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cxl/pmem: Remove the cxl_pmem_wq and related infrastructure 

Now that cxl_nvdimm and cxl_pmem_region objects are torn down
sychronously with the removal of either the bridge, or an endpoint, the
cxl_pmem_wq infrastructure can be jettisoned.

Tested-by: Robert Richter <rrichter@amd.com>
Link: https://lore.kernel.org/r/166993042335.1882361.17022872468068436287.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2022-12-01 13:33:43 -08:00
parent f17b558d66
commit 03ff079aa6
3 changed files with 1 additions and 181 deletions
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22
drivers/cxl/core/pmem.c
View File

@ -99,7 +99,6 @@ static struct cxl_nvdimm_bridge *cxl_nvdimm_bridge_alloc(struct cxl_port *port)
dev = &cxl_nvb->dev;
cxl_nvb->port = port;
cxl_nvb->state = CXL_NVB_NEW;
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_nvdimm_bridge_key);
device_set_pm_not_required(dev);
@ -117,28 +116,7 @@ err:
static void unregister_nvb(void *_cxl_nvb)
{
struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb;
bool flush;
/*
* If the bridge was ever activated then there might be in-flight state
* work to flush. Once the state has been changed to 'dead' then no new
* work can be queued by user-triggered bind.
*/
device_lock(&cxl_nvb->dev);
flush = cxl_nvb->state != CXL_NVB_NEW;
cxl_nvb->state = CXL_NVB_DEAD;
device_unlock(&cxl_nvb->dev);
/*
* Even though the device core will trigger device_release_driver()
* before the unregister, it does not know about the fact that
* cxl_nvdimm_bridge_driver defers ->remove() work. So, do the driver
* release not and flush it before tearing down the nvdimm device
* hierarchy.
*/
device_release_driver(&cxl_nvb->dev);
if (flush)
flush_work(&cxl_nvb->state_work);
device_unregister(&cxl_nvb->dev);
}

17
drivers/cxl/cxl.h
View File

@ -400,34 +400,17 @@ struct cxl_region {
struct cxl_region_params params;
};
/**
* enum cxl_nvdimm_brige_state - state machine for managing bus rescans
* @CXL_NVB_NEW: Set at bridge create and after cxl_pmem_wq is destroyed
* @CXL_NVB_DEAD: Set at brige unregistration to preclude async probing
* @CXL_NVB_ONLINE: Target state after successful ->probe()
* @CXL_NVB_OFFLINE: Target state after ->remove() or failed ->probe()
*/
enum cxl_nvdimm_brige_state {
CXL_NVB_NEW,
CXL_NVB_DEAD,
CXL_NVB_ONLINE,
CXL_NVB_OFFLINE,
};
struct cxl_nvdimm_bridge {
int id;
struct device dev;
struct cxl_port *port;
struct nvdimm_bus *nvdimm_bus;
struct nvdimm_bus_descriptor nd_desc;
struct work_struct state_work;
enum cxl_nvdimm_brige_state state;
};
struct cxl_nvdimm {
struct device dev;
struct cxl_memdev *cxlmd;
struct cxl_nvdimm_bridge *bridge;
};
struct cxl_pmem_region_mapping {

143
drivers/cxl/pmem.c
View File

@ -11,13 +11,6 @@
#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)
@ -191,105 +184,6 @@ static void unregister_nvdimm_bus(void *_cxl_nvb)
nvdimm_bus_unregister(nvdimm_bus);
}
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 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_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);
@ -306,15 +200,12 @@ static int cxl_nvdimm_bridge_probe(struct device *dev)
if (!cxl_nvb->nvdimm_bus)
return -ENOMEM;
INIT_WORK(&cxl_nvb->state_work, cxl_nvb_update_state);
return devm_add_action_or_reset(dev, unregister_nvdimm_bus, cxl_nvb);
}
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,
.drv = {
.suppress_bind_attrs = true,
@ -453,31 +344,6 @@ static struct cxl_driver cxl_pmem_region_driver = {
},
};
/*
* 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;
@ -485,13 +351,9 @@ static __init int cxl_pmem_init(void)
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;
return rc;
rc = cxl_driver_register(&cxl_nvdimm_driver);
if (rc)
@ -507,8 +369,6 @@ 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;
}
@ -517,7 +377,6 @@ 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");