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path: root/drivers/cxl/pmem.c
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2023-06-25cxl/mbox: Move mailbox related driver state to its own data structureDan Williams
'struct cxl_dev_state' makes too many assumptions about the capabilities of a CXL device. In particular it assumes a CXL device has a mailbox and all of the infrastructure and state that comes along with that. In preparation for supporting accelerator / Type-2 devices that may not have a mailbox and in general maintain a minimal core context structure, make mailbox functionality a super-set of 'struct cxl_dev_state' with 'struct cxl_memdev_state'. With this reorganization it allows for CXL devices that support HDM decoder mapping, but not other general-expander / Type-3 capabilities, to only enable that subset without the rest of the mailbox infrastructure coming along for the ride. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679260240.3436160.15520641540463704524.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-02-13cxl/pmem: Fix nvdimm registration racesDan Williams
A loop of the form: while true; do modprobe cxl_pci; modprobe -r cxl_pci; done ...fails with the following crash signature: BUG: kernel NULL pointer dereference, address: 0000000000000040 [..] RIP: 0010:cxl_internal_send_cmd+0x5/0xb0 [cxl_core] [..] Call Trace: <TASK> cxl_pmem_ctl+0x121/0x240 [cxl_pmem] nvdimm_get_config_data+0xd6/0x1a0 [libnvdimm] nd_label_data_init+0x135/0x7e0 [libnvdimm] nvdimm_probe+0xd6/0x1c0 [libnvdimm] nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm] really_probe+0xde/0x380 __driver_probe_device+0x78/0x170 driver_probe_device+0x1f/0x90 __device_attach_driver+0x85/0x110 bus_for_each_drv+0x7d/0xc0 __device_attach+0xb4/0x1e0 bus_probe_device+0x9f/0xc0 device_add+0x445/0x9c0 nd_async_device_register+0xe/0x40 [libnvdimm] async_run_entry_fn+0x30/0x130 ...namely that the bottom half of async nvdimm device registration runs after the CXL has already torn down the context that cxl_pmem_ctl() needs. Unlike the ACPI NFIT case that benefits from launching multiple nvdimm device registrations in parallel from those listed in the table, CXL is already marked PROBE_PREFER_ASYNCHRONOUS. So provide for a synchronous registration path to preclude this scenario. Fixes: 21083f51521f ("cxl/pmem: Register 'pmem' / cxl_nvdimm devices") Cc: <stable@vger.kernel.org> Reported-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-01-25cxl/pmem: Fix nvdimm unregistration when cxl_pmem driver is absentDan Williams
The cxl_pmem.ko module houses the driver for both cxl_nvdimm_bridge objects and cxl_nvdimm objects. When the core creates a cxl_nvdimm it arranges for it to be autoremoved when the bridge goes down. However, if the bridge never initialized because the cxl_pmem.ko module never loaded, it sets up a the following crash scenario: BUG: kernel NULL pointer dereference, address: 0000000000000478 [..] RIP: 0010:cxl_nvdimm_probe+0x99/0x140 [cxl_pmem] [..] Call Trace: <TASK> cxl_bus_probe+0x17/0x50 [cxl_core] really_probe+0xde/0x380 __driver_probe_device+0x78/0x170 driver_probe_device+0x1f/0x90 __driver_attach+0xd2/0x1c0 bus_for_each_dev+0x79/0xc0 bus_add_driver+0x1b1/0x200 driver_register+0x89/0xe0 cxl_pmem_init+0x50/0xff0 [cxl_pmem] It turns out the recent rework to simplify nvdimm probing obviated the need to unregister cxl_nvdimm objects at cxl_nvdimm_bridge ->remove() time. Leave the cxl_nvdimm device registered until the hosting cxl_memdev departs. The alternative is that the cxl_memdev needs to be reattached whenever the cxl_nvdimm_bridge attach state cycles, which is awkward and unnecessary. The only requirement is to make sure that when the cxl_nvdimm_bridge goes away any dependent cxl_nvdimm objects are shutdown. Handle that in unregister_nvdimm_bus(). With these registration entanglements removed there is no longer a need to pre-load the cxl_pmem module in cxl_acpi. Fixes: cb9cfff82f6a ("cxl/acpi: Simplify cxl_nvdimm_bridge probing") Reported-by: Gregory Price <gregory.price@memverge.com> Debugged-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/167426077263.3955046.9695309346988027311.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-06cxl/mbox: Enable cxl_mbox_send_cmd() users to validate output sizeDan Williams
Internally cxl_mbox_send_cmd() converts all passed-in parameters to a 'struct cxl_mbox_cmd' instance and sends that to cxlds->mbox_send(). It then teases the possibilty that the caller can validate the output size. However, they cannot since the resulting output size is not conveyed to the called. Fix that by making the caller pass in a constructed 'struct cxl_mbox_cmd'. This prepares for a future patch to add output size validation on a per-command basis. Given the change in signature, also change the name to differentiate it from the user command submission path that performs more validation before generating the 'struct cxl_mbox_cmd' instance to execute. Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/167030055370.4044561.17788093375112783036.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-05Merge branch 'for-6.2/cxl-security' into for-6.2/cxlDan Williams
Pick CXL PMEM security commands for v6.2. Resolve conflicts with the removal of the cxl_pmem_wq.
2022-12-02cxl: add dimm_id support for __nvdimm_create()Dave Jiang
Set the cxlds->serial as the dimm_id to be fed to __nvdimm_create(). The security code uses that as the key description for the security key of the memory device. The nvdimm unlock code cannot find the respective key without the dimm_id. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166863357043.80269.4337575149671383294.stgit@djiang5-desk3.ch.intel.com Link: https://lore.kernel.org/r/166983620459.2734609.10175456773200251184.stgit@djiang5-desk3.ch.intel.com Link: https://lore.kernel.org/r/166993219918.1995348.10786511454826454601.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-02cxl/pmem: Remove the cxl_pmem_wq and related infrastructureDan Williams
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>
2022-12-02cxl/pmem: Refactor nvdimm device registration, delete the workqueueDan Williams
The three objects 'struct cxl_nvdimm_bridge', 'struct cxl_nvdimm', and 'struct cxl_pmem_region' manage CXL persistent memory resources. The bridge represents base platform resources, the nvdimm represents one or more endpoints, and the region is a collection of nvdimms that contribute to an assembled address range. Their relationship is such that a region is torn down if any component endpoints are removed. All regions and endpoints are torn down if the foundational bridge device goes down. A workqueue was deployed to manage these interdependencies, but it is difficult to reason about, and fragile. A recent attempt to take the CXL root device lock in the cxl_mem driver was reported by lockdep as colliding with the flush_work() in the cxl_pmem flows. Instead of the workqueue, arrange for all pmem/nvdimm devices to be torn down immediately and hierarchically. A similar change is made to both the 'cxl_nvdimm' and 'cxl_pmem_region' objects. For bisect-ability both changes are made in the same patch which unfortunately makes the patch bigger than desired. Arrange for cxl_memdev and cxl_region to register a cxl_nvdimm and cxl_pmem_region as a devres release action of the bridge device. Additionally, include a devres release action of the cxl_memdev or cxl_region device that triggers the bridge's release action if an endpoint exits before the bridge. I.e. this allows either unplugging the bridge, or unplugging and endpoint to result in the same cleanup actions. To keep the patch smaller the cleanup of the now defunct workqueue infrastructure is saved for a follow-on patch. Tested-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/166993041773.1882361.16444301376147207609.stgit@dwillia2-xfh.jf.intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-02cxl/region: Drop redundant pmem region release handlingDan Williams
Now that a cxl_nvdimm object can only experience ->remove() via an unregistration event (because the cxl_nvdimm bind attributes are suppressed), additional cleanups are possible. It is already the case that the removal of a cxl_memdev object triggers ->remove() on any associated region. With that mechanism in place there is no need for the cxl_nvdimm removal to trigger the same. Just rely on cxl_region_detach() to tear down the whole cxl_pmem_region. Tested-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/166993041215.1882361.6321535567798911286.stgit@dwillia2-xfh.jf.intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-01cxl/acpi: Simplify cxl_nvdimm_bridge probingDan Williams
The 'struct cxl_nvdimm_bridge' object advertises platform CXL PMEM resources. It coordinates with libnvdimm to attach nvdimm devices and regions for each corresponding CXL object. That coordination is complicated, i.e. difficult to reason about, and it turns out redundant. It is already the case that the CXL core knows how to tear down a cxl_region when a cxl_memdev goes through ->remove(), so that pathway can be extended to directly cleanup cxl_nvdimm and cxl_pmem_region objects. Towards the goal of ripping out the cxl_nvdimm_bridge state machine, arrange for cxl_acpi to optionally pre-load the cxl_pmem driver so that the nvdimm bridge is active synchronously with devm_cxl_add_nvdimm_bridge(), and remove all the bind attributes for the cxl_nvdimm* objects since the cxl root device and cxl_memdev bind attributes are sufficient. Tested-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/166993040668.1882361.7450361097265836752.stgit@dwillia2-xfh.jf.intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-01cxl/pmem: add provider name to cxl pmem dimm attribute groupDave Jiang
Add provider name in order to associate cxl test dimm from cxl_test to the cxl pmem device when going through sysfs for security testing. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166983618174.2734609.15600031015423828810.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-01cxl/pmem: add id attribute to CXL based nvdimmDave Jiang
Add an id group attribute for CXL based nvdimm object. The addition allows ndctl to display the "unique id" for the nvdimm. The serial number for the CXL memory device will be used for this id. [ { "dev":"nmem10", "id":"0x4", "security":"disabled" }, ] The id attribute is needed by the ndctl security key management to setup a keyblob with a unique file name tied to the mem device. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166983617029.2734609.8251308562882142281.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-11-30cxl/pmem: Introduce nvdimm_security_ops with ->get_flags() operationDave Jiang
Add nvdimm_security_ops support for CXL memory device with the introduction of the ->get_flags() callback function. This is part of the "Persistent Memory Data-at-rest Security" command set for CXL memory device support. The ->get_flags() function provides the security state of the persistent memory device defined by the CXL 3.0 spec section 8.2.9.8.6.1. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166983609611.2734609.13231854299523325319.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-11-04cxl/pmem: Fix cxl_pmem_region and cxl_memdev leakDan Williams
When a cxl_nvdimm object goes through a ->remove() event (device physically removed, nvdimm-bridge disabled, or nvdimm device disabled), then any associated regions must also be disabled. As highlighted by the cxl-create-region.sh test [1], a single device may host multiple regions, but the driver was only tracking one region at a time. This leads to a situation where only the last enabled region per nvdimm device is cleaned up properly. Other regions are leaked, and this also causes cxl_memdev reference leaks. Fix the tracking by allowing cxl_nvdimm objects to track multiple region associations. Cc: <stable@vger.kernel.org> Link: https://github.com/pmem/ndctl/blob/main/test/cxl-create-region.sh [1] Reported-by: Vishal Verma <vishal.l.verma@intel.com> Fixes: 04ad63f086d1 ("cxl/region: Introduce cxl_pmem_region objects") Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/166752183647.947915.2045230911503793901.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-11-03cxl/pmem: Use size_add() against integer overflowYu Zhe
"struct_size() + n" may cause a integer overflow, use size_add() to handle it. Signed-off-by: Yu Zhe <yuzhe@nfschina.com> Link: https://lore.kernel.org/r/20220927070247.23148-1-yuzhe@nfschina.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-10-20cxl/pmem: Fix failure to account for 8 byte header for writes to the device LSA.Jonathan Cameron
Writes to the device must include an offset and size as defined in CXL 2.0 8.2.9.5.2.4 Set LSA (Opcode 4103h) Fixes tag is non obvious as this code has been through several reworks and variable names + wasn't in use until the addition of the region code. Due to a bug in QEMU CXL emulation this overrun resulted in QEMU crashing. Reported-by: Bobo WL <lmw.bobo@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Fixes: 60b8f17215de ("cxl/pmem: Translate NVDIMM label commands to CXL label commands") Link: https://lore.kernel.org/r/20220815154044.24733-3-Jonathan.Cameron@huawei.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-08-05cxl/region: Fix IS_ERR() vs NULL checkDan Carpenter
The nvdimm_pmem_region_create() function returns NULL on error. It does not return error pointers. Fixes: 04ad63f086d1 ("cxl/region: Introduce cxl_pmem_region objects") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/Yuo65lq2WtfdGJ0X@kili Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-26cxl/region: Introduce cxl_pmem_region objectsDan Williams
The LIBNVDIMM subsystem is a platform agnostic representation of system NVDIMM / persistent memory resources. To date, the CXL subsystem's interaction with LIBNVDIMM has been to register an nvdimm-bridge device and cxl_nvdimm objects to proxy CXL capabilities into existing LIBNVDIMM subsystem mechanics. With regions the approach is the same. Create a new cxl_pmem_region object to proxy CXL region details into a LIBNVDIMM definition. With this enabling LIBNVDIMM can partition CXL persistent memory regions with legacy namespace labels. A follow-on patch will add CXL region label and CXL namespace label support to persist region configurations across driver reload / system-reset events. Co-developed-by: Ben Widawsky <bwidawsk@kernel.org> Signed-off-by: Ben Widawsky <bwidawsk@kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784340111.1758207.3036498385188290968.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-26cxl/pmem: Fix offline_nvdimm_bus() to offline by bridgeDan Williams
Be careful to only disable cxl_pmem objects related to a given cxl_nvdimm_bridge. Otherwise, offline_nvdimm_bus() reaches across CXL domains and disables more than is expected. Fixes: 21083f51521f ("cxl/pmem: Register 'pmem' / cxl_nvdimm devices") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784339569.1758207.1557084545278004577.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-06-21cxl/mbox: Use __le32 in get,set_lsa mailbox structuresAlison Schofield
CXL specification defines these as little endian. Fixes: 60b8f17215de ("cxl/pmem: Translate NVDIMM label commands to CXL label commands") Reported-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/20220225221456.1025635-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28cxl: Drop cxl_device_lock()Dan Williams
Now that all CXL subsystem locking is validated with custom lock classes, there is no need for the custom usage of the lockdep_mutex. Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165055520383.3745911.53447786039115271.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/pmem: Remove CXL SET_PARTITION_INFO from exclusive_cmds listAlison Schofield
With SET_PARTITION_INFO on the exclusive_cmds list for the CXL_PMEM driver, userspace cannot execute a set-partition command without first unbinding the pmem driver from the device. When userspace requests a partition change to take effect on the next reboot this unbind requirement is unnecessarily restrictive. The driver does not need to enforce an unbind because partitions will not change until the next reboot. Of course, userspace still needs to be aware that changing the size of persistent capacity on the next reboot will result in the loss of data stored. That can happen regardless of whether it is presently bound at the time of issuing the set-partition command. When userspace requests a partition change to take effect immediately, restrictions are needed. The CXL_MEM driver currently blocks the usage of immediate mode, making the presence of SET_PARTITION_INFO, in this exclusive commands list, redundant. In the future, when the CXL_MEM driver adds support for immediate changes to device partitions it will ensure that the partition change will not affect any active decode. That means the work will not fall right back here, onto the CXL_PMEM driver. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/accc6abc878f0662093b81490a1a052f2ff6f06e.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl: Prove CXL lockingDan Williams
When CONFIG_PROVE_LOCKING is enabled the 'struct device' definition gets an additional mutex that is not clobbered by lockdep_set_novalidate_class() like the typical device_lock(). This allows for local annotation of subsystem locks with mutex_lock_nested() per the subsystem's object/lock hierarchy. For CXL, this primarily needs the ability to lock ports by depth and child objects of ports by their parent parent-port lock. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164365853422.99383.1052399160445197427.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/pmem: Fix module reload vs workqueue stateDan Williams
A test of the form: while true; do modprobe -r cxl_pmem; modprobe cxl_pmem; done May lead to a crash signature of the form: BUG: unable to handle page fault for address: ffffffffc0660030 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page [..] Workqueue: cxl_pmem 0xffffffffc0660030 RIP: 0010:0xffffffffc0660030 Code: Unable to access opcode bytes at RIP 0xffffffffc0660006. [..] Call Trace: ? process_one_work+0x4ec/0x9c0 ? pwq_dec_nr_in_flight+0x100/0x100 ? rwlock_bug.part.0+0x60/0x60 ? worker_thread+0x2eb/0x700 In that report the 0xffffffffc0660030 address corresponds to the former function address of cxl_nvb_update_state() from a previous load of the module, not the current address. Fix that by arranging for ->state_work in the 'struct cxl_nvdimm_bridge' object to be reinitialized on cxl_pmem module reload. Details: Recall that CXL subsystem wants to link a CXL memory expander device to an NVDIMM sub-hierarchy when both a persistent memory range has been registered by the CXL platform driver (cxl_acpi) *and* when that CXL memory expander has published persistent memory capacity (Get Partition Info). To this end the cxl_nvdimm_bridge driver arranges to rescan the CXL bus when either of those conditions change. The helper bus_rescan_devices() can not be called underneath the device_lock() for any device on that bus, so the cxl_nvdimm_bridge driver uses a workqueue for the rescan. Typically a driver allocates driver data to hold a 'struct work_struct' for a driven device, but for a workqueue that may run after ->remove() returns, driver data will have been freed. The 'struct cxl_nvdimm_bridge' object holds the state and work_struct directly. Unfortunately it was only arranging for that infrastructure to be initialized once per device creation rather than the necessary once per workqueue (cxl_pmem_wq) creation. Introduce is_cxl_nvdimm_bridge() and cxl_nvdimm_bridge_reset() in support of invalidating stale references to a recently destroyed cxl_pmem_wq. Cc: <stable@vger.kernel.org> Fixes: 8fdcb1704f61 ("cxl/pmem: Add initial infrastructure for pmem support") Reported-by: Vishal Verma <vishal.l.verma@intel.com> Tested-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/163665474585.3505991.8397182770066720755.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/memdev: Change cxl_mem to a more descriptive nameIra Weiny
The 'struct cxl_mem' object actually represents the state of a CXL device within the driver. Comments indicating that 'struct cxl_mem' is a device itself are incorrect. It is data layered on top of a CXL Memory Expander class device. Rename it 'struct cxl_dev_state'. The 'struct' cxl_memdev' structure represents a Linux CXL memory device object, and it uses services and information provided by 'struct cxl_dev_state'. Update the structure name, function names, and the kdocs to reflect the real uses of this structure. Some helper functions that were previously prefixed "cxl_mem_" are renamed to just "cxl_". Acked-by: Ben Widawsky <ben.widawsky@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211102202901.3675568-3-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/pmem: Fix reference counting for delayed workDan Williams
There is a potential race between queue_work() returning and the queued-work running that could result in put_device() running before get_device(). Introduce the cxl_nvdimm_bridge_state_work() helper that takes the reference unconditionally, but drops it if no new work was queued, to keep the references balanced. Fixes: 8fdcb1704f61 ("cxl/pmem: Add initial infrastructure for pmem support") Cc: <stable@vger.kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163553734757.2509761.3305231863616785470.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21tools/testing/cxl: Introduce a mock memory device + driverDan Williams
Introduce an emulated device-set plus driver to register CXL memory devices, 'struct cxl_memdev' instances, in the mock cxl_test topology. This enables the development of HDM Decoder (Host-managed Device Memory Decoder) programming flow (region provisioning) in an environment that can be updated alongside the kernel as it gains more functionality. Whereas the cxl_pci module looks for CXL memory expanders on the 'pci' bus, the cxl_mock_mem module attaches to CXL expanders on the platform bus emitted by cxl_test. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116440099.2460985.10692549614409346604.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Move command definitions to common locationDan Williams
In preparation for cxl_test to mock responses to mailbox command requests, move some definitions from core/mbox.c to cxlmem.h. No functional changes intended. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116439547.2460985.10457111177103589574.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pmem: Add support for multiple nvdimm-bridge objectsDan Williams
In preparation for a mocked unit test environment for CXL objects, allow for multiple unique nvdimm-bridge objects. For now, just allow multiple bridges to be registered. Later, when there are multiple present, further updates are needed to cxl_find_nvdimm_bridge() to identify which bridge is associated with which CXL hierarchy for nvdimm registration. Note that this does change the kernel device-name for the bridge object. User space should not have any attachment to the device name at this point as it is still early days in the CXL driver development. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163164647007.2831228.2150246954620721526.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pmem: Translate NVDIMM label commands to CXL label commandsDan Williams
The LIBNVDIMM IOCTL UAPI calls back to the nvdimm-bus-provider to translate the Linux command payload to the device native command format. The LIBNVDIMM commands get-config-size, get-config-data, and set-config-data, map to the CXL memory device commands device-identify, get-lsa, and set-lsa. Recall that the label-storage-area (LSA) on an NVDIMM device arranges for the provisioning of namespaces. Additionally for CXL the LSA is used for provisioning regions as well. The data from device-identify is already cached in the 'struct cxl_mem' instance associated with @cxl_nvd, so that payload return is simply crafted and no CXL command is issued. The conversion for get-lsa is straightforward, but the conversion for set-lsa requires an allocation to append the set-lsa header in front of the payload. Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163122524923.2534512.9431316965424264864.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Add exclusive kernel command supportDan Williams
The CXL_PMEM driver expects exclusive control of the label storage area space. Similar to the LIBNVDIMM expectation that the label storage area is only writable from userspace when the corresponding memory device is not active in any region, the expectation is the native CXL_PCI UAPI path is disabled while the cxl_nvdimm for a given cxl_memdev device is active in LIBNVDIMM. Add the ability to toggle the availability of a given command for the UAPI path. Use that new capability to shutdown changes to partitions and the label storage area while the cxl_nvdimm device is actively proxying commands for LIBNVDIMM. Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163164579468.2830966.6980053377428474263.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-06cxl: Move cxl_core to new directoryBen Widawsky
CXL core is growing, and it's already arguably unmanageable. To support future growth, move core functionality to a new directory and rename the file to represent just bus support. Future work will remove non-bus functionality. Note that mem.h is renamed to cxlmem.h to avoid a namespace collision with the global ARCH=um mem.h header. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/162792537866.368511.8915631504621088321.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-06-15cxl/pmem: Register 'pmem' / cxl_nvdimm devicesDan Williams
While a memX device on /sys/bus/cxl represents a CXL memory expander control interface, a pmemX device represents the persistent memory sub-functionality. It bridges the CXL subystem to the libnvdimm nmemX control interface. With this skeleton ndctl can now see persistent memory devices on a "CXL" bus. Later patches add support for translating libnvdimm native commands to CXL commands. # ndctl list -BDiu -b CXL { "provider":"CXL", "dev":"ndbus1", "dimms":[ { "dev":"nmem1", "state":"disabled" }, { "dev":"nmem0", "state":"disabled" } ] } Given nvdimm_bus_unregister() removes all devices on an ndbus0 the cxl_pmem infrastructure needs to arrange ->remove() to be triggered on cxl_nvdimm devices to keep their enabled state synchronized with the registration state of their corresponding device on the nvdimm_bus. In other words, always arrange for cxl_nvdimm_driver.remove() to unregister nvdimms from an nvdimm_bus ahead of the bus being unregistered. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/162380012696.3039556.4293801691038740850.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-06-15cxl/pmem: Add initial infrastructure for pmem supportDan Williams
Register an 'nvdimm-bridge' device to act as an anchor for a libnvdimm bus hierarchy. Also, flesh out the cxl_bus definition to allow a cxl_nvdimm_bridge_driver to attach to the bridge and trigger the nvdimm-bus registration. The creation of the bridge is gated on the detection of a PMEM capable address space registered to the root. The bridge indirection allows the libnvdimm module to remain unloaded on platforms without PMEM support. Given that the probing of ACPI0017 is asynchronous to CXL endpoint devices, and the expectation that CXL endpoint devices register other PMEM resources on the 'CXL' nvdimm bus, a workqueue is added. The workqueue is needed to run bus_rescan_devices() outside of the device_lock() of the nvdimm-bridge device to rendezvous nvdimm resources as they arrive. For now only the bus is taken online/offline in the workqueue. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/162379909706.2993820.14051258608641140169.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>