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2024-11-08cxl/acpi: Ensure ports ready at cxl_acpi_probe() returnDan Williams1-0/+7
[ Upstream commit 48f62d38a07d464a499fa834638afcfd2b68f852 ] In order to ensure root CXL ports are enabled upon cxl_acpi_probe() when the 'cxl_port' driver is built as a module, arrange for the module to be pre-loaded or built-in. The "Fixes:" but no "Cc: stable" on this patch reflects that the issue is merely by inspection since the bug that triggered the discovery of this potential problem [1] is fixed by other means. However, a stable backport should do no harm. Fixes: 8dd2bc0f8e02 ("cxl/mem: Add the cxl_mem driver") Link: http://lore.kernel.org/20241004212504.1246-1-gourry@gourry.net [1] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Gregory Price <gourry@gourry.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/172964781969.81806.17276352414854540808.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08cxl/port: Fix cxl_bus_rescan() vs bus_rescan_devices()Dan Williams1-3/+10
[ Upstream commit 3d6ebf16438de5d712030fefbb4182b46373d677 ] It turns out since its original introduction, pre-2.6.12, bus_rescan_devices() has skipped devices that might be in the process of attaching or detaching from their driver. For CXL this behavior is unwanted and expects that cxl_bus_rescan() is a probe barrier. That behavior is simple enough to achieve with bus_for_each_dev() paired with call to device_attach(), and it is unclear why bus_rescan_devices() took the position of lockless consumption of dev->driver which is racy. The "Fixes:" but no "Cc: stable" on this patch reflects that the issue is merely by inspection since the bug that triggered the discovery of this potential problem [1] is fixed by other means. However, a stable backport should do no harm. Fixes: 8dd2bc0f8e02 ("cxl/mem: Add the cxl_mem driver") Link: http://lore.kernel.org/20241004212504.1246-1-gourry@gourry.net [1] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Gregory Price <gourry@gourry.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/172964781104.81806.4277549800082443769.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08cxl/port: Fix use-after-free, permit out-of-order decoder shutdownDan Williams3-44/+57
commit 101c268bd2f37e965a5468353e62d154db38838e upstream. In support of investigating an initialization failure report [1], cxl_test was updated to register mock memory-devices after the mock root-port/bus device had been registered. That led to cxl_test crashing with a use-after-free bug with the following signature: cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem0:decoder7.0 @ 0 next: cxl_switch_uport.0 nr_eps: 1 nr_targets: 1 cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem4:decoder14.0 @ 1 next: cxl_switch_uport.0 nr_eps: 2 nr_targets: 1 cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[0] = cxl_switch_dport.0 for mem0:decoder7.0 @ 0 1) cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[1] = cxl_switch_dport.4 for mem4:decoder14.0 @ 1 [..] cxld_unregister: cxl decoder14.0: cxl_region_decode_reset: cxl_region region3: mock_decoder_reset: cxl_port port3: decoder3.0 reset 2) mock_decoder_reset: cxl_port port3: decoder3.0: out of order reset, expected decoder3.1 cxl_endpoint_decoder_release: cxl decoder14.0: [..] cxld_unregister: cxl decoder7.0: 3) cxl_region_decode_reset: cxl_region region3: Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bc3: 0000 [#1] PREEMPT SMP PTI [..] RIP: 0010:to_cxl_port+0x8/0x60 [cxl_core] [..] Call Trace: <TASK> cxl_region_decode_reset+0x69/0x190 [cxl_core] cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x5d/0x60 [cxl_core] At 1) a region has been established with 2 endpoint decoders (7.0 and 14.0). Those endpoints share a common switch-decoder in the topology (3.0). At teardown, 2), decoder14.0 is the first to be removed and hits the "out of order reset case" in the switch decoder. The effect though is that region3 cleanup is aborted leaving it in-tact and referencing decoder14.0. At 3) the second attempt to teardown region3 trips over the stale decoder14.0 object which has long since been deleted. The fix here is to recognize that the CXL specification places no mandate on in-order shutdown of switch-decoders, the driver enforces in-order allocation, and hardware enforces in-order commit. So, rather than fail and leave objects dangling, always remove them. In support of making cxl_region_decode_reset() always succeed, cxl_region_invalidate_memregion() failures are turned into warnings. Crashing the kernel is ok there since system integrity is at risk if caches cannot be managed around physical address mutation events like CXL region destruction. A new device_for_each_child_reverse_from() is added to cleanup port->commit_end after all dependent decoders have been disabled. In other words if decoders are allocated 0->1->2 and disabled 1->2->0 then port->commit_end only decrements from 2 after 2 has been disabled, and it decrements all the way to zero since 1 was disabled previously. Link: http://lore.kernel.org/20241004212504.1246-1-gourry@gourry.net [1] Cc: stable@vger.kernel.org Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/172964782781.81806.17902885593105284330.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08cxl/events: Fix Trace DRAM Event RecordShiju Jose1-3/+14
[ Upstream commit 53ab8678e7180834be29cf56cd52825fc3427c02 ] CXL spec rev 3.0 section 8.2.9.2.1.2 defines the DRAM Event Record. Fix decode memory event type field of DRAM Event Record. For e.g. if value is 0x1 it will be reported as an Invalid Address (General Media Event Record - Memory Event Type) instead of Scrub Media ECC Error (DRAM Event Record - Memory Event Type) and so on. Fixes: 2d6c1e6d60ba ("cxl/mem: Trace DRAM Event Record") Signed-off-by: Shiju Jose <shiju.jose@huawei.com> Link: https://patch.msgid.link/20241014143003.1170-1-shiju.jose@huawei.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-04cxl/pci: Fix to record only non-zero rangesYanfei Xu1-7/+1
[ Upstream commit 55e268694e8b07026c88191f9b6949b6887d9ce3 ] The function cxl_dvsec_rr_decode() retrieves and records DVSEC ranges into info->dvsec_range[], regardless of whether it is non-zero range, and the variable info->ranges indicates the number of non-zero ranges. However, in cxl_hdm_decode_init(), the validation for info->dvsec_range[] occurs in a for loop that iterates based on info->ranges. It may result in zero range to be validated but non-zero range not be validated, in turn, the number of allowed ranges is to be 0. Address it by only record non-zero ranges. This fix is not urgent as it requires a configuration that zeroes out the first dvsec range while populating the second. This has not been observed, but it is theoretically possible. If this gets picked up for -stable, no harm done, but there is no urgency to backport. Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Yanfei Xu <yanfei.xu@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240828084231.1378789-2-yanfei.xu@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-18cxl/core: Fix incorrect vendor debug UUID definepeng guo1-1/+1
[ Upstream commit 8ecef8e01a08c7e3e4ffc8f08d9f9663984f334b ] When user send a mbox command whose opcode is CXL_MBOX_OP_CLEAR_LOG and the in_payload is normal vendor debug log UUID according to the CXL specification cxl_payload_from_user_allowed() will return false unexpectedly, Sending mbox cmd operation fails and the kernel log will print: Clear Log: input payload not allowed. All CXL devices that support a debug log shall support the Vendor Debug Log to allow the log to be accessed through a common host driver, for any device, all versions of the CXL specification define the same value with Log Identifier of: 5e1819d9-11a9-400c-811f-d60719403d86 Refer to CXL spec r3.1 Table 8-71 Fix the definition value of DEFINE_CXL_VENDOR_DEBUG_UUID to match the CXL specification. Fixes: 472b1ce6e9d6 ("cxl/mem: Enable commands via CEL") Signed-off-by: peng guo <engguopeng@buaa.edu.cn> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240710023112.8063-1-engguopeng@buaa.edu.cn Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12cxl/region: Verify target positions using the ordered target listAlison Schofield1-1/+4
[ Upstream commit 82a3e3a235633aa0575fac9507d648dd80f3437f ] When a root decoder is configured the interleave target list is read from the BIOS populated CFMWS structure. Per the CXL spec 3.1 Table 9-22 the target list is in interleave order. The CXL driver populates its decoder target list in the same order and stores it in 'struct cxl_switch_decoder' field "@target: active ordered target list in current decoder configuration" Given the promise of an ordered list, the driver can stop duplicating the work of BIOS and simply check target positions against the ordered list during region configuration. The simplified check against the ordered list is presented here. A follow-on patch will remove the unused code. For Modulo arithmetic this is not a fix, only a simplification. For XOR arithmetic this is a fix for HB IW of 3,6,12. Fixes: f9db85bfec0d ("cxl/acpi: Support CXL XOR Interleave Math (CXIMS)") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/35d08d3aba08fee0f9b86ab1cef0c25116ca8a55.1719980933.git.alison.schofield@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05cxl/region: check interleave capabilityYao Xingtao4-0/+107
[ Upstream commit 84328c5acebc10c8cdcf17283ab6c6d548885bfc ] Since interleave capability is not verified, if the interleave capability of a target does not match the region need, committing decoder should have failed at the device end. In order to checkout this error as quickly as possible, driver needs to check the interleave capability of target during attaching it to region. Per CXL specification r3.1(8.2.4.20.1 CXL HDM Decoder Capability Register), bits 11 and 12 indicate the capability to establish interleaving in 3, 6, 12 and 16 ways. If these bits are not set, the target cannot be attached to a region utilizing such interleave ways. Additionally, bits 8 and 9 represent the capability of the bits used for interleaving in the address, Linux tracks this in the cxl_port interleave_mask. Per CXL specification r3.1(8.2.4.20.13 Decoder Protection): eIW means encoded Interleave Ways. eIG means encoded Interleave Granularity. in HPA: if eIW is 0 or 8 (interleave ways: 1, 3), all the bits of HPA are used, the interleave bits are none, the following check is ignored. if eIW is less than 8 (interleave ways: 2, 4, 8, 16), the interleave bits start at bit position eIG + 8 and end at eIG + eIW + 8 - 1. if eIW is greater than 8 (interleave ways: 6, 12), the interleave bits start at bit position eIG + 8 and end at eIG + eIW - 1. if the interleave mask is insufficient to cover the required interleave bits, the target cannot be attached to the region. Fixes: 384e624bb211 ("cxl/region: Attach endpoint decoders") Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240614084755.59503-2-yaoxt.fnst@fujitsu.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05cxl/region: Avoid null pointer dereference in region lookupAlison Schofield1-4/+15
[ Upstream commit 285f2a08841432fc3e498b1cd00cce5216cdf189 ] cxl_dpa_to_region() looks up a region based on a memdev and DPA. It wrongly assumes an endpoint found mapping the DPA is also of a fully assembled region. When not true it leads to a null pointer dereference looking up the region name. This appears during testing of region lookup after a failure to assemble a BIOS defined region or if the lookup raced with the assembly of the BIOS defined region. Failure to clean up BIOS defined regions that fail assembly is an issue in itself and a fix to that problem will alleviate some of the impact. It will not alleviate the race condition so let's harden this path. The behavior change is that the kernel oops due to a null pointer dereference is replaced with a dev_dbg() message noting that an endpoint was mapped. Additional comments are added so that future users of this function can more clearly understand what it provides. Fixes: 0a105ab28a4d ("cxl/memdev: Warn of poison inject or clear to a mapped region") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240604003609.202682-1-alison.schofield@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05cxl/region: Move cxl_dpa_to_region() work to the region driverAlison Schofield3-44/+51
[ Upstream commit b98d042698a32518c93e47730e9ad86b387a9c21 ] This helper belongs in the region driver as it is only useful with CONFIG_CXL_REGION. Add a stub in core.h for when the region driver is not built. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/05e30f788d62b3dd398aff2d2ea50a6aaa7c3313.1714496730.git.alison.schofield@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Stable-dep-of: 285f2a088414 ("cxl/region: Avoid null pointer dereference in region lookup") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21cxl/region: Fix memregion leaks in devm_cxl_add_region()Li Zhijian1-9/+9
[ Upstream commit 49ba7b515c4c0719b866d16f068e62d16a8a3dd1 ] Move the mode verification to __create_region() before allocating the memregion to avoid the memregion leaks. Fixes: 6e099264185d ("cxl/region: Add volatile region creation support") Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20240507053421.456439-1-lizhijian@fujitsu.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12cxl/region: Fix cxlr_pmem leaksLi Zhijian1-0/+1
[ Upstream commit 1c987cf22d6b65ade46145c03eef13f0e3e81d83 ] Before this error path, cxlr_pmem pointed to a kzalloc() memory, free it to avoid this memory leaking. Fixes: f17b558d6663 ("cxl/pmem: Refactor nvdimm device registration, delete the workqueue") Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20240428030748.318985-1-lizhijian@fujitsu.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12cxl/trace: Correct DPA field masks for general_media & dram eventsAlison Schofield1-2/+2
[ Upstream commit 2042d11cb57b7e0cbda7910e5ff80e9e8bf0ae17 ] The length of Physical Address in General Media and DRAM event records is 64-bit, so the field mask for extracting the DPA should be 64-bit also, otherwise the trace event reports DPA's with the upper 32 bits of a DPA address masked off. If users do DPA-to-HPA translations this could lead to incorrect page retirement decisions. Use GENMASK_ULL() for CXL_DPA_MASK to get all the DPA address bits. Tidy up CXL_DPA_FLAGS_MASK by using GENMASK() to only mask the exact flag bits. These bits are defined as part of the event record physical address descriptions of General Media and DRAM events in CXL Spec 3.1 Section 8.2.9.2 Events. Fixes: d54a531a430b ("cxl/mem: Trace General Media Event Record") Co-developed-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/2867fc43c57720a4a15a3179431829b8dbd2dc16.1714496730.git.alison.schofield@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-02cxl/core: Fix potential payload size confusion in cxl_mem_get_poison()Dan Williams1-21/+17
[ Upstream commit 4b759dd5765503bd466defac7d93aca14c23a15d ] A recent change to cxl_mem_get_records_log() [1] highlighted a subtle nuance of looping calls to cxl_internal_send_cmd(), i.e. that cxl_internal_send_cmd() modifies the 'size_out' member of the @mbox_cmd argument. That mechanism is useful for communicating underflow, but it is unwanted when reusing @mbox_cmd for a subsequent submission. It turns out that cxl_xfer_log() avoids this scenario by always redefining @mbox_cmd each iteration. Update cxl_mem_get_records_log() and cxl_mem_get_poison() to follow the same style as cxl_xfer_log(), i.e. re-define @mbox_cmd each iteration. The cxl_mem_get_records_log() change is just a style fixup, but the cxl_mem_get_poison() change is a potential fix, per Alison [2]: Poison list retrieval can hit this case if the MORE flag is set and a follow on read of the list delivers more records than the previous read. ie. device gives one record, sets the _MORE flag, then gives 5. Not an urgent fix since this behavior has not been seen in the wild, but worth tracking as a fix. Cc: Kwangjin Ko <kwangjin.ko@sk.com> Cc: Alison Schofield <alison.schofield@intel.com> Fixes: ed83f7ca398b ("cxl/mbox: Add GET_POISON_LIST mailbox command") Link: http://lore.kernel.org/r/20240402081404.1106-2-kwangjin.ko@sk.com [1] Link: http://lore.kernel.org/r/ZhAhAL/GOaWFrauw@aschofie-mobl2 [2] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/171235441633.2716581.12330082428680958635.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-17cxl/core: Fix initialization of mbox_cmd.size_out in get eventKwangjin Ko1-1/+2
[ Upstream commit f7c52345ccc96343c0a05bdea3121c8ac7b67d5f ] Since mbox_cmd.size_out is overwritten with the actual output size in the function below, it needs to be initialized every time. cxl_internal_send_cmd -> __cxl_pci_mbox_send_cmd Problem scenario: 1) The size_out variable is initially set to the size of the mailbox. 2) Read an event. - size_out is set to 160 bytes(header 32B + one event 128B). - Two event are created while reading. 3) Read the new *two* events. - size_out is still set to 160 bytes. - Although the value of out_len is 288 bytes, only 160 bytes are copied from the mailbox register to the local variable. - record_count is set to 2. - Accessing records[1] will result in reading incorrect data. Fixes: 6ebe28f9ec72 ("cxl/mem: Read, trace, and clear events on driver load") Tested-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Kwangjin Ko <kwangjin.ko@sk.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-17cxl/core/regs: Fix usage of map->reg_type in cxl_decode_regblock() before ↵Dave Jiang1-2/+3
assigned [ Upstream commit 5c88a9ccd4c431d58b532e4158b6999a8350062c ] In the error path, map->reg_type is being used for kernel warning before its value is setup. Found by code inspection. Exposure to user is wrong reg_type being emitted via kernel log. Use a local var for reg_type and retrieve value for usage. Fixes: 6c7f4f1e51c2 ("cxl/core/regs: Make cxl_map_{component, device}_regs() device generic") Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-17cxl/mem: Fix for the index of Clear Event Record HandleYuquan Wang1-1/+1
[ Upstream commit b7c59b038c656214f56432867056997c2e0fc268 ] The dev_dbg info for Clear Event Records mailbox command would report the handle of the next record to clear not the current one. This was because the index 'i' had incremented before printing the current handle value. Fixes: 6ebe28f9ec72 ("cxl/mem: Read, trace, and clear events on driver load") Signed-off-by: Yuquan Wang <wangyuquan1236@phytium.com.cn> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03cxl/trace: Properly initialize cxl_poison region nameAlison Schofield1-7/+7
[ Upstream commit 6c871260965255a1c142fb77ccee58b172d1690b ] The TP_STRUCT__entry that gets assigned the region name, or an empty string if no region is present, is erroneously initialized to the cxl_region pointer. It needs to be properly initialized otherwise it's length is wrong and garbage chars can appear in the kernel trace output: /sys/kernel/tracing/trace The bad initialization was due in part to a naming conflict with the parameter: struct cxl_region *region. The field 'region' is already exposed externally as the region name, so changing that to something logical, like 'region_name' is not an option. Instead rename the internal only struct cxl_region to the commonly used 'cxlr'. Impact is that tooling depending on that trace data can miss picking up a valid event when searching by region name. The TP_printk() output, if enabled, does emit the correct region names in the dmesg log. This was found during testing of the cxl-list option to report media-errors for a region. Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: stable@vger.kernel.org Fixes: ddf49d57b841 ("cxl/trace: Add TRACE support for CXL media-error records") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26cxl/region: Allow out of order assembly of autodiscovered regionsAlison Schofield1-10/+38
[ Upstream commit cb66b1d60c283bb340a2fc19deff7de8acea74b1 ] Autodiscovered regions can fail to assemble if they are not discovered in HPA decode order. The user will see failure messages like: [] cxl region0: endpoint5: HPA order violation region1 [] cxl region0: endpoint5: failed to allocate region reference The check that is causing the failure helps the CXL driver enforce a CXL spec mandate that decoders be committed in HPA order. The check is needless for autodiscovered regions since their decoders are already programmed. Trying to enforce order in the assembly of these regions is useless because they are assembled once all their member endpoints arrive, and there is no guarantee on the order in which endpoints are discovered during probe. Keep the existing check, but for autodiscovered regions, allow the out of order assembly after a sanity check that the lesser numbered decoder has the lesser HPA starting address. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Tested-by: Wonjae Lee <wj28.lee@samsung.com> Link: https://lore.kernel.org/r/3dec69ee97524ab229a20c6739272c3000b18408.1706736863.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26cxl/region: Handle endpoint decoders in cxl_region_find_decoder()Alison Schofield1-6/+8
[ Upstream commit 453a7fde8031a5192ed2f9646ad048c1a5e930dc ] In preparation for adding a new caller of cxl_region_find_decoders() teach it to find a decoder from a cxl_endpoint_decoder structure. Combining switch and endpoint decoder lookup in one function prevents code duplication in call sites. Update the existing caller. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Tested-by: Wonjae Lee <wj28.lee@samsung.com> Link: https://lore.kernel.org/r/79ae6d72978ef9f3ceec9722e1cb793820553c8e.1706736863.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS windowRobert Richter1-3/+3
commit 0cab687205986491302cd2e440ef1d253031c221 upstream. The Linux CXL subsystem is built on the assumption that HPA == SPA. That is, the host physical address (HPA) the HDM decoder registers are programmed with are system physical addresses (SPA). During HDM decoder setup, the DVSEC CXL range registers (cxl-3.1, 8.1.3.8) are checked if the memory is enabled and the CXL range is in a HPA window that is described in a CFMWS structure of the CXL host bridge (cxl-3.1, 9.18.1.3). Now, if the HPA is not an SPA, the CXL range does not match a CFMWS window and the CXL memory range will be disabled then. The HDM decoder stops working which causes system memory being disabled and further a system hang during HDM decoder initialization, typically when a CXL enabled kernel boots. Prevent a system hang and do not disable the HDM decoder if the decoder's CXL range is not found in a CFMWS window. Note the change only fixes a hardware hang, but does not implement HPA/SPA translation. Support for this can be added in a follow on patch series. Signed-off-by: Robert Richter <rrichter@amd.com> Fixes: 34e37b4c432c ("cxl/port: Enable HDM Capability after validating DVSEC Ranges") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20240216160113.407141-1-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01cxl/acpi: Fix load failures due to single window creation failureDan Williams1-18/+28
commit 5c6224bfabbf7f3e491c51ab50fd2c6f92ba1141 upstream. The expectation is that cxl_parse_cfwms() continues in the face the of failure as evidenced by code like: cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb); if (IS_ERR(cxlrd)) return 0; There are other error paths in that function which mistakenly follow idiomatic expectations and return an error when they should not. Most of those mistakes are innocuous checks that hardly ever fail in practice. However, a recent change succeed in making the implementation more fragile by applying an idiomatic, but still wrong "fix" [1]. In this failure case the kernel reports: cxl root0: Failed to populate active decoder targets cxl_acpi ACPI0017:00: Failed to add decode range: [mem 0x00000000-0x7fffffff flags 0x200] ...which is a real issue with that one window (to be fixed separately), but ends up failing the entirety of cxl_acpi_probe(). Undo that recent breakage while also removing the confusion about ignoring errors. Update all exits paths to return an error per typical expectations and let an outer wrapper function handle dropping the error. Fixes: 91019b5bc7c2 ("cxl/acpi: Return 'rc' instead of '0' in cxl_parse_cfmws()") [1] Cc: <stable@vger.kernel.org> Cc: Breno Leitao <leitao@debian.org> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31cxl/region:Fix overflow issue in alloc_hpa()Quanquan Cao1-2/+2
commit d76779dd3681c01a4c6c3cae4d0627c9083e0ee6 upstream. Creating a region with 16 memory devices caused a problem. The div_u64_rem function, used for dividing an unsigned 64-bit number by a 32-bit one, faced an issue when SZ_256M * p->interleave_ways. The result surpassed the maximum limit of the 32-bit divisor (4G), leading to an overflow and a remainder of 0. note: At this point, p->interleave_ways is 16, meaning 16 * 256M = 4G To fix this issue, I replaced the div_u64_rem function with div64_u64_rem and adjusted the type of the remainder. Signed-off-by: Quanquan Cao <caoqq@fujitsu.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Fixes: 23a22cd1c98b ("cxl/region: Allocate HPA capacity to regions") Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25cxl/port: Fix missing target list lockDan Williams2-17/+7
[ Upstream commit 5459e186a5c9f412334321cff58d70dcb0e48a04 ] cxl_port_setup_targets() modifies the ->targets[] array of a switch decoder. target_list_show() expects to be able to emit a coherent snapshot of that array by "holding" ->target_lock for read. The target_lock is held for write during initialization of the ->targets[] array, but it is not held for write during cxl_port_setup_targets(). The ->target_lock() predates the introduction of @cxl_region_rwsem. That semaphore protects changes to host-physical-address (HPA) decode which is precisely what writes to a switch decoder's target list affects. Replace ->target_lock with @cxl_region_rwsem. Now the side-effect of snapshotting a unstable view of a decoder's target list is likely benign so the Fixes: tag is presumptive. Fixes: 27b3f8d13830 ("cxl/region: Program target lists") Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25cxl/region: fix x9 interleave typoJim Harris1-1/+1
[ Upstream commit c7ad3dc3649730af483ee1e78be5d0362da25bfe ] CXL supports x3, x6 and x12 - not x9. Fixes: 80d10a6cee050 ("cxl/region: Add interleave geometry attributes") Signed-off-by: Jim Harris <jim.harris@samsung.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Link: https://lore.kernel.org/r/169904271254.204936.8580772404462743630.stgit@ubuntu Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25cxl/port: Fix decoder initialization when nr_targets > interleave_waysHuang Ying1-1/+1
commit d6488fee66472b468ed88d265b14aa3f04dc3bdf upstream. The decoder_populate_targets() helper walks all of the targets in a port and makes sure they can be looked up in @target_map. Where @target_map is a lookup table from target position to target id (corresponding to a cxl_dport instance). However @target_map is only responsible for conveying the active dport instances as indicated by interleave_ways. When nr_targets > interleave_ways it results in decoder_populate_targets() walking off the end of the valid entries in @target_map. Given target_map is initialized to 0 it results in the dport lookup failing if position 0 is not mapped to a dport with an id of 0: cxl_port port3: Failed to populate active decoder targets cxl_port port3: Failed to add decoder cxl_port port3: Failed to add decoder3.0 cxl_bus_probe: cxl_port port3: probe: -6 This bug also highlights that when the decoder's ->targets[] array is written in cxl_port_setup_targets() it is missing a hold of the targets_lock to synchronize against sysfs readers of the target list. A fix for that is saved for a later patch. Fixes: a5c258021689 ("cxl/bus: Populate the target list at decoder create") Cc: <stable@vger.kernel.org> Signed-off-by: Huang, Ying <ying.huang@intel.com> [djbw: rewrite the changelog, find the Fixes: tag] Co-developed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-10cxl/memdev: Hold region_rwsem during inject and clear poison opsAlison Schofield1-2/+16
commit 0e33ac9c3ffe5e4f55c68345f44cea7fec2fe750 upstream. Poison inject and clear are supported via debugfs where a privileged user can inject and clear poison to a device physical address. Commit 458ba8189cb4 ("cxl: Add cxl_decoders_committed() helper") added a lockdep assert that highlighted a gap in poison inject and clear functions where holding the dpa_rwsem does not assure that a a DPA is not added to a region. The impact for inject and clear is that if the DPA address being injected or cleared has been attached to a region, but not yet committed, the dev_dbg() message intended to alert the debug user that they are acting on a mapped address is not emitted. Also, the cxl_poison trace event that serves as a log of the inject and clear activity will not include region info. Close this gap by snapshotting an unchangeable region state during poison inject and clear operations. That means holding both the region_rwsem and the dpa_rwsem during the inject and clear ops. Fixes: d2fbc4865802 ("cxl/memdev: Add support for the Inject Poison mailbox command") Fixes: 9690b07748d1 ("cxl/memdev: Add support for the Clear Poison mailbox command") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/08721dc1df0a51e4e38fecd02425c3475912dfd5.1701041440.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-10cxl/hdm: Fix a benign lockdep splatDave Jiang1-0/+2
commit 36a1c2ee50f573972aea3c3019555f47ee0094c0 upstream. The new helper "cxl_num_decoders_committed()" added a lockdep assertion to validate that port->commit_end is protected against modification. That assertion fires in init_hdm_decoder() where it is initializing port->commit_end. Given that it is both accessing and writing that property it obstensibly needs the lock. In practice, CXL decoder commit rules (must commit in order) and the in-order discovery of device decoders makes the manipulation of ->commit_end in init_hdm_decoder() safe. However, rather than rely on the subtle rules of CXL hardware, just make the implementation obviously correct from a software perspective. The Fixes: tag is only for cleaning up a lockdep splat, there is no functional issue addressed by this fix. Fixes: 458ba8189cb4 ("cxl: Add cxl_decoders_committed() helper") Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170025232811.2147250.16376901801315194121.stgit@djiang5-mobl3 Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-10cxl/pmu: Ensure put_device on pmu devicesIra Weiny1-1/+1
[ Upstream commit ef3d5cf9c59cccb012aa6b93d99f4c6eb5d6648e ] The following kmemleaks were detected when removing the cxl module stack: unreferenced object 0xffff88822616b800 (size 1024): ... backtrace: [<00000000bedc6f83>] kmalloc_trace+0x26/0x90 [<00000000448d1afc>] devm_cxl_pmu_add+0x3a/0x110 [cxl_core] [<00000000ca3bfe16>] 0xffffffffa105213b [<00000000ba7f78dc>] local_pci_probe+0x41/0x90 [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0 ... unreferenced object 0xffff8882260abcc0 (size 16): ... hex dump (first 16 bytes): 70 6d 75 5f 6d 65 6d 30 2e 30 00 26 82 88 ff ff pmu_mem0.0.&.... backtrace: ... [<00000000152b5e98>] dev_set_name+0x43/0x50 [<00000000c228798b>] devm_cxl_pmu_add+0x102/0x110 [cxl_core] [<00000000ca3bfe16>] 0xffffffffa105213b [<00000000ba7f78dc>] local_pci_probe+0x41/0x90 [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0 ... unreferenced object 0xffff8882272af200 (size 256): ... backtrace: [<00000000bedc6f83>] kmalloc_trace+0x26/0x90 [<00000000a14d1813>] device_add+0x4ea/0x890 [<00000000a3f07b47>] devm_cxl_pmu_add+0xbe/0x110 [cxl_core] [<00000000ca3bfe16>] 0xffffffffa105213b [<00000000ba7f78dc>] local_pci_probe+0x41/0x90 [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0 ... devm_cxl_pmu_add() correctly registers a device remove function but it only calls device_del() which is only part of device unregistration. Properly call device_unregister() to free up the memory associated with the device. Fixes: 1ad3f701c399 ("cxl/pci: Find and register CXL PMU devices") Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231016-pmu-unregister-fix-v1-1-1e2eb2fa3c69@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-10cxl/core: Always hold region_rwsem while reading poison listsAlison Schofield2-6/+8
[ Upstream commit 5558b92e8d39e18aa19619be2ee37274e9592528 ] A read of a device poison list is triggered via a sysfs attribute and the results are logged as kernel trace events of type cxl_poison. The work is managed by either: a) the region driver when one of more regions map the device, or by b) the memdev driver when no regions map the device. In the case of a) the region driver holds the region_rwsem while reading the poison by committed endpoint decoder mappings and for any unmapped resources. This makes sure that the cxl_poison trace event trace reports valid region info. (Region name, HPA, and UUID). In the case of b) the memdev driver holds the dpa_rwsem preventing new DPA resources from being attached to a region. However, it leaves a gap between region attach and decoder commit actions. If a DPA in the gap is in the poison list, the cxl_poison trace event will omit the region info. Close the gap by holding the region_rwsem and the dpa_rwsem when reading poison per memdev. Since both methods now hold both locks, down_read both from the caller. Doing so also addresses the lockdep assert that found this issue: Commit 458ba8189cb4 ("cxl: Add cxl_decoders_committed() helper") Fixes: f0832a586396 ("cxl/region: Provide region info to the cxl_poison trace event") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/08e8e7ec9a3413b91d51de39e385653494b1eed0.1701041440.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-10cxl: Add cxl_decoders_committed() helperDave Jiang5-6/+15
[ Upstream commit 458ba8189cb4380aa6a6cc4d52ab067f80a64829 ] Add a helper to retrieve the number of decoders committed for the port. Replace all the open coding of the calculation with the helper. Link: https://lore.kernel.org/linux-cxl/651c98472dfed_ae7e729495@dwillia2-xfh.jf.intel.com.notmuch/ Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jim Harris <jim.harris@samsung.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/169747906849.272156.1729290904857372335.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com> Stable-dep-of: 5558b92e8d39 ("cxl/core: Always hold region_rwsem while reading poison lists") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-20cxl/hdm: Fix dpa translation lockingDan Williams2-4/+3
commit 6f5c4eca48ffe18307b4e1d375817691c9005c87 upstream. The helper, cxl_dpa_resource_start(), snapshots the dpa-address of an endpoint-decoder after acquiring the cxl_dpa_rwsem. However, it is sufficient to assert that cxl_dpa_rwsem is held rather than acquire it in the helper. Otherwise, it triggers multiple lockdep reports: 1/ Tracing callbacks are in an atomic context that can not acquire sleeping locks: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1525 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1288, name: bash preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 [..] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc38 05/24/2023 Call Trace: <TASK> dump_stack_lvl+0x71/0x90 __might_resched+0x1b2/0x2c0 down_read+0x1a/0x190 cxl_dpa_resource_start+0x15/0x50 [cxl_core] cxl_trace_hpa+0x122/0x300 [cxl_core] trace_event_raw_event_cxl_poison+0x1c9/0x2d0 [cxl_core] 2/ The rwsem is already held in the inject poison path: WARNING: possible recursive locking detected 6.7.0-rc2+ #12 Tainted: G W OE N -------------------------------------------- bash/1288 is trying to acquire lock: ffffffffc05f73d0 (cxl_dpa_rwsem){++++}-{3:3}, at: cxl_dpa_resource_start+0x15/0x50 [cxl_core] but task is already holding lock: ffffffffc05f73d0 (cxl_dpa_rwsem){++++}-{3:3}, at: cxl_inject_poison+0x7d/0x1e0 [cxl_core] [..] Call Trace: <TASK> dump_stack_lvl+0x71/0x90 __might_resched+0x1b2/0x2c0 down_read+0x1a/0x190 cxl_dpa_resource_start+0x15/0x50 [cxl_core] cxl_trace_hpa+0x122/0x300 [cxl_core] trace_event_raw_event_cxl_poison+0x1c9/0x2d0 [cxl_core] __traceiter_cxl_poison+0x5c/0x80 [cxl_core] cxl_inject_poison+0x1bc/0x1e0 [cxl_core] This appears to have been an issue since the initial implementation and uncovered by the new cxl-poison.sh test [1]. That test is now passing with these changes. Fixes: 28a3ae4ff66c ("cxl/trace: Add an HPA to cxl_poison trace events") Link: http://lore.kernel.org/r/e4f2716646918135ddbadf4146e92abb659de734.1700615159.git.alison.schofield@intel.com [1] Cc: <stable@vger.kernel.org> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28cxl/port: Fix delete_endpoint() vs parent unregistration raceDan Williams1-15/+19
commit 8d2ad999ca3c64cb08cf6a58d227b9d9e746d708 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28cxl/region: Fix x1 root-decoder granularity calculationsJim Harris1-1/+8
commit 98a04c7aced2b43b3ac4befe216c4eecc7257d4b upstream. 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: "inte