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

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Message-ID: <20241022104119.3149051-9-alexander.usyskin@intel.com>
Date: Tue, 22 Oct 2024 13:41:17 +0300
From: Alexander Usyskin <alexander.usyskin@...el.com>
To: 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>,
	Rodrigo Vivi <rodrigo.vivi@...el.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>
Cc: 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,
	Alexander Usyskin <alexander.usyskin@...el.com>
Subject: [PATCH 08/10] drm/i915/nvm: add support for access mode

Check NVM access mode from GSC FW status registers
and overwrite access status read from SPI descriptor, if needed.

Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
---
 drivers/gpu/drm/i915/intel_nvm.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_nvm.c b/drivers/gpu/drm/i915/intel_nvm.c
index 003c89cbcb88..98c11e027b76 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 +23,29 @@ static void i915_nvm_release_dev(struct device *dev)
 {
 }
 
+static bool i915_nvm_writeable_override(struct drm_i915_private *i915)
+{
+	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
+	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 {
+		dev_err(&pdev->dev, "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)
+		dev_info(&pdev->dev, "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 +67,7 @@ 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