Pull CXL (Compute Express Link) updates from Dave Jiang:
"The significant change of interest is the handling of soft reserved
memory conflict between CXL and HMEM. In essence CXL will be the first
to claim the soft reserved memory ranges that belongs to CXL and
attempt to enumerate them with best effort. If CXL is not able to
enumerate the ranges it will punt them to HMEM.
There are also MAINTAINERS email changes from Dan Williams and
Jonathan Cameron"
* tag 'cxl-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (37 commits)
MAINTAINERS: Update Jonathan Cameron's email address
cxl/hdm: Add support for 32 switch decoders
MAINTAINERS: Update address for Dan Williams
tools/testing/cxl: Enable replay of user regions as auto regions
cxl/region: Add a region sysfs interface for region lock status
tools/testing/cxl: Test dax_hmem takeover of CXL regions
tools/testing/cxl: Simulate auto-assembly failure
dax/hmem: Parent dax_hmem devices
dax/hmem: Fix singleton confusion between dax_hmem_work and hmem devices
dax/hmem: Reduce visibility of dax_cxl coordination symbols
cxl/region: Constify cxl_region_resource_contains()
cxl/region: Limit visibility of cxl_region_contains_resource()
dax/cxl: Fix HMEM dependencies
cxl/region: Fix use-after-free from auto assembly failure
cxl/core: Check existence of cxl_memdev_state in poison test
cxl/core: use cleanup.h for devm_cxl_add_dax_region
cxl/core/region: move dax region device logic into region_dax.c
cxl/core/region: move pmem region driver logic into region_pmem.c
dax/hmem, cxl: Defer and resolve Soft Reserved ownership
cxl/region: Add helper to check Soft Reserved containment by CXL regions
...
Per CXL r4.0 section 8.2.4.20.1. CXL host bridge and switch ports can
support 32 HDM decoders. Current implementation misses some decoders on
CXL host bridge and switch in the case that the value of Decoder Count
field in CXL HDM decoder Capability Register is greater than or equal to
9.
Update calculation implementation to ensure the decoder count calculation
is correct for CXL host bridge/switch ports.
Signed-off-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260321061459.1910205-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Refactor CXL core/region code to make region code more manageable by
splitting out DAX and PMEM code from RAM handling code.
cxl/core: use cleanup.h for devm_cxl_add_dax_region
cxl/core/region: move dax region device logic into region_dax.c
cxl/core/region: move pmem region driver logic into region_pmem.c
The series addresses conflicts between HMEM and CXL when handling Soft
Reserved memory ranges. CXL will try best effort in claiming the Soft
Reserved memory region that are CXL regions. If fails, it will punt
back to HMEM.
tools/testing/cxl: Test dax_hmem takeover of CXL regions
tools/testing/cxl: Simulate auto-assembly failure
dax/hmem: Parent dax_hmem devices
dax/hmem: Fix singleton confusion between dax_hmem_work and hmem devices
dax/hmem: Reduce visibility of dax_cxl coordination symbols
cxl/region: Constify cxl_region_resource_contains()
cxl/region: Limit visibility of cxl_region_contains_resource()
dax/cxl: Fix HMEM dependencies
cxl/region: Fix use-after-free from auto assembly failure
dax/hmem, cxl: Defer and resolve Soft Reserved ownership
cxl/region: Add helper to check Soft Reserved containment by CXL regions
dax: Track all dax_region allocations under a global resource tree
dax/cxl, hmem: Initialize hmem early and defer dax_cxl binding
dax/hmem: Gate Soft Reserved deferral on DEV_DAX_CXL
dax/hmem: Request cxl_acpi and cxl_pci before walking Soft Reserved ranges
dax/hmem: Factor HMEM registration into __hmem_register_device()
dax/bus: Use dax_region_put() in alloc_dax_region() error path
Prep patches for CXL type2 accelerator basic support
cxl/region: Factor out interleave granularity setup
cxl/region: Factor out interleave ways setup
cxl: Make region type based on endpoint type
cxl/pci: Remove redundant cxl_pci_find_port() call
cxl: Move pci generic code from cxl_pci to core/cxl_pci
cxl: export internal structs for external Type2 drivers
cxl: support Type2 when initializing cxl_dev_state
Add code to ensure the endpoint has completed initialization before
usage.
cxl/pci: Check memdev driver binding status in cxl_reset_done()
cxl/pci: Hold memdev lock in cxl_event_trace_record()
There are 3 scenarios that leads to a locked region:
1. A region is created on a root decoder with Fixed Device Confiuration
attribute.
2. CXL_HDM_DECODER0_CTRL_LOCK.
Both 1 & 1 are well described in:
commit 2230c4bdc4 ("cxl: Add handling of locked CXL decoder")
3) Platform that has region creation with PRMT address translation always
locks the region, regardless of the FIXED attribute or decoder ctrl bit.
Region locked means region destroy operations are not permitted. CXL
region driver returns -EPERM for region destroy operations.
Although the locked status of the corresponding root decoder implies the
region is also locked, exposing the region lock status directly to
userspace improves usability for users who may not be aware of this
relationship.
[ dj: Amended commit log with additional locking scenarios. ]
Signed-off-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260401124951.1290041-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
The dax_hmem dependency on cxl_region_contains_resource() is a one-off
special case. It is not suitable for other use cases.
Move the definition to the other CONFIG_CXL_REGION guarded definitions in
drivers/cxl/cxl.h and include that by a relative path include. This matches
what drivers/dax/cxl.c does for its limited private usage of CXL core
symbols.
Reduce the symbol export visibility from global to just dax_hmem, to
further clarify its applicability.
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>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260327052821.440749-4-dan.j.williams@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Before now, all CXL memdevs were assumed to have a mailbox-backed
cxl_memdev_state, so poison command checks could safely dereference
the @mds.
With the introduction of Type 2 devices, a memdev may not implement
a mailbox interface, and so there is no associated cxl_memdev_state.
Guard against this case by returning false when @mds is absent.
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Alejandro Lucero <alucerop@amd.com>
Link: https://patch.msgid.link/20260331005047.2813980-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
During the cxl_acpi probe process, it checks whether the cxl_nvb device
and driver have been attached. Currently, the startup priority of the
cxl_pmem driver is lower than that of the cxl_acpi driver. At this point,
the cxl_nvb driver has not yet been registered on the cxl_bus, causing
the attachment check to fail. This results in a failure to add the root
nvdimm bridge, leading to a cxl_acpi probe failure and ultimately
affecting the subsequent loading of cxl drivers. As a consequence, only
one mem device object exists on the cxl_bus, while the cxl_port device
objects and decoder device objects are missing.
The solution is to raise the startup priority of cxl_pmem to be higher
than that of cxl_acpi, ensuring that the cxl_pmem driver is registered
before the aforementioned attachment check occurs.
Co-developed-by: Wang Yinfeng <wangyinfeng@phytium.com.cn>
Signed-off-by: Wang Yinfeng <wangyinfeng@phytium.com.cn>
Signed-off-by: Cui Chao <cuichao1753@phytium.com.cn>
Fixes: e7e222ad73 ("cxl: Move devm_cxl_add_nvdimm_bridge() to cxl_pmem.ko")
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20260319074535.1709250-1-cuichao1753@phytium.com.cn
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
cxl_reset_done() accesses the endpoint of the corresponding CXL memdev
without endpoint validity checking. By default, cxlmd->endpoint is
initialized to -ENXIO, if cxl_reset_done() is triggered after the
corresponding CXL memdev probing failed, this results in access to an
invalid endpoint.
CXL subsystem can always check CXL memdev driver binding status to
confirm its endpoint validity. So adding the CXL memdev driver checking
inside cxl_reset_done() to avoid accessing an invalid endpoint.
Fixes: 934edcd436 ("cxl: Add post-reset warning if reset results in loss of previously committed HDM decoders")
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Li Ming <ming.li@zohomail.com>
Link: https://patch.msgid.link/20260314-fix_access_endpoint_without_drv_check-v2-4-4c09edf2e1db@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
cxl_event_config() invokes cxl_mem_get_event_record() to get remain
event logs from CXL device during cxl_pci_probe(). If CXL memdev probing
failed before that, it is possible to access an invalid endpoint. So
adding a cxlmd->driver binding status checking inside
cxl_dpa_to_region() to ensure the corresponding endpoint is valid.
Besides, cxl_event_trace_record() needs to hold memdev lock to invoke
cxl_dpa_to_region() to ensure the memdev probing completed. It is
possible that cxl_event_trace_record() is invoked during the CXL memdev
probing, especially user or cxl_acpi triggers CXL memdev re-probing.
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Li Ming <ming.li@zohomail.com>
Link: https://patch.msgid.link/20260314-fix_access_endpoint_without_drv_check-v2-3-4c09edf2e1db@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Check the global CXL_HDM_DECODER_ENABLE bit instead of looping over
per-decoder COMMITTED bits to determine whether to fall back to DVSEC
range emulation. When the HDM decoder capability is globally enabled,
ignore DVSEC range registers regardless of individual decoder commit
state.
should_emulate_decoders() currently loops over per-decoder COMMITTED
bits, which leads to an incorrect DVSEC fallback when those bits are
zero. One way to trigger this is to destroy a region and bounce the
memdev:
cxl disable-region region0
cxl destroy-region region0
cxl disable-memdev mem0
cxl enable-memdev mem0
Region teardown zeroes the HDM decoder registers including the committed
bits. The subsequent memdev re-probe finds uncommitted decoders and falls
back to DVSEC emulation, even though HDM remains globally enabled.
Observed failures:
should_emulate_decoders: cxl_port endpoint6: decoder6.0: committed: 0 base: 0x0_00000000 size: 0x0_00000000
devm_cxl_setup_hdm: cxl_port endpoint6: Fallback map 1 range register
..
devm_cxl_add_region: cxl_acpi ACPI0017:00: decoder0.0: created region0
__construct_region: cxl_pci 0000:e1:00.0: mem1:decoder6.0:
__construct_region region0 res: [mem 0x850000000-0x284fffffff flags 0x200] iw: 1 ig: 4096
cxl region0: pci0000:e0:port1 cxl_port_setup_targets expected iw: 1 ig: 4096 ..
cxl region0: pci0000:e0:port1 cxl_port_setup_targets got iw: 1 ig: 256 state: disabled ..
cxl_port endpoint6: failed to attach decoder6.0 to region0: -6
..
devm_cxl_add_region: cxl_acpi ACPI0017:00: decoder0.0: created region4
alloc_hpa: cxl region4: HPA allocation error (-34) ..
Fixes: 52cc48ad2a ("cxl/hdm: Limit emulation to the number of range registers")
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20260316201950.224567-1-Smita.KoralahalliChannabasappa@amd.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Linus Torvalds
Dave Jiang
Li MingandDave Jiang
Dan WilliamsandDave Jiang
Alison SchofieldandDave Jiang
Gregory PriceandDave Jiang
Smita KoralahalliandDave Jiang
Cui ChaoandDave Jiang
Davidlohr BuesoandDave Jiang
Alejandro LuceroandDave Jiang