CXL test environment hits the following error sometimes.
cxl_mem mem9: endpoint7 failed probe
All mock memdevs are platform firmware devices added by cxl_test module,
and cxl_test module also provides a platform device driver for them to
create a memdev device to CXL subsystem. cxl_test module uses
cxl_rcd/mem_single/mem arrays to store different types of mock memdevs.
CXL drivers calls registered mock functions for a mock memdev by
checking if a given memdev is in these arrays.
When cxl_test module adds these mock memdevs, it always calls
platform_device_add() before adding them to a suitable mock memdev
array. However, there is a small window where CXL drivers calls mock
function for a added memdev before it added to a mock memdev array. In
above case, cxl endpoint driver considers a added memdev was not a mock
memdev, then calling devm_cxl_endpoint_decoders_setup() for it rather
than mock_endpoint_decoders_setup().
An appropriate solution is that adding a new mock device to a mock
device array before calling platform_device_add() for it. It can
guarantee the new mock device is visible to CXL subsystem.
This patch introduces a new helped called cxl_mock_platform_device_add()
to handle the issue, and uses the function for all mock devices addition.
Fixes: 3a2b97b321 ("cxl/test: Improve init-order fidelity relative to real-world systems")
Signed-off-by: Li Ming <ming.li@zohomail.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260520121457.234404-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
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
The cxl_test module currently hard-codes auto regions in the mock
topology, limiting coverage of the driver's region auto-assembly
logic.
Teach cxl_test to replay previously committed decoder programming
across a cxl_acpi unbind/bind cycle. Decoder programming is recorded
in a registry keyed by a stable port identity and decoder id. The
registry is updated on decoder commit and reset events and consulted
during enumeration to restore previously enabled decoders.
This allows regions created through the user interface to be replayed
during enumeration and treated as auto-discovered regions, enabling
testing of region auto-assembly using configurations created in the
cxl_test topology.
Example workflow:
# cxl create-region ...
# echo 1 > /sys/bus/platform/devices/cxl_acpi.0/decoder_reset_preserve_registry
# echo cxl_acpi.0 > /sys/bus/platform/drivers/cxl_acpi/unbind
# echo cxl_acpi.0 > /sys/bus/platform/drivers/cxl_acpi/bind
# echo 0 > /sys/bus/platform/devices/cxl_acpi.0/decoder_reset_preserve_registry
The NDCTL CXL unit test, cxl-region-replay.sh, demonstrates the usage.
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Co-developed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260314061952.2221030-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
When platform firmware is committed to publishing EFI_CONVENTIONAL_MEMORY
in the memory map, but CXL fails to assemble the region, dax_hmem can
attempt to attach a dax device to the memory range.
Take advantage of the new ability to support multiple "hmem_platform"
devices, and to enable regression testing of several scenarios:
* CXL correctly assembles a region, check dax_hmem fails to attach dax
* CXL fails to assemble a region, check dax_hmem successfully attaches dax
* Check that loading the dax_cxl driver loads the dax_hmem driver
* Attempt to race cxl_mock_mem async probe vs dax_hmem probe flushing.
Check that both positive and negative cases.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260327052821.440749-10-dan.j.williams@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Pull CXL updates from Dave Jiang:
- Introduce cxl_memdev_attach and pave way for soft reserved handling,
type2 accelerator enabling, and LSA 2.0 enabling. All these series
require the endpoint driver to settle before continuing the memdev
driver probe.
- Address CXL port error protocol handling and reporting.
The large patch series was split into three parts. The first two
parts are included here with the final part coming later.
The first part consists of a series of code refactoring to PCI AER
sub-system that addresses CXL and also CXL RAS code to prepare for
port error handling.
The second part refactors the CXL code to move management of
component registers to cxl_port objects to allow all CXL AER errors
to be handled through the cxl_port hierarchy.
- Provide AMD Zen5 platform address translation for CXL using ACPI
PRMT. This includes a conventions document to explain why this is
needed and how it's implemented.
- Misc CXL patches of fixes, cleanups, and updates. Including CXL
address translation for unaligned MOD3 regions.
[ TLA service: CXL is "Compute Express Link" ]
* tag 'cxl-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (59 commits)
cxl: Disable HPA/SPA translation handlers for Normalized Addressing
cxl/region: Factor out code into cxl_region_setup_poison()
cxl/atl: Lock decoders that need address translation
cxl: Enable AMD Zen5 address translation using ACPI PRMT
cxl/acpi: Prepare use of EFI runtime services
cxl: Introduce callback for HPA address ranges translation
cxl/region: Use region data to get the root decoder
cxl/region: Add @hpa_range argument to function cxl_calc_interleave_pos()
cxl/region: Separate region parameter setup and region construction
cxl: Simplify cxl_root_ops allocation and handling
cxl/region: Store HPA range in struct cxl_region
cxl/region: Store root decoder in struct cxl_region
cxl/region: Rename misleading variable name @hpa to @hpa_range
Documentation/driver-api/cxl: ACPI PRM Address Translation Support and AMD Zen5 enablement
cxl, doc: Moving conventions in separate files
cxl, doc: Remove isonum.txt inclusion
cxl/port: Unify endpoint and switch port lookup
cxl/port: Move endpoint component register management to cxl_port
cxl/port: Map Port RAS registers
cxl/port: Move dport RAS setup to dport add time
...
Fixup and refactor downstream port enumeration to prepare for CXL port
protocol error handling. Main motivation is to move endpoint
component register mapping to a port object.
cxl/port: Unify endpoint and switch port lookup
cxl/port: Move endpoint component register management to cxl_port
cxl/port: Map Port RAS registers
cxl/port: Move dport RAS setup to dport add time
cxl/port: Move dport probe operations to a driver event
cxl/port: Move decoder setup before dport creation
cxl/port: Cleanup dport removal with a devres group
cxl/port: Reduce number of @dport variables in cxl_port_add_dport()
cxl/port: Cleanup handling of the nr_dports 0 -> 1 transition
Towards the end goal of making all CXL RAS capability handling uniform
across host bridge ports, upstream switch ports, and endpoint ports, move
dport RAS setup. Move it to cxl_switch_port_probe() context for switch / VH
dports (via cxl_port_add_dport()) and cxl_endpoint_port_probe() context for
an RCH dport. Rename the RAS setup helper to devm_cxl_dport_ras_setup() for
symmetry with devm_cxl_switch_port_decoders_setup().
Only the RCH version needs to be exported and the cxl_test mocking can be
deleted with a dev_is_pci() check on the dport_dev.
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Tested-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20260131000403.2135324-7-dan.j.williams@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
In preparation for adding more register setup to the cxl_port_add_dport()
path (for RAS register mapping), move the dport creation event to a driver
callback. This achieves two goals, it puts driver operations logically
where they belong, in a driver, and it obviates the gymnastics of
DECLARE_TESTABLE() which just makes a mess of grepping for CXL symbols.
In other words, a driver callback is less of an ongoing maintenance burden
than this DECLARE_TESTABLE arrangement that does not scale and diminishes
the grep-ability of the codebase.
cxl_port_add_dport() moves mostly unmodified from drivers/cxl/core/port.c.
The only deliberate change is that it now assumes that the device_lock is
held on entry and the driver is attached (just like cxl_port_probe()).
Reviewed-by: Terry Bowman <terry.bowman@amd.com>
Tested-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20260131000403.2135324-6-dan.j.williams@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Translation functions may return an invalid address in case of errors.
If the address is not checked the further use of the invalid value
will cause an address corruption.
Consistently check for a valid address returned by translation
functions. Use RESOURCE_SIZE_MAX to indicate an invalid address for
type resource_size_t. Depending on the type either RESOURCE_SIZE_MAX
or ULLONG_MAX is used to indicate an address error.
Propagating an invalid address from a failed translation may cause
userspace to think it has received a valid SPA, when in fact it is
wrong. The CXL userspace API, using trace events, expects ULLONG_MAX
to indicate a translation failure. If ULLONG_MAX is not returned
immediately, subsequent calculations can transform that bad address
into a different value (!ULLONG_MAX), and an invalid SPA may be
returned to userspace. This can lead to incorrect diagnostics and
erroneous corrective actions.
[ dj: Added user impact statement from Alison. ]
[ dj: Fixed checkpatch tab alignment issue. ]
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Fixes: c3dd67681c ("cxl/region: Add inject and clear poison by region offset")
Fixes: b78b9e7b79 ("cxl/region: Refactor address translation funcs for testing")
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260107120544.410993-1-rrichter@amd.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Unlike the cxl_pci class driver that opportunistically enables memory
expansion with no other dependent functionality, CXL accelerator drivers
have distinct PCIe-only and CXL-enhanced operation states. If CXL is
available some additional coherent memory/cache operations can be enabled,
otherwise traditional DMA+MMIO over PCIe/CXL.io is a fallback.
This constitutes a new mode of operation where the caller of
devm_cxl_add_memdev() wants to make a "go/no-go" decision about running
in CXL accelerated mode or falling back to PCIe-only operation. Part of
that decision making process likely also includes additional
CXL-acceleration-specific resource setup. Encapsulate both of those
requirements into 'struct cxl_memdev_attach' that provides a ->probe()
callback. The probe callback runs in cxl_mem_probe() context, after the
port topology is successfully attached for the given memdev. It supports
a contract where, upon successful return from devm_cxl_add_memdev(),
everything needed for CXL accelerated operation has been enabled.
Additionally the presence of @cxlmd->attach indicates that the accelerator
driver be detached when CXL operation ends. This conceptually makes a CXL
link loss event mirror a PCIe link loss event which results in triggering
the ->remove() callback of affected devices+drivers. A driver can re-attach
to recover back to PCIe-only operation. Live recovery, i.e. without a
->remove()/->probe() cycle, is left as a future consideration.
[ dj: Repalce with updated commit log from Dan ]
Cc: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20251216005616.3090129-7-dan.j.williams@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
mock_get_event() uses an uninitialized local variable, nr_overflow, to
populate the overflow_err_count field. That results in incorrect
overflow_err_count values in mocked cxl_overflow trace events, such as
this case where the records are reported as 0 and should be non-zero:
[] cxl_overflow: memdev=mem7 host=cxl_mem.6 serial=7: log=Failure : 0 records from 1763228189130895685 to 1763228193130896180
Fix by using log->nr_overflow and remove the unused local variable.
A follow-up change was considered in cxl_mem_get_records_log() to
confirm that the overflow_err_count is non-zero when the overflow flag
is set [1]. Since the driver has no functional dependency on this
constraint, and a device that violates this specific requirement does
not cause incorrect driver behavior, no validation check is added.
[1] CXL 3.2, Table 8-65 Get Event Records Output Payload
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>> ---
Link: https://patch.msgid.link/20251116013036.1713313-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Commit 364ee9f326 ("cxl/test: Enhance event testing") changed the
loop iterator in mock_get_event() from a static constant,
CXL_TEST_EVENT_CNT, to a dynamic global variable, ret_limit. The
intent was to vary the number of events returned per call to simulate
events occurring while logs are being read.
However, ret_limit is modified without synchronization. When multiple
threads call mock_get_event() concurrently, one thread may read
ret_limit, another thread may increment it, and the first thread's
loop condition and size calculation see and use the updated value.
This is visible during cxl_test module load when all memdevs are
initializing simultaneously, which includes getting event records. It
is not tied to the cxl-events.sh unit test specifically, as that
operates on a single memdev.
While no actual harm results (the buffer is always large enough and
the record count fields correctly reflect what was written), this is
a correctness issue. The race creates an inconsistent state within
mock_get_event() and adding variability based on a race appears
unintended.
Make ret_limit a local variable populated from an atomic counter. Each
call gets a stable value that won't change during execution. That
preserves the intended behavior of varying the return counts across
calls while eliminating the race condition.
This implementation uses "+ 1" to produce the full range of 1 to
CXL_TEST_EVENT_RET_MAX (4) records. Previously only 1, 2, 3 were
produced.
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>> ---
Link: https://patch.msgid.link/20251116013819.1713780-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Extended linear cache unit testing support
- Standardize CXL auto region size
- Add cxl_test CFMWS support for extended linear cache
- Add support for acpi extended linear cache
Add a module parameter to allow activation of extended linear cache
on the auto region for cxl_test. The current platform implementation
for extended linear cache is 1:1 of DRAM and CXL memory. A CFMWS is
created with the size of both memory together where DRAM takes the
first part of the memory range and CXL covers the second part. The
current CXL auto region on cxl_test consists of 2 256M devices that
creates a 512M region. The new extended linear cache setup will have
512M DRAM and 512M CXL memory for a total of 1G CFMWS. The hardware
decoders must have their starting offset moved to after the DRAM region
to handle the CXL regions.
[ dj: Fixup commenting style. (Jonathan) ]
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>
Link: https://patch.msgid.link/20251117144611.903692-3-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Add a loadable test module that validates CXL address translation
calculations using parameterized test vectors. The module tests both
host-to-device and device-to-host address translations for Modulo and
XOR interleave arithmetic.
Two types of testing are provided:
1. Parameterized test vectors:
Test vectors are passed as module parameters in the format:
"dpa pos r_eiw r_eig hb_ways math expected_spa".
Round-trip validation is performed:
- Translate a DPA and position to a SPA
- Verify the result matches expected SPA
- Translate that SPA back to a DPA and position
- Verify round-trip consistency
2. Internal validation testing:
When no test vectors are provided, the module performs validation
of the translation functions by checking parameter boundaries and
running 10,000 iterations of randomly generated valid parameters
to exercise the core calculation functions.
The module uses the CXL Driver translation functions through symbols
exported exclusively for cxl_translate.
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Li MingandDave Jiang
Alison SchofieldandDave Jiang
Dan WilliamsandDave Jiang
Alejandro LuceroandDave Jiang
Linus Torvalds
Robert RichterandDave Jiang