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2023-10-28cxl/port: Fix delete_endpoint() vs parent unregistration raceDan Williams1-15/+19
The CXL subsystem, at cxl_mem ->probe() time, establishes a lineage of ports (struct cxl_port objects) between an endpoint and the root of a CXL topology. Each port including the endpoint port is attached to the cxl_port driver. Given that setup, it follows that when either any port in that lineage goes through a cxl_port ->remove() event, or the memdev goes through a cxl_mem ->remove() event. The hierarchy below the removed port, or the entire hierarchy if the memdev is removed needs to come down. The delete_endpoint() callback is careful to check whether it is being called to tear down the hierarchy, or if it is only being called to teardown the memdev because an ancestor port is going through ->remove(). That care needs to take the device_lock() of the endpoint's parent. Which requires 2 bugs to be fixed: 1/ A reference on the parent is needed to prevent use-after-free scenarios like this signature: BUG: spinlock bad magic on CPU#0, kworker/u56:0/11 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc38 05/24/2023 Workqueue: cxl_port detach_memdev [cxl_core] RIP: 0010:spin_bug+0x65/0xa0 Call Trace: do_raw_spin_lock+0x69/0xa0 __mutex_lock+0x695/0xb80 delete_endpoint+0xad/0x150 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 detach_memdev+0x15/0x20 [cxl_core] process_one_work+0x1e3/0x4c0 worker_thread+0x1dd/0x3d0 2/ In the case of RCH topologies, the parent device that needs to be locked is not always @port->dev as returned by cxl_mem_find_port(), use endpoint->dev.parent instead. Fixes: 8dd2bc0f8e02 ("cxl/mem: Add the cxl_mem driver") Cc: <stable@vger.kernel.org> Reported-by: Robert Richter <rrichter@amd.com> Closes: http://lore.kernel.org/r/20231018171713.1883517-2-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/region: Fix x1 root-decoder granularity calculationsJim Harris1-1/+8
Root decoder granularity must match value from CFWMS, which may not be the region's granularity for non-interleaved root decoders. So when calculating granularities for host bridge decoders, use the region's granularity instead of the root decoder's granularity to ensure the correct granularities are set for the host bridge decoders and any downstream switch decoders. Test configuration is 1 host bridge * 2 switches * 2 endpoints per switch. Region created with 2048 granularity using following command line: cxl create-region -m -d decoder0.0 -w 4 mem0 mem2 mem1 mem3 \ -g 2048 -s 2048M Use "cxl list -PDE | grep granularity" to get a view of the granularity set at each level of the topology. Before this patch: "interleave_granularity":2048, "interleave_granularity":2048, "interleave_granularity":512, "interleave_granularity":2048, "interleave_granularity":2048, "interleave_granularity":512, "interleave_granularity":256, After: "interleave_granularity":2048, "interleave_granularity":2048, "interleave_granularity":4096, "interleave_granularity":2048, "interleave_granularity":2048, "interleave_granularity":4096, "interleave_granularity":2048, Fixes: 27b3f8d13830 ("cxl/region: Program target lists") Cc: <stable@vger.kernel.org> Signed-off-by: Jim Harris <jim.harris@samsung.com> Link: https://lore.kernel.org/r/169824893473.1403938.16110924262989774582.stgit@bgt-140510-bm03.eng.stellus.in [djbw: fixup the prebuilt cxl_test region] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/region: Fix cxl_region_rwsem lock held when returning to user spaceLi Zhijian1-1/+1
Fix a missed "goto out" to unlock on error to cleanup this splat: WARNING: lock held when returning to user space! 6.6.0-rc3-lizhijian+ #213 Not tainted ------------------------------------------------ cxl/673 is leaving the kernel with locks still held! 1 lock held by cxl/673: #0: ffffffffa013b9d0 (cxl_region_rwsem){++++}-{3:3}, at: commit_store+0x7d/0x3e0 [cxl_core] In terms of user visible impact of this bug for backports: cxl_region_invalidate_memregion() on x86 invokes wbinvd which is a problematic instruction for virtualized environments. So, on virtualized x86, cxl_region_invalidate_memregion() returns an error. This failure case got missed because CXL memory-expander device passthrough is not a production use case, and emulation of CXL devices is typically limited to kernel development builds with CONFIG_CXL_REGION_INVALIDATION_TEST=y, that makes cxl_region_invalidate_memregion() succeed. In other words, the expected exposure of this bug is limited to CXL subsystem development environments using QEMU that neglected CONFIG_CXL_REGION_INVALIDATION_TEST=y. Fixes: d1257d098a5a ("cxl/region: Move cache invalidation before region teardown, and before setup") Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20231025085450.2514906-1-lizhijian@fujitsu.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/region: Use cxl_calc_interleave_pos() for auto-discoveryAlison Schofield1-112/+15
For auto-discovered regions the driver must assign each target to a valid position in the region interleave set based on the decoder topology. The current implementation fails to parse valid decode topologies, as it does not consider the child offset into a parent port. The sort put all targets of one port ahead of another port when an interleave was expected, causing the region assembly to fail. Replace the existing relative sort with cxl_calc_interleave_pos() that finds the exact position in a region interleave for an endpoint based on a walk up the ancestral tree from endpoint to root decoder. cxl_calc_interleave_pos() was introduced in a prior patch, so the work here is to use it in cxl_region_sort_targets(). Remove the obsoleted helper functions from the prior sort. Testing passes on pre-production hardware with BIOS defined regions that natively trigger this autodiscovery path of the region driver. Testing passes a CXL unit test using the dev_dbg() calculation test (see cxl_region_attach()) across an expanded set of region configs: 1, 1, 1+1, 1+1+1, 2, 2+2, 2+2+2, 2+2+2+2, 4, 4+4, where each number represents the count of endpoints per host bridge. Fixes: a32320b71f08 ("cxl/region: Add region autodiscovery") Reported-by: Dmytro Adamenko <dmytro.adamenko@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jim Harris <jim.harris@samsung.com> Link: https://lore.kernel.org/r/3946cc55ddc19678733eddc9de2c317749f43f3b.1698263080.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/region: Calculate a target position in a region interleaveAlison Schofield1-0/+127
Introduce a calculation to find a target's position in a region interleave. Perform a self-test of the calculation on user-defined regions. The region driver uses the kernel sort() function to put region targets in relative order. Positions are assigned based on each target's index in that sorted list. That relative sort doesn't consider the offset of a port into its parent port which causes some auto-discovered regions to fail creation. In one failure case, a 2 + 2 config (2 host bridges each with 2 endpoints), the sort puts all the targets of one port ahead of another port when they were expected to be interleaved. In preparation for repairing the autodiscovery region assembly, introduce a new method for discovering a target position in the region interleave. cxl_calc_interleave_pos() adds a method to find the target position by ascending from an endpoint to a root decoder. The calculation starts with the endpoint's local position and position in the parent port. It traverses towards the root decoder and examines both position and ways in order to allow the position to be refined all the way to the root decoder. This calculation: position = position * parent_ways + parent_pos; applied iteratively yields the correct position. Include a self-test that exercises this new position calculation against every successfully configured user-defined region. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/0ac32c75cf81dd8b86bf07d70ff139d33c2300bc.1698263080.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-26cxl/region: Prepare the decoder match range helper for reuseAlison Schofield1-6/+11
match_decoder_by_range() and decoder_match_range() both determine if an HPA range matches a decoder. The first does it for root decoders and the second one operates on switch decoders. Tidy these up with clear naming and make the switch helper more like the root decoder helper in style and functionality. Make it take the actual range, rather than an endpoint decoder from which it extracts the range. Require an exact match on switch decoders, because unlike a root decoder that maps an entire region, Linux only supports 1:1 mapping of switch to endpoint decoders. Note that root-decoders are a super-set of switch-decoders and the range they cover is a super-set of a region, hence the use of range_contains() for that case. Aside from aesthetics and maintainability, this is in preparation for reuse. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jim Harris <jim.harris@samsung.com> Link: https://lore.kernel.org/r/011b1f498e1758bb8df17c5951be00bd8d489e3b.1698263080.git.alison.schofield@intel.com [djbw: fixup root decoder vs switch decoder range checks] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-25cxl/mbox: Remove useless cast in cxl_mem_create_range_info()Alison Schofield1-2/+1
DEFINE_RES_MEM() is a wrapper around the DEFINE_RES_NAMED() macro which already has the (struct resource) for the compound literal. The user of the macro should not repeat the cast. Cleans up these sparse warnings: drivers/cxl/core/mbox.c:1184:18: warning: cast to non-scalar drivers/cxl/core/mbox.c:1184:18: warning: cast from non-scalar Fixes: 52c4d11f1dce ("resource: Convert DEFINE_RES_NAMED() to be compound literal") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230815172052.22514-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-25cxl/region: Do not try to cleanup after cxl_region_setup_targets() failsJim Harris1-7/+7
Commit 5e42bcbc3fef ("cxl/region: decrement ->nr_targets on error in cxl_region_attach()") tried to avoid 'eiw' initialization errors when ->nr_targets exceeded 16, by just decrementing ->nr_targets when cxl_region_setup_targets() failed. Commit 86987c766276 ("cxl/region: Cleanup target list on attach error") extended that cleanup to also clear cxled->pos and p->targets[pos]. The initialization error was incidentally fixed separately by: Commit 8d4285425714 ("cxl/region: Fix port setup uninitialized variable warnings") which was merged a few days after 5e42bcbc3fef. But now the original cleanup when cxl_region_setup_targets() fails prevents endpoint and switch decoder resources from being reused: 1) the cleanup does not set the decoder's region to NULL, which results in future dpa_size_store() calls returning -EBUSY 2) the decoder is not properly freed, which results in future commit errors associated with the upstream switch Now that the initialization errors were fixed separately, the proper cleanup for this case is to just return immediately. Then the resources associated with this target get cleanup up as normal when the failed region is deleted. The ->nr_targets decrement in the error case also helped prevent a p->targets[] array overflow, so add a new check to prevent against that overflow. Tested by trying to create an invalid region for a 2 switch * 2 endpoint topology, and then following up with creating a valid region. Fixes: 5e42bcbc3fef ("cxl/region: decrement ->nr_targets on error in cxl_region_attach()") Cc: <stable@vger.kernel.org> Signed-off-by: Jim Harris <jim.harris@samsung.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/169703589120.1202031.14696100866518083806.stgit@bgt-140510-bm03.eng.stellus.in Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-09cxl/mem: Fix shutdown orderDan Williams1-1/+1
Ira reports that removing cxl_mock_mem causes a crash with the following trace: BUG: kernel NULL pointer dereference, address: 0000000000000044 [..] RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core] [..] Call Trace: <TASK> cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x29/0x40 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 device_unregister+0x13/0x60 devm_release_action+0x4d/0x90 ? __pfx_unregister_port+0x10/0x10 [cxl_core] delete_endpoint+0x121/0x130 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 ? lock_release+0x142/0x290 cdev_device_del+0x15/0x50 cxl_memdev_unregister+0x54/0x70 [cxl_core] This crash is due to the clearing out the cxl_memdev's driver context (@cxlds) before the subsystem is done with it. This is ultimately due to the region(s), that this memdev is a member, being torn down and expecting to be able to de-reference @cxlds, like here: static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) ... if (cxlds->rcd) goto endpoint_reset; ... Fix it by keeping the driver context valid until memdev-device unregistration, and subsequently the entire stack of related dependencies, unwinds. Fixes: 9cc238c7a526 ("cxl/pci: Introduce cdevm_file_operations") Reported-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-06cxl/memdev: Fix sanitize vs decoder setup lockingDan Williams6-48/+82
The sanitize operation is destructive and the expectation is that the device is unmapped while in progress. The current implementation does a lockless check for decoders being active, but then does nothing to prevent decoders from racing to be committed. Introduce state tracking to resolve this race. This incidentally cleans up unpriveleged userspace from triggering mmio read cycles by spinning on reading the 'security/state' attribute. Which at a minimum is a waste since the kernel state machine can cache the completion result. Lastly cxl_mem_sanitize() was mistakenly marked EXPORT_SYMBOL() in the original implementation, but an export was never required. Fixes: 0c36b6ad436a ("cxl/mbox: Add sanitization handling machinery") Cc: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-06cxl/pci: Fix sanitize notifier setupDan Williams1-42/+44
Fix a race condition between the mailbox-background command interrupt firing and the security-state sysfs attribute being removed. The race is difficult to see due to the awkward placement of the sanitize-notifier setup code and the multiple places the teardown calls are made, cxl_memdev_security_init() and cxl_memdev_security_shutdown(). Unify setup in one place, cxl_sanitize_setup_notifier(). Arrange for the paired cxl_sanitize_teardown_notifier() to safely quiet the notifier and let the cxl_memdev + irq be unregistered later in the flow. Note: The special wrinkle of the sanitize notifier is that it interacts with interrupts, which are enabled early in the flow, and it interacts with memdev sysfs which is not initialized until late in the flow. Hence why this setup routine takes an @cxlmd argument, and not just @mds. This fix is also needed as a preparation fix for a memdev unregistration crash. Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Closes: http://lore.kernel.org/r/20230929100316.00004546@Huawei.com Cc: Dave Jiang <dave.jiang@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Fixes: 0c36b6ad436a ("cxl/mbox: Add sanitization handling machinery") Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-06cxl/pci: Clarify devm host for memdev relative setupDan Williams1-8/+8
It is all too easy to get confused about @dev usage in the CXL driver stack. Before adding a new cxl_pci_probe() setup operation that has a devm lifetime dependent on @cxlds->dev binding, but also references @cxlmd->dev, and prints messages, rework the devm_cxl_add_memdev() and cxl_memdev_setup_fw_upload() function signatures to make this distinction explicit. I.e. pass in the devm context as an @host argument rather than infer it from other objects. This is in preparation for adding a devm_cxl_sanitize_setup_notifier(). Note the whitespace fixup near the change of the devm_cxl_add_memdev() signature. That uncaught typo originated in the patch that added cxl_memdev_security_init(). Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-06cxl/pci: Remove inconsistent usage of dev_err_probe()Dan Williams1-11/+2
If dev_err_probe() is to be used it should at least be used consistently within the same function. It is also worth questioning whether every potential -ENOMEM needs an explicit error message. Remove the cxl_setup_fw_upload() error prints for what are rare / hardware-independent failures. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-30cxl/pci: Cleanup 'sanitize' to always pollDan Williams1-2/+1
In preparation for fixing the init/teardown of the 'sanitize' workqueue and sysfs notification mechanism, arrange for cxl_mbox_sanitize_work() to be the single location where the sysfs attribute is notified. With that change there is no distinction between polled mode and interrupt mode. All the interrupt does is accelerate the polling interval. The change to check for "mds->security.sanitize_node" under the lock is there to ensure that the interrupt, the work routine and the setup/teardown code can all have a consistent view of the registered notifier and the workqueue state. I.e. the expectation is that the interrupt is live past the point that the sanitize sysfs attribute is published, and it may race teardown, so it must be consulted under a lock. Given that new locking requirement, cxl_pci_mbox_irq() is moved from hard to thread irq context. Lastly, some opportunistic replacements of "queue_delayed_work(system_wq, ...)", which is just open coded schedule_delayed_work(), are included. Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-23cxl/port: Fix cxl_test register enumeration regressionDan Williams1-4/+9
The cxl_test unit test environment models a CXL topology for sysfs/user-ABI regression testing. It uses interface mocking via the "--wrap=" linker option to redirect cxl_core routines that parse hardware registers with versions that just publish objects, like devm_cxl_enumerate_decoders(). Starting with: Commit 19ab69a60e3b ("cxl/port: Store the port's Component Register mappings in struct cxl_port") ...port register enumeration is moved into devm_cxl_add_port(). This conflicts with the "cxl_test avoids emulating registers stance" so either the port code needs to be refactored (too violent), or modified so that register enumeration is skipped on "fake" cxl_test ports (annoying, but straightforward). This conflict has happened previously and the "check for platform device" workaround to avoid instrusive refactoring was deployed in those scenarios. In general, refactoring should only benefit production code, test code needs to remain minimally instrusive to the greatest extent possible. This was missed previously because it may sometimes just cause warning messages to be emitted, but it can also cause test failures. The backport to -stable is only nice to have for clean cxl_test runs. Fixes: 19ab69a60e3b ("cxl/port: Store the port's Component Register mappings in struct cxl_port") Cc: stable@vger.kernel.org Reported-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/169476525052.1013896.6235102957693675187.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-16cxl/port: Quiet warning messages from the cxl_test environmentDan Williams2-2/+7
The cxl_test platform device CXL port hierarchy is useful for testing, but throws warning messages of the form: cxl_mem mem2: at cxl_root_port.1 no parent for dport: platform cxl_mem mem3: at cxl_root_port.2 no parent for dport: platform cxl_mem mem4: at cxl_root_port.3 no parent for dport: platform cxl_mem mem5: at cxl_root_port.0 no parent for dport: platform cxl_mem mem6: at cxl_root_port.1 no parent for dport: platform cxl_mem mem7: at cxl_root_port.2 no parent for dport: platform cxl_mem mem8: at cxl_root_port.3 no parent for dport: platform cxl_mem mem9: at cxl_root_port.4 no parent for dport: platform cxl_mem mem10: at cxl_root_port.4 no parent for dport: platform ...and this message when running testing in QEMU: cxl_region region4: Bypassing cpu_cache_invalidate_memregion() for testing! Noisy cxl_test warnings have caused other regressions to be missed. In the interest of using cxl_test for early detection of dev_err() and dev_warn() messages, silence platform device topology and cache-invalidation messages. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-15cxl/region: Refactor granularity select in cxl_port_setup_targets()Alison Schofield1-9/+8
In cxl_port_setup_targets() the region driver validates the configuration of auto-discovered region decoders, as well as decoders the driver is preparing to program. The existing calculations use the encoded interleave granularity value to create an interleave granularity that properly fans out when routing an x1 interleave to a greater than x1 interleave. That all worked well, until this config came along: Host Bridge: 2 way at 256 granularity Switch Decoder_A: 1 way at 512 Endpoint_X: 2 way at 256 Switch Decoder_B: 1 way at 512 Endpoint_Y: 2 way at 256 When the Host Bridge interleave is greater than 1 and the root decoder interleave is exactly 1, the region driver needs to consider the number of targets in the region when calculating the expected granularity. While examining the existing logic, and trying to cover the case above, a couple of simplifications appeared, hence this proposed refactoring. The first simplification is to apply the logic to the nominal values and use the existing helper function granularity_to_eig() to translate the desired granularity to the encoded form. This means the comment and code regarding setting address bits is discarded. Although that logic is not wrong, it adds a level of complexity that is not required in the granularity selection. The eig and eiw are indeed part of the routing instructions programmed into the decoders. Up-level the discussion to nominal ways and granularity for clearer analysis. The second simplification reduces the logic to a single granularity calculation that works for all cases. The new calculation doesn't care if parent_iw => 1 because parent_iw is used as a multiplier. The refactor cleans up a useless assignment of eiw made after the iw is already calculated. Regression testing included an examination of all of the ways and granularity selections made during a run of the cxl_test unit tests. There were no differences in selections before and after this patch. Fixes: ("27b3f8d13830 cxl/region: Program target lists") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20230822180928.117596-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-15cxl/region: Match auto-discovered region decoders by HPA rangeAlison Schofield1-1/+23
Currently, when the region driver attaches a region to a port, it selects the ports next available decoder to program. With the addition of auto-discovered regions, a port decoder has already been programmed so grabbing the next available decoder can be a mismatch when there is more than one region using the port. The failure appears like this with CXL DEBUG enabled: [] cxl_core:alloc_region_ref:754: cxl region0: endpoint9: HPA order violation region0:[mem 0x14780000000-0x1478fffffff flags 0x200] vs [mem 0x880000000-0x185fffffff flags 0x200] [] cxl_core:cxl_port_attach_region:972: cxl region0: endpoint9: failed to allocate region reference When CXL DEBUG is not enabled, there is no failure message. The region just never materializes. Users can suspect this issue if they know their firmware has programmed decoders so that more than one region is using a port. Note that the problem may appear intermittently, ie not on every reboot. Add a matching method for auto-discovered regions that finds a decoder based on an HPA range. The decoder range must exactly match the region resource parameter. Fixes: a32320b71f08 ("cxl/region: Add region autodiscovery") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230905211007.256385-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-14cxl/mbox: Fix CEL logic for poison and security commandsIra Weiny1-11/+12
The following debug output was observed while testing CXL cxl_core:cxl_walk_cel:721: cxl_mock_mem cxl_mem.0: Opcode 0x4300 unsupported by driver opcode 0x4300 (Get Poison) is supported by the driver and the mock device supports it. The logic should be checking that the opcode is both not poison and not security. Fix the logic to allow poison and security commands. Fixes: ad64f5952ce3 ("cxl/memdev: Only show sanitize sysfs files when supported") Cc: <stable@vger.kernel.org> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230903-cxl-cel-fix-v1-1-e260c9467be3@intel.com [cleanup cxl_walk_cel() to centralized "enabled" checks] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-07-28cxl/memdev: Only show sanitize sysfs files when supportedDavidlohr Bueso2-1/+63
If the device does not support Sanitize or Secure Erase commands, hide the respective sysfs interfaces such that the operation can never be attempted. In order to be generic, keep track of the enabled security commands found in the CEL - the driver does not support Security Passthrough. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/20230726051940.3570-4-dave@stgolabs.net Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-06-30cxl: Fix one kernel-doc commentYang Li1-1/+1
Fix a merge error that updated the argument to cxl_mem_get_fw_info() but not the kernel-doc. drivers/cxl/core/memdev.c:678: warning: Function parameter or member 'mds' not described in 'cxl_mem_get_fw_info' drivers/cxl/core/memdev.c:678: warning: Excess function parameter 'cxlds' description in 'cxl_mem_get_fw_info' Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Link: https://lore.kernel.org/r/20230629021118.102744-1-yang.lee@linux.alibaba.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxlDan Williams6-84/+239
Pick up the first half of the RCH error handling series. The back half needs some fixups for test regressions. Small conflicts with the PMU work around register enumeration and setup helpers.
2023-06-26Merge branch 'for-6.5/cxl-perf' into for-6.5/cxlDan Williams5-6/+141
Pick up initial support for the CXL 3.0 performance monitoring definition. Small conflicts with the firmware update work as they both placed their init code in the same location.
2023-06-26Merge branch 'for-6.5/cxl-region-fixes' into for-6.5/cxlDan Williams1-39/+63
Pick up the recent fixes to how CPU caches are managed relative to region setup / teardown, and make sure that all decoders transition successfully before updating the region state from COMMIT => ACTIVE.
2023-06-26Merge branch 'for-6.5/cxl-type-2' into for-6.5/cxlDan Williams8-262/+302
Pick up the driver cleanups identified in preparation for CXL "type-2" (accelerator) device support. The major change here from a conflict generation perspective is the split of 'struct cxl_memdev_state' from the core 'struct cxl_dev_state'. Since an accelerator may not care about all the optional features that are standard on a CXL "type-3" (host-only memory expander) device. A silent conflict also occurs with the move of the endpoint port to be a formal property of a 'struct cxl_memdev' rather than drvdata.
2023-06-26Merge branch 'for-6.5/cxl-fwupd' into for-6.5/cxlDan Williams1-0/+308
Add the first typical (non-sanitization) consumer of the new background command infrastructure, firmware update. Given both firmware-update and sanitization were developed in parallel from the common background-command baseline, resolve some minor context conflicts.
2023-06-26Merge branch 'for-6.5/cxl-background' into for-6.5/cxlDan Williams2-1/+199
Pick up the sanitization work and the infrastructure for other background commands for 6.5. Sanitization has a different completion path than typical background commands so it was important to have both thought out and implemented before either went upstream.
2023-06-26cxl: add a firmware update mechanism using the sysfs firmware loaderVishal Verma1-0/+308
The sysfs based firmware loader mechanism was created to easily allow userspace to upload firmware images to FPGA cards. This also happens to be pretty suitable to create a user-initiated but kernel-controlled firmware update mechanism for CXL devices, using the CXL specified mailbox commands. Since firmware update commands can be long-running, and can be processed in the background by the endpoint device, it is desirable to have the ability to chunk the firmware transfer down to smaller pieces, so that one operation does not monopolize the mailbox, locking out any other long running background commands entirely - e.g. security commands like 'sanitize' or poison scanning operations. The firmware loader mechanism allows a natural way to perform this chunking, as after each mailbox command, that is restricted to the maximum mailbox payload size, the cxl memdev driver relinquishes control back to the fw_loader system and awaits the next chunk of data to transfer. This opens opportunities for other background commands to access the mailbox and send their own slices of background commands. Add the necessary helpers and state tracking to be able to perform the 'Get FW Info', 'Transfer FW', and 'Activate FW' mailbox commands as described in the CXL spec. Wire these up to the firmware loader callbacks, and register with that system to create the memX/firmware/ sysfs ABI. Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Cc: Russ Weight <russell.h.weight@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ben Widawsky <bwidawsk@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/20230602-vv-fw_update-v4-1-c6265bd7343b@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/mem: Support Secure EraseDavidlohr Bueso2-1/+33
Implement support for the non-pmem exclusive secure erase, per CXL specs. Create a write-only 'security/erase' sysfs file to perform the requested operation. As with the sanitation this requires the device being offline and thus no active HPA-DPA decoding. The expectation is that userspace can use it such as: cxl disable-memdev memX echo 1 > /sys/bus/cxl/devices/memX/security/erase cxl enable-memdev memX Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/20230612181038.14421-7-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/mem: Wire up Sanitization supportDavidlohr Bueso2-0/+122
Implement support for CXL 3.0 8.2.9.8.5.1 Sanitize. This is done by adding a security/sanitize' memdev sysfs file to trigger the operation and extend the status file to make it poll(2)-capable for completion. Unlike all other background commands, this is the only operation that is special and monopolizes the device for long periods of time. In addition to the traditional pmem security requirements, all regions must also be offline in order to perform the operation. This permits avoiding explicit global CPU cache management, relying instead on the implict cache management when a region transitions between CXL_CONFIG_ACTIVE and CXL_CONFIG_COMMIT. The expectation is that userspace can use it such as: cxl disable-memdev memX echo 1 > /sys/bus/cxl/devices/memX/security/sanitize cxl wait-sanitize memX cxl enable-memdev memX Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/20230612181038.14421-5-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/mbox: Add sanitization handling machineryDavidlohr Bueso1-0/+10
Sanitization is by definition a device-monopolizing operation, and thus the timeslicing rules for other background commands do not apply. As such handle this special case asynchronously and return immediately. Subsequent changes will allow completion to be pollable from userspace via a sysfs file interface. For devices that don't support interrupts for notifying background command completion, self-poll with the caveat that the poller can be out of sync with the ready hardware, and therefore care must be taken to not allow any new commands to go through until the poller sees the hw completion. The poller takes the mbox_mutex to stabilize the flagging, minimizing any runtime overhead in the send path to check for 'sanitize_tmo' for uncommon poll scenarios. The irq case is much simpler as hardware will serialize/error appropriately. Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230612181038.14421-4-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/mem: Introduce security state sysfs fileDavidlohr Bueso1-0/+33
Add a read-only sysfs file to display the security state of a device (currently only pmem): /sys/bus/cxl/devices/memX/security/state This introduces a cxl_security_state structure that is to be the placeholder for common CXL security features. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20230612181038.14421-3-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26Revert "cxl/port: Enable the HDM decoder capability for switch ports"Dan Williams1-23/+4
commit eb0764b822b9 ("cxl/port: Enable the HDM decoder capability for switch ports") ...was added on the observation of CXL memory not being accessible after setting up a region on a "cold-plugged" device. A "cold-plugged" CXL device is one that was not present at boot, so platform-firmware/BIOS has no chance to set it up. While it is true that the debug found the enable bit clear in the host-bridge's instance of the global control register (CXL 3.0 8.2.4.19.2 CXL HDM Decoder Global Control Register), that bit is described as: "This bit is only applicable to CXL.mem devices and shall return 0 on CXL Host Bridges and Upstream Switch Ports." So it is meant to be zero, and further testing confirmed that this "fix" had no effect on the failure. Revert it, and be more vigilant about proposed fixes in the future. Since the original copied stable@, flag this revert for stable@ as well. Cc: <stable@vger.kernel.org> Fixes: eb0764b822b9 ("cxl/port: Enable the HDM decoder capability for switch ports") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168685882012.3475336.16733084892658264991.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/memdev: Formalize endpoint port linkageDan Williams3-5/+6
Move the endpoint port that the cxl_mem driver establishes from drvdata to a first class attribute. This is in preparation for device-memory drivers reusing the CXL core for memory region management. Those drivers need a type-safe method to retrieve their CXL port linkage. Leave drvdata for private usage of the cxl_mem driver not external consumers of a 'struct cxl_memdev' object. Reviewed-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679264292.3436160.3901392135863405807.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/region: Manage decoder target_type at decoder-attach timeDan Williams1-0/+12
Switch-level (mid-level) decoders between the platform root and an endpoint can dynamically switch modes between HDM-H and HDM-D[B] depending on which region they target. Use the region type to fixup each decoder that gets allocated to map the given region. Note that endpoint decoders are meant to determine the region type, so warn if those ever need to be fixed up, but since it is possible to continue do so. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679262543.3436160.13053831955768440312.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/hdm: Default CXL_DEVTYPE_DEVMEM decoders to CXL_DECODER_DEVMEMDan Williams1-9/+26
In preparation for device-memory region creation, arrange for decoders of CXL_DEVTYPE_DEVMEM memdevs to default to CXL_DECODER_DEVMEM for their target type. Revisit this if a device ever shows up that wants to offer mixed HDM-H (Host-Only Memory) and HDM-DB support, or an CXL_DEVTYPE_DEVMEM device that supports HDM-H. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679261945.3436160.11673393474107374595.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/port: Rename CXL_DECODER_{EXPANDER, ACCELERATOR} => {HOSTONLYMEM, DEVMEM}Dan Williams3-9/+10
In preparation for support for HDM-D and HDM-DB configuration (device-memory, and device-memory with back-invalidate). Rename the current type designators to use HOSTONLYMEM and DEVMEM as a suffix. HDM-DB can be supported by devices that are not accelerators, so DEVMEM is a more generic term for that case. Fixup one location where this type value was open coded. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679261369.3436160.7042443847605280593.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/memdev: Make mailbox functionality optionalDan Williams2-1/+10
In support of the Linux CXL core scaling for a wider set of CXL devices, allow for the creation of memdevs with some memory device capabilities disabled. Specifically, allow for CXL devices outside of those claiming to be compliant with the generic CXL memory device class code, like vendor specific Type-2/3 devices that host CXL.mem. This implies, allow for the creation of memdevs that only support component-registers, not necessarily memory-device-registers (like mailbox registers). A memdev derived from a CXL endpoint that does not support generic class code expectations is tagged "CXL_DEVTYPE_DEVMEM", while a memdev derived from a class-code compliant endpoint is tagged "CXL_DEVTYPE_CLASSMEM". The primary assumption of a CXL_DEVTYPE_DEVMEM memdev is that it optionally may not host a mailbox. Disable the command passthrough ioctl for memdevs that are not CXL_DEVTYPE_CLASSMEM, and return empty strings from memdev attributes associated with data retrieved via the class-device-standard IDENTIFY command. Note that empty strings were chosen over attribute visibility to maintain compatibility with shipping versions of cxl-cli that expect those attributes to always be present. Once cxl-cli has dropped that requirement this workaround can be deprecated. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679260782.3436160.7587293613945445365.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-26cxl/mbox: Move mailbox related driver state to its own data structureDan Williams2-150/+163
'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>
2023-06-26cxl/regs: Clarify when a 'struct cxl_register_map' is input vs outputDan Williams1-4/+4
The @map parameter to cxl_probe_X_registers() is filled in with the mapping parameters of the register block. The @map parameter to cxl_map_X_registers() only reads that information to perform the mapping. Mark @map const for cxl_map_X_registers() to clarify that it is only an input to those helpers. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679258103.3436160.4941603739448763855.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/region: Fix state transitions after reset failureDan Williams1-11/+15
Jonathan reports that failed attempts to reset a region (teardown its HDM decoder configuration) mistakenly advance the state of the region to "not committed". Revert to the previous state of the region on reset failure so that the reset can be re-attempted. Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Closes: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168696507968.3590522.14484000711718573626.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/region: Flag partially torn down regions as unusableDan Williams1-0/+12
cxl_region_decode_reset() walks all the decoders associated with a given region and disables them. Due to decoder ordering rules it is possible that a switch in the topology notices that a given decoder can not be shutdown before another region with a higher HPA is shutdown first. That can leave the region in a partially committed state. Capture that state in a new CXL_REGION_F_NEEDS_RESET flag and require that a successful cxl_region_decode_reset() attempt must be completed before cxl_region_probe() accepts the region. This is a corollary for the bug that Jonathan identified in "CXL/region : commit reset of out of order region appears to succeed." [1]. Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Link: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com [1] Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168696507423.3590522.16254212607926684429.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/region: Move cache invalidation before region teardown, and before setupDan Williams1-29/+37
Vikram raised a concern with the theoretical case of a CPU sending MemClnEvict to a device that is not prepared to receive. MemClnEvict is a message that is sent after a CPU has taken ownership of a cacheline from accelerator memory (HDM-DB). In the case of hotplug or HDM decoder reconfiguration it is possible that the CPU is holding old contents for a new device that has taken over the physical address range being cached by the CPU. To avoid this scenario, invalidate caches prior to tearing down an HDM decoder configuration. Now, this poses another problem that it is possible for something to speculate into that space while the decode configuration is still up, so to close that gap also invalidate prior to establish new contents behind a given physical address range. With this change the cache invalidation is now explicit and need not be checked in cxl_region_probe(), and that obviates the need for CXL_REGION_F_INCOHERENT. Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Fixes: d18bc74aced6 ("cxl/region: Manage CPU caches relative to DPA invalidation events") Reported-by: Vikram Sethi <vsethi@nvidia.com> Closes: http://lore.kernel.org/r/BYAPR12MB33364B5EB908BF7239BB996BBD53A@BYAPR12MB3336.namprd12.prod.outlook.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168696506886.3590522.4597053660991916591.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/port: Store the downstream port's Component Register mappings in struct ↵Robert Richter1-0/+11
cxl_dport Same as for ports, also store the downstream port's Component Register mappings, use struct cxl_dport for that. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-16-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/port: Store the port's Component Register mappings in struct cxl_portRobert Richter1-0/+27
CXL capabilities are stored in the Component Registers. To use them, the specific I/O ranges of the capabilities must be determined by probing the registers. For this, the whole Component Register range needs to be mapped temporarily to detect the offset and length of a capability range. In order to use more than one capability of a component (e.g. RAS and HDM) the Component Register are probed and its mappings created multiple times. This also causes overlapping I/O ranges as the whole Component Register range must be mapped again while a capability's I/O range is already mapped. Different capabilities cannot be setup at the same time. E.g. the RAS capability must be made available as soon as the PCI driver is bound, the HDM decoder is setup later during port enumeration. Moreover, during early setup it is still unknown if a certain capability is needed. A central capability setup is therefore not possible, capabilities must be individually enabled once needed during initialization. To avoid a duplicate register probe and overlapping I/O mappings, only probe the Component Registers one time and store the Component Register mapping in struct port. The stored mappings can be used later to iomap the capability register range when enabling the capability, which will be implemented in a follow-on patch. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-15-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/pci: Early setup RCH dport component registers from RCRBRobert Richter1-0/+7
CXL RAS capabilities must be enabled and accessible as soon as the CXL endpoint is detected in the PCI hierarchy and bound to the cxl_pci driver. This needs to be independent of other modules such as cxl_port or cxl_mem. CXL RAS capabilities reside in the Component Registers. For an RCH this is determined by probing RCRB which is implemented very late once the CXL Memory Device is created. Change this by moving the RCRB probe to the cxl_pci driver. Do this by using a new introduced function cxl_pci_find_port() similar to cxl_mem_find_port() to determine the involved dport by the endpoint's PCI handle. Plug this into the existing cxl_pci_setup_regs() function to setup Component Registers. Probe the RCRB in case the Component Registers cannot be located through the CXL Register Locator capability. This unifies code and early sets up the Component Registers at the same time for both, VH and RCH mode. Only the cxl_pci driver is involved for this. This allows an early mapping of the CXL RAS capability registers. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-14-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/regs: Remove early capability checks in Component Register setupRobert Richter1-8/+0
When probing the Component Registers in function cxl_probe_regs() there are also checks for the existence of the HDM and RAS capabilities. The checks may fail for components that do not implement the HDM capability causing the Component Registers setup to fail too. Remove the checks for a generalized use of cxl_probe_regs() and check them directly before mapping the RAS or HDM capabilities. This allows it to setup other Component Registers esp. of an RCH Downstream Port, which will be implemented in a follow-on patch. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-12-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/port: Remove Component Register base address from struct cxl_dportRobert Richter1-1/+0
The Component Register base address @component_reg_phys is no longer used after the rework of the Component Register setup which now uses struct member @comp_map instead. Remove the base address. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-11-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/pci: Refactor component register discovery for reuseTerry Bowman1-0/+77
The endpoint implements component register setup code. Refactor it for reuse with RCRB, downstream port, and upstream port setup. Move PCI specifics from cxl_setup_regs() into cxl_pci_setup_regs(). Move cxl_setup_regs() into cxl/core/regs.c and export it. This also includes supporting static functions cxl_map_registerblock(), cxl_unmap_register_block() and cxl_probe_regs(). Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-8-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/core/regs: Add @dev to cxl_register_mapRobert Richter2-8/+14
The corresponding device of a register mapping is used for devm operations and logging. For operations with struct cxl_register_map the device needs to be kept track separately. To simpify the involved function interfaces, add @dev to cxl_register_map. While at it also reorder function arguments of cxl_map_device_regs() and cxl_map_component_regs() to have the object @cxl_register_map first. As a result a bunch of functions are available to be used with a @cxl_register_map object. This patch is in preparation of reworking the component register setup code. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-7-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>