diff options
Diffstat (limited to 'drivers/dax/hmem/hmem.c')
| -rw-r--r-- | drivers/dax/hmem/hmem.c | 171 |
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"); |