linux-kernel - Re: [PATCH v2 08/10] drm/i915/nvm: add support for access mode

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Message-ID: <Zy00AoxE0_8p5xCY@intel.com>
Date: Thu, 7 Nov 2024 16:41:22 -0500
From: Rodrigo Vivi <rodrigo.vivi@...el.com>
To: Alexander Usyskin <alexander.usyskin@...el.com>
CC: Miquel Raynal <miquel.raynal@...tlin.com>, Richard Weinberger
	<richard@....at>, Vignesh Raghavendra <vigneshr@...com>, Lucas De Marchi
	<lucas.demarchi@...el.com>, Thomas Hellström
	<thomas.hellstrom@...ux.intel.com>, Maarten Lankhorst
	<maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>, Jani Nikula <jani.nikula@...ux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>, Tvrtko Ursulin
	<tursulin@...ulin.net>, Oren Weil <oren.jer.weil@...el.com>,
	<linux-mtd@...ts.infradead.org>, <dri-devel@...ts.freedesktop.org>,
	<intel-gfx@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 08/10] drm/i915/nvm: add support for access mode

On Thu, Nov 07, 2024 at 03:13:54PM +0200, Alexander Usyskin wrote:
> Check NVM access mode from GSC FW status registers
> and overwrite access status read from SPI descriptor, if needed.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@...el.com>

> 
> Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
> ---
>  drivers/gpu/drm/i915/intel_nvm.c | 25 ++++++++++++++++++++++++-
>  1 file changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_nvm.c b/drivers/gpu/drm/i915/intel_nvm.c
> index 214c4d47a9cd..cbd776e667ad 100644
> --- a/drivers/gpu/drm/i915/intel_nvm.c
> +++ b/drivers/gpu/drm/i915/intel_nvm.c
> @@ -10,6 +10,7 @@
>  #include "intel_nvm.h"
>  
>  #define GEN12_GUNIT_NVM_SIZE 0x80
> +#define HECI_FW_STATUS_2_NVM_ACCESS_MODE BIT(3)
>  
>  static const struct intel_dg_nvm_region regions[INTEL_DG_NVM_REGIONS] = {
>  	[0] = { .name = "DESCRIPTOR", },
> @@ -22,6 +23,28 @@ static void i915_nvm_release_dev(struct device *dev)
>  {
>  }
>  
> +static bool i915_nvm_writeable_override(struct drm_i915_private *i915)
> +{
> +	resource_size_t base;
> +	bool writeable_override;
> +
> +	if (IS_DG1(i915)) {
> +		base = DG1_GSC_HECI2_BASE;
> +	} else if (IS_DG2(i915)) {
> +		base = DG2_GSC_HECI2_BASE;
> +	} else {
> +		drm_err(&i915->drm, "Unknown platform\n");
> +		return true;
> +	}
> +
> +	writeable_override =
> +		!(intel_uncore_read(&i915->uncore, HECI_FWSTS(base, 2)) &
> +		  HECI_FW_STATUS_2_NVM_ACCESS_MODE);
> +	if (writeable_override)
> +		drm_info(&i915->drm, "NVM access overridden by jumper\n");
> +	return writeable_override;
> +}
> +
>  void intel_nvm_init(struct drm_i915_private *i915)
>  {
>  	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> @@ -43,7 +66,7 @@ void intel_nvm_init(struct drm_i915_private *i915)
>  
>  	nvm = i915->nvm;
>  
> -	nvm->writeable_override = true;
> +	nvm->writeable_override = i915_nvm_writeable_override(i915);
>  	nvm->bar.parent = &pdev->resource[0];
>  	nvm->bar.start = GEN12_GUNIT_NVM_BASE + pdev->resource[0].start;
>  	nvm->bar.end = nvm->bar.start + GEN12_GUNIT_NVM_SIZE - 1;
> -- 
> 2.43.0
>