summaryrefslogtreecommitdiff
path: root/drivers/cxl/core/hdm.c
AgeCommit message (Collapse)Author
2022-12-05cxl: update names for interleave granularity conversion macrosDave Jiang
Change names for granularity macros to clearly indicate which variable is encoded and which is the actual granularity. granularity == interleave granularity eig == encoded interleave granularity Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/167027493237.3124429.8948852388671827664.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-03cxl/pci: Prepare for mapping RAS Capability StructureDan Williams
The RAS Capabilitiy Structure is a CXL Component register capability block. Unlike the HDM Decoder Capability, it will be referenced by the cxl_pci driver in response to PCIe AER events. Due to this it is no longer the case that cxl_map_component_regs() can assume that it should map all component registers. Plumb a bitmask of capability ids to map through cxl_map_component_regs(). For symmetry cxl_probe_device_regs() is updated to populate @id in 'struct cxl_reg_map' even though cxl_map_device_regs() does not have a need to map a subset of the device registers per caller. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166974412214.1608150.11487843455070795378.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-03cxl/port: Limit the port driver to just the HDM Decoder CapabilityDan Williams
Update the port driver to use cxl_map_component_registers() so that the component register block can be shared between the cxl_pci driver and the cxl_port driver. I.e. stop the port driver from reserving the entire component register block for itself via request_region() when it only needs the HDM Decoder Capability subset. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166974411625.1608150.7149373371599960307.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-08-05cxl/hdm: Fix skip allocations vs multiple pmem allocationsDan Williams
Vishal notes that when attempting to define a second pmem region on a device the DPA allocation fails with a message of the form: decoder11.1: failed to reserve skipped space Recall that the skip setting is used when there is a pmem allocation in the presence of free ram DPA space. The first pmem allocation skips over the free ram and subsequent pmem allocations do not require a skip. The bug is that a skip is still attempted and the DPA reservation code flags the double skip allocation conflict. Fixes: cf880423b6a0 ("cxl/hdm: Add support for allocating DPA to an endpoint decoder") Reported-by: Vishal Verma <vishal.l.verma@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/165973754730.1558392.15466392461645857658.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-08-05cxl/region: Move HPA setup to cxl_region_attach()Dan Williams
A recent bug fix added the setup of the endpoint decoder interleave geometry settings to cxl_region_attach(). Move the HPA setup there as well to keep all endpoint decoder parameter setting in a central location. For symmetry, move endpoint HPA teardown to cxl_region_detach(), and for switches move HPA setup / teardown to cxl_port_{setup,reset}_targets(). Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165973126020.1526540.14701949254436069807.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-08-01cxl/hdm: Fix DPA reservation vs cxl_endpoint_decoder lifetimeDan Williams
After adding support for emulating platform firmware established DPA reservations, the cxl-topology.sh [1] unit test started crashing with the following signature: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bc3: 0000 [#1] PREEMPT SMP [..] RIP: 0010:to_cxl_port+0x8/0x60 [cxl_core] [..] Call Trace: <TASK> __cxl_dpa_release+0x1b/0xd0 [cxl_core] cxl_dpa_release+0x1d/0x30 [cxl_core] release_nodes+0x63/0x90 devres_release_all+0x88/0xc0 ...i.e. a use after free of a 'struct cxl_endpoint_decoder' object. This results from the ordering of init_hdm_decoder() before add_hdm_decoder() where, at release time, the decoder is unregistered and released before the DPA reservation. Fix this by extending the life of the object until all DPA reservations have been released which also preserves platform decoder settings being settled by the time the decoder is published in sysfs (KOBJ_ADD time). Note that the @len == 0 case in __cxl_dpa_reserve() is avoided in practice as this function is only called for committed decoders and new non-zero DPA allocations. Link: https://github.com/pmem/ndctl/blob/pending/test/cxl-topology.sh [1] Fixes: 9c57cde0dcbd ("cxl/hdm: Enumerate allocated DPA") Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/165896020625.3546860.12390103413706292760.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-25cxl/hdm: Commit decoder state to hardwareDan Williams
After all the soft validation of the region has completed, convey the region configuration to hardware while being careful to commit decoders in specification mandated order. In addition to programming the endpoint decoder base-address, interleave ways and granularity, the switch decoder target lists are also established. While the kernel can enforce spec-mandated commit order, it can not enforce spec-mandated reset order. For example, the kernel can't stop someone from removing an endpoint device that is occupying decoderN in a switch decoder where decoderN+1 is also committed. To reset decoderN, decoderN+1 must be torn down first. That "tear down the world" implementation is saved for a follow-on patch. Callback operations are provided for the 'commit' and 'reset' operations. While those callbacks may prove useful for CXL accelerators (Type-2 devices with memory) the primary motivation is to enable a simple way for cxl_test to intercept those operations. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784338418.1758207.14659830845389904356.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-25cxl/region: Enable the assignment of endpoint decoders to regionsDan Williams
The region provisioning process involves allocating DPA to a set of endpoint decoders, and HPA plus the region geometry to a region device. Then the decoder is assigned to the region. At this point several validation steps can be performed to validate that the decoder is suitable to participate in the region. Co-developed-by: Ben Widawsky <bwidawsk@kernel.org> Signed-off-by: Ben Widawsky <bwidawsk@kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/165784336184.1758207.16403282029203949622.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21cxl/port: Move dport tracking to an xarrayDan Williams
Reduce the complexity and the overhead of walking the topology to determine endpoint connectivity to root decoder interleave configurations. Note that cxl_detach_ep(), after it determines that the last @ep has departed and decides to delete the port, now needs to walk the dport array with the device_lock() held to remove entries. Previously list_splice_init() could be used atomically delete all dport entries at once and then perform entry tear down outside the lock. There is no list_splice_init() equivalent for the xarray. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784331647.1758207.6345820282285119339.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21cxl/hdm: Add support for allocating DPA to an endpoint decoderDan Williams
The region provisioning flow will roughly follow a sequence of: 1/ Allocate DPA to a set of decoders 2/ Allocate HPA to a region 3/ Associate decoders with a region and validate that the DPA allocations and topologies match the parameters of the region. For now, this change (step 1) arranges for DPA capacity to be allocated and deleted from non-committed decoders based on the decoder's mode / partition selection. Capacity is allocated from the lowest DPA in the partition and any 'pmem' allocation blocks out all remaining ram capacity in its 'skip' setting. DPA allocations are enforced in decoder instance order. I.e. decoder N + 1 always starts at a higher DPA than instance N, and deleting allocations must proceed from the highest-instance allocated decoder to the lowest. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784329399.1758207.16732038126938632700.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21cxl/hdm: Track next decoder to allocateDan Williams
The CXL specification enforces that endpoint decoders are committed in hw instance id order. In preparation for adding dynamic DPA allocation, record the hw instance id in endpoint decoders, and enforce allocations to occur in hw instance id order. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784328827.1758207.9627538529944559954.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21cxl/hdm: Add 'mode' attribute to decoder objectsDan Williams
Recall that the Device Physical Address (DPA) space of a CXL Memory Expander is potentially partitioned into a volatile and persistent portion. A decoder maps a Host Physical Address (HPA) range to a DPA range and that translation depends on the value of all previous (lower instance number) decoders before the current one. In preparation for allowing dynamic provisioning of regions, decoders need an ABI to indicate which DPA partition a decoder targets. This ABI needs to be prepared for the possibility that some other agent committed and locked a decoder that spans the partition boundary. Add 'decoderX.Y/mode' to endpoint decoders that indicates which partition 'ram' / 'pmem' the decoder targets, or 'mixed' if the decoder currently spans the partition boundary. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165603881967.551046.6007594190951596439.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21cxl/hdm: Enumerate allocated DPADan Williams
In preparation for provisioning CXL regions, add accounting for the DPA space consumed by existing regions / decoders. Recall, a CXL region is a memory range comprised from one or more endpoint devices contributing a mapping of their DPA into HPA space through a decoder. Record the DPA ranges covered by committed decoders at initial probe of endpoint ports relative to a per-device resource tree of the DPA type (pmem or volatile-ram). The cxl_dpa_rwsem semaphore is introduced to globally synchronize DPA state across all endpoints and their decoders at once. The vast majority of DPA operations are reads as region creation is expected to be as rare as disk partitioning and volume creation. The device_lock() for this synchronization is specifically avoided for concern of entangling with sysfs attribute removal. 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/165784327682.1758207.7914919426043855876.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21cxl/core: Define a 'struct cxl_endpoint_decoder'Dan Williams
Previously the target routing specifics of switch decoders and platform CXL window resource tracking of root decoders were factored out of 'struct cxl_decoder'. While switch decoders translate from SPA to downstream ports, endpoint decoders translate from SPA to DPA. This patch, 3 of 3, adds a 'struct cxl_endpoint_decoder' that tracks an endpoint-specific Device Physical Address (DPA) resource. For now this just defines ->dpa_res, a follow-on patch will handle requesting DPA resource ranges from a device-DPA resource tree. 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/165784327088.1758207.15502834501671201192.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21cxl/core: Define a 'struct cxl_switch_decoder'Dan Williams
Currently 'struct cxl_decoder' contains the superset of attributes needed for all decoder types. Before more type-specific attributes are added to the common definition, reorganize 'struct cxl_decoder' into type specific objects. This patch, the first of three, factors out a cxl_switch_decoder type. See the new kdoc for what a 'struct cxl_switch_decoder' represents in a CXL topology. Co-developed-by: Ben Widawsky <bwidawsk@kernel.org> Signed-off-by: Ben Widawsky <bwidawsk@kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/165784325340.1758207.5064717153608954960.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-10cxl/hdm: Initialize decoder type for memory expander devicesDan Williams
Unless and until accelerator (type-2) drivers start registering for CXL.mem mapping services from the CXL subsystem core, initialize idle HDM decoders to the "expander" type. I.e. the only CXL devices using the CXL core presently are those implementing the CXL 2.0 Type-3 memory expander device class code that the cxl_pci driver claims. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220624041950.559155-6-dan.j.williams@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-10cxl/mem: Add a debugfs version of 'iomem' for DPA, 'dpamem'Dan Williams
Dump the device-physical-address map for a CXL expander in /proc/iomem style format. E.g.: cat /sys/kernel/debug/cxl/mem1/dpamem 00000000-0fffffff : ram 10000000-1fffffff : pmem Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165603885318.551046.8308248564880066726.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-09cxl/hdm: Require all decoders to be enumeratedBen Widawsky
In preparation for region provisioning all device decoders need to be enumerated since DPA allocations are calculated by summing the capacities of all decoders in a set. I.e. the programming for decoder[N] depends on the state of decoder[N-1], so skipping over decoders that fail to initialize prevents accurate DPA accounting. Signed-off-by: Ben Widawsky <bwidawsk@kernel.org> [djbw: reword changelog] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165603879664.551046.6863805202478861026.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-09cxl: Introduce cxl_to_{ways,granularity}Dan Williams
Interleave granularity and ways have CXL specification defined encodings. Promote the conversion helpers to a common header, and use them to replace other open-coded instances. Force caller to consider the error case of the conversion similarly to other conversion helpers like kstrto*(). 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/165603875016.551046.17236943065932132355.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-09cxl/core: Rename ->decoder_range ->hpa_rangeDan Williams
In preparation for growing a ->dpa_range attribute for endpoint decoders, rename the current ->decoder_range to the more descriptive ->hpa_range. Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Adam Manzanares <a.manzanares@samsung.com> Link: https://lore.kernel.org/r/165603872867.551046.2170426227407458814.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-09cxl/hdm: Use local hdm variableBen Widawsky
Save a few characters and use the already initialized local variable. Signed-off-by: Ben Widawsky <bwidawsk@kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Adam Manzanares <a.manzanares@samsung.com> Link: https://lore.kernel.org/r/165603872171.551046.913207574344536475.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-06-21cxl/core: Use is_endpoint_decoderBen Widawsky
Save some characters and directly check decoder type rather than port type. There's no need to check if the port is an endpoint port since, by this point, cxl_endpoint_decoder_alloc() has a specified type. Reviewed by: Adam Manzanares <a.manzanares@samsung.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Handle invalid decodersDan Williams
In case init_hdm_decoder() finds invalid settings, skip to the next valid decoder. Only fail port enumeration if zero valid decoders are found. This protects the driver init against broken hardware and / or future interleave capabilities. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164317464918.3438644.12371149695618136198.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Add endpoint decodersBen Widawsky
Recall that a CXL Port is any object that publishes a CXL HDM Decoder Capability structure. That is Host Bridge and Switches that have been enabled so far. Now, add decoder support to the 'endpoint' CXL Ports registered by the cxl_mem driver. They mostly share the same enumeration as Bridges and Switches, but witout a target list. The target of endpoint decode is device-internal DPA space, not another downstream port. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> [djbw: clarify changelog, hookup enumeration in the port driver] Link: https://lore.kernel.org/r/164386092069.765089.14895687988217608642.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Remove @host argument for dport + decoder enumerationDan Williams
Now that dport and decoder enumeration is centralized in the port driver, the @host argument for these helpers can be made implicit. For the root port the host is the port's uport device (ACPI0017 for cxl_acpi), and for all other descendant ports the devm context is the parent of @port. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164375043390.484143.17617734732003230076.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/hdm: Add CXL standard decoder enumeration to the coreDan Williams
Unlike the decoder enumeration for "root decoders" described by platform firmware, standard decoders can be enumerated from the component registers space once the base address has been identified (via PCI, ACPI, or another mechanism). Add common infrastructure for HDM (Host-managed-Device-Memory) Decoder enumeration and share it between host-bridge, upstream switch port, and cxl_test defined decoders. The locking model for switch level decoders is to hold the port lock over the enumeration. This facilitates moving the dport and decoder enumeration to a 'port' driver. For now, the only enumerator of decoder resources is the cxl_acpi root driver. Co-developed-by: Ben Widawsky <ben.widawsky@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/164374688404.395335.9239248252443123526.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>