[Nouveau] [PATCH v2 2/4] pci: enable pcie link changes for pascal

[Bjorn Helgaas]

On Tue, May 07, 2019 at 10:12:43PM +0200, Karol Herbst wrote:
> Signed-off-by: Karol Herbst <kherbst at redhat.com>
> Reviewed-by: Lyude Paul <lyude at redhat.com>
> ---
>  drm/nouveau/nvkm/subdev/pci/gk104.c |  8 ++++----
>  drm/nouveau/nvkm/subdev/pci/gp100.c | 10 ++++++++++
>  drm/nouveau/nvkm/subdev/pci/priv.h  |  5 +++++
>  3 files changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/drm/nouveau/nvkm/subdev/pci/gk104.c b/drm/nouveau/nvkm/subdev/pci/gk104.c
> index e6803050..66489018 100644
> --- a/drm/nouveau/nvkm/subdev/pci/gk104.c
> +++ b/drm/nouveau/nvkm/subdev/pci/gk104.c
> @@ -23,7 +23,7 @@
>   */
>  #include "priv.h"
>  
> -static int
> +int
>  gk104_pcie_version_supported(struct nvkm_pci *pci)
>  {
>  	return (nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x4) == 0x4 ? 2 : 1;
> @@ -108,7 +108,7 @@ gk104_pcie_lnkctl_speed(struct nvkm_pci *pci)
>  	return -1;
>  }
>  
> -static enum nvkm_pcie_speed
> +enum nvkm_pcie_speed
>  gk104_pcie_max_speed(struct nvkm_pci *pci)
>  {
>  	u32 max_speed = nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x300000;

Some of this looks pretty similar to the PCI core code that reads
PCI_EXP_LNKSTA to find the link speed (but admittedly there's not
really a good interface to do that unless bus->cur_bus_speed already
has what you need).

It doesn't look like this is directly reading the PCI_EXP_LNKSTA from
PCI config space; maybe it's reading a mirror of that via a
device-specific MMIO address, or maybe it's reading something else
completely.

But it makes me wonder if there's a way to make generic PCI core
interfaces for some of this stuff.

> @@ -146,7 +146,7 @@ gk104_pcie_set_link_speed(struct nvkm_pci *pci, enum nvkm_pcie_speed speed)
>  	nvkm_mask(device, 0x8c040, 0x1, 0x1);
>  }
>  
> -static int
> +int
>  gk104_pcie_init(struct nvkm_pci * pci)
>  {
>  	enum nvkm_pcie_speed lnkctl_speed, max_speed, cap_speed;
> @@ -178,7 +178,7 @@ gk104_pcie_init(struct nvkm_pci * pci)
>  	return 0;
>  }
>  
> -static int
> +int
>  gk104_pcie_set_link(struct nvkm_pci *pci, enum nvkm_pcie_speed speed, u8 width)
>  {
>  	struct nvkm_subdev *subdev = &pci->subdev;
> diff --git a/drm/nouveau/nvkm/subdev/pci/gp100.c b/drm/nouveau/nvkm/subdev/pci/gp100.c
> index 82c5234a..eb19c7a4 100644
> --- a/drm/nouveau/nvkm/subdev/pci/gp100.c
> +++ b/drm/nouveau/nvkm/subdev/pci/gp100.c
> @@ -35,6 +35,16 @@ gp100_pci_func = {
>  	.wr08 = nv40_pci_wr08,
>  	.wr32 = nv40_pci_wr32,
>  	.msi_rearm = gp100_pci_msi_rearm,
> +
> +	.pcie.init = gk104_pcie_init,
> +	.pcie.set_link = gk104_pcie_set_link,
> +
> +	.pcie.max_speed = gk104_pcie_max_speed,
> +	.pcie.cur_speed = g84_pcie_cur_speed,
> +
> +	.pcie.set_version = gf100_pcie_set_version,
> +	.pcie.version = gf100_pcie_version,
> +	.pcie.version_supported = gk104_pcie_version_supported,
>  };
>  
>  int
> diff --git a/drm/nouveau/nvkm/subdev/pci/priv.h b/drm/nouveau/nvkm/subdev/pci/priv.h
> index c17f6063..a0d4c007 100644
> --- a/drm/nouveau/nvkm/subdev/pci/priv.h
> +++ b/drm/nouveau/nvkm/subdev/pci/priv.h
> @@ -54,6 +54,11 @@ int gf100_pcie_cap_speed(struct nvkm_pci *);
>  int gf100_pcie_init(struct nvkm_pci *);
>  int gf100_pcie_set_link(struct nvkm_pci *, enum nvkm_pcie_speed, u8);
>  
> +int gk104_pcie_init(struct nvkm_pci *);
> +int gk104_pcie_set_link(struct nvkm_pci *, enum nvkm_pcie_speed, u8 width);
> +enum nvkm_pcie_speed gk104_pcie_max_speed(struct nvkm_pci *);
> +int gk104_pcie_version_supported(struct nvkm_pci *);
> +
>  int nvkm_pcie_oneinit(struct nvkm_pci *);
>  int nvkm_pcie_init(struct nvkm_pci *);
>  #endif
> -- 
> 2.21.0
>