drm/xe/nvm: add on-die non-volatile memory device

Enable access to internal non-volatile memory on DGFX
with GSC/CSC devices via a child device.
The nvm child device is exposed via auxiliary bus.

Reviewed-by: Rodrigo Vivi <[e-mail]>
Acked-by: Rodrigo Vivi <[e-mail]>
Signed-off-by: Alexander Usyskin <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rodrigo Vivi <[e-mail]>

drivers/gpu/drm/xe/Makefile

···
 	xe_mmio.o \
 	xe_mocs.o \
 	xe_module.o \
+	xe_nvm.o \
 	xe_oa.o \
 	xe_observation.o \
 	xe_pat.o \

drivers/gpu/drm/xe/xe_device.c

···
 #include "xe_memirq.h"
 #include "xe_mmio.h"
 #include "xe_module.h"
+#include "xe_nvm.h"
 #include "xe_oa.h"
 #include "xe_observation.h"
 #include "xe_pat.h"
···
 			return err;
 	}
 
+	xe_nvm_init(xe);
+
 	err = xe_heci_gsc_init(xe);
 	if (err)
 		return err;
···
 void xe_device_remove(struct xe_device *xe)
 {
 	xe_display_unregister(xe);
+
+	xe_nvm_fini(xe);
 
 	drm_dev_unplug(&xe->drm);
 

drivers/gpu/drm/xe/xe_device_types.h

···
 
 struct dram_info;
 struct intel_display;
+struct intel_dg_nvm_dev;
 struct xe_ggtt;
 struct xe_pat_ops;
 struct xe_pxp;
···
 		u8 has_fan_control:1;
 		/** @info.has_flat_ccs: Whether flat CCS metadata is used */
 		u8 has_flat_ccs:1;
+		/** @info.has_gsc_nvm: Device has gsc non-volatile memory */
+		u8 has_gsc_nvm:1;
 		/** @info.has_heci_cscfi: device has heci cscfi */
 		u8 has_heci_cscfi:1;
 		/** @info.has_heci_gscfi: device has heci gscfi */
···
 
 	/** @heci_gsc: graphics security controller */
 	struct xe_heci_gsc heci_gsc;
+
+	/** @nvm: discrete graphics non-volatile memory */
+	struct intel_dg_nvm_dev *nvm;
 
 	/** @oa: oa observation subsystem */
 	struct xe_oa oa;

drivers/gpu/drm/xe/xe_nvm.c

···
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright(c) 2019-2025, Intel Corporation. All rights reserved.
+ */
+
+#include <linux/intel_dg_nvm_aux.h>
+#include <linux/pci.h>
+
+#include "xe_device_types.h"
+#include "xe_nvm.h"
+#include "xe_sriov.h"
+
+#define GEN12_GUNIT_NVM_BASE 0x00102040
+#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", },
+	[2] = { .name = "GSC", },
+	[9] = { .name = "PADDING", },
+	[11] = { .name = "OptionROM", },
+	[12] = { .name = "DAM", },
+};
+
+static void xe_nvm_release_dev(struct device *dev)
+{
+}
+
+int xe_nvm_init(struct xe_device *xe)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	struct auxiliary_device *aux_dev;
+	struct intel_dg_nvm_dev *nvm;
+	int ret;
+
+	if (!xe->info.has_gsc_nvm)
+		return 0;
+
+	/* No access to internal NVM from VFs */
+	if (IS_SRIOV_VF(xe))
+		return 0;
+
+	/* Nvm pointer should be NULL here */
+	if (WARN_ON(xe->nvm))
+		return -EFAULT;
+
+	xe->nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
+	if (!xe->nvm)
+		return -ENOMEM;
+
+	nvm = xe->nvm;
+
+	nvm->writable_override = false;
+	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;
+	nvm->bar.flags = IORESOURCE_MEM;
+	nvm->bar.desc = IORES_DESC_NONE;
+	nvm->regions = regions;
+
+	aux_dev = &nvm->aux_dev;
+
+	aux_dev->name = "nvm";
+	aux_dev->id = (pci_domain_nr(pdev->bus) << 16) | pci_dev_id(pdev);
+	aux_dev->dev.parent = &pdev->dev;
+	aux_dev->dev.release = xe_nvm_release_dev;
+
+	ret = auxiliary_device_init(aux_dev);
+	if (ret) {
+		drm_err(&xe->drm, "xe-nvm aux init failed %d\n", ret);
+		goto err;
+	}
+
+	ret = auxiliary_device_add(aux_dev);
+	if (ret) {
+		drm_err(&xe->drm, "xe-nvm aux add failed %d\n", ret);
+		auxiliary_device_uninit(aux_dev);
+		goto err;
+	}
+	return 0;
+
+err:
+	kfree(nvm);
+	xe->nvm = NULL;
+	return ret;
+}
+
+void xe_nvm_fini(struct xe_device *xe)
+{
+	struct intel_dg_nvm_dev *nvm = xe->nvm;
+
+	if (!xe->info.has_gsc_nvm)
+		return;
+
+	/* No access to internal NVM from VFs */
+	if (IS_SRIOV_VF(xe))
+		return;
+
+	/* Nvm pointer should not be NULL here */
+	if (WARN_ON(!nvm))
+		return;
+
+	auxiliary_device_delete(&nvm->aux_dev);
+	auxiliary_device_uninit(&nvm->aux_dev);
+	kfree(nvm);
+	xe->nvm = NULL;
+}

drivers/gpu/drm/xe/xe_nvm.h

···
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright(c) 2019-2025 Intel Corporation. All rights reserved.
+ */
+
+#ifndef __XE_NVM_H__
+#define __XE_NVM_H__
+
+struct xe_device;
+
+int xe_nvm_init(struct xe_device *xe);
+
+void xe_nvm_fini(struct xe_device *xe);
+
+#endif

drivers/gpu/drm/xe/xe_pci.c

···
 
 	u8 has_display:1;
 	u8 has_fan_control:1;
+	u8 has_gsc_nvm:1;
 	u8 has_heci_gscfi:1;
 	u8 has_heci_cscfi:1;
 	u8 has_llc:1;
···
 	PLATFORM(DG1),
 	.dma_mask_size = 39,
 	.has_display = true,
+	.has_gsc_nvm = 1,
 	.has_heci_gscfi = 1,
 	.require_force_probe = true,
 };
···
 #define DG2_FEATURES \
 	DGFX_FEATURES, \
 	PLATFORM(DG2), \
+	.has_gsc_nvm = 1, \
 	.has_heci_gscfi = 1, \
 	.subplatforms = (const struct xe_subplatform_desc[]) { \
 		{ XE_SUBPLATFORM_DG2_G10, "G10", dg2_g10_ids }, \
···
 	PLATFORM(PVC),
 	.dma_mask_size = 52,
 	.has_display = false,
+	.has_gsc_nvm = 1,
 	.has_heci_gscfi = 1,
 	.max_remote_tiles = 1,
 	.require_force_probe = true,
···
 	.has_display = true,
 	.has_fan_control = true,
 	.has_mbx_power_limits = true,
+	.has_gsc_nvm = 1,
 	.has_heci_cscfi = 1,
 	.needs_scratch = true,
 };
···
 	xe->info.is_dgfx = desc->is_dgfx;
 	xe->info.has_fan_control = desc->has_fan_control;
 	xe->info.has_mbx_power_limits = desc->has_mbx_power_limits;
+	xe->info.has_gsc_nvm = desc->has_gsc_nvm;
 	xe->info.has_heci_gscfi = desc->has_heci_gscfi;
 	xe->info.has_heci_cscfi = desc->has_heci_cscfi;
 	xe->info.has_llc = desc->has_llc;