Re: [RFC 13/16] drm/nouveau/ibus: add GK20A support

[Ilia Mirkin <imirkin@alum.mit.edu>]

Some very trivial comments below:

On Fri, Jan 31, 2014 at 10:16 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> Add support for initializing the priv ring of GK20A. This is done by the
> BIOS on desktop GPUs, but needs to be done by hand on Tegra.
>
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
>  drivers/gpu/drm/nouveau/Makefile                   |   1 +
>  drivers/gpu/drm/nouveau/core/include/subdev/ibus.h |   1 +
>  drivers/gpu/drm/nouveau/core/subdev/ibus/nvea.c    | 108 +++++++++++++++++++++
>  3 files changed, 110 insertions(+)
>  create mode 100644 drivers/gpu/drm/nouveau/core/subdev/ibus/nvea.c
>
> diff --git a/drivers/gpu/drm/nouveau/Makefile b/drivers/gpu/drm/nouveau/Makefile
> index 6c4b76d..3548fcd 100644
> --- a/drivers/gpu/drm/nouveau/Makefile
> +++ b/drivers/gpu/drm/nouveau/Makefile
> @@ -132,6 +132,7 @@ nouveau-y += core/subdev/i2c/nv94.o
>  nouveau-y += core/subdev/i2c/nvd0.o
>  nouveau-y += core/subdev/ibus/nvc0.o
>  nouveau-y += core/subdev/ibus/nve0.o
> +nouveau-y += core/subdev/ibus/nvea.o
>  nouveau-y += core/subdev/instmem/base.o
>  nouveau-y += core/subdev/instmem/nv04.o
>  nouveau-y += core/subdev/instmem/nv40.o
> diff --git a/drivers/gpu/drm/nouveau/core/include/subdev/ibus.h b/drivers/gpu/drm/nouveau/core/include/subdev/ibus.h
> index 88814f1..056a42f 100644
> --- a/drivers/gpu/drm/nouveau/core/include/subdev/ibus.h
> +++ b/drivers/gpu/drm/nouveau/core/include/subdev/ibus.h
> @@ -30,5 +30,6 @@ nouveau_ibus(void *obj)
>
>  extern struct nouveau_oclass nvc0_ibus_oclass;
>  extern struct nouveau_oclass nve0_ibus_oclass;
> +extern struct nouveau_oclass nvea_ibus_oclass;
>
>  #endif
> diff --git a/drivers/gpu/drm/nouveau/core/subdev/ibus/nvea.c b/drivers/gpu/drm/nouveau/core/subdev/ibus/nvea.c
> new file mode 100644
> index 0000000..0bcd281
> --- /dev/null
> +++ b/drivers/gpu/drm/nouveau/core/subdev/ibus/nvea.c
> @@ -0,0 +1,108 @@
> +/*
> + * Copyright (c) 2014, NVIDIA Corporation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + */
> +
> +#include <subdev/ibus.h>
> +
> +struct nvea_ibus_priv {
> +       struct nouveau_ibus base;
> +};
> +
> +static void
> +nvea_ibus_init_priv_ring(struct nvea_ibus_priv *priv)
> +{
> +       u32 data;
> +
> +       data = nv_rd32(priv, 0x137250);
> +       data &= (~0x3f);
> +       nv_wr32(priv, 0x137250, data);

nv_mask(priv, 0x137250, 0x3f, 0) should do this, right?

> +
> +       nv_mask(priv, 0x000200, 0x20, 0);
> +       udelay(20);
> +       nv_mask(priv, 0x000200, 0x20, 0x20);
> +
> +       nv_wr32(priv, 0x12004c, 0x4);
> +       nv_wr32(priv, 0x122204, 0x2);
> +       nv_rd32(priv, 0x122204);
> +}
> +
> +static void
> +nvea_ibus_intr(struct nouveau_subdev *subdev)
> +{
> +       struct nvea_ibus_priv *priv = (void *)subdev;
> +       u32 status0 = nv_rd32(priv, 0x120058);
> +       s32 retry = 100;
> +       u32 command;
> +
> +       if (status0 & 0x7) {
> +               nv_debug(priv, "resetting priv ring\n");
> +               nvea_ibus_init_priv_ring(priv);
> +       }
> +
> +       /* Acknowledge interrupt */
> +       command = nv_rd32(priv, 0x0012004c);
> +       command |= 0x2;
> +       nv_wr32(priv, 0x0012004c, command);

nv_mask(priv, 0x12004c, 0x2, 0x2)

> +
> +       while (--retry >= 0) {
> +               command = nv_rd32(priv, 0x12004c) & 0x3f;
> +               if (command == 0)
> +                       break;
> +       }
> +
> +       if (retry < 0)
> +               nv_debug(priv, "timeout waiting for ringmaster ack\n");

this sounds kinda bad, no? perhaps a nv_warn?

> +}
> +
> +static int
> +nvea_ibus_init(struct nouveau_object *object)
> +{
> +       struct nvea_ibus_priv *priv = (void *)object;
> +       int ret;
> +
> +       ret = _nouveau_ibus_init(object);
> +       if (ret)
> +               return ret;
> +
> +       nvea_ibus_init_priv_ring(priv);
> +
> +       return 0;
> +}
> +
> +static int
> +nvea_ibus_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
> +              struct nouveau_oclass *oclass, void *data, u32 size,
> +              struct nouveau_object **pobject)
> +{
> +       struct nvea_ibus_priv *priv;
> +       int ret;
> +
> +       ret = nouveau_ibus_create(parent, engine, oclass, &priv);
> +       *pobject = nv_object(priv);
> +       if (ret)
> +               return ret;
> +
> +       nv_subdev(priv)->intr = nvea_ibus_intr;
> +       return 0;
> +}
> +
> +struct nouveau_oclass
> +nvea_ibus_oclass = {
> +       .handle = NV_SUBDEV(IBUS, 0xea),
> +       .ofuncs = &(struct nouveau_ofuncs) {
> +               .ctor = nvea_ibus_ctor,
> +               .dtor = _nouveau_ibus_dtor,
> +               .init = nvea_ibus_init,
> +               .fini = _nouveau_ibus_fini,
> +       },
> +};
> --
> 1.8.5.3
>
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