610 Commits

Author SHA1 Message Date
Dan Williams
516b300c4c cxl/memdev: Formalize endpoint port linkage
Move the endpoint port that the cxl_mem driver establishes from drvdata
to a first class attribute. This is in preparation for device-memory
drivers reusing the CXL core for memory region management. Those drivers
need a type-safe method to retrieve their CXL port linkage. Leave
drvdata for private usage of the cxl_mem driver not external consumers
of a 'struct cxl_memdev' object.

Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679264292.3436160.3901392135863405807.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:33 -07:00
Dan Williams
f3c8a37a43 cxl/pci: Unconditionally unmask 256B Flit errors
The current check for 256B Flit mode is incomplete and unnecessary. It
is incomplete because it fails to consider the link speed, or check for
CXL link capabilities. It is unnecessary because unconditionally
unmasking 256B Flit errors is a nop when 256B Flit operation is not
available.

Remove this check in preparation for creating a cxl_probe_link() helper
to centralize this detection.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679263124.3436160.6228910132469454346.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:09 -07:00
Dan Williams
8c897b366c cxl/region: Manage decoder target_type at decoder-attach time
Switch-level (mid-level) decoders between the platform root and an
endpoint can dynamically switch modes between HDM-H and HDM-D[B]
depending on which region they target. Use the region type to fixup each
decoder that gets allocated to map the given region.

Note that endpoint decoders are meant to determine the region type, so
warn if those ever need to be fixed up, but since it is possible to
continue do so.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679262543.3436160.13053831955768440312.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:09 -07:00
Dan Williams
cecbb5da92 cxl/hdm: Default CXL_DEVTYPE_DEVMEM decoders to CXL_DECODER_DEVMEM
In preparation for device-memory region creation, arrange for decoders
of CXL_DEVTYPE_DEVMEM memdevs to default to CXL_DECODER_DEVMEM for their
target type.

Revisit this if a device ever shows up that wants to offer mixed HDM-H
(Host-Only Memory) and HDM-DB support, or an CXL_DEVTYPE_DEVMEM device
that supports HDM-H.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679261945.3436160.11673393474107374595.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
Dan Williams
5aa39a9165 cxl/port: Rename CXL_DECODER_{EXPANDER, ACCELERATOR} => {HOSTONLYMEM, DEVMEM}
In preparation for support for HDM-D and HDM-DB configuration
(device-memory, and device-memory with back-invalidate). Rename the current
type designators to use HOSTONLYMEM and DEVMEM as a suffix.

HDM-DB can be supported by devices that are not accelerators, so DEVMEM is
a more generic term for that case.

Fixup one location where this type value was open coded.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679261369.3436160.7042443847605280593.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
Dan Williams
f6b8ab32e3 cxl/memdev: Make mailbox functionality optional
In support of the Linux CXL core scaling for a wider set of CXL devices,
allow for the creation of memdevs with some memory device capabilities
disabled. Specifically, allow for CXL devices outside of those claiming
to be compliant with the generic CXL memory device class code, like
vendor specific Type-2/3 devices that host CXL.mem. This implies, allow
for the creation of memdevs that only support component-registers, not
necessarily memory-device-registers (like mailbox registers). A memdev
derived from a CXL endpoint that does not support generic class code
expectations is tagged "CXL_DEVTYPE_DEVMEM", while a memdev derived from a
class-code compliant endpoint is tagged "CXL_DEVTYPE_CLASSMEM".

The primary assumption of a CXL_DEVTYPE_DEVMEM memdev is that it
optionally may not host a mailbox. Disable the command passthrough ioctl
for memdevs that are not CXL_DEVTYPE_CLASSMEM, and return empty strings
from memdev attributes associated with data retrieved via the
class-device-standard IDENTIFY command. Note that empty strings were
chosen over attribute visibility to maintain compatibility with shipping
versions of cxl-cli that expect those attributes to always be present.
Once cxl-cli has dropped that requirement this workaround can be
deprecated.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679260782.3436160.7587293613945445365.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
Dan Williams
59f8d15107 cxl/mbox: Move mailbox related driver state to its own data structure
'struct cxl_dev_state' makes too many assumptions about the capabilities
of a CXL device. In particular it assumes a CXL device has a mailbox and
all of the infrastructure and state that comes along with that.

In preparation for supporting accelerator / Type-2 devices that may not
have a mailbox and in general maintain a minimal core context structure,
make mailbox functionality a super-set of  'struct cxl_dev_state' with
'struct cxl_memdev_state'.

With this reorganization it allows for CXL devices that support HDM
decoder mapping, but not other general-expander / Type-3 capabilities,
to only enable that subset without the rest of the mailbox
infrastructure coming along for the ride.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679260240.3436160.15520641540463704524.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
Dan Williams
3fe7feb0f3 cxl: Remove leftover attribute documentation in 'struct cxl_dev_state'
commit 14d788740774 ("cxl/mem: Consolidate CXL DVSEC Range enumeration
in the core")

...removed @info from 'struct cxl_dev_state', but neglected to remove
the corresponding kernel-doc entry. Complete the removal.

Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Closes: http://lore.kernel.org/r/20230606121054.000069e1@Huawei.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679259703.3436160.12583306507362357946.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
Dan Williams
c192e5432f cxl: Fix kernel-doc warnings
After Jonathan noticed [1] that 'struct cxl_dev_state' had a kernel-doc
entry without a corresponding struct attribute I ran the kernel-doc
script to see what else might be broken. Fix these warnings:

drivers/cxl/cxlmem.h:199: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Event Interrupt Policy
drivers/cxl/cxlmem.h:224: warning: Function parameter or member 'buf' not described in 'cxl_event_state'
drivers/cxl/cxlmem.h:224: warning: Function parameter or member 'log_lock' not described in 'cxl_event_state'

Note that scripts/kernel-doc only finds missing kernel-doc entries. It
does not warn on too many kernel-doc entries, i.e. it did not catch the
fact that @info refers to a not present member.

Link: http://lore.kernel.org/r/20230606121054.000069e1@Huawei.com [1]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679259170.3436160.3686460404739136336.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
Dan Williams
688baac109 cxl/regs: Clarify when a 'struct cxl_register_map' is input vs output
The @map parameter to cxl_probe_X_registers() is filled in with the
mapping parameters of the register block. The @map parameter to
cxl_map_X_registers() only reads that information to perform the
mapping. Mark @map const for cxl_map_X_registers() to clarify that it is
only an input to those helpers.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679258103.3436160.4941603739448763855.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
Dan Williams
adfe19738b cxl/region: Fix state transitions after reset failure
Jonathan reports that failed attempts to reset a region (teardown its
HDM decoder configuration) mistakenly advance the state of the region
to "not committed". Revert to the previous state of the region on reset
failure so that the reset can be re-attempted.

Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Closes: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com
Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168696507968.3590522.14484000711718573626.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 13:45:40 -07:00
Dan Williams
2ab47045ac cxl/region: Flag partially torn down regions as unusable
cxl_region_decode_reset() walks all the decoders associated with a given
region and disables them. Due to decoder ordering rules it is possible
that a switch in the topology notices that a given decoder can not be
shutdown before another region with a higher HPA is shutdown first. That
can leave the region in a partially committed state.

Capture that state in a new CXL_REGION_F_NEEDS_RESET flag and require
that a successful cxl_region_decode_reset() attempt must be completed
before cxl_region_probe() accepts the region.

This is a corollary for the bug that Jonathan identified in "CXL/region
:  commit reset of out of order region appears to succeed." [1].

Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Link: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com [1]
Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168696507423.3590522.16254212607926684429.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 13:45:40 -07:00
Dan Williams
d1257d098a cxl/region: Move cache invalidation before region teardown, and before setup
Vikram raised a concern with the theoretical case of a CPU sending
MemClnEvict to a device that is not prepared to receive. MemClnEvict is
a message that is sent after a CPU has taken ownership of a cacheline
from accelerator memory (HDM-DB). In the case of hotplug or HDM decoder
reconfiguration it is possible that the CPU is holding old contents for
a new device that has taken over the physical address range being cached
by the CPU.

To avoid this scenario, invalidate caches prior to tearing down an HDM
decoder configuration.

Now, this poses another problem that it is possible for something to
speculate into that space while the decode configuration is still up, so
to close that gap also invalidate prior to establish new contents behind
a given physical address range.

With this change the cache invalidation is now explicit and need not be
checked in cxl_region_probe(), and that obviates the need for
CXL_REGION_F_INCOHERENT.

Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Fixes: d18bc74aced6 ("cxl/region: Manage CPU caches relative to DPA invalidation events")
Reported-by: Vikram Sethi <vsethi@nvidia.com>
Closes: http://lore.kernel.org/r/BYAPR12MB33364B5EB908BF7239BB996BBD53A@BYAPR12MB3336.namprd12.prod.outlook.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168696506886.3590522.4597053660991916591.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 13:45:40 -07:00
Robert Richter
5d2ffbe4b8 cxl/port: Store the downstream port's Component Register mappings in struct cxl_dport
Same as for ports, also store the downstream port's Component Register
mappings, use struct cxl_dport for that.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-16-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 12:22:53 -07:00
Robert Richter
19ab69a60e cxl/port: Store the port's Component Register mappings in struct cxl_port
CXL capabilities are stored in the Component Registers. To use them,
the specific I/O ranges of the capabilities must be determined by
probing the registers. For this, the whole Component Register range
needs to be mapped temporarily to detect the offset and length of a
capability range.

In order to use more than one capability of a component (e.g. RAS and
HDM) the Component Register are probed and its mappings created
multiple times. This also causes overlapping I/O ranges as the whole
Component Register range must be mapped again while a capability's I/O
range is already mapped.

Different capabilities cannot be setup at the same time. E.g. the RAS
capability must be made available as soon as the PCI driver is bound,
the HDM decoder is setup later during port enumeration. Moreover,
during early setup it is still unknown if a certain capability is
needed. A central capability setup is therefore not possible,
capabilities must be individually enabled once needed during
initialization.

To avoid a duplicate register probe and overlapping I/O mappings, only
probe the Component Registers one time and store the Component
Register mapping in struct port. The stored mappings can be used later
to iomap the capability register range when enabling the capability,
which will be implemented in a follow-on patch.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-15-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 12:22:44 -07:00
Robert Richter
733b57f262 cxl/pci: Early setup RCH dport component registers from RCRB
CXL RAS capabilities must be enabled and accessible as soon as the CXL
endpoint is detected in the PCI hierarchy and bound to the cxl_pci
driver. This needs to be independent of other modules such as cxl_port
or cxl_mem.

CXL RAS capabilities reside in the Component Registers. For an RCH
this is determined by probing RCRB which is implemented very late once
the CXL Memory Device is created.

Change this by moving the RCRB probe to the cxl_pci driver. Do this by
using a new introduced function cxl_pci_find_port() similar to
cxl_mem_find_port() to determine the involved dport by the endpoint's
PCI handle. Plug this into the existing cxl_pci_setup_regs() function
to setup Component Registers. Probe the RCRB in case the Component
Registers cannot be located through the CXL Register Locator
capability.

This unifies code and early sets up the Component Registers at the
same time for both, VH and RCH mode. Only the cxl_pci driver is
involved for this. This allows an early mapping of the CXL RAS
capability registers.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-14-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:57:11 -07:00
Robert Richter
86917c560d cxl/mem: Prepare for early RCH dport component register setup
In order to move the RCH dport component register setup to cxl_pci the
base address must be stored in CXL device state (cxlds) for both
modes, RCH and VH. Store it in cxlds->component_reg_phys and use it
for endpoint creation.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-13-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:57:02 -07:00
Robert Richter
f1d0525eff cxl/regs: Remove early capability checks in Component Register setup
When probing the Component Registers in function cxl_probe_regs()
there are also checks for the existence of the HDM and RAS
capabilities. The checks may fail for components that do not implement
the HDM capability causing the Component Registers setup to fail too.

Remove the checks for a generalized use of cxl_probe_regs() and check
them directly before mapping the RAS or HDM capabilities. This allows
it to setup other Component Registers esp. of an RCH Downstream Port,
which will be implemented in a follow-on patch.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-12-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:51:36 -07:00
Robert Richter
d8bffff201 cxl/port: Remove Component Register base address from struct cxl_dport
The Component Register base address @component_reg_phys is no longer
used after the rework of the Component Register setup which now uses
struct member @comp_map instead. Remove the base address.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-11-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:51:17 -07:00
Robert Richter
d02034b402 cxl/acpi: Directly bind the CEDT detected CHBCR to the Host Bridge's port
During a Host Bridge's downstream port enumeration the CHBS entries in
the CEDT table are parsed, its Component Register base address
extracted and then stored in struct cxl_dport. The CHBS may contain
either the RCRB (RCH mode) or the Host Bridge's Component Registers
(CHBCR, VH mode). The RCRB further contains the CXL downstream port
register base address, while in VH mode the CXL Downstream Switch
Ports are visible in the PCI hierarchy and the DP's component regs are
disovered using the CXL DVSEC register locator capability. The
Component Registers derived from the CHBS for both modes are different
and thus also must be treated differently. That is, in RCH mode, the
component regs base should be bound to the dport, but in VH mode to
the CXL host bridge's port object.

The current implementation stores the CHBCR in addition in struct
cxl_dport and copies it later from there to struct cxl_port. As a
result, the dport contains the wrong Component Registers base address
and, e.g. the RAS capability of a CXL Root Port cannot be detected.

To fix the CHBCR binding, attach it directly to the Host Bridge's
@cxl_port structure. Do this during port creation of the Host Bridge
in add_host_bridge_uport(). Factor out CHBS parsing code in
add_host_bridge_dport() and use it in both functions.

Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-10-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:41:45 -07:00
Robert Richter
f44c7b7ad9 cxl/acpi: Move add_host_bridge_uport() after cxl_get_chbs()
Just moving code to reorder functions to later share cxl_get_chbs()
with add_host_bridge_uport().

This makes changes in the next patch visible. No other changes at all.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-9-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:41:34 -07:00
Terry Bowman
d076bb8c4c cxl/pci: Refactor component register discovery for reuse
The endpoint implements component register setup code. Refactor it for
reuse with RCRB, downstream port, and upstream port setup.

Move PCI specifics from cxl_setup_regs() into cxl_pci_setup_regs().

Move cxl_setup_regs() into cxl/core/regs.c and export it. This also
includes supporting static functions cxl_map_registerblock(),
cxl_unmap_register_block() and cxl_probe_regs().

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-8-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:39:38 -07:00
Robert Richter
573408049b cxl/core/regs: Add @dev to cxl_register_map
The corresponding device of a register mapping is used for devm
operations and logging. For operations with struct cxl_register_map
the device needs to be kept track separately. To simpify the involved
function interfaces, add @dev to cxl_register_map.

While at it also reorder function arguments of cxl_map_device_regs()
and cxl_map_component_regs() to have the object @cxl_register_map
first.

As a result a bunch of functions are available to be used with a
@cxl_register_map object.

This patch is in preparation of reworking the component register setup
code.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-7-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:37:58 -07:00
Dan Williams
7481653dee cxl: Rename 'uport' to 'uport_dev'
For symmetry with the recent rename of ->dport_dev for a 'struct
cxl_dport', add the "_dev" suffix to the ->uport property of a 'struct
cxl_port'. These devices represent the downstream-port-device and
upstream-port-device respectively in the CXL/PCIe topology.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-6-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:37:54 -07:00
Robert Richter
227db57459 cxl: Rename member @dport of struct cxl_dport to @dport_dev
Reading code like dport->dport does not immediately suggest that this
points to the corresponding device structure of the dport. Rename
struct member @dport to @dport_dev.

While at it, also rename @new argument of add_dport() to @dport. This
better describes the variable as a dport (e.g. new->dport becomes to
dport->dport_dev).

Co-developed-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-5-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:37:49 -07:00
Dan Williams
0619337856 cxl/rch: Prepare for caching the MMIO mapped PCIe AER capability
Prepare cxl_probe_rcrb() for retrieving more than just the component
register block. The RCH AER handling code wants to get back to the AER
capability that happens to be MMIO mapped rather then configuration
cycles.

Move RCRB specific downstream port data, like the RCRB base and the
AER capability offset, into its own data structure ('struct
cxl_rcrb_info') for cxl_probe_rcrb() to fill. Extend 'struct
cxl_dport' to include a 'struct cxl_rcrb_info' attribute.

This centralizes all RCRB scanning in one routine.

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-4-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:35:26 -07:00
Robert Richter
eb4663b07e cxl/acpi: Probe RCRB later during RCH downstream port creation
The RCRB is extracted already during ACPI CEDT table parsing while the
data of this is needed not earlier than dport creation. This
implementation comes with drawbacks: During ACPI table scan there is
already MMIO access including mapping and unmapping, but only ACPI
data should be collected here. The collected data must be transferred
through a couple of interfaces until it is finally consumed when
creating the dport. This causes complex data structures and function
interfaces. Additionally, RCRB parsing will be extended to also
extract AER data, it would be much easier do this at a later point
during port and dport creation when the data structures are available
to hold that data.

To simplify all that, probe the RCRB at a later point during RCH
downstream port creation. Change ACPI table parser to only extract the
base address of either the component registers or the RCRB. Parse and
extract the RCRB in devm_cxl_add_rch_dport().

This is in preparation to centralize all RCRB scanning.

Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-2-terry.bowman@amd.com
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20230622205523.85375-3-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 11:35:20 -07:00
Jonathan Cameron
1ad3f701c3 cxl/pci: Find and register CXL PMU devices
CXL PMU devices can be found from entries in the Register
Locator DVSEC.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230526095824.16336-4-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-30 11:20:35 -07:00
Jonathan Cameron
d717d7f3df cxl: Add functions to get an instance of / count regblocks of a given type
Until the recently release CXL 3.0 specification, there
was only ever one instance of any given register block pointed
to by the Register Block Locator DVSEC. Now, the specification allows
for multiple CXL PMU instances, each with their own register block.

To enable this add cxl_find_regblock_instance() that takes an index
parameter and use that to implement cxl_count_regblock() and
cxl_find_regblock().

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230526095824.16336-3-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-30 11:20:35 -07:00
Dave Jiang
793a539ac7 cxl: Explicitly initialize resources when media is not ready
When media is not ready do not assume that the capacity information from
the identify command is valid, i.e. ->total_bytes
->partition_align_bytes ->{volatile,persistent}_only_bytes. Explicitly
zero out the capacity resources and exit early.

Given zero-init of those fields this patch is functionally equivalent to
the prior state, but it improves readability and robustness going
forward.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168506118166.3004974.13523455340007852589.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-26 13:34:39 -07:00
Davidlohr Bueso
ccadf1310f cxl/mbox: Add background cmd handling machinery
This adds support for handling background operations, as defined in
the CXL 3.0 spec. Commands that can take too long (over ~2 seconds)
can run in the background asynchronously (to the hardware).

The driver will deal with such commands synchronously, blocking all
other incoming commands for a specified period of time, allowing
time-slicing the command such that the caller can send incremental
requests to avoid monopolizing the driver/device. Any out of sync
(timeout) between the driver and hardware is just disregarded as
an invalid state until the next successful submission. Such timeouts
are considered a rare occurrence, either a real device problem or a
driver issue that needs to reduce the size of the background operation
to fit the timeout.

On devices where mbox interrupts are supported, this will still use
a poller that will wakeup in the specified wait intervals. The irq
handler will simply awake the blocked cmd, which is also safe vs a
task that is either waking (timing out) or already awoken. Similarly
any irq setup error during the probing falls back to polling, thus
avoids unnecessarily erroring out.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/20230523170927.20685-5-dave@stgolabs.net
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-23 12:55:12 -07:00
Davidlohr Bueso
9f7a320d16 cxl/pci: Introduce cxl_request_irq()
Factor out common functionality/semantics for cxl shared interrupts
into a new helper on top of devm_request_irq().

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/20230523170927.20685-4-dave@stgolabs.net
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-23 12:55:12 -07:00
Davidlohr Bueso
f279d0bc13 cxl/pci: Allocate irq vectors earlier during probe
Move the cxl_alloc_irq_vectors() call further up in the probing
in order to allow for mailbox interrupt usage. No change in
semantics.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/20230523170927.20685-3-dave@stgolabs.net
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-23 12:55:12 -07:00
Robert Richter
a70fc4ed20 cxl/port: Fix NULL pointer access in devm_cxl_add_port()
In devm_cxl_add_port() the port creation may fail and its associated
pointer does not contain a valid address. During error message
generation this invalid port address is used. Fix that wrong address
access.

Fixes: f3cd264c4ec1 ("cxl: Unify debug messages when calling devm_cxl_add_port()")
Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230519215436.3394532-1-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-19 17:47:01 -07:00
Dave Jiang
e764f12208 cxl: Move cxl_await_media_ready() to before capacity info retrieval
Move cxl_await_media_ready() to cxl_pci probe before driver starts issuing
IDENTIFY and retrieving memory device information to ensure that the
device is ready to provide the information. Allow cxl_pci_probe() to succeed
even if media is not ready. Cache the media failure in cxlds and don't ask
the device for any media information.

The rationale for proceeding in the !media_ready case is to allow for
mailbox operations to interrogate and/or remediate the device. After
media is repaired then rebinding the cxl_pci driver is expected to
restart the capacity scan.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Fixes: b39cb1052a5c ("cxl/mem: Register CXL memX devices")
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168445310026.3251520.8124296540679268206.stgit@djiang5-mobl3
[djbw: fixup cxl_test]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-18 16:43:45 -07:00
Dave Jiang
ce17ad0d54 cxl: Wait Memory_Info_Valid before access memory related info
The Memory_Info_Valid bit (CXL 3.0 8.1.3.8.2) indicates that the CXL
Range Size High and Size Low registers are valid. The bit must be set
within 1 second of reset deassertion to the device. Check valid bit
before we check the Memory_Active bit when waiting for
cxl_await_media_ready() to ensure that the memory info is valid for
consumption. Also ensures both DVSEC ranges 1 and 2 are ready if DVSEC
Capability indicates they are both supported.

Fixes: 523e594d9cc0 ("cxl/pci: Implement wait for media active")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168444687469.3134781.11033518965387297327.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-18 16:42:41 -07:00
Dan Williams
eb0764b822 cxl/port: Enable the HDM decoder capability for switch ports
Derick noticed, when testing hot plug, that hot-add behaves nominally
after a removal. However, if the hot-add is done without a prior
removal, CXL.mem accesses fail. It turns out that the original
implementation of the port driver and region programming wrongly assumed
that platform-firmware always enables the host-bridge HDM decoder
capability. Add support turning on switch-level HDM decoders in the case
where platform-firmware has not.

The implementation is careful to only arrange for the enable to be
undone if the current instance of the driver was the one that did the
enable. This is to interoperate with platform-firmware that may expect
CXL.mem to remain active after the driver is shutdown. This comes at the
cost of potentially not shutting down the enable on kexec flows, but it
is mitigated by the fact that the related HDM decoders still need to be
enabled on an individual basis.

Cc: <stable@vger.kernel.org>
Reported-by: Derick Marks <derick.w.marks@intel.com>
Fixes: 54cdbf845cf7 ("cxl/port: Add a driver for 'struct cxl_port' objects")
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/168437998331.403037.15719879757678389217.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-18 13:18:49 -07:00
Dave Jiang
764d102ef9 cxl: Add missing return to cdat read error path
Add a return to the error path when cxl_cdat_read_table() fails. Current
code continues with the table pointer points to freed memory.

Fixes: 7a877c923995 ("cxl/pci: Simplify CDAT retrieval error path")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/168382793506.3510737.4792518576623749076.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-13 00:20:06 -07:00
Linus Torvalds
7acc137211 cxl for v6.4
- Refactor the DOE infrastructure (Data Object Exchange PCI-config-cycle
   mailbox) to be a facility of the PCI core rather than the CXL core.
   This is foundational for upcoming support for PCI device-attestation and
   PCIe / CXL link encryption.
 
 - Add support for retrieving and injecting poison for CXL memory
   expanders. This enabling uses trace-events to convey CXL media error
   records to user tooling. It includes translation of device-local
   addresses (DPA) to system physical addresses (SPA) and their
   corresponding CXL region.
 
 - Fixes for decoder enumeration that missed v6.3-final
 
 - Miscellaneous fixups
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Merge tag 'cxl-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull compute express link updates from Dan Williams:
 "DOE support is promoted from drivers/cxl/ to drivers/pci/ with Bjorn's
  blessing, and the CXL core continues to mature its media management
  capabilities with support for listing and injecting media errors. Some
  late fixes that missed v6.3-final are also included:

   - Refactor the DOE infrastructure (Data Object Exchange
     PCI-config-cycle mailbox) to be a facility of the PCI core rather
     than the CXL core.

     This is foundational for upcoming support for PCI
     device-attestation and PCIe / CXL link encryption.

   - Add support for retrieving and injecting poison for CXL memory
     expanders.

     This enabling uses trace-events to convey CXL media error records
     to user tooling. It includes translation of device-local addresses
     (DPA) to system physical addresses (SPA) and their corresponding
     CXL region.

   - Fixes for decoder enumeration that missed v6.3-final

   - Miscellaneous fixups"

* tag 'cxl-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (38 commits)
  cxl/test: Add mock test for set_timestamp
  cxl/mbox: Update CMD_RC_TABLE
  tools/testing/cxl: Require CONFIG_DEBUG_FS
  tools/testing/cxl: Add a sysfs attr to test poison inject limits
  tools/testing/cxl: Use injected poison for get poison list
  tools/testing/cxl: Mock the Clear Poison mailbox command
  tools/testing/cxl: Mock the Inject Poison mailbox command
  cxl/mem: Add debugfs attributes for poison inject and clear
  cxl/memdev: Trace inject and clear poison as cxl_poison events
  cxl/memdev: Warn of poison inject or clear to a mapped region
  cxl/memdev: Add support for the Clear Poison mailbox command
  cxl/memdev: Add support for the Inject Poison mailbox command
  tools/testing/cxl: Mock support for Get Poison List
  cxl/trace: Add an HPA to cxl_poison trace events
  cxl/region: Provide region info to the cxl_poison trace event
  cxl/memdev: Add trigger_poison_list sysfs attribute
  cxl/trace: Add TRACE support for CXL media-error records
  cxl/mbox: Add GET_POISON_LIST mailbox command
  cxl/mbox: Initialize the poison state
  cxl/mbox: Restrict poison cmds to debugfs cxl_raw_allow_all
  ...
2023-04-30 11:51:51 -07:00
Linus Torvalds
556eb8b791 Driver core changes for 6.4-rc1
Here is the large set of driver core changes for 6.4-rc1.
 
 Once again, a busy development cycle, with lots of changes happening in
 the driver core in the quest to be able to move "struct bus" and "struct
 class" into read-only memory, a task now complete with these changes.
 
 This will make the future rust interactions with the driver core more
 "provably correct" as well as providing more obvious lifetime rules for
 all busses and classes in the kernel.
 
 The changes required for this did touch many individual classes and
 busses as many callbacks were changed to take const * parameters
 instead.  All of these changes have been submitted to the various
 subsystem maintainers, giving them plenty of time to review, and most of
 them actually did so.
 
 Other than those changes, included in here are a small set of other
 things:
   - kobject logging improvements
   - cacheinfo improvements and updates
   - obligatory fw_devlink updates and fixes
   - documentation updates
   - device property cleanups and const * changes
   - firwmare loader dependency fixes.
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...
2023-04-27 11:53:57 -07:00
Davidlohr Bueso
bfe58458fd cxl/mbox: Update CMD_RC_TABLE
As of CXL 3.0 there have some added return codes, update the
driver accordingly.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230307042655.6714-1-dave@stgolabs.net
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 12:10:26 -07:00
Dan Williams
ca899f4021 Merge branch 'for-6.3/cxl-autodetect-fixes' into for-6.4/cxl
Pick up late v6.3 fixes for v6.4.
2023-04-23 12:10:13 -07:00
Dan Williams
856ef55e7e Merge branch 'for-6.4/cxl-poison' into for-6.4/cxl
Include the poison list and injection infrastructure from Alison for
v6.4.
2023-04-23 12:09:56 -07:00
Alison Schofield
50d527f52c cxl/mem: Add debugfs attributes for poison inject and clear
Inject and Clear Poison commands are optionally supported by CXL
memdev devices and are intended for use in debug environments only.
Add debugfs attributes for user access.

Documentation/ABI/testing/debugfs-cxl describes the usage.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/0c9ea8e671b8e58465d18722788b60d325c675c7.1681874357.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 12:08:39 -07:00
Alison Schofield
98b6926562 cxl/memdev: Trace inject and clear poison as cxl_poison events
The cxl_poison trace event allows users to view the history of poison
list reads. With the addition of inject and clear poison capabilities,
users will expect similar tracing.

Add trace types 'Inject' and 'Clear' to the cxl_poison trace_event and
trace successful operations only.

If the driver finds that the DPA being injected or cleared of poison
is mapped in a region, that region info is included in the cxl_poison
trace event. Region reconfigurations can make this extra info useless
if the debug operations are not carefully managed.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/e20eb7c3029137b480ece671998c183da0477e2e.1681874357.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 12:08:39 -07:00
Alison Schofield
0a105ab28a cxl/memdev: Warn of poison inject or clear to a mapped region
Inject and clear poison capabilities and intended for debug usage only.
In order to be useful in debug environments, the driver needs to allow
inject and clear operations on DPAs mapped in regions.

dev_warn_once() when either operation occurs.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/f911ca5277c9d0f9757b72d7e6842871bfff4fa2.1681874357.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 11:46:22 -07:00
Alison Schofield
9690b07748 cxl/memdev: Add support for the Clear Poison mailbox command
CXL devices optionally support the CLEAR POISON mailbox command. Add
memdev driver support for clearing poison.

Per the CXL Specification (3.0 8.2.9.8.4.3), after receiving a valid
clear poison request, the device removes the address from the device's
Poison List and writes 0 (zero) for 64 bytes starting at address. If
the device cannot clear poison from the address, it returns a permanent
media error and -ENXIO is returned to the user.

Additionally, and per the spec also, it is not an error to clear poison
of an address that is not poisoned.

If the address is not contained in the device's dpa resource, or is
not 64 byte aligned, the driver returns -EINVAL without sending the
command to the device.

Poison clearing is intended for debug only and will be exposed to
userspace through debugfs. Restrict compilation to CONFIG_DEBUG_FS.

Implementation note: Although the CXL specification defines the clear
command to accept 64 bytes of 'write-data', this implementation always
uses zeroes as write-data.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/8682c30ec24bd9c45af5feccb04b02be51e58c0a.1681874357.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 11:46:22 -07:00
Alison Schofield
d2fbc48658 cxl/memdev: Add support for the Inject Poison mailbox command
CXL devices optionally support the INJECT POISON mailbox command. Add
memdev driver support for the mailbox command.

Per the CXL Specification (3.0 8.2.9.8.4.2), after receiving a valid
inject poison request, the device will return poison when the address
is accessed through the CXL.mem driver. Injecting poison adds the address
to the device's Poison List and the error source is set to Injected.
In addition, the device adds a poison creation event to its internal
Informational Event log, updates the Event Status register, and if
configured, interrupts the host.

Also, per the CXL Specification, it is not an error to inject poison
into an address that already has poison present and no error is
returned from the device.

If the address is not contained in the device's dpa resource, or is
not 64 byte aligned, return -EINVAL without issuing the mbox command.

Poison injection is intended for debug only and will be exposed to
userspace through debugfs. Restrict compilation to CONFIG_DEBUG_FS.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/241c64115e6bd2effed9c7a20b08b3908dd7be8f.1681874357.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 11:46:22 -07:00
Alison Schofield
28a3ae4ff6 cxl/trace: Add an HPA to cxl_poison trace events
When a cxl_poison trace event is reported for a region, the poisoned
Device Physical Address (DPA) can be translated to a Host Physical
Address (HPA) for consumption by user space.

Translate and add the resulting HPA to the cxl_poison trace event.
Follow the device decode logic as defined in the CXL Spec 3.0 Section
8.2.4.19.13.

If no region currently maps the poison, assign ULLONG_MAX to the
cxl_poison event hpa field.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/6d3cd726f9042a59902785b0a2cb3ddfb70e0219.1681838292.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 11:46:13 -07:00
Alison Schofield
f0832a5863 cxl/region: Provide region info to the cxl_poison trace event
User space may need to know which region, if any, maps the poison
address(es) logged in a cxl_poison trace event. Since the mapping
of DPAs (device physical addresses) to a region can change, the
kernel must provide this information at the time the poison list
is read. The event informs user space that at event <timestamp>
this <region> mapped to this <DPA>, which is poisoned.

The cxl_poison trace event is already wired up to log the region
name and uuid if it receives param 'struct cxl_region'.

In order to provide that cxl_region, add another method for gathering
poison - by committed endpoint decoder mappings. This method is only
available with CONFIG_CXL_REGION and is only used if a region actually
maps the memdev where poison is being read. After the region driver
reads the poison list for all the mapped resources, poison is read for
any remaining unmapped resources.

The default method remains: read the poison by memdev resource.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/438b01ccaa70592539e8eda4eb2b1d617ba03160.1681838292.git.alison.schofield@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-23 11:46:06 -07:00