Re: [PATCH 07/83] drm/radeon: Add kfd-->kgd interface of locking srbm_gfx_cntl register

From: Jerome Glisse
Date: Fri Jul 11 2014 - 12:34:47 EST


On Fri, Jul 11, 2014 at 12:50:07AM +0300, Oded Gabbay wrote:
> This patch adds a new interface to kfd2kgd_calls structure, which
> allows the kfd to lock and unlock the srbm_gfx_cntl register

Why does kfd needs to lock this register if kfd can not access
any of those register ? This sounds broken to me, exposing a
driver internal mutex to another driver is not something i am
fan of.

Cheers,
Jérôme

>
> Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxx>
> ---
> drivers/gpu/drm/radeon/radeon_kfd.c | 20 ++++++++++++++++++++
> include/linux/radeon_kfd.h | 4 ++++
> 2 files changed, 24 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_kfd.c b/drivers/gpu/drm/radeon/radeon_kfd.c
> index 66ee36b..594020e 100644
> --- a/drivers/gpu/drm/radeon/radeon_kfd.c
> +++ b/drivers/gpu/drm/radeon/radeon_kfd.c
> @@ -43,6 +43,10 @@ static void unkmap_mem(struct kgd_dev *kgd, struct kgd_mem *mem);
>
> static uint64_t get_vmem_size(struct kgd_dev *kgd);
>
> +static void lock_srbm_gfx_cntl(struct kgd_dev *kgd);
> +static void unlock_srbm_gfx_cntl(struct kgd_dev *kgd);
> +
> +
> static const struct kfd2kgd_calls kfd2kgd = {
> .allocate_mem = allocate_mem,
> .free_mem = free_mem,
> @@ -51,6 +55,8 @@ static const struct kfd2kgd_calls kfd2kgd = {
> .kmap_mem = kmap_mem,
> .unkmap_mem = unkmap_mem,
> .get_vmem_size = get_vmem_size,
> + .lock_srbm_gfx_cntl = lock_srbm_gfx_cntl,
> + .unlock_srbm_gfx_cntl = unlock_srbm_gfx_cntl,
> };
>
> static const struct kgd2kfd_calls *kgd2kfd;
> @@ -233,3 +239,17 @@ static uint64_t get_vmem_size(struct kgd_dev *kgd)
>
> return rdev->mc.real_vram_size;
> }
> +
> +static void lock_srbm_gfx_cntl(struct kgd_dev *kgd)
> +{
> + struct radeon_device *rdev = (struct radeon_device *)kgd;
> +
> + mutex_lock(&rdev->srbm_mutex);
> +}
> +
> +static void unlock_srbm_gfx_cntl(struct kgd_dev *kgd)
> +{
> + struct radeon_device *rdev = (struct radeon_device *)kgd;
> +
> + mutex_unlock(&rdev->srbm_mutex);
> +}
> diff --git a/include/linux/radeon_kfd.h b/include/linux/radeon_kfd.h
> index c7997d4..40b691c 100644
> --- a/include/linux/radeon_kfd.h
> +++ b/include/linux/radeon_kfd.h
> @@ -81,6 +81,10 @@ struct kfd2kgd_calls {
> void (*unkmap_mem)(struct kgd_dev *kgd, struct kgd_mem *mem);
>
> uint64_t (*get_vmem_size)(struct kgd_dev *kgd);
> +
> + /* SRBM_GFX_CNTL mutex */
> + void (*lock_srbm_gfx_cntl)(struct kgd_dev *kgd);
> + void (*unlock_srbm_gfx_cntl)(struct kgd_dev *kgd);
> };
>
> bool kgd2kfd_init(unsigned interface_version,
> --
> 1.9.1
>
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