Re: [PATCH 05/83] drm/radeon: Add kfd-->kgd interface to get virtual ram size

[Jerome Glisse <j.glisse@gmail.com>]

On Fri, Jul 11, 2014 at 12:50:05AM +0300, Oded Gabbay wrote:
> This patch adds a new interface to kfd2kgd_calls structure so that
> the kfd driver could get the virtual ram size of a specific
> radeon device.
> 
> Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>

What is vmem_size ? This need to be documented. I assume this is the
number of bits the gpu can handle and i would assume that the minimum
requirement is that the device have at least as many bit as the cpu ?
ie on 48bits x86-64 the hardware also needs to support that.

Otherwise this sounds like broken things can happen.

Cheers,
Jérôme

> ---
>  drivers/gpu/drm/radeon/radeon_kfd.c | 12 ++++++++++++
>  include/linux/radeon_kfd.h          |  1 +
>  2 files changed, 13 insertions(+)
> 
> diff --git a/drivers/gpu/drm/radeon/radeon_kfd.c b/drivers/gpu/drm/radeon/radeon_kfd.c
> index 7c7f808..1b859b5 100644
> --- a/drivers/gpu/drm/radeon/radeon_kfd.c
> +++ b/drivers/gpu/drm/radeon/radeon_kfd.c
> @@ -25,7 +25,10 @@
>  #include <drm/drmP.h>
>  #include "radeon.h"
>  
> +static uint64_t get_vmem_size(struct kgd_dev *kgd);
> +
>  static const struct kfd2kgd_calls kfd2kgd = {
> +	.get_vmem_size = get_vmem_size,
>  };
>  
>  static const struct kgd2kfd_calls *kgd2kfd;
> @@ -92,3 +95,12 @@ void radeon_kfd_device_fini(struct radeon_device *rdev)
>  		rdev->kfd = NULL;
>  	}
>  }
> +
> +static uint64_t get_vmem_size(struct kgd_dev *kgd)
> +{
> +	struct radeon_device *rdev = (struct radeon_device *)kgd;
> +
> +	BUG_ON(kgd == NULL);
> +
> +	return rdev->mc.real_vram_size;
> +}
> diff --git a/include/linux/radeon_kfd.h b/include/linux/radeon_kfd.h
> index 59785e9..28cddf5 100644
> --- a/include/linux/radeon_kfd.h
> +++ b/include/linux/radeon_kfd.h
> @@ -57,6 +57,7 @@ struct kgd2kfd_calls {
>  };
>  
>  struct kfd2kgd_calls {
> +	uint64_t (*get_vmem_size)(struct kgd_dev *kgd);
>  };
>  
>  bool kgd2kfd_init(unsigned interface_version,
> -- 
> 1.9.1
>