- CXL RAM region enumeration: instantiate 'struct cxl_region' objects
for platform firmware created memory regions
- CXL RAM region provisioning: complement the existing PMEM region
creation support with RAM region support
- "Soft Reservation" policy change: Online (memory hot-add)
soft-reserved memory (EFI_MEMORY_SP) by default, but still allow for
setting aside such memory for dedicated access via device-dax.
- CXL Events and Interrupts: Takeover CXL event handling from
platform-firmware (ACPI calls this CXL Memory Error Reporting) and
export CXL Events via Linux Trace Events.
- Convey CXL _OSC results to drivers: Similar to PCI, let the CXL
subsystem interrogate the result of CXL _OSC negotiation.
- Emulate CXL DVSEC Range Registers as "decoders": Allow for
first-generation devices that pre-date the definition of the CXL HDM
Decoder Capability to translate the CXL DVSEC Range Registers into
'struct cxl_decoder' objects.
- Set timestamp: Per spec, set the device timestamp in case of hotplug,
or if platform-firwmare failed to set it.
- General fixups: linux-next build issues, non-urgent fixes for
pre-production hardware, unit test fixes, spelling and debug message
improvements.
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Merge tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull Compute Express Link (CXL) updates from Dan Williams:
"To date Linux has been dependent on platform-firmware to map CXL RAM
regions and handle events / errors from devices. With this update we
can now parse / update the CXL memory layout, and report events /
errors from devices. This is a precursor for the CXL subsystem to
handle the end-to-end "RAS" flow for CXL memory. i.e. the flow that
for DDR-attached-DRAM is handled by the EDAC driver where it maps
system physical address events to a field-replaceable-unit (FRU /
endpoint device). In general, CXL has the potential to standardize
what has historically been a pile of memory-controller-specific error
handling logic.
Another change of note is the default policy for handling RAM-backed
device-dax instances. Previously the default access mode was "device",
mmap(2) a device special file to access memory. The new default is
"kmem" where the address range is assigned to the core-mm via
add_memory_driver_managed(). This saves typical users from wondering
why their platform memory is not visible via free(1) and stuck behind
a device-file. At the same time it allows expert users to deploy
policy to, for example, get dedicated access to high performance
memory, or hide low performance memory from general purpose kernel
allocations. This affects not only CXL, but also systems with
high-bandwidth-memory that platform-firmware tags with the
EFI_MEMORY_SP (special purpose) designation.
Summary:
- CXL RAM region enumeration: instantiate 'struct cxl_region' objects
for platform firmware created memory regions
- CXL RAM region provisioning: complement the existing PMEM region
creation support with RAM region support
- "Soft Reservation" policy change: Online (memory hot-add)
soft-reserved memory (EFI_MEMORY_SP) by default, but still allow
for setting aside such memory for dedicated access via device-dax.
- CXL Events and Interrupts: Takeover CXL event handling from
platform-firmware (ACPI calls this CXL Memory Error Reporting) and
export CXL Events via Linux Trace Events.
- Convey CXL _OSC results to drivers: Similar to PCI, let the CXL
subsystem interrogate the result of CXL _OSC negotiation.
- Emulate CXL DVSEC Range Registers as "decoders": Allow for
first-generation devices that pre-date the definition of the CXL
HDM Decoder Capability to translate the CXL DVSEC Range Registers
into 'struct cxl_decoder' objects.
- Set timestamp: Per spec, set the device timestamp in case of
hotplug, or if platform-firwmare failed to set it.
- General fixups: linux-next build issues, non-urgent fixes for
pre-production hardware, unit test fixes, spelling and debug
message improvements"
* tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (66 commits)
dax/kmem: Fix leak of memory-hotplug resources
cxl/mem: Add kdoc param for event log driver state
cxl/trace: Add serial number to trace points
cxl/trace: Add host output to trace points
cxl/trace: Standardize device information output
cxl/pci: Remove locked check for dvsec_range_allowed()
cxl/hdm: Add emulation when HDM decoders are not committed
cxl/hdm: Create emulated cxl_hdm for devices that do not have HDM decoders
cxl/hdm: Emulate HDM decoder from DVSEC range registers
cxl/pci: Refactor cxl_hdm_decode_init()
cxl/port: Export cxl_dvsec_rr_decode() to cxl_port
cxl/pci: Break out range register decoding from cxl_hdm_decode_init()
cxl: add RAS status unmasking for CXL
cxl: remove unnecessary calling of pci_enable_pcie_error_reporting()
dax/hmem: build hmem device support as module if possible
dax: cxl: add CXL_REGION dependency
cxl: avoid returning uninitialized error code
cxl/pmem: Fix nvdimm registration races
cxl/mem: Fix UAPI command comment
cxl/uapi: Tag commands from cxl_query_cmd()
...
Pick up the CXL DVSEC range register emulation for v6.3, and resolve
conflicts with the cxl_port_probe() split (from for-6.3/cxl-ram-region)
and event handling (from for-6.3/cxl-events).
Call cxl_dvsec_rr_decode() in the beginning of cxl_port_probe() and
preserve the decoded information in a local
'struct cxl_endpoint_dvsec_info'. This info can be passed to various
functions later on in order to support the HDM decoder emulation.
The invocation of cxl_dvsec_rr_decode() in cxl_hdm_decode_init() is
removed and a pointer to the 'struct cxl_endpoint_dvsec_info' is passed
in.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/167640367377.935665.2848747799651019676.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Include the support for enumerating and provisioning ram regions for
v6.3. This also include a default policy change for ram / volatile
device-dax instances to assign them to the dax_kmem driver by default.
CXL_CMD_FLAG_NONE is not used, remove it.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221222-cxl-misc-v4-1-62f701c1cdd1@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Take two endpoints attached to the first switch on the first host-bridge
in the cxl_test topology and define a pre-initialized region. This is a
x2 interleave underneath a x1 CXL Window.
$ modprobe cxl_test
$ # cxl list -Ru
{
"region":"region3",
"resource":"0xf010000000",
"size":"512.00 MiB (536.87 MB)",
"interleave_ways":2,
"interleave_granularity":4096,
"decode_state":"commit"
}
Tested-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/167602000547.1924368.11613151863880268868.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Testing of ram region support [1], stimulates a long standing bug in
cxl_detach_ep() where some cxl_ep_remove() cleanup is skipped due to
inability to walk ports after dports have been unregistered. That
results in a failure to re-register a memdev after the port is
re-enabled leading to a crash like the following:
cxl_port_setup_targets: cxl region4: cxl_host_bridge.0:port4 iw: 1 ig: 256
general protection fault, ...
[..]
RIP: 0010:cxl_region_setup_targets+0x897/0x9e0 [cxl_core]
dev_name at include/linux/device.h:700
(inlined by) cxl_port_setup_targets at drivers/cxl/core/region.c:1155
(inlined by) cxl_region_setup_targets at drivers/cxl/core/region.c:1249
[..]
Call Trace:
<TASK>
attach_target+0x39a/0x760 [cxl_core]
? __mutex_unlock_slowpath+0x3a/0x290
cxl_add_to_region+0xb8/0x340 [cxl_core]
? lockdep_hardirqs_on+0x7d/0x100
discover_region+0x4b/0x80 [cxl_port]
? __pfx_discover_region+0x10/0x10 [cxl_port]
device_for_each_child+0x58/0x90
cxl_port_probe+0x10e/0x130 [cxl_port]
cxl_bus_probe+0x17/0x50 [cxl_core]
Change the port ancestry walk to be by depth rather than by dport. This
ensures that even if a port has unregistered its dports a deferred
memdev cleanup will still be able to cleanup the memdev's interest in
that port.
The parent_port->dev.driver check is only needed for determining if the
bottom up removal beat the top-down removal, but cxl_ep_remove() can
always proceed given the port is pinned. That is, the two sources of
cxl_ep_remove() are in cxl_detach_ep() and cxl_port_release(), and
cxl_port_release() can not run if cxl_detach_ep() holds a reference.
Fixes: 2703c16c75 ("cxl/core/port: Add switch port enumeration")
Link: http://lore.kernel.org/r/167564534874.847146.5222419648551436750.stgit@dwillia2-xfh.jf.intel.com [1]
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/167601992789.1924368.8083994227892600608.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
CXL r3.0 section 8.2.9.4.2 "Set Timestamp" recommends that the host sets
the timestamp after every Conventional or CXL Reset to ensure accurate
timestamps. This should include on initial boot up. The time base that
is being set is used by a device for the poison list overflow timestamp
and all event timestamps. Note that the command is optional and if
not supported and the device cannot return accurate timestamps it will
fill the fields in with an appropriate marker (see the specification
description of each timestamp).
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230130151327.32415-1-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CXL rev 3.0 section 8.2.9.2.1.3 defines the Memory Module Event Record.
Determine if the event read is memory module record and if so trace the
record.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221216-cxl-ev-log-v7-5-2316a5c8f7d8@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
CXL rev 3.0 section 8.2.9.2.1.2 defines the DRAM Event Record.
Determine if the event read is a DRAM event record and if so trace the
record.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221216-cxl-ev-log-v7-4-2316a5c8f7d8@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
CXL rev 3.0 section 8.2.9.2.1.1 defines the General Media Event Record.
Determine if the event read is a general media record and if so trace
the record as a General Media Event Record.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221216-cxl-ev-log-v7-3-2316a5c8f7d8@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Currently the only CXL features targeted for irq support require their
message numbers to be within the first 16 entries. The device may
however support less than 16 entries depending on the support it
provides.
Attempt to allocate these 16 irq vectors. If the device supports less
then the PCI infrastructure will allocate that number. Upon successful
allocation, users can plug in their respective isr at any point
thereafter.
CXL device events are signaled via interrupts. Each event log may have
a different interrupt message number. These message numbers are
reported in the Get Event Interrupt Policy mailbox command.
Add interrupt support for event logs. Interrupts are allocated as
shared interrupts. Therefore, all or some event logs can share the same
message number.
In addition all logs are queried on any interrupt in order of the most
to least severe based on the status register.
Finally place all event configuration logic into cxl_event_config().
Previously the logic was a simple 'read all' on start up. But
interrupts must be configured prior to any reads to ensure no events are
missed. A single event configuration function results in a cleaner over
all implementation.
Cc: Bjorn Helgaas <helgaas@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Co-developed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221216-cxl-ev-log-v7-2-2316a5c8f7d8@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
CXL devices have multiple event logs which can be queried for CXL event
records. Devices are required to support the storage of at least one
event record in each event log type.
Devices track event log overflow by incrementing a counter and tracking
the time of the first and last overflow event seen.
Software queries events via the Get Event Record mailbox command; CXL
rev 3.0 section 8.2.9.2.2 and clears events via CXL rev 3.0 section
8.2.9.2.3 Clear Event Records mailbox command.
If the result of negotiating CXL Error Reporting Control is OS control,
read and clear all event logs on driver load.
Ensure a clean slate of events by reading and clearing the events on
driver load.
The status register is not used because a device may continue to trigger
events and the only requirement is to empty the log at least once. This
allows for the required transition from empty to non-empty for interrupt
generation. Handling of interrupts is in a follow on patch.
The device can return up to 1MB worth of event records per query.
Allocate a shared large buffer to handle the max number of records based
on the mailbox payload size.
This patch traces a raw event record and leaves specific event record
type tracing to subsequent patches. Macros are created to aid in
tracing the common CXL Event header fields.
Each record is cleared explicitly. A clear all bit is specified but is
only valid when the log overflows.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221216-cxl-ev-log-v7-1-2316a5c8f7d8@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
cxl_internal_send_cmd() skips output size validation for variable output
commands which is not ideal. Most of the time internal usages want to
fail if the output size does not match what was requested. For other
commands where the caller cannot predict the size there is usually a
a header that conveys how much vaild data is in the payload. For those
cases add @min_out as a parameter to specify what the minimum response
payload needs to be for the caller to parse the rest of the payload.
In this patch only Get Supported Logs has that behavior, but going
forward records retrieval commands like Get Poison List and Get Event
Records can use @min_out to retrieve a variable amount of records.
Critically, this validation scheme skips the needs to interrogate the
cxl_mem_commands array which in turn frees up the implementation to
support internal command enabling without also enabling external / user
commands.
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/167030055918.4044561.10339573829837910505.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Internally cxl_mbox_send_cmd() converts all passed-in parameters to a
'struct cxl_mbox_cmd' instance and sends that to cxlds->mbox_send(). It
then teases the possibilty that the caller can validate the output size.
However, they cannot since the resulting output size is not conveyed to
the called. Fix that by making the caller pass in a constructed 'struct
cxl_mbox_cmd'. This prepares for a future patch to add output size
validation on a per-command basis.
Given the change in signature, also change the name to differentiate it
from the user command submission path that performs more validation
before generating the 'struct cxl_mbox_cmd' instance to execute.
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/167030055370.4044561.17788093375112783036.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Unlike a CXL memory expander in a VH topology that has at least one
intervening 'struct cxl_port' instance between itself and the CXL root
device, an RCD attaches one-level higher. For example:
VH
┌──────────┐
│ ACPI0017 │
│ root0 │
└─────┬────┘
│
┌─────┴────┐
│ dport0 │
┌─────┤ ACPI0016 ├─────┐
│ │ port1 │ │
│ └────┬─────┘ │
│ │ │
┌──┴───┐ ┌──┴───┐ ┌───┴──┐
│dport0│ │dport1│ │dport2│
│ RP0 │ │ RP1 │ │ RP2 │
└──────┘ └──┬───┘ └──────┘
│
┌───┴─────┐
│endpoint0│
│ port2 │
└─────────┘
...vs:
RCH
┌──────────┐
│ ACPI0017 │
│ root0 │
└────┬─────┘
│
┌───┴────┐
│ dport0 │
│ACPI0016│
└───┬────┘
│
┌────┴─────┐
│endpoint0 │
│ port1 │
└──────────┘
So arrange for endpoint port in the RCH/RCD case to appear directly
connected to the host-bridge in its singular role as a dport. Compare
that to the VH case where the host-bridge serves a dual role as a
'cxl_dport' for the CXL root device *and* a 'cxl_port' upstream port for
the Root Ports in the Root Complex that are modeled as 'cxl_dport'
instances in the CXL topology.
Another deviation from the VH case is that RCDs may need to look up
their component registers from the Root Complex Register Block (RCRB).
That platform firmware specified RCRB area is cached by the cxl_acpi
driver and conveyed via the host-bridge dport to the cxl_mem driver to
perform the cxl_rcrb_to_component() lookup for the endpoint port
(See 9.11.8 CXL Devices Attached to an RCH for the lookup of the
upstream port component registers).
Tested-by: Robert Richter <rrichter@amd.com>
Link: https://lore.kernel.org/r/166993045621.1882361.1730100141527044744.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Camerom <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
tl;dr: Clean up an unnecessary export and enable cxl_test.
An RCD (Restricted CXL Device), in contrast to a typical CXL device in
a VH topology, obtains its component registers from the bottom half of
the associated CXL host bridge RCRB (Root Complex Register Block). In
turn this means that cxl_rcrb_to_component() needs to be called from
devm_cxl_add_endpoint().
Presently devm_cxl_add_endpoint() is part of the CXL core, but the only
user is the CXL mem module. Move it from cxl_core to cxl_mem to not only
get rid of an unnecessary export, but to also enable its call out to
cxl_rcrb_to_component(), in a subsequent patch, to be mocked by
cxl_test. Recall that cxl_test can only mock exported symbols, and since
cxl_rcrb_to_component() is itself inside the core, all callers must be
outside of cxl_core to allow cxl_test to mock it.
Reviewed-by: Robert Richter <rrichter@amd.com>
Link: https://lore.kernel.org/r/166993045072.1882361.13944923741276843683.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Add nominal error handling that tears down CXL.mem in response to error
notifications that imply a device reset. Given some CXL.mem may be
operating as System RAM, there is a high likelihood that these error
events are fatal. However, if the system survives the notification the
expectation is that the driver behavior is equivalent to a hot-unplug
and re-plug of an endpoint.
Note that this does not change the mask values from the default. That
awaits CXL _OSC support to determine whether platform firmware is in
control of the mask registers.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166974413966.1608150.15522782911404473932.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The three objects 'struct cxl_nvdimm_bridge', 'struct cxl_nvdimm', and
'struct cxl_pmem_region' manage CXL persistent memory resources. The
bridge represents base platform resources, the nvdimm represents one or
more endpoints, and the region is a collection of nvdimms that
contribute to an assembled address range.
Their relationship is such that a region is torn down if any component
endpoints are removed. All regions and endpoints are torn down if the
foundational bridge device goes down.
A workqueue was deployed to manage these interdependencies, but it is
difficult to reason about, and fragile. A recent attempt to take the CXL
root device lock in the cxl_mem driver was reported by lockdep as
colliding with the flush_work() in the cxl_pmem flows.
Instead of the workqueue, arrange for all pmem/nvdimm devices to be torn
down immediately and hierarchically. A similar change is made to both
the 'cxl_nvdimm' and 'cxl_pmem_region' objects. For bisect-ability both
changes are made in the same patch which unfortunately makes the patch
bigger than desired.
Arrange for cxl_memdev and cxl_region to register a cxl_nvdimm and
cxl_pmem_region as a devres release action of the bridge device.
Additionally, include a devres release action of the cxl_memdev or
cxl_region device that triggers the bridge's release action if an endpoint
exits before the bridge. I.e. this allows either unplugging the bridge,
or unplugging and endpoint to result in the same cleanup actions.
To keep the patch smaller the cleanup of the now defunct workqueue
infrastructure is saved for a follow-on patch.
Tested-by: Robert Richter <rrichter@amd.com>
Link: https://lore.kernel.org/r/166993041773.1882361.16444301376147207609.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Create callback function to support the nvdimm_security_ops() ->erase()
callback. Translate the operation to send "Passphrase Secure Erase"
security command for CXL memory device.
When the mem device is secure erased, cpu_cache_invalidate_memregion() is
called in order to invalidate all CPU caches before attempting to access
the mem device again.
See CXL 3.0 spec section 8.2.9.8.6.6 for reference.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983615293.2734609.10358657600295932156.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Create callback function to support the nvdimm_security_ops() ->unlock()
callback. Translate the operation to send "Unlock" security command for CXL
mem device.
When the mem device is unlocked, cpu_cache_invalidate_memregion() is called
in order to invalidate all CPU caches before attempting to access the mem
device.
See CXL rev3.0 spec section 8.2.9.8.6.4 for reference.
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983614167.2734609.15124543712487741176.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Create callback function to support the nvdimm_security_ops() ->freeze()
callback. Translate the operation to send "Freeze Security State" security
command for CXL memory device.
See CXL rev3.0 spec section 8.2.9.8.6.5 for reference.
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983613019.2734609.10645754779802492122.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Create callback function to support the nvdimm_security_ops ->disable()
callback. Translate the operation to send "Disable Passphrase" security
command for CXL memory device. The operation supports disabling a
passphrase for the CXL persistent memory device. In the original
implementation of nvdimm_security_ops, this operation only supports
disabling of the user passphrase. This is due to the NFIT version of
disable passphrase only supported disabling of user passphrase. The CXL
spec allows disabling of the master passphrase as well which
nvidmm_security_ops does not support yet. In this commit, the callback
function will only support user passphrase.
See CXL rev3.0 spec section 8.2.9.8.6.3 for reference.
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983611878.2734609.10602135274526390127.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Create callback function to support the nvdimm_security_ops ->change_key()
callback. Translate the operation to send "Set Passphrase" security command
for CXL memory device. The operation supports setting a passphrase for the
CXL persistent memory device. It also supports the changing of the
currently set passphrase. The operation allows manipulation of a user
passphrase or a master passphrase.
See CXL rev3.0 spec section 8.2.9.8.6.2 for reference.
However, the spec leaves a gap WRT master passphrase usages. The spec does
not define any ways to retrieve the status of if the support of master
passphrase is available for the device, nor does the commands that utilize
master passphrase will return a specific error that indicates master
passphrase is not supported. If using a device does not support master
passphrase and a command is issued with a master passphrase, the error
message returned by the device will be ambiguous.
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983610751.2734609.4445075071552032091.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Add nvdimm_security_ops support for CXL memory device with the introduction
of the ->get_flags() callback function. This is part of the "Persistent
Memory Data-at-rest Security" command set for CXL memory device support.
The ->get_flags() function provides the security state of the persistent
memory device defined by the CXL 3.0 spec section 8.2.9.8.6.1.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983609611.2734609.13231854299523325319.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
CXL regions (interleave sets) are made up of a set of memory devices
where each device maps a portion of the interleave with one of its
decoders (see CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure).
As endpoint decoders are identified by a provisioning tool they can be
added to a region provided the region interleave properties are set
(way, granularity, HPA) and DPA has been assigned to the decoder.
The attach event triggers several validation checks, for example:
- is the DPA sized appropriately for the region
- is the decoder reachable via the host-bridges identified by the
region's root decoder
- is the device already active in a different region position slot
- are there already regions with a higher HPA active on a given port
(per CXL 2.0 8.2.5.12.20 Committing Decoder Programming)
...and the attach event affords an opportunity to collect data and
resources relevant to later programming the target lists in switch
decoders, for example:
- allocate a decoder at each cxl_port in the decode chain
- for a given switch port, how many the region's endpoints are hosted
through the port
- how many unique targets (next hops) does a port need to map to reach
those endpoints
The act of reconciling this information and deploying it to the decoder
configuration is saved for a follow-on patch.
Co-developed-by: Ben Widawsky <bwidawsk@kernel.org>
Signed-off-by: Ben Widawsky <bwidawsk@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165784337277.1758207.4108508181328528703.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In preparation for provisioning CXL regions, add accounting for the DPA
space consumed by existing regions / decoders. Recall, a CXL region is a
memory range comprised from one or more endpoint devices contributing a
mapping of their DPA into HPA space through a decoder.
Record the DPA ranges covered by committed decoders at initial probe of
endpoint ports relative to a per-device resource tree of the DPA type
(pmem or volatile-ram).
The cxl_dpa_rwsem semaphore is introduced to globally synchronize DPA
state across all endpoints and their decoders at once. The vast majority
of DPA operations are reads as region creation is expected to be as rare
as disk partitioning and volume creation. The device_lock() for this
synchronization is specifically avoided for concern of entangling with
sysfs attribute removal.
Co-developed-by: Ben Widawsky <bwidawsk@kernel.org>
Signed-off-by: Ben Widawsky <bwidawsk@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165784327682.1758207.7914919426043855876.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
DOE mailbox objects will be needed for various mailbox communications
with each memory device.
Iterate each DOE mailbox capability and create PCI DOE mailbox objects
as found.
It is not anticipated that this is the final resting place for the
iteration of the DOE devices. The support of switch ports will drive
this code into the PCIe side. In this imagined architecture the CXL
port driver would then query into the PCI device for the DOE mailbox
array.
For now creating the mailboxes in the CXL port is good enough for the
endpoints. Later PCIe ports will need to support this to support switch
ports more generically.
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20220719205249.566684-5-ira.weiny@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In support of testing DPA allocation mechanisms in the CXL core, the
cxl_test environment needs to support establishing and retrieving the
'pmem partition boundary.
Replace the platform_device_add_resources() method for delineating DPA
within an endpoint with an emulated DEV_SIZE amount of partitionable
capacity. Set DEV_SIZE such that an endpoint has enough capacity to
simultaneously participate in 8 distinct regions.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165603887411.551046.13234212587991192347.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Dump the device-physical-address map for a CXL expander in /proc/iomem
style format. E.g.:
cat /sys/kernel/debug/cxl/mem1/dpamem
00000000-0fffffff : ram
10000000-1fffffff : pmem
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165603885318.551046.8308248564880066726.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
To date the per-device-partition DPA range information has only been
used for enumeration purposes. In preparation for allocating regions
from available DPA capacity, convert those ranges into DPA-type resource
trees.
With resources and the new add_dpa_res() helper some open coded end
address calculations and debug prints can be cleaned.
The 'cxlds->pmem_res' and 'cxlds->ram_res' resources are child resources
of the total-device DPA space and they in turn will host DPA allocations
from cxl_endpoint_decoder instances (tracked by cxled->dpa_res).
Cc: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165603878921.551046.8127845916514734142.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
CXL specification defines these as little endian.
Fixes: 60b8f17215 ("cxl/pmem: Translate NVDIMM label commands to CXL label commands")
Reported-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/20220225221456.1025635-1-alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In preparation for fixing the setting of the 'mem_enabled' bit in CXL
DVSEC Control register, move all CXL DVSEC range enumeration into the
same source file.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165291688886.1426646.15046138604010482084.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Allow cxl_await_media_ready() to be mocked for testing purposes rather
than carrying the maintenance burden of an indirect function call in the
mainline driver.
With the move cxl_await_media_ready() can no longer reuse the mailbox
timeout override, so add a media_ready_timeout module parameter to the
core to backfill.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165291688340.1426646.4755627801983775011.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The CXL specification claims S3 support at a hardware level, but at a
system software level there are some missing pieces. Section 9.4 (CXL
2.0) rightly claims that "CXL mem adapters may need aux power to retain
memory context across S3", but there is no enumeration mechanism for the
OS to determine if a given adapter has that support. Moreover the save
state and resume image for the system may inadvertantly end up in a CXL
device that needs to be restored before the save state is recoverable.
I.e. a circular dependency that is not resolvable without a third party
save-area.
Arrange for the cxl_mem driver to fail S3 attempts. This still nominaly
allows for suspend, but requires unbinding all CXL memory devices before
the suspend to ensure the typical DRAM flow is taken. The cxl_mem unbind
flow is intended to also tear down all CXL memory regions associated
with a given cxl_memdev.
It is reasonable to assume that any device participating in a System RAM
range published in the EFI memory map is covered by aux power and
save-area outside the device itself. So this restriction can be
minimized in the future once pre-existing region enumeration support
arrives, and perhaps a spec update to clarify if the EFI memory map is
sufficent for determining the range of devices managed by
platform-firmware for S3 support.
Per Rafael, if the CXL configuration prevents suspend then it should
fail early before tasks are frozen, and mem_sleep should stop showing
'mem' as an option [1]. Effectively CXL augments the platform suspend
->valid() op since, for example, the ACPI ops are not aware of the CXL /
PCI dependencies. Given the split role of platform firmware vs OS
provisioned CXL memory it is up to the cxl_mem driver to determine if
the CXL configuration has elements that platform firmware may not be
prepared to restore.
Link: https://lore.kernel.org/r/CAJZ5v0hGVN_=3iU8OLpHY3Ak35T5+JcBM-qs8SbojKrpd0VXsA@mail.gmail.com [1]
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/165066828317.3907920.5690432272182042556.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Upon a completed command the caller is still expected to check
the actual return_code register to ensure it succeed. This
adds, per the spec, the potential command return codes. It maps
the hardware return code with the kernel's errno style, and by
default continues to use -ENXIO (Command completed, but device
reported an error).
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Link: https://lore.kernel.org/r/20220404021216.66841-4-dave@stgolabs.net
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
User space may send the SET_PARTITION_INFO mailbox command using
the IOCTL interface. Inspect the input payload and fail if the
immediate flag is set.
This is the first instance of the driver inspecting an input payload
from user space. Assume there will be more such cases and implement
with an extensible helper.
In order for the kernel to react to an immediate partition change it
needs to assert that the change will not affect any active decode. At
a minimum this requires validating that the device is using HDM
decoders instead of the CXL DVSEC for decode, and that none of the
active HDM decoders are affected by the partition change. For now,
just fail until that support arrives.
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/241821186c363833980adbc389e2c547bc5a6395.1648687552.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
At this point the subsystem can enumerate all CXL ports (CXL.mem decode
resources in upstream switch ports and host bridges) in a system. The
last mile is connecting those ports to endpoints.
The cxl_mem driver connects an endpoint device to the platform CXL.mem
protoctol decode-topology. At ->probe() time it walks its
device-topology-ancestry and adds a CXL Port object at every Upstream
Port hop until it gets to CXL root. The CXL root object is only present
after a platform firmware driver registers platform CXL resources. For
ACPI based platform this is managed by the ACPI0017 device and the
cxl_acpi driver.
The ports are registered such that disabling a given port automatically
unregisters all descendant ports, and the chain can only be registered
after the root is established.
Given ACPI device scanning may run asynchronously compared to PCI device
scanning the root driver is tasked with rescanning the bus after the
root successfully probes.
Conversely if any ports in a chain between the root and an endpoint
becomes disconnected it subsequently triggers the endpoint to
unregister. Given lock depenedencies the endpoint unregistration happens
in a workqueue asynchronously. If userspace cares about synchronizing
delayed work after port events the /sys/bus/cxl/flush attribute is
available for that purpose.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[djbw: clarify changelog, rework hotplug support]
Link: https://lore.kernel.org/r/164398782997.903003.9725273241627693186.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Per the CXL specification (8.1.12.2 Memory Device PCIe Capabilities and
Extended Capabilities) the Device Serial Number capability is mandatory.
Emit it for user tooling to identify devices.
It is reasonable to ask whether the attribute should be added to the
list of PCI sysfs device attributes. The PCI layer can optionally emit
it too, but the CXL subsystem is aiming to preserve its independence and
the possibility of CXL topologies with non-PCI devices in it. To date
that has only proven useful for the 'cxl_test' model, but as can be seen
with seen with ACPI0016 devices, sometimes all that is needed is a
platform firmware table to point to CXL Component Registers in MMIO
space to define a "CXL" device.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164366608838.196598.16856227191534267098.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
CXL 2.0 8.1.3.8.2 states:
Memory_Active: When set, indicates that the CXL Range 1 memory is
fully initialized and available for software use. Must be set within
Range 1. Memory_Active_Timeout of deassertion of reset to CXL device
if CXL.mem HwInit Mode=1
Unfortunately, Memory_Active can take quite a long time depending on
media size (up to 256s per 2.0 spec). Provide a callback for the
eventual establishment of CXL.mem operations via the 'cxl_mem' driver
the 'struct cxl_memdev'. The implementation waits for 60s by default for
now and can be overridden by the mbox_ready_time module parameter.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
[djbw: switch to sleeping wait]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164298427373.3018233.9309741847039301834.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Before CXL 2.0 HDM Decoder Capability mechanisms can be utilized in a
device the driver must determine that the device is ready for CXL.mem
operation and that platform firmware, or some other agent, has
established an active decode via the legacy CXL 1.1 decoder mechanism.
This legacy mechanism is defined in the CXL DVSEC as a set of range
registers and status bits that take time to settle after a reset.
Validate the CXL memory decode setup via the DVSEC and cache it for
later consideration by the cxl_mem driver (to be added). Failure to
validate is not fatal to the cxl_pci driver since that is only providing
CXL command support over PCI.mmio, and might be needed to rectify CXL
DVSEC validation problems.
Any potential ranges that the device is already claiming via DVSEC need
to be reconciled with the dynamic provisioning ranges provided by
platform firmware (like ACPI CEDT.CFMWS). Leave that reconciliation to
the cxl_mem driver.
[djbw: shorten defines]
[djbw: change precise spin wait to generous msleep]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
[djbw: clarify changelog]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164375911821.559935.7375160041663453400.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The PCIe device DVSEC, defined in the CXL 2.0 spec, 8.1.3 is required to
be implemented by CXL 2.0 endpoint devices. In preparation for consuming
this information in a new cxl_mem driver, retrieve the CXL DVSEC
position and warn about the implications of not finding it. Allow for
mailbox operation even if the CXL DVSEC is missing.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164375309615.513620.7874131241128599893.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In preparation for defining a cxl_port object to represent the decoder
resources of a memory expander capture the component register base
address.
The port driver uses the component register base to enumerate the HDM
Decoder Capability structure. Unlike other cxl_port objects the endpoint
port decodes from upstream SPA to downstream DPA rather than upstream
port to downstream port.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[djbw: clarify changelog]
Link: https://lore.kernel.org/r/164375084181.484304.3919737667590006795.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Unlike the decoder enumeration for "root decoders" described by platform
firmware, standard decoders can be enumerated from the component
registers space once the base address has been identified (via PCI,
ACPI, or another mechanism).
Add common infrastructure for HDM (Host-managed-Device-Memory) Decoder
enumeration and share it between host-bridge, upstream switch port, and
cxl_test defined decoders.
The locking model for switch level decoders is to hold the port lock
over the enumeration. This facilitates moving the dport and decoder
enumeration to a 'port' driver. For now, the only enumerator of decoder
resources is the cxl_acpi root driver.
Co-developed-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164374688404.395335.9239248252443123526.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Linus Torvalds