blob: bbeef91e637e9e7f5c3615234f50f0fc3d6b951d [file] [log] [blame]
// 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 "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)
{
nvdimm_delete(nvdimm);
}
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(cxl_nvd);
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(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);
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,
};
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 = cmd->in_offset,
.length = 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 (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 = 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 *data)
{
if (!is_cxl_nvdimm(dev))
return 0;
device_release_driver(dev);
return 0;
}
static void offline_nvdimm_bus(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, NULL, 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(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,
};
/*
* 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;
return 0;
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_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);