6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams <dan.j.williams@xxxxxxxxx> [ Upstream commit 4029c32fb601d505dfb92bdf0db9fdcc41fe1434 ] Now that the cxl_mem driver has a need to take the root device lock, the cxl_bus_rescan() needs to run outside of the root lock context. That need arises from RCH topologies and the locking that the cxl_mem driver does to attach a descendant to an upstream port. In the RCH case the lock needed is the CXL root device lock [1]. Link: http://lore.kernel.org/r/166993045621.1882361.1730100141527044744.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx [1] Tested-by: Robert Richter <rrichter@xxxxxxx> Link: http://lore.kernel.org/r/166993042884.1882361.5633723613683058881.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Stable-dep-of: 3d6ebf16438d ("cxl/port: Fix cxl_bus_rescan() vs bus_rescan_devices()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/cxl/acpi.c | 17 +++++++++++++++-- drivers/cxl/core/port.c | 19 +++++++++++++++++-- drivers/cxl/cxl.h | 3 ++- 3 files changed, 34 insertions(+), 5 deletions(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index dd610556a3afa..d7d789211c173 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -509,7 +509,8 @@ static int cxl_acpi_probe(struct platform_device *pdev) return rc; /* In case PCI is scanned before ACPI re-trigger memdev attach */ - return cxl_bus_rescan(); + cxl_bus_rescan(); + return 0; } static const struct acpi_device_id cxl_acpi_ids[] = { @@ -533,7 +534,19 @@ static struct platform_driver cxl_acpi_driver = { .id_table = cxl_test_ids, }; -module_platform_driver(cxl_acpi_driver); +static int __init cxl_acpi_init(void) +{ + return platform_driver_register(&cxl_acpi_driver); +} + +static void __exit cxl_acpi_exit(void) +{ + platform_driver_unregister(&cxl_acpi_driver); + cxl_bus_drain(); +} + +module_init(cxl_acpi_init); +module_exit(cxl_acpi_exit); MODULE_LICENSE("GPL v2"); MODULE_IMPORT_NS(CXL); MODULE_IMPORT_NS(ACPI); diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 1f1483a9e5252..f0875fa86c616 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -1786,12 +1786,27 @@ static void cxl_bus_remove(struct device *dev) static struct workqueue_struct *cxl_bus_wq; -int cxl_bus_rescan(void) +static void cxl_bus_rescan_queue(struct work_struct *w) { - return bus_rescan_devices(&cxl_bus_type); + int rc = bus_rescan_devices(&cxl_bus_type); + + pr_debug("CXL bus rescan result: %d\n", rc); +} + +void cxl_bus_rescan(void) +{ + static DECLARE_WORK(rescan_work, cxl_bus_rescan_queue); + + queue_work(cxl_bus_wq, &rescan_work); } EXPORT_SYMBOL_NS_GPL(cxl_bus_rescan, CXL); +void cxl_bus_drain(void) +{ + drain_workqueue(cxl_bus_wq); +} +EXPORT_SYMBOL_NS_GPL(cxl_bus_drain, CXL); + bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd) { return queue_work(cxl_bus_wq, &cxlmd->detach_work); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 7750ccb7652db..827fa94cddda1 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -564,7 +564,8 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, struct cxl_dport *parent_dport); struct cxl_port *find_cxl_root(struct device *dev); int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); -int cxl_bus_rescan(void); +void cxl_bus_rescan(void); +void cxl_bus_drain(void); struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd, struct cxl_dport **dport); bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd); -- 2.43.0
