[PATCH 07/21] drm/amdkfd: Clean up KFD_MMAP_ offset handling

Oded Gabbay oded.gabbay at gmail.com
Fri May 11 08:52:50 UTC 2018


On Wed, Apr 11, 2018 at 12:33 AM, Felix Kuehling <Felix.Kuehling at amd.com> wrote:
> From: Harish Kasiviswanathan <Harish.Kasiviswanathan at amd.com>
>
> Use bit-rotate for better clarity and remove _MASK from the #defines as
> these represent mmap types.
>
> Centralize all the parsing of the mmap offset in kfd_mmap and add device
> parameter to doorbell and reserved_mem map functions.
>
> Encode gpu_id into upper bits of vm_pgoff. This frees up the lower bits
> for encoding the the doorbell ID on Vega10.
>
> Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan at amd.com>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_chardev.c  | 35 ++++++++++++++++++----------
>  drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c |  9 ++------
>  drivers/gpu/drm/amd/amdkfd/kfd_events.c   |  2 +-
>  drivers/gpu/drm/amd/amdkfd/kfd_priv.h     | 38 ++++++++++++++++++++++++-------
>  drivers/gpu/drm/amd/amdkfd/kfd_process.c  |  8 +++----
>  5 files changed, 59 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> index b5e5f0e..f6b35f4 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> @@ -292,7 +292,8 @@ static int kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
>
>
>         /* Return gpu_id as doorbell offset for mmap usage */
> -       args->doorbell_offset = (KFD_MMAP_DOORBELL_MASK | args->gpu_id);
> +       args->doorbell_offset = KFD_MMAP_TYPE_DOORBELL;
> +       args->doorbell_offset |= KFD_MMAP_GPU_ID(args->gpu_id);
>         args->doorbell_offset <<= PAGE_SHIFT;
>
>         mutex_unlock(&p->mutex);
> @@ -1645,23 +1646,33 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
>  static int kfd_mmap(struct file *filp, struct vm_area_struct *vma)
>  {
>         struct kfd_process *process;
> +       struct kfd_dev *dev = NULL;
> +       unsigned long vm_pgoff;
> +       unsigned int gpu_id;
>
>         process = kfd_get_process(current);
>         if (IS_ERR(process))
>                 return PTR_ERR(process);
>
> -       if ((vma->vm_pgoff & KFD_MMAP_DOORBELL_MASK) ==
> -                       KFD_MMAP_DOORBELL_MASK) {
> -               vma->vm_pgoff = vma->vm_pgoff ^ KFD_MMAP_DOORBELL_MASK;
> -               return kfd_doorbell_mmap(process, vma);
> -       } else if ((vma->vm_pgoff & KFD_MMAP_EVENTS_MASK) ==
> -                       KFD_MMAP_EVENTS_MASK) {
> -               vma->vm_pgoff = vma->vm_pgoff ^ KFD_MMAP_EVENTS_MASK;
> +       vm_pgoff = vma->vm_pgoff;
> +       vma->vm_pgoff = KFD_MMAP_OFFSET_VALUE_GET(vm_pgoff);
> +       gpu_id = KFD_MMAP_GPU_ID_GET(vm_pgoff);
> +       if (gpu_id)
> +               dev = kfd_device_by_id(gpu_id);
> +
> +       switch (vm_pgoff & KFD_MMAP_TYPE_MASK) {
> +       case KFD_MMAP_TYPE_DOORBELL:
> +               if (!dev)
> +                       return -ENODEV;
> +               return kfd_doorbell_mmap(dev, process, vma);
> +
> +       case KFD_MMAP_TYPE_EVENTS:
>                 return kfd_event_mmap(process, vma);
> -       } else if ((vma->vm_pgoff & KFD_MMAP_RESERVED_MEM_MASK) ==
> -                       KFD_MMAP_RESERVED_MEM_MASK) {
> -               vma->vm_pgoff = vma->vm_pgoff ^ KFD_MMAP_RESERVED_MEM_MASK;
> -               return kfd_reserved_mem_mmap(process, vma);
> +
> +       case KFD_MMAP_TYPE_RESERVED_MEM:
> +               if (!dev)
> +                       return -ENODEV;
> +               return kfd_reserved_mem_mmap(dev, process, vma);
>         }
>
>         return -EFAULT;
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> index 4840314..efc59de 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> @@ -126,15 +126,10 @@ void kfd_doorbell_fini(struct kfd_dev *kfd)
>                 iounmap(kfd->doorbell_kernel_ptr);
>  }
>
> -int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma)
> +int kfd_doorbell_mmap(struct kfd_dev *dev, struct kfd_process *process,
> +                     struct vm_area_struct *vma)
>  {
>         phys_addr_t address;
> -       struct kfd_dev *dev;
> -
> -       /* Find kfd device according to gpu id */
> -       dev = kfd_device_by_id(vma->vm_pgoff);
> -       if (!dev)
> -               return -EINVAL;
>
>         /*
>          * For simplicitly we only allow mapping of the entire doorbell
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
> index 4890a90..bccf2f7 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
> @@ -345,7 +345,7 @@ int kfd_event_create(struct file *devkfd, struct kfd_process *p,
>         case KFD_EVENT_TYPE_DEBUG:
>                 ret = create_signal_event(devkfd, p, ev);
>                 if (!ret) {
> -                       *event_page_offset = KFD_MMAP_EVENTS_MASK;
> +                       *event_page_offset = KFD_MMAP_TYPE_EVENTS;
>                         *event_page_offset <<= PAGE_SHIFT;
>                         *event_slot_index = ev->event_id;
>                 }
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> index d9c0fe12..2d575c0 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> @@ -41,9 +41,33 @@
>
>  #define KFD_SYSFS_FILE_MODE 0444
>
> -#define KFD_MMAP_DOORBELL_MASK 0x8000000000000ull
> -#define KFD_MMAP_EVENTS_MASK 0x4000000000000ull
> -#define KFD_MMAP_RESERVED_MEM_MASK 0x2000000000000ull
> +/* GPU ID hash width in bits */
> +#define KFD_GPU_ID_HASH_WIDTH 16
> +
> +/* Use upper bits of mmap offset to store KFD driver specific information.
> + * BITS[63:62] - Encode MMAP type
> + * BITS[61:46] - Encode gpu_id. To identify to which GPU the offset belongs to
> + * BITS[45:0]  - MMAP offset value
> + *
> + * NOTE: struct vm_area_struct.vm_pgoff uses offset in pages. Hence, these
> + *  defines are w.r.t to PAGE_SIZE
> + */
> +#define KFD_MMAP_TYPE_SHIFT    (62 - PAGE_SHIFT)
> +#define KFD_MMAP_TYPE_MASK     (0x3ULL << KFD_MMAP_TYPE_SHIFT)
> +#define KFD_MMAP_TYPE_DOORBELL (0x3ULL << KFD_MMAP_TYPE_SHIFT)
> +#define KFD_MMAP_TYPE_EVENTS   (0x2ULL << KFD_MMAP_TYPE_SHIFT)
> +#define KFD_MMAP_TYPE_RESERVED_MEM     (0x1ULL << KFD_MMAP_TYPE_SHIFT)

Isn't this new definition breaks existing user-space library (kfd thunk) ?
If that is the case we have a problem here.

Oded


> +
> +#define KFD_MMAP_GPU_ID_SHIFT (46 - PAGE_SHIFT)
> +#define KFD_MMAP_GPU_ID_MASK (((1ULL << KFD_GPU_ID_HASH_WIDTH) - 1) \
> +                               << KFD_MMAP_GPU_ID_SHIFT)
> +#define KFD_MMAP_GPU_ID(gpu_id) ((((uint64_t)gpu_id) << KFD_MMAP_GPU_ID_SHIFT)\
> +                               & KFD_MMAP_GPU_ID_MASK)
> +#define KFD_MMAP_GPU_ID_GET(offset)    ((offset & KFD_MMAP_GPU_ID_MASK) \
> +                               >> KFD_MMAP_GPU_ID_SHIFT)
> +
> +#define KFD_MMAP_OFFSET_VALUE_MASK     (0x3FFFFFFFFFFFULL >> PAGE_SHIFT)
> +#define KFD_MMAP_OFFSET_VALUE_GET(offset) (offset & KFD_MMAP_OFFSET_VALUE_MASK)
>
>  /*
>   * When working with cp scheduler we should assign the HIQ manually or via
> @@ -55,9 +79,6 @@
>  #define KFD_CIK_HIQ_PIPE 4
>  #define KFD_CIK_HIQ_QUEUE 0
>
> -/* GPU ID hash width in bits */
> -#define KFD_GPU_ID_HASH_WIDTH 16
> -
>  /* Macro for allocating structures */
>  #define kfd_alloc_struct(ptr_to_struct)        \
>         ((typeof(ptr_to_struct)) kzalloc(sizeof(*ptr_to_struct), GFP_KERNEL))
> @@ -698,7 +719,7 @@ struct kfd_process_device *kfd_get_process_device_data(struct kfd_dev *dev,
>  struct kfd_process_device *kfd_create_process_device_data(struct kfd_dev *dev,
>                                                         struct kfd_process *p);
>
> -int kfd_reserved_mem_mmap(struct kfd_process *process,
> +int kfd_reserved_mem_mmap(struct kfd_dev *dev, struct kfd_process *process,
>                           struct vm_area_struct *vma);
>
>  /* KFD process API for creating and translating handles */
> @@ -728,7 +749,8 @@ void kfd_pasid_free(unsigned int pasid);
>  /* Doorbells */
>  int kfd_doorbell_init(struct kfd_dev *kfd);
>  void kfd_doorbell_fini(struct kfd_dev *kfd);
> -int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma);
> +int kfd_doorbell_mmap(struct kfd_dev *dev, struct kfd_process *process,
> +                     struct vm_area_struct *vma);
>  void __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
>                                         unsigned int *doorbell_off);
>  void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr);
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> index 2791e72..131fe2a 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> @@ -451,7 +451,8 @@ static int kfd_process_init_cwsr_apu(struct kfd_process *p, struct file *filep)
>                 if (!dev->cwsr_enabled || qpd->cwsr_kaddr || qpd->cwsr_base)
>                         continue;
>
> -               offset = (dev->id | KFD_MMAP_RESERVED_MEM_MASK) << PAGE_SHIFT;
> +               offset = (KFD_MMAP_TYPE_RESERVED_MEM | KFD_MMAP_GPU_ID(dev->id))
> +                       << PAGE_SHIFT;
>                 qpd->tba_addr = (int64_t)vm_mmap(filep, 0,
>                         KFD_CWSR_TBA_TMA_SIZE, PROT_READ | PROT_EXEC,
>                         MAP_SHARED, offset);
> @@ -989,15 +990,12 @@ int kfd_resume_all_processes(void)
>         return ret;
>  }
>
> -int kfd_reserved_mem_mmap(struct kfd_process *process,
> +int kfd_reserved_mem_mmap(struct kfd_dev *dev, struct kfd_process *process,
>                           struct vm_area_struct *vma)
>  {
> -       struct kfd_dev *dev = kfd_device_by_id(vma->vm_pgoff);
>         struct kfd_process_device *pdd;
>         struct qcm_process_device *qpd;
>
> -       if (!dev)
> -               return -EINVAL;
>         if ((vma->vm_end - vma->vm_start) != KFD_CWSR_TBA_TMA_SIZE) {
>                 pr_err("Incorrect CWSR mapping size.\n");
>                 return -EINVAL;
> --
> 2.7.4
>


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