On Thu, Apr 24, 2025 at 04:25:26PM +0300, Alexander Usyskin wrote:
> Add auxiliary driver for intel discrete graphics
> non-volatile memory device.
...
> +static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
> + const struct auxiliary_device_id *aux_dev_id)
> +{
> + struct intel_dg_nvm_dev *invm =
> auxiliary_dev_to_intel_dg_nvm_dev(aux_dev);
> + struct device *device;
> + struct intel_dg_nvm *nvm;
> + unsigned int nregions;
> + unsigned int i, n;
> + char *name;
Perhaps move this to the loop it is being used in?
> + int ret;
> +
> + device = &aux_dev->dev;
> +
> + /* count available regions */
> + for (nregions = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
> + if (invm->regions[i].name)
> + nregions++;
> + }
> +
> + if (!nregions) {
> + dev_err(device, "no regions defined\n");
> + return -ENODEV;
> + }
> +
> + nvm = kzalloc(struct_size(nvm, regions, nregions), GFP_KERNEL);
> + if (!nvm)
> + return -ENOMEM;
> +
> + kref_init(&nvm->refcnt);
> +
> + nvm->nregions = nregions;
Is this assignment useful?
> + for (n = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
> + if (!invm->regions[i].name)
> + continue;
> +
> + name = kasprintf(GFP_KERNEL, "%s.%s",
> + dev_name(&aux_dev->dev),
> invm->regions[i].name);
> + if (!name)
> + continue;
> + nvm->regions[n].name = name;
> + nvm->regions[n].id = i;
> + n++;
> + }
> + nvm->nregions = n; /* in case where kasprintf fail */
Considering kasprintf failure, should we move forward if n == 0?
> + nvm->base = devm_ioremap_resource(device, &invm->bar);
> + if (IS_ERR(nvm->base)) {
> + dev_err(device, "mmio not mapped\n");
Is this useful? Perhaps the helper already does it for us.
> + ret = PTR_ERR(nvm->base);
> + goto err;
> + }
> +
> + dev_set_drvdata(&aux_dev->dev, nvm);
> +
> + return 0;
> +
> +err:
> + kref_put(&nvm->refcnt, intel_dg_nvm_release);
> + return ret;
> +}
> +
> +static void intel_dg_mtd_remove(struct auxiliary_device *aux_dev)
> +{
> + struct intel_dg_nvm *nvm = dev_get_drvdata(&aux_dev->dev);
> +
> + if (!nvm)
> + return;
Are we expecting this?
> + dev_set_drvdata(&aux_dev->dev, NULL);
Do we need this?
> + kref_put(&nvm->refcnt, intel_dg_nvm_release);
> +}
> +
> +static const struct auxiliary_device_id intel_dg_mtd_id_table[] = {
> + {
> + .name = "i915.nvm",
> + },
> + {
> + .name = "xe.nvm",
> + },
> + {
> + /* sentinel */
> + }
> +};
> +MODULE_DEVICE_TABLE(auxiliary, intel_dg_mtd_id_table);
> +
> +static struct auxiliary_driver intel_dg_mtd_driver = {
> + .probe = intel_dg_mtd_probe,
> + .remove = intel_dg_mtd_remove,
> + .driver = {
> + /* auxiliary_driver_register() sets .name to be the modname */
> + },
> + .id_table = intel_dg_mtd_id_table
> +};
> +
Nit: Redundant blank line.
> +module_auxiliary_driver(intel_dg_mtd_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_DESCRIPTION("Intel DGFX MTD driver");
> diff --git a/include/linux/intel_dg_nvm_aux.h
> b/include/linux/intel_dg_nvm_aux.h
> new file mode 100644
> index 000000000000..68df634c994c
> --- /dev/null
> +++ b/include/linux/intel_dg_nvm_aux.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright(c) 2019-2025, Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef __INTEL_DG_NVM_AUX_H__
> +#define __INTEL_DG_NVM_AUX_H__
> +
> +#include <linux/auxiliary_bus.h>
Missing types.h, container_of.h
> +#define INTEL_DG_NVM_REGIONS 13
> +
> +struct intel_dg_nvm_region {
> + const char *name;
> +};
> +
> +struct intel_dg_nvm_dev {
> + struct auxiliary_device aux_dev;
> + bool writable_override;
> + struct resource bar;
> + const struct intel_dg_nvm_region *regions;
> +};
> +
> +#define auxiliary_dev_to_intel_dg_nvm_dev(auxiliary_dev) \
> + container_of(auxiliary_dev, struct intel_dg_nvm_dev, aux_dev)
> +
> +#endif /* __INTEL_DG_NVM_AUX_H__ */
> --
> 2.43.0
>
