Re: [PATCH v2 07/10] drm/i915/nvm: add nvm device for discrete graphics

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Thu, Nov 07, 2024 at 03:13:53PM +0200, Alexander Usyskin wrote:
> Enable access to internal non-volatile memory on
> DGFX devices via a child device.
> The nvm child device is exposed via auxiliary bus.

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

> 
> CC: Rodrigo Vivi <rodrigo.vivi@intel.com>
> CC: Lucas De Marchi <lucas.demarchi@intel.com>
> Co-developed-by: Tomas Winkler <tomasw@gmail.com>
> Signed-off-by: Tomas Winkler <tomasw@gmail.com>
> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
> ---
>  drivers/gpu/drm/i915/Makefile      |  4 ++
>  drivers/gpu/drm/i915/i915_driver.c |  6 ++
>  drivers/gpu/drm/i915/i915_drv.h    |  3 +
>  drivers/gpu/drm/i915/i915_reg.h    |  1 +
>  drivers/gpu/drm/i915/intel_nvm.c   | 94 ++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_nvm.h   | 15 +++++
>  6 files changed, 123 insertions(+)
>  create mode 100644 drivers/gpu/drm/i915/intel_nvm.c
>  create mode 100644 drivers/gpu/drm/i915/intel_nvm.h
> 
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index e033bcaef4f3..09f509843b4e 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -212,6 +212,10 @@ i915-y += \
>  i915-y += \
>  	gt/intel_gsc.o
>  
> +# graphics nvm device (DGFX) support
> +i915-y += \
> +	intel_nvm.o
> +
>  # graphics hardware monitoring (HWMON) support
>  i915-$(CONFIG_HWMON) += \
>  	i915_hwmon.o
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index 365329ff8a07..7f7dffdc8852 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -80,6 +80,8 @@
>  #include "soc/intel_dram.h"
>  #include "soc/intel_gmch.h"
>  
> +#include "intel_nvm.h"
> +
>  #include "i915_debugfs.h"
>  #include "i915_driver.h"
>  #include "i915_drm_client.h"
> @@ -620,6 +622,8 @@ static void i915_driver_register(struct drm_i915_private *dev_priv)
>  	/* Depends on sysfs having been initialized */
>  	i915_perf_register(dev_priv);
>  
> +	intel_nvm_init(dev_priv);
> +
>  	for_each_gt(gt, dev_priv, i)
>  		intel_gt_driver_register(gt);
>  
> @@ -663,6 +667,8 @@ static void i915_driver_unregister(struct drm_i915_private *dev_priv)
>  
>  	i915_hwmon_unregister(dev_priv);
>  
> +	intel_nvm_fini(dev_priv);
> +
>  	i915_perf_unregister(dev_priv);
>  	i915_pmu_unregister(dev_priv);
>  
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index a66e5bb078cf..faaad8b16ab9 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -67,6 +67,7 @@
>  struct drm_i915_clock_gating_funcs;
>  struct vlv_s0ix_state;
>  struct intel_pxp;
> +struct intel_dg_nvm_dev;
>  
>  #define GEM_QUIRK_PIN_SWIZZLED_PAGES	BIT(0)
>  
> @@ -316,6 +317,8 @@ struct drm_i915_private {
>  
>  	struct i915_perf perf;
>  
> +	struct intel_dg_nvm_dev *nvm;
> +
>  	struct i915_hwmon *hwmon;
>  
>  	struct intel_gt *gt[I915_MAX_GT];
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 818142f5a10c..eddafd5d7628 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -323,6 +323,7 @@
>  #define DG2_GSC_HECI2_BASE	0x00374000
>  #define MTL_GSC_HECI1_BASE	0x00116000
>  #define MTL_GSC_HECI2_BASE	0x00117000
> +#define GEN12_GUNIT_NVM_BASE	0x00102040
>  
>  #define HECI_H_CSR(base)	_MMIO((base) + 0x4)
>  #define   HECI_H_CSR_IE		REG_BIT(0)
> diff --git a/drivers/gpu/drm/i915/intel_nvm.c b/drivers/gpu/drm/i915/intel_nvm.c
> new file mode 100644
> index 000000000000..214c4d47a9cd
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/intel_nvm.c
> @@ -0,0 +1,94 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright(c) 2019-2024, Intel Corporation. All rights reserved.
> + */
> +
> +#include <linux/intel_dg_nvm_aux.h>
> +#include <linux/irq.h>
> +#include "i915_reg.h"
> +#include "i915_drv.h"
> +#include "intel_nvm.h"
> +
> +#define GEN12_GUNIT_NVM_SIZE 0x80
> +
> +static const struct intel_dg_nvm_region regions[INTEL_DG_NVM_REGIONS] = {
> +	[0] = { .name = "DESCRIPTOR", },
> +	[2] = { .name = "GSC", },
> +	[11] = { .name = "OptionROM", },
> +	[12] = { .name = "DAM", },
> +};
> +
> +static void i915_nvm_release_dev(struct device *dev)
> +{
> +}
> +
> +void intel_nvm_init(struct drm_i915_private *i915)
> +{
> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> +	struct intel_dg_nvm_dev *nvm;
> +	struct auxiliary_device *aux_dev;
> +	int ret;
> +
> +	/* Only the DGFX devices have internal NVM */
> +	if (!IS_DGFX(i915))
> +		return;
> +
> +	/* Nvm pointer should be NULL here */
> +	if (WARN_ON(i915->nvm))
> +		return;
> +
> +	i915->nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
> +	if (!i915->nvm)
> +		return;
> +
> +	nvm = i915->nvm;
> +
> +	nvm->writeable_override = true;
> +	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_DEVID(pdev->bus->number, pdev->devfn);
> +	aux_dev->dev.parent = &pdev->dev;
> +	aux_dev->dev.release = i915_nvm_release_dev;
> +
> +	ret = auxiliary_device_init(aux_dev);
> +	if (ret) {
> +		drm_err(&i915->drm, "i915-nvm aux init failed %d\n", ret);
> +		return;
> +	}
> +
> +	ret = auxiliary_device_add(aux_dev);
> +	if (ret) {
> +		drm_err(&i915->drm, "i915-nvm aux add failed %d\n", ret);
> +		auxiliary_device_uninit(aux_dev);
> +		return;
> +	}
> +}
> +
> +void intel_nvm_fini(struct drm_i915_private *i915)
> +{
> +	struct intel_dg_nvm_dev *nvm = i915->nvm;
> +
> +	/* Only the DGFX devices have internal NVM */
> +	if (!IS_DGFX(i915))
> +		return;
> +
> +	/* Nvm pointer should not be NULL here */
> +	if (WARN_ON(!nvm))
> +		return;
> +
> +	drm_err(&i915->drm, "removing i915-nvm cell\n");
> +
> +	auxiliary_device_delete(&nvm->aux_dev);
> +	auxiliary_device_uninit(&nvm->aux_dev);
> +	kfree(nvm);
> +	i915->nvm = NULL;
> +}
> diff --git a/drivers/gpu/drm/i915/intel_nvm.h b/drivers/gpu/drm/i915/intel_nvm.h
> new file mode 100644
> index 000000000000..7bc3d1114a3f
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/intel_nvm.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright(c) 2019-2024 Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef __INTEL_NVM_H__
> +#define __INTEL_NVM_H__
> +
> +struct drm_i915_private;
> +
> +void intel_nvm_init(struct drm_i915_private *i915);
> +
> +void intel_nvm_fini(struct drm_i915_private *i915);
> +
> +#endif /* __INTEL_NVM_H__ */
> -- 
> 2.43.0
>