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a6c7f4c6ae
Platform firmware like EFI/ACPI may publish "hmem" platform devices. Such a device is a performance differentiated memory range likely reserved for an application specific use case. The driver gives access to 100% of the capacity via a device-dax mmap instance by default. However, if over-subscription and other kernel memory management is desired the resulting dax device can be assigned to the core-mm via the kmem driver. This consumes "hmem" devices the producer of "hmem" devices is saved for a follow-on patch so that it can reference the new CONFIG_DEV_DAX_HMEM symbol to gate performing the enumeration work. Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
57 lines
1.3 KiB
C
57 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/platform_device.h>
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#include <linux/memregion.h>
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#include <linux/module.h>
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#include <linux/pfn_t.h>
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#include "bus.h"
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static int dax_hmem_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct dev_pagemap pgmap = { };
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struct dax_region *dax_region;
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struct memregion_info *mri;
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struct dev_dax *dev_dax;
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struct resource *res;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENOMEM;
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mri = dev->platform_data;
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memcpy(&pgmap.res, res, sizeof(*res));
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dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
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PMD_SIZE, PFN_DEV|PFN_MAP);
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if (!dax_region)
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return -ENOMEM;
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dev_dax = devm_create_dev_dax(dax_region, 0, &pgmap);
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if (IS_ERR(dev_dax))
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return PTR_ERR(dev_dax);
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/* child dev_dax instances now own the lifetime of the dax_region */
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dax_region_put(dax_region);
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return 0;
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}
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static int dax_hmem_remove(struct platform_device *pdev)
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{
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/* devm handles teardown */
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return 0;
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}
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static struct platform_driver dax_hmem_driver = {
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.probe = dax_hmem_probe,
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.remove = dax_hmem_remove,
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.driver = {
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.name = "hmem",
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},
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};
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module_platform_driver(dax_hmem_driver);
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MODULE_ALIAS("platform:hmem*");
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Intel Corporation");
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