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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/dax/hmem/hmem.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/dax/hmem/hmem.c')
-rw-r--r--drivers/dax/hmem/hmem.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
new file mode 100644
index 0000000000..5d2ddef0f8
--- /dev/null
+++ b/drivers/dax/hmem/hmem.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/platform_device.h>
+#include <linux/memregion.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include <linux/dax.h>
+#include "../bus.h"
+
+static bool region_idle;
+module_param_named(region_idle, region_idle, bool, 0644);
+
+static int dax_hmem_probe(struct platform_device *pdev)
+{
+ unsigned long flags = IORESOURCE_DAX_KMEM;
+ struct device *dev = &pdev->dev;
+ struct dax_region *dax_region;
+ struct memregion_info *mri;
+ struct dev_dax_data data;
+
+ /*
+ * @region_idle == true indicates that an administrative agent
+ * wants to manipulate the range partitioning before the devices
+ * are created, so do not send them to the dax_kmem driver by
+ * default.
+ */
+ if (region_idle)
+ flags = 0;
+
+ mri = dev->platform_data;
+ dax_region = alloc_dax_region(dev, pdev->id, &mri->range,
+ mri->target_node, PMD_SIZE, flags);
+ if (!dax_region)
+ return -ENOMEM;
+
+ data = (struct dev_dax_data) {
+ .dax_region = dax_region,
+ .id = -1,
+ .size = region_idle ? 0 : range_len(&mri->range),
+ };
+
+ return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
+}
+
+static struct platform_driver dax_hmem_driver = {
+ .probe = dax_hmem_probe,
+ .driver = {
+ .name = "hmem",
+ },
+};
+
+static void release_memregion(void *data)
+{
+ memregion_free((long) data);
+}
+
+static void release_hmem(void *pdev)
+{
+ platform_device_unregister(pdev);
+}
+
+static int hmem_register_device(struct device *host, int target_nid,
+ const struct resource *res)
+{
+ struct platform_device *pdev;
+ struct memregion_info info;
+ long id;
+ int rc;
+
+ if (IS_ENABLED(CONFIG_CXL_REGION) &&
+ region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
+ IORES_DESC_CXL) != REGION_DISJOINT) {
+ dev_dbg(host, "deferring range to CXL: %pr\n", res);
+ return 0;
+ }
+
+ rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
+ IORES_DESC_SOFT_RESERVED);
+ if (rc != REGION_INTERSECTS)
+ return 0;
+
+ id = memregion_alloc(GFP_KERNEL);
+ if (id < 0) {
+ dev_err(host, "memregion allocation failure for %pr\n", res);
+ return -ENOMEM;
+ }
+ rc = devm_add_action_or_reset(host, release_memregion, (void *) id);
+ if (rc)
+ return rc;
+
+ pdev = platform_device_alloc("hmem", id);
+ if (!pdev) {
+ dev_err(host, "device allocation failure for %pr\n", res);
+ return -ENOMEM;
+ }
+
+ pdev->dev.numa_node = numa_map_to_online_node(target_nid);
+ info = (struct memregion_info) {
+ .target_node = target_nid,
+ .range = {
+ .start = res->start,
+ .end = res->end,
+ },
+ };
+ rc = platform_device_add_data(pdev, &info, sizeof(info));
+ if (rc < 0) {
+ dev_err(host, "memregion_info allocation failure for %pr\n",
+ res);
+ goto out_put;
+ }
+
+ rc = platform_device_add(pdev);
+ if (rc < 0) {
+ dev_err(host, "%s add failed for %pr\n", dev_name(&pdev->dev),
+ res);
+ goto out_put;
+ }
+
+ return devm_add_action_or_reset(host, release_hmem, pdev);
+
+out_put:
+ platform_device_put(pdev);
+ return rc;
+}
+
+static int dax_hmem_platform_probe(struct platform_device *pdev)
+{
+ return walk_hmem_resources(&pdev->dev, hmem_register_device);
+}
+
+static struct platform_driver dax_hmem_platform_driver = {
+ .probe = dax_hmem_platform_probe,
+ .driver = {
+ .name = "hmem_platform",
+ },
+};
+
+static __init int dax_hmem_init(void)
+{
+ int rc;
+
+ rc = platform_driver_register(&dax_hmem_platform_driver);
+ if (rc)
+ return rc;
+
+ rc = platform_driver_register(&dax_hmem_driver);
+ if (rc)
+ platform_driver_unregister(&dax_hmem_platform_driver);
+
+ return rc;
+}
+
+static __exit void dax_hmem_exit(void)
+{
+ platform_driver_unregister(&dax_hmem_driver);
+ platform_driver_unregister(&dax_hmem_platform_driver);
+}
+
+module_init(dax_hmem_init);
+module_exit(dax_hmem_exit);
+
+/* Allow for CXL to define its own dax regions */
+#if IS_ENABLED(CONFIG_CXL_REGION)
+#if IS_MODULE(CONFIG_CXL_ACPI)
+MODULE_SOFTDEP("pre: cxl_acpi");
+#endif
+#endif
+
+MODULE_ALIAS("platform:hmem*");
+MODULE_ALIAS("platform:hmem_platform*");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");