd_bind_process_to_device(dev, p);
> +       if (IS_ERR(pdd)) {
> +               err = -ESRCH;
> +               goto out;
> +       }
> +
> +       if (dev->dqm->ops.set_trap_handler(dev->dqm,
> +                                       &pdd->qpd,
> +                                       args->tba_addr,
> +                                       args->tma_addr))
> +               err = -EINVAL;
> +
> +out:
> +       mutex_unlock(&p->mutex);
> +
> +       return err;
> +}
> +
>  static int kfd_ioctl_dbg_register(struct file *filep,
>                                 struct kfd_process *p, void *data)
>  {
> @@ -980,7 +1012,10 @@ static const struct amdkfd_ioctl_desc amdkfd_ioctls[] = {
>                         kfd_ioctl_set_scratch_backing_va, 0),
>
>         AMDKFD_IOCTL_DEF(AMDKFD_IOC_GET_TILE_CONFIG,
> -                       kfd_ioctl_get_tile_config, 0)
> +                       kfd_ioctl_get_tile_config, 0),
> +
> +       AMDKFD_IOCTL_DEF(AMDKFD_IOC_SET_TRAP_HANDLER,
> +                       kfd_ioctl_set_trap_handler, 0),
>  };
>
>  #define AMDKFD_CORE_IOCTL_COUNT        ARRAY_SIZE(amdkfd_ioctls)
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> index 5c06502..8447810 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> @@ -1116,6 +1116,26 @@ static bool set_cache_memory_policy(struct device_queue_manager *dqm,
>         return retval;
>  }
>
> +static int set_trap_handler(struct device_queue_manager *dqm,
> +                               struct qcm_process_device *qpd,
> +                               uint64_t tba_addr,
> +                               uint64_t tma_addr)
> +{
> +       uint64_t *tma;
> +
> +       if (dqm->dev->cwsr_enabled) {
> +               /* Jump from CWSR trap handler to user trap */
> +               tma = (uint64_t *)(qpd->cwsr_kaddr + KFD_CWSR_TMA_OFFSET);
> +               tma[0] = tba_addr;
> +               tma[1] = tma_addr;
> +       } else {
> +               qpd->tba_addr = tba_addr;
> +               qpd->tma_addr = tma_addr;
> +       }
> +
> +       return 0;
> +}
> +
>  static int process_termination_nocpsch(struct device_queue_manager *dqm,
>                 struct qcm_process_device *qpd)
>  {
> @@ -1247,6 +1267,7 @@ struct device_queue_manager *device_queue_manager_init(struct kfd_dev *dev)
>                 dqm->ops.create_kernel_queue = create_kernel_queue_cpsch;
>                 dqm->ops.destroy_kernel_queue = destroy_kernel_queue_cpsch;
>                 dqm->ops.set_cache_memory_policy = set_cache_memory_policy;
> +               dqm->ops.set_trap_handler = set_trap_handler;
>                 dqm->ops.process_termination = process_termination_cpsch;
>                 break;
>         case KFD_SCHED_POLICY_NO_HWS:
> @@ -1262,6 +1283,7 @@ struct device_queue_manager *device_queue_manager_init(struct kfd_dev *dev)
>                 dqm->ops.initialize = initialize_nocpsch;
>                 dqm->ops.uninitialize = uninitialize;
>                 dqm->ops.set_cache_memory_policy = set_cache_memory_policy;
> +               dqm->ops.set_trap_handler = set_trap_handler;
>                 dqm->ops.process_termination = process_termination_nocpsch;
>                 break;
>         default:
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h
> index 5b77cb6..8752edf 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h
> @@ -123,6 +123,11 @@ struct device_queue_manager_ops {
>                                            void __user *alternate_aperture_base,
>                                            uint64_t alternate_aperture_size);
>
> +       int     (*set_trap_handler)(struct device_queue_manager *dqm,
> +                                   struct qcm_process_device *qpd,
> +                                   uint64_t tba_addr,
> +                                   uint64_t tma_addr);
> +
>         int (*process_termination)(struct device_queue_manager *dqm,
>                         struct qcm_process_device *qpd);
>  };
> diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h
> index 7039f16..4c58795 100644
> --- a/include/uapi/linux/kfd_ioctl.h
> +++ b/include/uapi/linux/kfd_ioctl.h
> @@ -262,6 +262,13 @@ struct kfd_ioctl_get_tile_config_args {
>          */
>  };
>
> +struct kfd_ioctl_set_trap_handler_args {
> +       uint64_t tba_addr;              /* to KFD */
> +       uint64_t tma_addr;              /* to KFD */
> +       uint32_t gpu_id;                /* to KFD */
> +       uint32_t pad;
> +};
> +
>  #define AMDKFD_IOCTL_BASE 'K'
>  #define AMDKFD_IO(nr)                  _IO(AMDKFD_IOCTL_BASE, nr)
>  #define AMDKFD_IOR(nr, type)           _IOR(AMDKFD_IOCTL_BASE, nr, type)
> @@ -322,7 +329,10 @@ struct kfd_ioctl_get_tile_config_args {
>  #define AMDKFD_IOC_GET_TILE_CONFIG                                      \
>                 AMDKFD_IOWR(0x12, struct kfd_ioctl_get_tile_config_args)
>
> +#define AMDKFD_IOC_SET_TRAP_HANDLER            \
> +               AMDKFD_IOW(0x13, struct kfd_ioctl_set_trap_handler_args)
> +
>  #define AMDKFD_COMMAND_START           0x01
> -#define AMDKFD_COMMAND_END             0x13
> +#define AMDKFD_COMMAND_END             0x14
>
>  #endif
> --
> 2.7.4
>


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