[Intel-xe] [PATCH] drm/xe/xe2: Extend reserved stolen sizes

[Matt Roper]

On Thu, Sep 28, 2023 at 09:49:59PM -0700, Lucas De Marchi wrote:
> For xe2, besides the previous sizes, the reserved portion of stolen can
> also have 16MB and 32MB.
> 
> Bspec: 53148
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

While looking at this I'm trying to remember why we don't need to also
use the media WOPCM field (13:11) from this register?  Is the media
allocation already included in the value we're reading here?


Matt

> ---
>  drivers/gpu/drm/xe/regs/xe_regs.h      |  2 +-
>  drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c | 32 ++++++++++++++++++++++----
>  2 files changed, 29 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/regs/xe_regs.h b/drivers/gpu/drm/xe/regs/xe_regs.h
> index 8a93ab169e04..dbb0ea1a585e 100644
> --- a/drivers/gpu/drm/xe/regs/xe_regs.h
> +++ b/drivers/gpu/drm/xe/regs/xe_regs.h
> @@ -69,7 +69,7 @@
>  #define GSMBASE					XE_REG(0x108100)
>  
>  #define STOLEN_RESERVED				XE_REG(0x1082c0)
> -#define   WOPCM_SIZE_MASK			REG_GENMASK64(8, 7)
> +#define   WOPCM_SIZE_MASK			REG_GENMASK64(9, 7)
>  
>  #define MTL_RP_STATE_CAP			XE_REG(0x138000)
>  
> diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
> index 6ba6b1b7f34b..79fbd74a3944 100644
> --- a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
> +++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
> @@ -86,6 +86,29 @@ static s64 detect_bar2_dgfx(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
>  	return ALIGN_DOWN(stolen_size, SZ_1M);
>  }
>  
> +static u32 get_wopcm_size(struct xe_device *xe)
> +{
> +	u32 wopcm_size;
> +	u64 val;
> +
> +	val = xe_mmio_read64_2x32(xe_root_mmio_gt(xe), STOLEN_RESERVED);
> +	val = REG_FIELD_GET64(WOPCM_SIZE_MASK, val);
> +
> +	switch (val) {
> +	case 0x5 ... 0x6:
> +		val--;
> +		fallthrough;
> +	case 0x0 ... 0x3:
> +		wopcm_size = (1U << val) * SZ_1M;
> +		break;
> +	default:
> +		WARN(1, "Missing case wopcm_size=%llx\n", val);
> +		wopcm_size = 0;
> +	}
> +
> +	return wopcm_size;
> +}
> +
>  static u32 detect_bar2_integrated(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
>  {
>  	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> @@ -125,10 +148,11 @@ static u32 detect_bar2_integrated(struct xe_device *xe, struct xe_ttm_stolen_mgr
>  	}
>  
>  	/* Carve out the top of DSM as it contains the reserved WOPCM region */
> -	wopcm_size = REG_FIELD_GET64(WOPCM_SIZE_MASK,
> -				     xe_mmio_read64_2x32(xe_root_mmio_gt(xe),
> -							 STOLEN_RESERVED));
> -	stolen_size -= (1U << wopcm_size) * SZ_1M;
> +	wopcm_size = get_wopcm_size(xe);
> +	if (drm_WARN_ON(&xe->drm, !wopcm_size))
> +		return 0;
> +
> +	stolen_size -= wopcm_size;
>  
>  	if (drm_WARN_ON(&xe->drm, stolen_size + SZ_8M > pci_resource_len(pdev, 2)))
>  		return 0;
> -- 
> 2.40.1
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation