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path: root/drivers/cxl/core/region.c
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2025-01-13Merge 6.13-rc7 into driver-core-nextGreg Kroah-Hartman
We need the debugfs / driver-core fixes in here as well for testing and to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: Correct API device_for_each_child_reverse_from() prototypeZijun Hu
For API device_for_each_child_reverse_from(..., const void *data, int (*fn)(struct device *dev, const void *data)) - Type of @data is const pointer, and means caller's data @*data is not allowed to be modified, but that usually is not proper for such non finding device iterating API. - Types for both @data and @fn are not consistent with all other for_each device iterating APIs device_for_each_child(_reverse)(), bus_for_each_dev() and (driver|class)_for_each_device(). Correct its prototype by removing const from parameter types, then adapt for various existing usages. An dedicated typedef device_iter_t will be introduced as @fn() type for various for_each device interating APIs later. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-6-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-03driver core: Constify API device_find_child() and adapt for various usagesZijun Hu
Constify the following API: struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); To : struct device *device_find_child(struct device *dev, const void *data, device_match_t match); typedef int (*device_match_t)(struct device *dev, const void *data); with the following reasons: - Protect caller's match data @*data which is for comparison and lookup and the API does not actually need to modify @*data. - Make the API's parameters (@match)() and @data have the same type as all of other device finding APIs (bus|class|driver)_find_device(). - All kinds of existing device match functions can be directly taken as the API's argument, they were exported by driver core. Constify the API and adapt for various existing usages. BTW, various subsystem changes are squashed into this commit to meet 'git bisect' requirement, and this commit has the minimal and simplest changes to complement squashing shortcoming, and that may bring extra code improvement. Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-10cxl/region: Fix region creation for greater than x2 switchesHuaisheng Ye
The cxl_port_setup_targets() algorithm fails to identify valid target list ordering in the presence of 4-way and above switches resulting in 'cxl create-region' failures of the form: $ cxl create-region -d decoder0.0 -g 1024 -s 2G -t ram -w 8 -m mem4 mem1 mem6 mem3 mem2 mem5 mem7 mem0 cxl region: create_region: region0: failed to set target7 to mem0 cxl region: cmd_create_region: created 0 regions [kernel debug message] check_last_peer:1213: cxl region0: pci0000:0c:port1: cannot host mem6:decoder7.0 at 2 bus_remove_device:574: bus: 'cxl': remove device region0 QEMU can create this failing topology: ACPI0017:00 [root0] | HB_0 [port1] / \ RP_0 RP_1 | | USP [port2] USP [port3] / / \ \ / / \ \ DSP DSP DSP DSP DSP DSP DSP DSP | | | | | | | | mem4 mem6 mem2 mem7 mem1 mem3 mem5 mem0 Pos: 0 2 4 6 1 3 5 7 HB: Host Bridge RP: Root Port USP: Upstream Port DSP: Downstream Port ...with the following command steps: $ qemu-system-x86_64 -machine q35,cxl=on,accel=tcg \ -smp cpus=8 \ -m 8G \ -hda /home/work/vm-images/centos-stream8-02.qcow2 \ -object memory-backend-ram,size=4G,id=m0 \ -object memory-backend-ram,size=4G,id=m1 \ -object memory-backend-ram,size=2G,id=cxl-mem0 \ -object memory-backend-ram,size=2G,id=cxl-mem1 \ -object memory-backend-ram,size=2G,id=cxl-mem2 \ -object memory-backend-ram,size=2G,id=cxl-mem3 \ -object memory-backend-ram,size=2G,id=cxl-mem4 \ -object memory-backend-ram,size=2G,id=cxl-mem5 \ -object memory-backend-ram,size=2G,id=cxl-mem6 \ -object memory-backend-ram,size=2G,id=cxl-mem7 \ -numa node,memdev=m0,cpus=0-3,nodeid=0 \ -numa node,memdev=m1,cpus=4-7,nodeid=1 \ -netdev user,id=net0,hostfwd=tcp::2222-:22 \ -device virtio-net-pci,netdev=net0 \ -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \ -device cxl-rp,port=0,bus=cxl.1,id=root_port0,chassis=0,slot=0 \ -device cxl-rp,port=1,bus=cxl.1,id=root_port1,chassis=0,slot=1 \ -device cxl-upstream,bus=root_port0,id=us0 \ -device cxl-downstream,port=0,bus=us0,id=swport0,chassis=0,slot=4 \ -device cxl-type3,bus=swport0,volatile-memdev=cxl-mem0,id=cxl-vmem0 \ -device cxl-downstream,port=1,bus=us0,id=swport1,chassis=0,slot=5 \ -device cxl-type3,bus=swport1,volatile-memdev=cxl-mem1,id=cxl-vmem1 \ -device cxl-downstream,port=2,bus=us0,id=swport2,chassis=0,slot=6 \ -device cxl-type3,bus=swport2,volatile-memdev=cxl-mem2,id=cxl-vmem2 \ -device cxl-downstream,port=3,bus=us0,id=swport3,chassis=0,slot=7 \ -device cxl-type3,bus=swport3,volatile-memdev=cxl-mem3,id=cxl-vmem3 \ -device cxl-upstream,bus=root_port1,id=us1 \ -device cxl-downstream,port=4,bus=us1,id=swport4,chassis=0,slot=8 \ -device cxl-type3,bus=swport4,volatile-memdev=cxl-mem4,id=cxl-vmem4 \ -device cxl-downstream,port=5,bus=us1,id=swport5,chassis=0,slot=9 \ -device cxl-type3,bus=swport5,volatile-memdev=cxl-mem5,id=cxl-vmem5 \ -device cxl-downstream,port=6,bus=us1,id=swport6,chassis=0,slot=10 \ -device cxl-type3,bus=swport6,volatile-memdev=cxl-mem6,id=cxl-vmem6 \ -device cxl-downstream,port=7,bus=us1,id=swport7,chassis=0,slot=11 \ -device cxl-type3,bus=swport7,volatile-memdev=cxl-mem7,id=cxl-vmem7 \ -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=32G & In Guest OS: $ cxl create-region -d decoder0.0 -g 1024 -s 2G -t ram -w 8 -m mem4 mem1 mem6 mem3 mem2 mem5 mem7 mem0 Fix the method to calculate @distance by iterativeley multiplying the number of targets per switch port. This also follows the algorithm recommended here [1]. Fixes: 27b3f8d13830 ("cxl/region: Program target lists") Link: http://lore.kernel.org/6538824b52349_7258329466@dwillia2-xfh.jf.intel.com.notmuch [1] Signed-off-by: Huaisheng Ye <huaisheng.ye@intel.com> Tested-by: Li Zhijian <lizhijian@fujitsu.com> [djbw: add a comment explaining 'distance'] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/173378716722.1270362.9546805175813426729.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-12-02module: Convert symbol namespace to string literalPeter Zijlstra
Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-11-22Merge tag 'cxl-for-6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl updates from Dave Jiang: - Constify range_contains() input parameters to prevent changes - Add support for displaying RCD capabilities in sysfs to support lspci for CXL device - Downgrade warning message to debug in cxl_probe_component_regs() - Add support for adding a printf specifier '%pra' to emit 'struct range' content: - Add sanity tests for 'struct resource' - Add documentation for special case - Add %pra for 'struct range' - Add %pra usage in CXL code - Add preparation code for DCD support: - Add range_overlaps() - Add CDAT DSMAS table shared and read only flag in ACPICA - Add documentation to 'struct dev_dax_range' - Delay event buffer allocation in CXL PCI code until needed - Use guard() in cxl_dpa_set_mode() - Refactor create region code to consolidate common code * tag 'cxl-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/region: Refactor common create region code cxl/hdm: Use guard() in cxl_dpa_set_mode() cxl/pci: Delay event buffer allocation dax: Document struct dev_dax_range ACPI/CDAT: Add CDAT/DSMAS shared and read only flag values range: Add range_overlaps() cxl/cdat: Use %pra for dpa range outputs printf: Add print format (%pra) for struct range Documentation/printf: struct resource add start == end special case test printf: Add very basic struct resource tests cxl: downgrade a warning message to debug level in cxl_probe_component_regs() cxl/pci: Add sysfs attribute for CXL 1.1 device link status cxl/core/regs: Add rcd_pcie_cap initialization kernel/range: Const-ify range_contains parameters
2024-11-08cxl/region: Refactor common create region codeIra Weiny
create_pmem_region_store() and create_ram_region_store() are identical with the exception of the region mode. With the addition of DC region mode this would end up being 3 copies of the same code. Refactor create_pmem_region_store() and create_ram_region_store() to use a single common function to be used in subsequent DC code. Suggested-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Li Ming <ming4.li@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/20241107-dcd-type2-upstream-v7-6-56a84e66bc36@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-10-25cxl/port: Prevent out-of-order decoder allocationDan Williams
With the recent change to allow out-of-order decoder de-commit it highlights a need to strengthen the in-order decoder commit guarantees. As it stands match_free_decoder() ensures that if 2 regions are racing decoder allocations the one that wins the race will get the lower id decoder, but that still leaves the race to *commit* the decoder. Rather than have this complicated case of "reserved in-order, but may still commit out-of-order", just arrange for the reservation order to match the commit-order. In other words, prevent subsequent allocations until the last reservation is committed. This precludes overlapping region creation events and requires the previous regionN to either move forward to the decoder commit stage or drop its reservation before regionN+1 can move forward. That is, provided that regionN and regionN+1 decode through the same switch port. As a side effect this allows match_free_decoder() to drop its dependency on needing write access to the device_find_child() @data parameter [1]. Reported-by: Zijun Hu <quic_zijuhu@quicinc.com> Closes: http://lore.kernel.org/20240905-const_dfc_prepare-v4-0-4180e1d5a244@quicinc.com Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/172964783668.81806.14962699553881333486.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com>
2024-10-25cxl/port: Fix use-after-free, permit out-of-order decoder shutdownDan Williams
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>
2024-09-22cxl: Calculate region bandwidth of targets with shared upstream linkDave Jiang
The current bandwidth calculation aggregates all the targets. This simple method does not take into account where multiple targets sharing under a switch or a root port where the aggregated bandwidth can be greater than the upstream link of the switch. To accurately account for the shared upstream uplink cases, a new update function is introduced by walking from the leaves to the root of the hierarchy and clamp the bandwidth in the process as needed. This process is done when all the targets for a region are present but before the final values are send to the HMAT handling code cached access_coordinate targets. The original perf calculation path was kept to calculate the latency performance data that does not require the shared link consideration. The shared upstream link calculation is done as a second pass when all the endpoints have arrived. Testing is done via qemu with CXL hierarchy. run_qemu[1] is modified to support several CXL hierarchy layouts. The following layouts are tested: HB: Host Bridge RP: Root Port SW: Switch EP: End Point 2 HB 2 RP 2 EP: resulting bandwidth: 624 1 HB 2 RP 2 EP: resulting bandwidth: 624 2 HB 2 RP 2 SW 4 EP: resulting bandwidth: 624 Current testing, perf number from SRAT/HMAT is hacked into the kernel code. However with new QEMU support of Generic Target Port that's incoming, the perf data injection is no longer needed. [1]: https://github.com/pmem/run_qemu Suggested-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://lore.kernel.org/linux-cxl/20240501152503.00002e60@Huawei.com/ Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20240904001316.1688225-3-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-09cxl/region: Remove lock from memory notifier callbackIra Weiny
In testing Dynamic Capacity Device (DCD) support, a lockdep splat revealed an ABBA issue between the memory notifiers and the DCD extent processing code.[0] Changing the lock ordering within DCD proved difficult because regions must be stable while searching for the proper region and then the device lock must be held to properly notify the DAX region driver of memory changes. Dan points out in the thread that notifiers should be able to trust that it is safe to access static data. Region data is static once the device is realized and until it's destruction. Thus it is better to manage the notifiers within the region driver. Remove the need for a lock by ensuring the notifiers are active only during the region's lifetime. Furthermore, remove cxl_region_nid() because resource can't be NULL while the region is stable. Link: https://lore.kernel.org/all/66b4cf539a79b_a36e829416@iweiny-mobl.notmuch/ [0] Cc: Ying Huang <ying.huang@intel.com> Suggested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ying Huang <ying.huang@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/20240904-fix-notifiers-v3-1-576b4e950266@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-03cxl/port: Use scoped_guard()/guard() to drop device_lock() for cxl_portLi Ming
A device_lock() and device_unlock() pair can be replaced by a cleanup helper scoped_guard() or guard(), that can enhance code readability. In CXL subsystem, still use device_lock() and device_unlock() pairs for cxl port resource protection, most of them can be replaced by a scoped_guard() or a guard() simply. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Ming <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240830013138.2256244-2-ming4.li@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-07-28Merge tag 'cxl-for-6.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull CXL updates from Dave Jiang: "Core: - A CXL maturity map has been added to the documentation to detail the current state of CXL enabling. It provides the status of the current state of various CXL features to inform current and future contributors of where things are and which areas need contribution. - A notifier handler has been added in order for a newly created CXL memory region to trigger the abstract distance metrics calculation. This should bring parity for CXL memory to the same level vs hotplugged DRAM for NUMA abstract distance calculation. The abstract distance reflects relative performance used for memory tiering handling. - An addition for XOR math has been added to address the CXL DPA to SPA translation. CXL address translation did not support address interleave math with XOR prior to this change. Fixes: - Fix to address race condition in the CXL memory hotplug notifier - Add missing MODULE_DESCRIPTION() for CXL modules - Fix incorrect vendor debug UUID define Misc: - A warning has been added to inform users of an unsupported configuration when mixing CXL VH and RCH/RCD hierarchies - The ENXIO error code has been replaced with EBUSY for inject poison limit reached via debugfs and cxl-test support - Moving the PCI config read in cxl_dvsec_rr_decode() to avoid unnecessary PCI config reads - A refactor to a common struct for DRAM and general media CXL events" * tag 'cxl-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/core/pci: Move reading of control register to immediately before usage cxl: Remove defunct code calculating host bridge target positions cxl/region: Verify target positions using the ordered target list cxl: Restore XOR'd position bits during address translation cxl/core: Fold cxl_trace_hpa() into cxl_dpa_to_hpa() cxl/test: Replace ENXIO with EBUSY for inject poison limit reached cxl/memdev: Replace ENXIO with EBUSY for inject poison limit reached cxl/acpi: Warn on mixed CXL VH and RCH/RCD Hierarchy cxl/core: Fix incorrect vendor debug UUID define Documentation: CXL Maturity Map cxl/region: Simplify cxl_region_nid() cxl/region: Support to calculate memory tier abstract distance cxl/region: Fix a race condition in memory hotplug notifier cxl: add missing MODULE_DESCRIPTION() macros cxl/events: Use a common struct for DRAM and General Media events
2024-07-11Merge branch 'for-6.11/xor_fixes' into cxl-for-nextDave Jiang
Series to fix XOR math for DPA to SPA translation - Refactor and fold cxl_trace_hpa() into cxl_dpa_to_hpa() - Complete DPA->HPA->SPA translation and correct XOR translation issue - Add new method to verify a CXL target position - Remove old method of CXL target position verifiation
2024-07-11cxl/region: Verify target positions using the ordered target listAlison Schofield
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>
2024-07-11cxl: Restore XOR'd position bits during address translationAlison Schofield
When a device reports a DPA in events like poison, general_media, and dram, the driver translates that DPA back to an HPA. Presently, the CXL driver translation only considers the Modulo position and will report the wrong HPA for XOR configured root decoders. Add a helper function that restores the XOR'd bits during DPA->HPA address translation. Plumb a root decoder callback to the new helper when XOR interleave arithmetic is in use. For Modulo arithmetic, just let the callback be NULL - as in no extra work required. Upon completion of a DPA->HPA translation a couple of checks are performed on the result. One simply confirms that the calculated HPA is within the address range of the region. That test is useful for both Modulo and XOR interleave arithmetic decodes. A second check confirms that the HPA is within an expected chunk based on the endpoints position in the region and the region granularity. An XOR decode disrupts the Modulo pattern making the chunk check useless. To align the checks with the proper decode, pull the region range check inline and use the helper to do the chunk check for Modulo decodes only. A cxl-test unit test is posted for upstream review here: https://lore.kernel.org/20240624210644.495563-1-alison.schofield@intel.com/ Fixes: 28a3ae4ff66c ("cxl/trace: Add an HPA to cxl_poison trace events") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Tested-by: Diego Garcia Rodriguez <diego.garcia.rodriguez@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/1a1ac880d9f889bd6384e657e810431b9a0a72e5.1719980933.git.alison.schofield@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-07-11cxl/core: Fold cxl_trace_hpa() into cxl_dpa_to_hpa()Alison Schofield
Although cxl_trace_hpa() is used to populate TRACE EVENTs with HPA addresses the work it performs is a DPA to HPA translation not a trace. Tidy up this naming by moving the minimal work done in cxl_trace_hpa() into cxl_dpa_to_hpa() and use cxl_dpa_to_hpa() for trace event callbacks. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Robert Richter <rrichter@amd.com> Link: https://patch.msgid.link/452a9b0c525b774c72d9d5851515ffa928750132.1719980933.git.alison.schofield@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-07-02cxl/region: Simplify cxl_region_nid()Huang Ying
The node ID of the region can be gotten via resource start address directly. This simplifies the implementation of cxl_region_nid(). Signed-off-by: Huang Ying <ying.huang@intel.com> Suggested-by: Alison Schofield <alison.schofield@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240618084639.1419629-4-ying.huang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-07-02cxl/region: Support to calculate memory tier abstract distanceHuang Ying
An abstract distance value must be assigned by the driver that makes the memory available to the system. It reflects relative performance and is used to place memory nodes backed by CXL regions in the appropriate memory tiers allowing promotion/demotion within the existing memory tiering mechanism. The abstract distance is calculated based on the memory access latency and bandwidth of CXL regions. Signed-off-by: Huang, Ying <ying.huang@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240618084639.1419629-3-ying.huang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-07-02cxl/region: Fix a race condition in memory hotplug notifierHuang Ying
In the memory hotplug notifier function of the CXL region, cxl_region_perf_attrs_callback(), the node ID is obtained by checking the host address range of the region. However, the address range information is not available when the region is registered in devm_cxl_add_region(). Additionally, this information may be removed or added under the protection of cxl_region_rwsem during runtime. If the memory notifier is called for nodes other than that backed by the region, a race condition may occur, potentially leading to a NULL dereference or an invalid address range. The race condition is addressed by checking the availability of the address range information under the protection of cxl_region_rwsem. To enhance code readability and use guard(), the relevant code has been moved into a newly added function: cxl_region_nid(). Fixes: 067353a46d8c ("cxl/region: Add memory hotplug notifier for cxl region") Signed-off-by: Huang, Ying <ying.huang@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240618084639.1419629-2-ying.huang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-06-25cxl/region: check interleave capabilityYao Xingtao
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>
2024-06-25cxl/region: Avoid null pointer dereference in region lookupAlison Schofield
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>
2024-06-18cxl/mem: Fix no cxl_nvd during pmem region auto-assemblingLi Ming
When CXL subsystem is auto-assembling a pmem region during cxl endpoint port probing, always hit below calltrace. BUG: kernel NULL pointer dereference, address: 0000000000000078 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:cxl_pmem_region_probe+0x22e/0x360 [cxl_pmem] Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? do_user_addr_fault+0x65/0x6b0 ? exc_page_fault+0x7d/0x170 ? asm_exc_page_fault+0x26/0x30 ? cxl_pmem_region_probe+0x22e/0x360 [cxl_pmem] ? cxl_pmem_region_probe+0x1ac/0x360 [cxl_pmem] cxl_bus_probe+0x1b/0x60 [cxl_core] really_probe+0x173/0x410 ? __pfx___device_attach_driver+0x10/0x10 __driver_probe_device+0x80/0x170 driver_probe_device+0x1e/0x90 __device_attach_driver+0x90/0x120 bus_for_each_drv+0x84/0xe0 __device_attach+0xbc/0x1f0 bus_probe_device+0x90/0xa0 device_add+0x51c/0x710 devm_cxl_add_pmem_region+0x1b5/0x380 [cxl_core] cxl_bus_probe+0x1b/0x60 [cxl_core] The cxl_nvd of the memdev needs to be available during the pmem region probe. Currently the cxl_nvd is registered after the endpoint port probe. The endpoint probe, in the case of autoassembly of regions, can cause a pmem region probe requiring the not yet available cxl_nvd. Adjust the sequence so this dependency is met. This requires adding a port parameter to cxl_find_nvdimm_bridge() that can be used to query the ancestor root port. The endpoint port is not yet available, but will share a common ancestor with its parent, so start the query from there instead. Fixes: f17b558d6663 ("cxl/pmem: Refactor nvdimm device registration, delete the workqueue") Co-developed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Ming <ming4.li@intel.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240612064423.2567625-1-ming4.li@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-05-28cxl/region: Fix memregion leaks in devm_cxl_add_region()Li Zhijian
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>
2024-05-01cxl/region: Convert cxl_pmem_region_alloc to scope-based resource managementDan Williams
A recent bugfix to cxl_pmem_region_alloc() to fix an error-unwind-memleak [1], highlighted a use case for scope-based resource management. Delete the goto for releasing @cxl_region_rwsem, and return error codes directly from error condition paths. The caller, devm_cxl_add_pmem_region(), is no longer given @cxlr_pmem directly it must retrieve it from @cxlr->cxlr_pmem. This retrieval from @cxlr was already in place for @cxlr->cxl_nvb, and converting cxl_pmem_region_alloc() to return an int makes it less awkward to handle no_free_ptr(). Cc: Li Zhijian <lizhijian@fujitsu.com> Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Closes: http://lore.kernel.org/r/20240430174540.000039ce@Huawei.com Link: http://lore.kernel.org/r/20240428030748.318985-1-lizhijian@fujitsu.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/171451430965.1147997.15782562063090960666.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-04-30cxl/region: Fix cxlr_pmem leaksLi Zhijian
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>
2024-04-30cxl/region: Move cxl_trace_hpa() work to the region driverAlison Schofield
This work 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/183222631f11a43c5e6debc42ec22fe1bd4b818a.1714496730.git.alison.schofield@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-04-30cxl/region: Move cxl_dpa_to_region() work to the region driverAlison Schofield
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>
2024-03-12cxl/region: Deal with numa nodes not enumerated by SRATDave Jiang
For the numa nodes that are not created by SRAT, no memory_target is allocated and is not managed by the HMAT_REPORTING code. Therefore hmat_callback() memory hotplug notifier will exit early on those NUMA nodes. The CXL memory hotplug notifier will need to call node_set_perf_attrs() directly in order to setup the access sysfs attributes. In acpi_numa_init(), the last proximity domain (pxm) id created by SRAT is stored. Add a helper function acpi_node_backed_by_real_pxm() in order to check if a NUMA node id is defined by SRAT or created by CFMWS. node_set_perf_attrs() symbol is exported to allow update of perf attribs for a node. The sysfs path of /sys/devices/system/node/nodeX/access0/initiators/* is created by node_set_perf_attrs() for the various attributes where nodeX is matched to the NUMA node of the CXL region. Cc: Rafael J. Wysocki <rafael@kernel.org> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20240308220055.2172956-13-dave.jiang@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-03-12cxl/region: Add memory hotplug notifier for cxl regionDave Jiang
When the CXL region is formed, the driver computes the performance data for the region. However this data is not available at the node data collection that has been populated by the HMAT during kernel initialization. Add a memory hotplug notifier to update the access coordinates to the 'struct memory_target' context kept by the HMAT_REPORTING code. Add CXL_CALLBACK_PRI for a memory hotplug callback priority. Set the priority number to be called before HMAT_CALLBACK_PRI. The CXL update must happen before hmat_callback(). A new HMAT_REPORTING helper hmat_update_target_coordinates() is added in order to allow CXL to update the memory_target access coordinates. A new ext_updated member is added to the memory_target to indicate that the access coordinates within the memory_target has been updated by an external agent such as CXL. This prevents data being overwritten by the hmat_update_target_attrs() triggered by hmat_callback(). Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Reviewed-by: Huang, Ying <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20240308220055.2172956-12-dave.jiang@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-03-12cxl/region: Add sysfs attribute for locality attributes of CXL regionsDave Jiang
Add read/write latencies and bandwidth sysfs attributes for the enabled CXL region. The bandwidth is the aggregated bandwidth of all devices that contribute to the CXL region. The latency is the worst latency of the device amongst all the devices that contribute to the CXL region. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20240308220055.2172956-11-dave.jiang@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-03-12cxl/region: Calculate performance data for a regionDave Jiang
Calculate and store the performance data for a CXL region. Find the worst read and write latency for all the included ranges from each of the devices that attributes to the region and designate that as the latency data. Sum all the read and write bandwidth data for each of the device region and that is the total bandwidth for the region. The perf list is expected to be constructed before the endpoint decoders are registered and thus there should be no early reading of the entries from the region assemble action. The calling of the region qos calculate function is under the protection of cxl_dpa_rwsem and will ensure that all DPA associated work has completed. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20240308220055.2172956-10-dave.jiang@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-02-16cxl/region: Allow out of order assembly of autodiscovered regionsAlison Schofield
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>
2024-02-16cxl/region: Handle endpoint decoders in cxl_region_find_decoder()Alison Schofield
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>
2024-01-24cxl/region:Fix overflow issue in alloc_hpa()Quanquan Cao
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>
2024-01-05Merge branch 'for-6.8/cxl-misc' into for-6.8/cxlDan Williams
Pick up some miscellaneous fixups for v6.8.
2024-01-03cxl/region: fix x9 interleave typoJim Harris
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>
2024-01-02Merge branch 'for-6.8/cxl-cdat' into for-6.8/cxlDan Williams
Pick up the CDAT parsing and QOS class infrastructure for v6.8.
2024-01-02cxl/region: use %pap format to print resource_size_tRandy Dunlap
Use "%pap" to print a resource_size_t (phys_addr_t derived type) to prevent build warnings on 32-bit arches (seen on i386 and riscv-32). ../drivers/cxl/core/region.c: In function 'alloc_hpa': ../drivers/cxl/core/region.c:556:25: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 5 has type 'resource_size_t' {aka 'unsigned int'} [-Wformat=] 556 | "HPA allocation error (%ld) for size:%#llx in %s %pr\n", Fixes: 7984d22f1315 ("cxl/region: Add dev_dbg() detail on failure to allocate HPA space") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Fan Ni <fan.ni@samsung.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <linux-cxl@vger.kernel.org> Link: https://lore.kernel.org/r/20240102173917.19718-1-rdunlap@infradead.org Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-24cxl/region: Add dev_dbg() detail on failure to allocate HPA spaceAlison Schofield
When the region driver fails while allocating HPA space for a new region it can be because the parent resource, the CXL Window, has no more available space. In that case, the debug user sees this message: cxl_core:alloc_hpa:555: cxl region2: failed to allocate HPA: -34 Expand the message like this: cxl_core:alloc_hpa:555: cxl region8: HPA allocation error (-34) for size:0x20000000 in CXL Window 0 [mem 0xf010000000-0xf04fffffff flags 0x200] Now the debug user can examine /proc/iomem and consider actions like removing other allocations in that space or reducing the size of their region request. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Link: https://lore.kernel.org/r/20231223004740.1401858-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-18cxl: Fix unregister_region() callback parameter assignmentDave Jiang
In devm_cxl_add_region(), devm_add_action_or_reset() is called by passing in unregister_region() with data ptr of 'cxlr'. However, in unregister_region(), the passed in parameter is incorrectly assumed to be a 'struct device' rather than the 'cxlr' pointer. The code has been working because 'struct device' is the first member of 'struct cxl_region'. Issue found by inspection. Fix the assignment so that cxlr is pointing directly to the passed in parameter. Not flagged for -stable since there is no functional impact of this fix. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/170258123810.952211.3907381447996426480.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-11-29cxl/core: Always hold region_rwsem while reading poison listsAlison Schofield
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>
2023-10-31cxl/hdm: Remove broken error pathDan Williams
Dan reports that cxl_decoder_commit() potentially leaks a hold of cxl_dpa_rwsem. The potential error case is a "should not" happen scenario, turn it into a "can not" happen scenario by adding the error check to cxl_port_setup_targets() where other setting validation occurs. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: http://lore.kernel.org/r/63295673-5d63-4919-b851-3b06d48734c0@moroto.mountain Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-31Merge branch 'for-6.7/cxl' into cxl/nextDan Williams
Pickup some misc. CXL updates for v6.7.
2023-10-27cxl/region: Fix x1 root-decoder granularity calculationsJim Harris
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 Zhijian
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 Schofield
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 Schofield
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 Schofield
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>
2023-10-24cxl/region: Do not try to cleanup after cxl_region_setup_targets() failsJim Harris
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>