diff options
Diffstat (limited to 'drivers/cxl/pmem.c')
| -rw-r--r-- | drivers/cxl/pmem.c | 662 |
1 files changed, 662 insertions, 0 deletions
diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c new file mode 100644 index 000000000..1fca98488 --- /dev/null +++ b/drivers/cxl/pmem.c @@ -0,0 +1,662 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2021 Intel Corporation. All rights reserved. */ +#include <linux/libnvdimm.h> +#include <asm/unaligned.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/ndctl.h> +#include <linux/async.h> +#include <linux/slab.h> +#include <linux/nd.h> +#include "cxlmem.h" +#include "cxl.h" + +/* + * Ordered workqueue for cxl nvdimm device arrival and departure + * to coordinate bus rescans when a bridge arrives and trigger remove + * operations when the bridge is removed. + */ +static struct workqueue_struct *cxl_pmem_wq; + +static __read_mostly DECLARE_BITMAP(exclusive_cmds, CXL_MEM_COMMAND_ID_MAX); + +static void clear_exclusive(void *cxlds) +{ + clear_exclusive_cxl_commands(cxlds, exclusive_cmds); +} + +static void unregister_nvdimm(void *nvdimm) +{ + struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm); + struct cxl_nvdimm_bridge *cxl_nvb = cxl_nvd->bridge; + struct cxl_pmem_region *cxlr_pmem; + unsigned long index; + + device_lock(&cxl_nvb->dev); + dev_set_drvdata(&cxl_nvd->dev, NULL); + xa_for_each(&cxl_nvd->pmem_regions, index, cxlr_pmem) { + get_device(&cxlr_pmem->dev); + device_unlock(&cxl_nvb->dev); + + device_release_driver(&cxlr_pmem->dev); + put_device(&cxlr_pmem->dev); + + device_lock(&cxl_nvb->dev); + } + device_unlock(&cxl_nvb->dev); + + nvdimm_delete(nvdimm); + cxl_nvd->bridge = NULL; +} + +static int cxl_nvdimm_probe(struct device *dev) +{ + struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); + struct cxl_memdev *cxlmd = cxl_nvd->cxlmd; + unsigned long flags = 0, cmd_mask = 0; + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_nvdimm_bridge *cxl_nvb; + struct nvdimm *nvdimm; + int rc; + + cxl_nvb = cxl_find_nvdimm_bridge(dev); + if (!cxl_nvb) + return -ENXIO; + + device_lock(&cxl_nvb->dev); + if (!cxl_nvb->nvdimm_bus) { + rc = -ENXIO; + goto out; + } + + set_exclusive_cxl_commands(cxlds, exclusive_cmds); + rc = devm_add_action_or_reset(dev, clear_exclusive, cxlds); + if (rc) + goto out; + + set_bit(NDD_LABELING, &flags); + set_bit(NDD_REGISTER_SYNC, &flags); + set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask); + set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask); + set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask); + nvdimm = nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, NULL, flags, + cmd_mask, 0, NULL); + if (!nvdimm) { + rc = -ENOMEM; + goto out; + } + + dev_set_drvdata(dev, nvdimm); + cxl_nvd->bridge = cxl_nvb; + rc = devm_add_action_or_reset(dev, unregister_nvdimm, nvdimm); +out: + device_unlock(&cxl_nvb->dev); + put_device(&cxl_nvb->dev); + + return rc; +} + +static struct cxl_driver cxl_nvdimm_driver = { + .name = "cxl_nvdimm", + .probe = cxl_nvdimm_probe, + .id = CXL_DEVICE_NVDIMM, +}; + +static int cxl_pmem_get_config_size(struct cxl_dev_state *cxlds, + struct nd_cmd_get_config_size *cmd, + unsigned int buf_len) +{ + if (sizeof(*cmd) > buf_len) + return -EINVAL; + + *cmd = (struct nd_cmd_get_config_size) { + .config_size = cxlds->lsa_size, + .max_xfer = cxlds->payload_size - sizeof(struct cxl_mbox_set_lsa), + }; + + return 0; +} + +static int cxl_pmem_get_config_data(struct cxl_dev_state *cxlds, + struct nd_cmd_get_config_data_hdr *cmd, + unsigned int buf_len) +{ + struct cxl_mbox_get_lsa get_lsa; + int rc; + + if (sizeof(*cmd) > buf_len) + return -EINVAL; + if (struct_size(cmd, out_buf, cmd->in_length) > buf_len) + return -EINVAL; + + get_lsa = (struct cxl_mbox_get_lsa) { + .offset = cpu_to_le32(cmd->in_offset), + .length = cpu_to_le32(cmd->in_length), + }; + + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_LSA, &get_lsa, + sizeof(get_lsa), cmd->out_buf, cmd->in_length); + cmd->status = 0; + + return rc; +} + +static int cxl_pmem_set_config_data(struct cxl_dev_state *cxlds, + struct nd_cmd_set_config_hdr *cmd, + unsigned int buf_len) +{ + struct cxl_mbox_set_lsa *set_lsa; + int rc; + + if (sizeof(*cmd) > buf_len) + return -EINVAL; + + /* 4-byte status follows the input data in the payload */ + if (size_add(struct_size(cmd, in_buf, cmd->in_length), 4) > buf_len) + return -EINVAL; + + set_lsa = + kvzalloc(struct_size(set_lsa, data, cmd->in_length), GFP_KERNEL); + if (!set_lsa) + return -ENOMEM; + + *set_lsa = (struct cxl_mbox_set_lsa) { + .offset = cpu_to_le32(cmd->in_offset), + }; + memcpy(set_lsa->data, cmd->in_buf, cmd->in_length); + + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_SET_LSA, set_lsa, + struct_size(set_lsa, data, cmd->in_length), + NULL, 0); + + /* + * Set "firmware" status (4-packed bytes at the end of the input + * payload. + */ + put_unaligned(0, (u32 *) &cmd->in_buf[cmd->in_length]); + kvfree(set_lsa); + + return rc; +} + +static int cxl_pmem_nvdimm_ctl(struct nvdimm *nvdimm, unsigned int cmd, + void *buf, unsigned int buf_len) +{ + struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm); + unsigned long cmd_mask = nvdimm_cmd_mask(nvdimm); + struct cxl_memdev *cxlmd = cxl_nvd->cxlmd; + struct cxl_dev_state *cxlds = cxlmd->cxlds; + + if (!test_bit(cmd, &cmd_mask)) + return -ENOTTY; + + switch (cmd) { + case ND_CMD_GET_CONFIG_SIZE: + return cxl_pmem_get_config_size(cxlds, buf, buf_len); + case ND_CMD_GET_CONFIG_DATA: + return cxl_pmem_get_config_data(cxlds, buf, buf_len); + case ND_CMD_SET_CONFIG_DATA: + return cxl_pmem_set_config_data(cxlds, buf, buf_len); + default: + return -ENOTTY; + } +} + +static int cxl_pmem_ctl(struct nvdimm_bus_descriptor *nd_desc, + struct nvdimm *nvdimm, unsigned int cmd, void *buf, + unsigned int buf_len, int *cmd_rc) +{ + /* + * No firmware response to translate, let the transport error + * code take precedence. + */ + *cmd_rc = 0; + + if (!nvdimm) + return -ENOTTY; + return cxl_pmem_nvdimm_ctl(nvdimm, cmd, buf, buf_len); +} + +static bool online_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) +{ + if (cxl_nvb->nvdimm_bus) + return true; + cxl_nvb->nvdimm_bus = + nvdimm_bus_register(&cxl_nvb->dev, &cxl_nvb->nd_desc); + return cxl_nvb->nvdimm_bus != NULL; +} + +static int cxl_nvdimm_release_driver(struct device *dev, void *cxl_nvb) +{ + struct cxl_nvdimm *cxl_nvd; + + if (!is_cxl_nvdimm(dev)) + return 0; + + cxl_nvd = to_cxl_nvdimm(dev); + if (cxl_nvd->bridge != cxl_nvb) + return 0; + + device_release_driver(dev); + return 0; +} + +static int cxl_pmem_region_release_driver(struct device *dev, void *cxl_nvb) +{ + struct cxl_pmem_region *cxlr_pmem; + + if (!is_cxl_pmem_region(dev)) + return 0; + + cxlr_pmem = to_cxl_pmem_region(dev); + if (cxlr_pmem->bridge != cxl_nvb) + return 0; + + device_release_driver(dev); + return 0; +} + +static void offline_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb, + struct nvdimm_bus *nvdimm_bus) +{ + if (!nvdimm_bus) + return; + + /* + * Set the state of cxl_nvdimm devices to unbound / idle before + * nvdimm_bus_unregister() rips the nvdimm objects out from + * underneath them. + */ + bus_for_each_dev(&cxl_bus_type, NULL, cxl_nvb, + cxl_pmem_region_release_driver); + bus_for_each_dev(&cxl_bus_type, NULL, cxl_nvb, + cxl_nvdimm_release_driver); + nvdimm_bus_unregister(nvdimm_bus); +} + +static void cxl_nvb_update_state(struct work_struct *work) +{ + struct cxl_nvdimm_bridge *cxl_nvb = + container_of(work, typeof(*cxl_nvb), state_work); + struct nvdimm_bus *victim_bus = NULL; + bool release = false, rescan = false; + + device_lock(&cxl_nvb->dev); + switch (cxl_nvb->state) { + case CXL_NVB_ONLINE: + if (!online_nvdimm_bus(cxl_nvb)) { + dev_err(&cxl_nvb->dev, + "failed to establish nvdimm bus\n"); + release = true; + } else + rescan = true; + break; + case CXL_NVB_OFFLINE: + case CXL_NVB_DEAD: + victim_bus = cxl_nvb->nvdimm_bus; + cxl_nvb->nvdimm_bus = NULL; + break; + default: + break; + } + device_unlock(&cxl_nvb->dev); + + if (release) + device_release_driver(&cxl_nvb->dev); + if (rescan) { + int rc = bus_rescan_devices(&cxl_bus_type); + + dev_dbg(&cxl_nvb->dev, "rescan: %d\n", rc); + } + offline_nvdimm_bus(cxl_nvb, victim_bus); + + put_device(&cxl_nvb->dev); +} + +static void cxl_nvdimm_bridge_state_work(struct cxl_nvdimm_bridge *cxl_nvb) +{ + /* + * Take a reference that the workqueue will drop if new work + * gets queued. + */ + get_device(&cxl_nvb->dev); + if (!queue_work(cxl_pmem_wq, &cxl_nvb->state_work)) + put_device(&cxl_nvb->dev); +} + +static void cxl_nvdimm_bridge_remove(struct device *dev) +{ + struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); + + if (cxl_nvb->state == CXL_NVB_ONLINE) + cxl_nvb->state = CXL_NVB_OFFLINE; + cxl_nvdimm_bridge_state_work(cxl_nvb); +} + +static int cxl_nvdimm_bridge_probe(struct device *dev) +{ + struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); + + if (cxl_nvb->state == CXL_NVB_DEAD) + return -ENXIO; + + if (cxl_nvb->state == CXL_NVB_NEW) { + cxl_nvb->nd_desc = (struct nvdimm_bus_descriptor) { + .provider_name = "CXL", + .module = THIS_MODULE, + .ndctl = cxl_pmem_ctl, + }; + + INIT_WORK(&cxl_nvb->state_work, cxl_nvb_update_state); + } + + cxl_nvb->state = CXL_NVB_ONLINE; + cxl_nvdimm_bridge_state_work(cxl_nvb); + + return 0; +} + +static struct cxl_driver cxl_nvdimm_bridge_driver = { + .name = "cxl_nvdimm_bridge", + .probe = cxl_nvdimm_bridge_probe, + .remove = cxl_nvdimm_bridge_remove, + .id = CXL_DEVICE_NVDIMM_BRIDGE, +}; + +static int match_cxl_nvdimm(struct device *dev, void *data) +{ + return is_cxl_nvdimm(dev); +} + +static void unregister_nvdimm_region(void *nd_region) +{ + nvdimm_region_delete(nd_region); +} + +static int cxl_nvdimm_add_region(struct cxl_nvdimm *cxl_nvd, + struct cxl_pmem_region *cxlr_pmem) +{ + int rc; + + rc = xa_insert(&cxl_nvd->pmem_regions, (unsigned long)cxlr_pmem, + cxlr_pmem, GFP_KERNEL); + if (rc) + return rc; + + get_device(&cxlr_pmem->dev); + return 0; +} + +static void cxl_nvdimm_del_region(struct cxl_nvdimm *cxl_nvd, + struct cxl_pmem_region *cxlr_pmem) +{ + /* + * It is possible this is called without a corresponding + * cxl_nvdimm_add_region for @cxlr_pmem + */ + cxlr_pmem = xa_erase(&cxl_nvd->pmem_regions, (unsigned long)cxlr_pmem); + if (cxlr_pmem) + put_device(&cxlr_pmem->dev); +} + +static void release_mappings(void *data) +{ + int i; + struct cxl_pmem_region *cxlr_pmem = data; + struct cxl_nvdimm_bridge *cxl_nvb = cxlr_pmem->bridge; + + device_lock(&cxl_nvb->dev); + for (i = 0; i < cxlr_pmem->nr_mappings; i++) { + struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i]; + struct cxl_nvdimm *cxl_nvd = m->cxl_nvd; + + cxl_nvdimm_del_region(cxl_nvd, cxlr_pmem); + } + device_unlock(&cxl_nvb->dev); +} + +static void cxlr_pmem_remove_resource(void *res) +{ + remove_resource(res); +} + +struct cxl_pmem_region_info { + u64 offset; + u64 serial; +}; + +static int cxl_pmem_region_probe(struct device *dev) +{ + struct nd_mapping_desc mappings[CXL_DECODER_MAX_INTERLEAVE]; + struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev); + struct cxl_region *cxlr = cxlr_pmem->cxlr; + struct cxl_pmem_region_info *info = NULL; + struct cxl_nvdimm_bridge *cxl_nvb; + struct nd_interleave_set *nd_set; + struct nd_region_desc ndr_desc; + struct cxl_nvdimm *cxl_nvd; + struct nvdimm *nvdimm; + struct resource *res; + int rc, i = 0; + + cxl_nvb = cxl_find_nvdimm_bridge(&cxlr_pmem->mapping[0].cxlmd->dev); + if (!cxl_nvb) { + dev_dbg(dev, "bridge not found\n"); + return -ENXIO; + } + cxlr_pmem->bridge = cxl_nvb; + + device_lock(&cxl_nvb->dev); + if (!cxl_nvb->nvdimm_bus) { + dev_dbg(dev, "nvdimm bus not found\n"); + rc = -ENXIO; + goto out_nvb; + } + + memset(&mappings, 0, sizeof(mappings)); + memset(&ndr_desc, 0, sizeof(ndr_desc)); + + res = devm_kzalloc(dev, sizeof(*res), GFP_KERNEL); + if (!res) { + rc = -ENOMEM; + goto out_nvb; + } + + res->name = "Persistent Memory"; + res->start = cxlr_pmem->hpa_range.start; + res->end = cxlr_pmem->hpa_range.end; + res->flags = IORESOURCE_MEM; + res->desc = IORES_DESC_PERSISTENT_MEMORY; + + rc = insert_resource(&iomem_resource, res); + if (rc) + goto out_nvb; + + rc = devm_add_action_or_reset(dev, cxlr_pmem_remove_resource, res); + if (rc) + goto out_nvb; + + ndr_desc.res = res; + ndr_desc.provider_data = cxlr_pmem; + + ndr_desc.numa_node = memory_add_physaddr_to_nid(res->start); + ndr_desc.target_node = phys_to_target_node(res->start); + if (ndr_desc.target_node == NUMA_NO_NODE) { + ndr_desc.target_node = ndr_desc.numa_node; + dev_dbg(&cxlr->dev, "changing target node from %d to %d", + NUMA_NO_NODE, ndr_desc.target_node); + } + + nd_set = devm_kzalloc(dev, sizeof(*nd_set), GFP_KERNEL); + if (!nd_set) { + rc = -ENOMEM; + goto out_nvb; + } + + ndr_desc.memregion = cxlr->id; + set_bit(ND_REGION_CXL, &ndr_desc.flags); + set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags); + + info = kmalloc_array(cxlr_pmem->nr_mappings, sizeof(*info), GFP_KERNEL); + if (!info) { + rc = -ENOMEM; + goto out_nvb; + } + + rc = devm_add_action_or_reset(dev, release_mappings, cxlr_pmem); + if (rc) + goto out_nvd; + + for (i = 0; i < cxlr_pmem->nr_mappings; i++) { + struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i]; + struct cxl_memdev *cxlmd = m->cxlmd; + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct device *d; + + d = device_find_child(&cxlmd->dev, NULL, match_cxl_nvdimm); + if (!d) { + dev_dbg(dev, "[%d]: %s: no cxl_nvdimm found\n", i, + dev_name(&cxlmd->dev)); + rc = -ENODEV; + goto out_nvd; + } + + /* safe to drop ref now with bridge lock held */ + put_device(d); + + cxl_nvd = to_cxl_nvdimm(d); + nvdimm = dev_get_drvdata(&cxl_nvd->dev); + if (!nvdimm) { + dev_dbg(dev, "[%d]: %s: no nvdimm found\n", i, + dev_name(&cxlmd->dev)); + rc = -ENODEV; + goto out_nvd; + } + + /* + * Pin the region per nvdimm device as those may be released + * out-of-order with respect to the region, and a single nvdimm + * maybe associated with multiple regions + */ + rc = cxl_nvdimm_add_region(cxl_nvd, cxlr_pmem); + if (rc) + goto out_nvd; + m->cxl_nvd = cxl_nvd; + mappings[i] = (struct nd_mapping_desc) { + .nvdimm = nvdimm, + .start = m->start, + .size = m->size, + .position = i, + }; + info[i].offset = m->start; + info[i].serial = cxlds->serial; + } + ndr_desc.num_mappings = cxlr_pmem->nr_mappings; + ndr_desc.mapping = mappings; + + /* + * TODO enable CXL labels which skip the need for 'interleave-set cookie' + */ + nd_set->cookie1 = + nd_fletcher64(info, sizeof(*info) * cxlr_pmem->nr_mappings, 0); + nd_set->cookie2 = nd_set->cookie1; + ndr_desc.nd_set = nd_set; + + cxlr_pmem->nd_region = + nvdimm_pmem_region_create(cxl_nvb->nvdimm_bus, &ndr_desc); + if (!cxlr_pmem->nd_region) { + rc = -ENOMEM; + goto out_nvd; + } + + rc = devm_add_action_or_reset(dev, unregister_nvdimm_region, + cxlr_pmem->nd_region); +out_nvd: + kfree(info); +out_nvb: + device_unlock(&cxl_nvb->dev); + put_device(&cxl_nvb->dev); + + return rc; +} + +static struct cxl_driver cxl_pmem_region_driver = { + .name = "cxl_pmem_region", + .probe = cxl_pmem_region_probe, + .id = CXL_DEVICE_PMEM_REGION, +}; + +/* + * Return all bridges to the CXL_NVB_NEW state to invalidate any + * ->state_work referring to the now destroyed cxl_pmem_wq. + */ +static int cxl_nvdimm_bridge_reset(struct device *dev, void *data) +{ + struct cxl_nvdimm_bridge *cxl_nvb; + + if (!is_cxl_nvdimm_bridge(dev)) + return 0; + + cxl_nvb = to_cxl_nvdimm_bridge(dev); + device_lock(dev); + cxl_nvb->state = CXL_NVB_NEW; + device_unlock(dev); + + return 0; +} + +static void destroy_cxl_pmem_wq(void) +{ + destroy_workqueue(cxl_pmem_wq); + bus_for_each_dev(&cxl_bus_type, NULL, NULL, cxl_nvdimm_bridge_reset); +} + +static __init int cxl_pmem_init(void) +{ + int rc; + + set_bit(CXL_MEM_COMMAND_ID_SET_SHUTDOWN_STATE, exclusive_cmds); + set_bit(CXL_MEM_COMMAND_ID_SET_LSA, exclusive_cmds); + + cxl_pmem_wq = alloc_ordered_workqueue("cxl_pmem", 0); + if (!cxl_pmem_wq) + return -ENXIO; + + rc = cxl_driver_register(&cxl_nvdimm_bridge_driver); + if (rc) + goto err_bridge; + + rc = cxl_driver_register(&cxl_nvdimm_driver); + if (rc) + goto err_nvdimm; + + rc = cxl_driver_register(&cxl_pmem_region_driver); + if (rc) + goto err_region; + + return 0; + +err_region: + cxl_driver_unregister(&cxl_nvdimm_driver); +err_nvdimm: + cxl_driver_unregister(&cxl_nvdimm_bridge_driver); +err_bridge: + destroy_cxl_pmem_wq(); + return rc; +} + +static __exit void cxl_pmem_exit(void) +{ + cxl_driver_unregister(&cxl_pmem_region_driver); + cxl_driver_unregister(&cxl_nvdimm_driver); + cxl_driver_unregister(&cxl_nvdimm_bridge_driver); + destroy_cxl_pmem_wq(); +} + +MODULE_LICENSE("GPL v2"); +module_init(cxl_pmem_init); +module_exit(cxl_pmem_exit); +MODULE_IMPORT_NS(CXL); +MODULE_ALIAS_CXL(CXL_DEVICE_NVDIMM_BRIDGE); +MODULE_ALIAS_CXL(CXL_DEVICE_NVDIMM); +MODULE_ALIAS_CXL(CXL_DEVICE_PMEM_REGION); |