[PATCH v9 09/12] drm/i915/nvm: add support for access mode

From: Alexander Usyskin <alexander.usyskin@intel.com>
To: "Miquel Raynal" <miquel.raynal@bootlin.com>,
	"Richard Weinberger" <richard@nod.at>,
	"Vignesh Raghavendra" <vigneshr@ti.com>,
	"Lucas De Marchi" <lucas.demarchi@intel.com>,
	"Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
	"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"David Airlie" <airlied@gmail.com>,
	"Simona Vetter" <simona@ffwll.ch>,
	"Jani Nikula" <jani.nikula@linux.intel.com>,
	"Joonas Lahtinen" <joonas.lahtinen@linux.intel.com>,
	"Tvrtko Ursulin" <tursulin@ursulin.net>,
	"Karthik Poosa" <karthik.poosa@intel.com>
Cc: Reuven Abliyev <reuven.abliyev@intel.com>,
	Oren Weil <oren.jer.weil@intel.com>,
	linux-mtd@lists.infradead.org, intel-xe@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
	linux-kernel@vger.kernel.org,
	Alexander Usyskin <alexander.usyskin@intel.com>
Subject: [PATCH v9 09/12] drm/i915/nvm: add support for access mode
Date: Thu, 24 Apr 2025 16:25:33 +0300	[thread overview]
Message-ID: <20250424132536.3043825-10-alexander.usyskin@intel.com> (raw)
In-Reply-To: <20250424132536.3043825-1-alexander.usyskin@intel.com>

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@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.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 75d3ebe669ff..dd3999c934a7 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_writable_override(struct drm_i915_private *i915)
+{
+	resource_size_t base;
+	bool writable_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;
+	}
+
+	writable_override =
+		!(intel_uncore_read(&i915->uncore, HECI_FWSTS(base, 2)) &
+		  HECI_FW_STATUS_2_NVM_ACCESS_MODE);
+	if (writable_override)
+		drm_info(&i915->drm, "NVM access overridden by jumper\n");
+	return writable_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->writable_override = i915_nvm_writable_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


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