drivers/dax/cxl.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2023 Intel Corporation. All rights reserved. */
#include <linux/module.h>
#include <linux/dax.h>

#include "../cxl/cxl.h"
#include "bus.h"

static int cxl_dax_region_probe(struct device *dev)
{
	struct cxl_dax_region *cxlr_dax = to_cxl_dax_region(dev);
	int nid = phys_to_target_node(cxlr_dax->hpa_range.start);
	struct cxl_region *cxlr = cxlr_dax->cxlr;
	struct dax_region *dax_region;
	struct dev_dax_data data;
	struct dev_dax *dev_dax;

	if (nid == NUMA_NO_NODE)
		nid = memory_add_physaddr_to_nid(cxlr_dax->hpa_range.start);

	dax_region = alloc_dax_region(dev, cxlr->id, &cxlr_dax->hpa_range, nid,
				      PMD_SIZE, IORESOURCE_DAX_KMEM);
	if (!dax_region)
		return -ENOMEM;

	data = (struct dev_dax_data) {
		.dax_region = dax_region,
		.id = -1,
		.size = range_len(&cxlr_dax->hpa_range),
	};
	dev_dax = devm_create_dev_dax(&data);
	if (IS_ERR(dev_dax))
		return PTR_ERR(dev_dax);

	/* child dev_dax instances now own the lifetime of the dax_region */
	dax_region_put(dax_region);
	return 0;
}

static struct cxl_driver cxl_dax_region_driver = {
	.name = "cxl_dax_region",
	.probe = cxl_dax_region_probe,
	.id = CXL_DEVICE_DAX_REGION,
	.drv = {
		.suppress_bind_attrs = true,
	},
};

module_cxl_driver(cxl_dax_region_driver);
MODULE_ALIAS_CXL(CXL_DEVICE_DAX_REGION);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");
MODULE_IMPORT_NS(CXL);