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2022-02-08cxl/core/port: Use dedicated lock for decoder target listDan Williams2-7/+25
Lockdep reports: ====================================================== WARNING: possible circular locking dependency detected 5.16.0-rc1+ #142 Tainted: G OE ------------------------------------------------------ cxl/1220 is trying to acquire lock: ffff979b85475460 (kn->active#144){++++}-{0:0}, at: __kernfs_remove+0x1ab/0x1e0 but task is already holding lock: ffff979b87ab38e8 (&dev->lockdep_mutex#2/4){+.+.}-{3:3}, at: cxl_remove_ep+0x50c/0x5c0 [cxl_core] ...where cxl_remove_ep() is a helper that wants to delete ports while holding a lock on the host device for that port. That sets up a lockdep violation whereby target_list_show() can not rely holding the decoder's device lock while walking the target_list. Switch to a dedicated seqlock for this purpose. Reported-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164367209095.208169.1171673319121271280.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl: Prove CXL lockingDan Williams5-24/+130
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>
2022-02-08cxl/core: Track port depthBen Widawsky2-0/+4
In preparation for proving CXL subsystem usage of the device_lock() order track the depth of ports with the expectation that shallower port locks can be held over deeper port locks. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164298419321.3018233.4469731547378993606.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Make passthrough decoder init implicitBen Widawsky2-6/+8
Unused CXL decoders, or ports which use a passthrough decoder (no HDM decoder registers) are expected to be initialized in a specific way. Since upcoming drivers will want the same initialization, and it was already a requirement to have consumers of the API configure the decoder specific to their needs, initialize to this passthrough state by default. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164298418778.3018233.13573986275832546547.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core: Fix cxl_probe_component_regs() error messageDan Williams1-1/+1
Fix a '\n' vs '/n' typo. Fixes: 08422378c4ad ("cxl/pci: Add HDM decoder capabilities") Acked-by: Ben Widawsky <ben.widawsky@intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164298418268.3018233.17790073375430834911.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Clarify decoder creationBen Widawsky3-11/+92
Add wrappers for the creation of decoder objects at the root level and switch level, and keep the core helper private to cxl/core/port.c. Root decoders are static descriptors conveyed from platform firmware (e.g. ACPI CFMWS). Switch decoders are CXL standard decoders enumerated via the HDM decoder capability structure. The base address for the HDM decoder capability structure may be conveyed either by PCIe or platform firmware (ACPI CEDT.CHBS). Additionally, the kdoc descriptions for these helpers and their dependencies is updated. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> [djbw: fixup changelog, clarify kdoc] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164366463014.111117.9714595404002687111.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core: Convert decoder range to resourceBen Widawsky3-18/+35
CXL decoders manage address ranges in a hierarchical fashion whereby a leaf is a unique subregion of its parent decoder (midlevel or root). It therefore makes sense to use the resource API for handling this. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> (v1) Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164298417191.3018233.5201055578165414714.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/decoder: Hide physical address information from non-rootDan Williams1-1/+1
Just like /proc/iomem, CXL physical address information is reserved for root only. Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164298416650.3018233.450720006145238709.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Rename bus.c to port.cDan Williams2-1/+1
Given it is dominated by port infrastructure, and will only acquire more, rename bus.c to port.c. Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164298416136.3018233.15442880970000855425.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl: Introduce module_cxl_driverBen Widawsky1-0/+3
Many CXL drivers simply want to register and unregister themselves. module_driver already supported this. A simple wrapper around that reduces a decent amount of boilerplate in upcoming patches. Suggested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dan Williams <dan.j.williams@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/164298415591.3018233.13608495220547681412.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/acpi: Map component registers for Root PortsBen Widawsky5-54/+80
This implements the TODO in cxl_acpi for mapping component registers. cxl_acpi becomes the second consumer of CXL register block enumeration (cxl_pci being the first). Moving the functionality to cxl_core allows both of these drivers to use the functionality. Equally importantly it allows cxl_core to use the functionality in the future. CXL 2.0 root ports are similar to CXL 2.0 Downstream Ports with the main distinction being they're a part of the CXL 2.0 host bridge. While mapping their component registers is not immediately useful for the CXL drivers, the movement of register block enumeration into core is a vital step towards HDM decoder programming. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> [djbw: fix cxl_regmap_to_base() failure cases] Link: https://lore.kernel.org/r/164298415080.3018233.14694957480228676592.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/pci: Add new DVSEC definitionsBen Widawsky1-0/+15
In preparation for properly supporting memory active timeout, and later on, other attributes obtained from DVSEC fields, add the full list of DVSEC identifiers from the CXL 2.0 specification. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huwei.com> (v1) Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164298414567.3018233.12005290051592771878.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl: Flesh out register namesBen Widawsky2-16/+17
Get a better naming scheme in place for upcoming additions. By dropping redundant usages of CXL and DVSEC where appropriate we can get more concise and also more grepable defines. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164298414022.3018233.15522855498759815097.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/pci: Defer mailbox status checks to command timeoutsDan Williams1-101/+33
Device status can change without warning at any point in time. This effectively means that no amount of status checking before a command is submitted can guarantee that the device is not in an error condition when the command is later submitted. The clearest signal that a device is not able to process commands is if it fails to process commands. With the above understanding in hand, update cxl_pci_setup_mailbox() to validate the readiness of the mailbox once at the beginning of time, and then use timeouts and busy sequencing errors as the only occasions to report status. Just as before, unless and until the driver gains a reset recovery path, doorbell clearing failures by the device are fatal to mailbox operations. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164298413480.3018233.9643395389297971819.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/pci: Implement Interface Ready TimeoutBen Widawsky1-0/+35
The original driver implementation used the doorbell timeout for the Mailbox Interface Ready bit to piggy back off of, since the latter does not have a defined timeout. This functionality, introduced in commit 8adaf747c9f0 ("cxl/mem: Find device capabilities"), needs improvement as the recent "Add Mailbox Ready Time" ECN timeout indicates that the mailbox ready time can be significantly longer that 2 seconds. While the specification limits the maximum timeout to 256s, the cxl_pci driver gives up on the mailbox after 60s. This value corresponds with important timeout values already present in the kernel. A module parameter is provided as an emergency override and represents the default Linux policy for all devices. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> [djbw: add modparam, drop check_device_status()] Co-developed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/164367306565.208548.1932299464604450843.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl: Rename CXL_MEM to CXL_PCIBen Widawsky2-12/+13
The cxl_mem module was renamed cxl_pci in commit 21e9f76733a8 ("cxl: Rename mem to pci"). In preparation for adding an ancillary driver for cxl_memdev devices (registered on the cxl bus by cxl_pci), go ahead and rename CONFIG_CXL_MEM to CONFIG_CXL_PCI. Free up the CXL_MEM name for that new driver to manage CXL.mem endpoint operations. Suggested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164298412409.3018233.12407355692407890752.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-01-04cxl/core: Remove cxld_const_init in cxl_decoder_alloc()Nathan Chancellor2-5/+3
Commit 48667f676189 ("cxl/core: Split decoder setup into alloc + add") aimed to fix a large stack frame warning but from v5 to v6, it introduced a new instance of the warning due to allocating cxld_const_init on the stack, which was done due to the use of const on the nr_target member of the cxl_decoder struct. With ARCH=arm allmodconfig minus CONFIG_KASAN: GCC 11.2.0: drivers/cxl/core/bus.c: In function ‘cxl_decoder_alloc’: drivers/cxl/core/bus.c:523:1: error: the frame size of 1032 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] 523 | } | ^ cc1: all warnings being treated as errors Clang 12.0.1: drivers/cxl/core/bus.c:486:21: error: stack frame size of 1056 bytes in function 'cxl_decoder_alloc' [-Werror,-Wframe-larger-than=] struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets) ^ 1 error generated. Revert that part of the change, which makes the stack frame of cxl_decoder_alloc() much more reasonable. Fixes: 48667f676189 ("cxl/core: Split decoder setup into alloc + add") Link: https://github.com/ClangBuiltLinux/linux/issues/1539 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20211210213627.2477370-1-nathan@kernel.org Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/pmem: Fix module reload vs workqueue stateDan Williams3-3/+42
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>
2021-11-15ACPI: NUMA: Add a node and memblk for each CFMWS not in SRATAlison Schofield1-1/+2
During NUMA init, CXL memory defined in the SRAT Memory Affinity subtable may be assigned to a NUMA node. Since there is no requirement that the SRAT be comprehensive for CXL memory another mechanism is needed to assign NUMA nodes to CXL memory not identified in the SRAT. Use the CXL Fixed Memory Window Structure (CFMWS) of the ACPI CXL Early Discovery Table (CEDT) to find all CXL memory ranges. Create a NUMA node for each CFMWS that is not already assigned to a NUMA node. Add a memblk attaching its host physical address range to the node. Note that these ranges may not actually map any memory at boot time. They may describe persistent capacity or may be present to enable hot-plug. Consumers can use phys_to_target_node() to discover the NUMA node. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/163553711933.2509508.2203471175679990.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/test: Mock acpi_table_parse_cedt()Dan Williams1-0/+2
Now that cxl_acpi has been converted to use the core ACPI CEDT sub-table parser, update cxl_test to inject CFMWS and CHBS data directly into cxl_acpi's handlers. Cc: Alison Schofield <alison.schofield@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/163553711363.2509508.17428994087868269952.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/acpi: Convert CFMWS parsing to ACPI sub-table helpersDan Williams2-147/+88
The cxl_acpi driver originally open-coded its table parsing since the ACPI subtable helpers were marked __init and only used in early NUMA initialization. Now that those helpers have been exported for driver usage replace the open-coded solution with the common one. Cc: Alison Schofield <alison.schofield@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/163553710810.2509508.14686373989517930921.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/memdev: Remove unused cxlmd fieldIra Weiny1-2/+0
This field was left over when the connection between the cxl_memdev and cxl_mem was tighter. It is no longer set nor used so remove it.[1] Link: https://lore.kernel.org/r/CAPcyv4hcgh2gb8qsS_UXTBSGqYfMPnC6p5kkvNUjm+V6kVKM5g@mail.gmail.com/ Suggested-by: Jonathan.Cameron@huawei.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211103234857.3689354-1-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/core: Convert to EXPORT_SYMBOL_NS_GPLDan Williams6-29/+29
It turns out that the usb example of specifying the subsystem namespace at build time is not preferred. The rationale for that preference has become more apparent as CXL patches with plain EXPORT_SYMBOL_GPL beg the question, "why would any code other than CXL care about this symbol?". Make the namespace explicit. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163676356810.3618264.601632777702192938.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 Weiny5-211/+214
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/mbox: Remove bad commentIra Weiny1-2/+0
__cxl_mem_mbox_send_cmd() no longer exists. Remove the reference. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211102202901.3675568-2-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/pmem: Fix reference counting for delayed workDan Williams1-4/+13
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>
2021-11-08Merge tag 'cxl-for-5.16' of ↵Linus Torvalds12-1311/+1580
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl updates from Dan Williams: "More preparation and plumbing work in the CXL subsystem. From an end user perspective the highlight here is lighting up the CXL Persistent Memory related commands (label read / write) with the generic ioctl() front-end in LIBNVDIMM. Otherwise, the ability to instantiate new persistent and volatile memory regions is still on track for v5.17. Summary: - Fix support for platforms that do not enumerate every ACPI0016 (CXL Host Bridge) in the CHBS (ACPI Host Bridge Structure). - Introduce a common pci_find_dvsec_capability() helper, clean up open coded implementations in various drivers. - Add 'cxl_test' for regression testing CXL subsystem ABIs. 'cxl_test' is a module built from tools/testing/cxl/ that mocks up a CXL topology to augment the nascent support for emulation of CXL devices in QEMU. - Convert libnvdimm to use the uuid API. - Complete the definition of CXL namespace labels in libnvdimm. - Tunnel libnvdimm label operations from nd_ioctl() back to the CXL mailbox driver. Enable 'ndctl {read,write}-labels' for CXL. - Continue to sort and refactor functionality into distinct driver and core-infrastructure buckets. For example, mailbox handling is now a generic core capability consumed by the PCI and cxl_test drivers" * tag 'cxl-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (34 commits) ocxl: Use pci core's DVSEC functionality cxl/pci: Use pci core's DVSEC functionality PCI: Add pci_find_dvsec_capability to find designated VSEC cxl/pci: Split cxl_pci_setup_regs() cxl/pci: Add @base to cxl_register_map cxl/pci: Make more use of cxl_register_map cxl/pci: Remove pci request/release regions cxl/pci: Fix NULL vs ERR_PTR confusion cxl/pci: Remove dev_dbg for unknown register blocks cxl/pci: Convert register block identifiers to an enum cxl/acpi: Do not fail cxl_acpi_probe() based on a missing CHBS cxl/pci: Disambiguate cxl_pci further from cxl_mem Documentation/cxl: Add bus internal docs cxl/core: Split decoder setup into alloc + add tools/testing/cxl: Introduce a mock memory device + driver cxl/mbox: Move command definitions to common location cxl/bus: Populate the target list at decoder create tools/testing/cxl: Introduce a mocked-up CXL port hierarchy cxl/pmem: Add support for multiple nvdimm-bridge objects cxl/pmem: Translate NVDIMM label commands to CXL label commands ...
2021-10-29cxl/pci: Use pci core's DVSEC functionalityBen Widawsky1-24/+2
Reduce maintenance burden of DVSEC query implementation by using the centralized PCI core implementation. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> [djbw: kill cxl_pci_dvsec()] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163379788528.692348.11581080806976608802.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Split cxl_pci_setup_regs()Ben Widawsky1-36/+37
In preparation for moving parts of register mapping to cxl_core, split cxl_pci_setup_regs() into a helper that finds register blocks, (cxl_find_regblock()), and a generic wrapper that probes the precise register sets within a block (cxl_setup_regs()). Move the actual mapping (cxl_map_regs()) of the only register-set that cxl_pci cares about (memory device registers) up a level from the former cxl_pci_setup_regs() into cxl_pci_probe(). With this change the unused component registers are no longer mapped, but the helpers are primed to move into the core. [djbw: drop cxl_map_regs() for component registers] Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> [djbw: rebase on the cxl_register_map refactor] Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163434053788.914258.18412599112859205220.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Add @base to cxl_register_mapDan Williams2-15/+26
In addition to carrying @barno, @block_offset, and @reg_type, add @base to keep all map/unmap parameters in one object. The helpers cxl_{map,unmap}_regblock() handle adjusting @base to the @block_offset at map and unmap time. Document that @base incorporates @block_offset so that downstream consumers of a mapped cxl_register_map instance do not need perform any fixups / can use @base directly. Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163433497228.889435.11271988238496181536.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Make more use of cxl_register_mapBen Widawsky1-34/+25
The structure exists to pass around information about register mapping. Use it for passing @barno and @block_offset, and eliminate duplicate local variables. The helpers that use @map do not care about @cxlm, so just pass them a pdev instead. [djbw: reorder before cxl_pci_setup_regs() refactor to improver readability] Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> [djbw: separate @base conversion] Link: https://lore.kernel.org/r/163416901172.806743.10056306321247850914.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Remove pci request/release regionsBen Widawsky1-5/+0
Quoting Dan, "... the request + release regions should probably just be dropped. It's not like any of the register enumeration would collide with someone else who already has the registers mapped. The collision only comes when the registers are mapped for their final usage, and that will have more precision in the request." Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163379785872.692348.8981679111988251260.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Fix NULL vs ERR_PTR confusionDan Williams1-1/+1
cxl_pci_map_regblock() may return an ERR_PTR(), but cxl_pci_setup_regs() is only prepared for NULL as the error case. Pick the minimal fix for -stable backport purposes and just have cxl_pci_map_regblock() return NULL for errors. Fixes: f8a7e8c29be8 ("cxl/pci: Reserve all device regions at once") Cc: <stable@vger.kernel.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163433325724.834522.17809774578178224149.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Remove dev_dbg for unknown register blocksBen Widawsky1-3/+0
While interesting to driver developers, the dev_dbg message doesn't do much except clutter up logs. This information should be attainable through sysfs, and someday lspci like utilities. This change additionally helps reduce the LOC in a subsequent patch to refactor some of cxl_pci register mapping. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163379784717.692348.3478221381958300790.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Convert register block identifiers to an enumBen Widawsky1-6/+8
In preparation for passing around the Register Block Indicator (RBI) as a parameter, it is desirable to convert the type to an enum so that the interface can use a well defined parameter. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> [djbw: changelog fixups ] Link: https://lore.kernel.org/r/163379784199.692348.4366131432595112771.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-08cxl/acpi: Do not fail cxl_acpi_probe() based on a missing CHBSAlison Schofield1-4/+6
When an ACPI0016 Host Bridge device is present yet no corresponding CEDT Host Bridge Structure (CHBS) exists, the ACPI probe method fails. Rather than fail, emit this warning and continue: cxl_acpi ACPI0017:00: No CHBS found for Host Bridge: ACPI0016:02 This error may occur on systems that are not compliant with the ACPI specification. Compliant systems include a CHBS entry for every CXL host bridge that is present at boot. Suggested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Tested-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211007213426.392644-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-25cxl/core: Replace unions with struct_group()Kees Cook1-43/+18
Use the newly introduced struct_group_typed() macro to clean up the declaration of struct cxl_regs. 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: linux-cxl@vger.kernel.org Suggested-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2021-09-21cxl/pci: Disambiguate cxl_pci further from cxl_memBen Widawsky1-33/+35
Commit 21e9f76733a8 ("cxl: Rename mem to pci") introduced the cxl_pci driver which had formerly been named cxl_mem. At the time, the goal was to be as light touch as possible because there were other patches in flight. Since things have settled now, and a new cxl_mem driver will be introduced shortly, spend the LOC now to clean up the existing names. While here, fix the kernel docs to explain the situation better after the core rework that has already landed. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/20210913163324.1008564-4-ben.widawsky@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/core: Split decoder setup into alloc + addDan Williams5-126/+114
The kbuild robot reports: drivers/cxl/core/bus.c:516:1: warning: stack frame size (1032) exceeds limit (1024) in function 'devm_cxl_add_decoder' It is also the case the devm_cxl_add_decoder() is unwieldy to use for all the different decoder types. Fix the stack usage by splitting the creation into alloc and add steps. This also allows for context specific construction before adding. With the split the caller is responsible for registering a devm callback to trigger device_unregister() for the decoder rather than it being implicit in the decoder registration. I.e. the routine that calls alloc is responsible for calling put_device() if the "add" operation fails. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163225205828.3038145.6831131648369404859.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 Williams3-5/+5
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 Williams3-48/+65
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/bus: Populate the target list at decoder createDan Williams3-27/+91
As found by cxl_test, the implementation populated the target_list for the single dport exceptional case, it missed populating the target_list for the typical multi-dport case. Root decoders always know their target list at the beginning of time, and even switch-level decoders should have a target list of one or more zeros by default, depending on the interleave-ways setting. Walk the hosting port's dport list and populate based on the passed in map. Move devm_cxl_add_passthrough_decoder() out of line now that it does the work of generating a target_map. Before: $ cat /sys/bus/cxl/devices/root2/decoder*/target_list 0 0 After: $ cat /sys/bus/cxl/devices/root2/decoder*/target_list 0 0,1,2,3 0 0,1,2,3 Where root2 is a CXL topology root object generated by 'cxl_test'. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116439000.2460985.11713777051267946018.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21tools/testing/cxl: Introduce a mocked-up CXL port hierarchyDan Williams2-15/+37
Create an environment for CXL plumbing unit tests. Especially when it comes to an algorithm for HDM Decoder (Host-managed Device Memory Decoder) programming, the availability of an in-kernel-tree emulation environment for CXL configuration complexity and corner cases speeds development and deters regressions. The approach taken mirrors what was done for tools/testing/nvdimm/. I.e. an external module, cxl_test.ko built out of the tools/testing/cxl/ directory, provides mock implementations of kernel APIs and kernel objects to simulate a real world device hierarchy. One feedback for the tools/testing/nvdimm/ proposal was "why not do this in QEMU?". In fact, the CXL development community has developed a QEMU model for CXL [1]. However, there are a few blocking issues that keep QEMU from being a tight fit for topology + provisioning unit tests: 1/ The QEMU community has yet to show interest in merging any of this support that has had patches on the list since November 2020. So, testing CXL to date involves building custom QEMU with out-of-tree patches. 2/ CXL mechanisms like cross-host-bridge interleave do not have a clear path to be emulated by QEMU without major infrastructure work. This is easier to achieve with the alloc_mock_res() approach taken in this patch to shortcut-define emulated system physical address ranges with interleave behavior. The QEMU enabling has been critical to get the driver off the ground, and may still move forward, but it does not address the ongoing needs of a regression testing environment and test driven development. This patch adds an ACPI CXL Platform definition with emulated CXL multi-ported host-bridges. A follow on patch adds emulated memory expander devices. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reported-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/20210202005948.241655-1-ben.widawsky@intel.com [1] Link: https://lore.kernel.org/r/163164680798.2831381.838684634806668012.stgit@dwillia2-desk3.amr.corp.intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pmem: Add support for multiple nvdimm-bridge objectsDan Williams3-16/+33
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 Williams1-4/+124
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 Williams4-3/+67
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>
2021-09-21cxl/mbox: Convert 'enabled_cmds' to DECLARE_BITMAPDan Williams2-12/+2
Define enabled_cmds as an embedded member of 'struct cxl_mem' rather than a pointer to another dynamic allocation. As this leaves only one user of cxl_cmd_count, just open code it and delete the helper. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116436415.2460985.10101824045493194813.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pci: Use module_pci_driverDan Williams1-22/+8
Now that cxl_mem_{init,exit} no longer need to manage debugfs, switch back to the smaller form of the boiler plate. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116435825.2460985.7201322215431441130.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Move mailbox and other non-PCI specific infrastructure to the coreDan Williams7-949/+972
Now that the internals of mailbox operations are abstracted from the PCI specifics a bulk of infrastructure can move to the core. The CXL_PMEM driver intends to proxy LIBNVDIMM UAPI and driver requests to the equivalent functionality provided by the CXL hardware mailbox interface. In support of that intent move the mailbox implementation to a shared location for the CXL_PCI driver native IOCTL path and CXL_PMEM nvdimm command proxy path to share. A unit test framework seeks to implement a unit test backend transport for mailbox commands to communicate mocked up payloads. It can reuse all of the mailbox infrastructure minus the PCI specifics, so that also gets moved to the core. Finally with the mailbox infrastructure and ioctl handling being transport generic there is no longer any need to pass file file_operations to devm_cxl_add_memdev(). That allows all the ioctl boilerplate to move into the core for unit test reuse. No functional change intended, just code movement. 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/163116435233.2460985.16197340449713287180.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pci: Drop idr.hDan Williams1-1/+0
Commit 3d135db51024 ("cxl/core: Move memdev management to core") left this straggling include for cxl_memdev setup. Clean it up. Cc: Ben Widawsky <ben.widawsky@intel.com> Reported-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163116434668.2460985.12264757586266849616.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-25 13:33:33 +0000