Commit eedf634a authored by David Hildenbrand's avatar David Hildenbrand Committed by Linus Torvalds
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dax/kmem: use a single static memory group for a single probed unit 

Although dax/kmem users often disable auto-onlining and instead online
memory manually (usually to ZONE_MOVABLE), there is still value in having
auto-onlining be aware of the relationship of memory blocks.

Let's treat one probed unit as a single static memory device, similar to a
single ACPI memory device.

Link: https://lkml.kernel.org/r/20210806124715.17090-7-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hui Zhu <teawater@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2a157839

drivers/dax/kmem.c

+32 −8
Original line number Diff line number Diff line
@@ -37,15 +37,16 @@ static int dax_kmem_range(struct dev_dax *dev_dax, int i, struct range *r) 


struct dax_kmem_data {

	const char *res_name;

	int mgid;

	struct resource *res[];

};



static int dev_dax_kmem_probe(struct dev_dax *dev_dax)

{

	struct device *dev = &dev_dax->dev;

	unsigned long total_len = 0;

	struct dax_kmem_data *data;

	int rc = -ENOMEM;

	int i, mapped = 0;

	int i, rc, mapped = 0;

	int numa_node;



	/*
@@ -61,24 +62,44 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) 
		return -EINVAL;

	}



	for (i = 0; i < dev_dax->nr_range; i++) {

		struct range range;



		rc = dax_kmem_range(dev_dax, i, &range);

		if (rc) {

			dev_info(dev, "mapping%d: %#llx-%#llx too small after alignment\n",

					i, range.start, range.end);

			continue;

		}

		total_len += range_len(&range);

	}



	if (!total_len) {

		dev_warn(dev, "rejecting DAX region without any memory after alignment\n");

		return -EINVAL;

	}



	data = kzalloc(struct_size(data, res, dev_dax->nr_range), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	rc = -ENOMEM;

	data->res_name = kstrdup(dev_name(dev), GFP_KERNEL);

	if (!data->res_name)

		goto err_res_name;



	rc = memory_group_register_static(numa_node, total_len);

	if (rc < 0)

		goto err_reg_mgid;

	data->mgid = rc;



	for (i = 0; i < dev_dax->nr_range; i++) {

		struct resource *res;

		struct range range;



		rc = dax_kmem_range(dev_dax, i, &range);

		if (rc) {

			dev_info(dev, "mapping%d: %#llx-%#llx too small after alignment\n",

					i, range.start, range.end);

		if (rc)

			continue;

		}



		/* Region is permanently reserved if hotremove fails. */

		res = request_mem_region(range.start, range_len(&range), data->res_name);
@@ -108,8 +129,8 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) 
		 * Ensure that future kexec'd kernels will not treat

		 * this as RAM automatically.

		 */

		rc = add_memory_driver_managed(numa_node, range.start,

				range_len(&range), kmem_name, MHP_NONE);

		rc = add_memory_driver_managed(data->mgid, range.start,

				range_len(&range), kmem_name, MHP_NID_IS_MGID);



		if (rc) {

			dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n",
@@ -129,6 +150,8 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) 
	return 0;



err_request_mem:

	memory_group_unregister(data->mgid);

err_reg_mgid:

	kfree(data->res_name);

err_res_name:

	kfree(data);
@@ -171,6 +194,7 @@ static void dev_dax_kmem_remove(struct dev_dax *dev_dax) 
	}



	if (success >= dev_dax->nr_range) {

		memory_group_unregister(data->mgid);

		kfree(data->res_name);

		kfree(data);

		dev_set_drvdata(dev, NULL);