Commit graph

521 commits

Author SHA1 Message Date
Alison Schofield
8a2e2336b8 cxl/trace: Properly initialize cxl_poison region name
[ Upstream commit 6c87126096 ]

The TP_STRUCT__entry that gets assigned the region name, or an
empty string if no region is present, is erroneously initialized
to the cxl_region pointer. It needs to be properly initialized
otherwise it's length is wrong and garbage chars can appear in
the kernel trace output: /sys/kernel/tracing/trace

The bad initialization was due in part to a naming conflict with
the parameter: struct cxl_region *region. The field 'region' is
already exposed externally as the region name, so changing that
to something logical, like 'region_name' is not an option. Instead
rename the internal only struct cxl_region to the commonly used
'cxlr'.

Impact is that tooling depending on that trace data can miss
picking up a valid event when searching by region name. The
TP_printk() output, if enabled, does emit the correct region
names in the dmesg log.

This was found during testing of the cxl-list option to report
media-errors for a region.

Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: stable@vger.kernel.org
Fixes: ddf49d57b8 ("cxl/trace: Add TRACE support for CXL media-error records")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:28:36 +02:00
Alison Schofield
0468ac5624 cxl/region: Allow out of order assembly of autodiscovered regions
[ Upstream commit cb66b1d60c ]

Autodiscovered regions can fail to assemble if they are not discovered
in HPA decode order. The user will see failure messages like:

[] cxl region0: endpoint5: HPA order violation region1
[] cxl region0: endpoint5: failed to allocate region reference

The check that is causing the failure helps the CXL driver enforce
a CXL spec mandate that decoders be committed in HPA order. The
check is needless for autodiscovered regions since their decoders
are already programmed. Trying to enforce order in the assembly of
these regions is useless because they are assembled once all their
member endpoints arrive, and there is no guarantee on the order in
which endpoints are discovered during probe.

Keep the existing check, but for autodiscovered regions, allow the
out of order assembly after a sanity check that the lesser numbered
decoder has the lesser HPA starting address.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Wonjae Lee <wj28.lee@samsung.com>
Link: https://lore.kernel.org/r/3dec69ee97524ab229a20c6739272c3000b18408.1706736863.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:19:12 -04:00
Alison Schofield
9f57eecf94 cxl/region: Handle endpoint decoders in cxl_region_find_decoder()
[ Upstream commit 453a7fde80 ]

In preparation for adding a new caller of cxl_region_find_decoders()
teach it to find a decoder from a cxl_endpoint_decoder structure.

Combining switch and endpoint decoder lookup in one function prevents
code duplication in call sites.

Update the existing caller.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Wonjae Lee <wj28.lee@samsung.com>
Link: https://lore.kernel.org/r/79ae6d72978ef9f3ceec9722e1cb793820553c8e.1706736863.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:19:12 -04:00
Robert Richter
2cc1a530ab cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window
commit 0cab687205 upstream.

The Linux CXL subsystem is built on the assumption that HPA == SPA.
That is, the host physical address (HPA) the HDM decoder registers are
programmed with are system physical addresses (SPA).

During HDM decoder setup, the DVSEC CXL range registers (cxl-3.1,
8.1.3.8) are checked if the memory is enabled and the CXL range is in
a HPA window that is described in a CFMWS structure of the CXL host
bridge (cxl-3.1, 9.18.1.3).

Now, if the HPA is not an SPA, the CXL range does not match a CFMWS
window and the CXL memory range will be disabled then. The HDM decoder
stops working which causes system memory being disabled and further a
system hang during HDM decoder initialization, typically when a CXL
enabled kernel boots.

Prevent a system hang and do not disable the HDM decoder if the
decoder's CXL range is not found in a CFMWS window.

Note the change only fixes a hardware hang, but does not implement
HPA/SPA translation. Support for this can be added in a follow on
patch series.

Signed-off-by: Robert Richter <rrichter@amd.com>
Fixes: 34e37b4c43 ("cxl/port: Enable HDM Capability after validating DVSEC Ranges")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20240216160113.407141-1-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01 13:34:59 +01:00
Dan Williams
8d584cc8e7 cxl/acpi: Fix load failures due to single window creation failure
commit 5c6224bfab upstream.

The expectation is that cxl_parse_cfwms() continues in the face the of
failure as evidenced by code like:

    cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb);
    if (IS_ERR(cxlrd))
    	return 0;

There are other error paths in that function which mistakenly follow
idiomatic expectations and return an error when they should not. Most of
those mistakes are innocuous checks that hardly ever fail in practice.
However, a recent change succeed in making the implementation more
fragile by applying an idiomatic, but still wrong "fix" [1]. In this
failure case the kernel reports:

    cxl root0: Failed to populate active decoder targets
    cxl_acpi ACPI0017:00: Failed to add decode range: [mem 0x00000000-0x7fffffff flags 0x200]

...which is a real issue with that one window (to be fixed separately),
but ends up failing the entirety of cxl_acpi_probe().

Undo that recent breakage while also removing the confusion about
ignoring errors. Update all exits paths to return an error per typical
expectations and let an outer wrapper function handle dropping the
error.

Fixes: 91019b5bc7 ("cxl/acpi: Return 'rc' instead of '0' in cxl_parse_cfmws()") [1]
Cc: <stable@vger.kernel.org>
Cc: Breno Leitao <leitao@debian.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01 13:34:59 +01:00
Quanquan Cao
40cb184ec8 cxl/region:Fix overflow issue in alloc_hpa()
commit d76779dd36 upstream.

Creating a region with 16 memory devices caused a problem. The div_u64_rem
function, used for dividing an unsigned 64-bit number by a 32-bit one,
faced an issue when SZ_256M * p->interleave_ways. The result surpassed
the maximum limit of the 32-bit divisor (4G), leading to an overflow
and a remainder of 0.
note: At this point, p->interleave_ways is 16, meaning 16 * 256M = 4G

To fix this issue, I replaced the div_u64_rem function with div64_u64_rem
and adjusted the type of the remainder.

Signed-off-by: Quanquan Cao <caoqq@fujitsu.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Fixes: 23a22cd1c9 ("cxl/region: Allocate HPA capacity to regions")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:19:13 -08:00
Dan Williams
1a5369728c cxl/port: Fix missing target list lock
[ Upstream commit 5459e186a5 ]

cxl_port_setup_targets() modifies the ->targets[] array of a switch
decoder. target_list_show() expects to be able to emit a coherent
snapshot of that array by "holding" ->target_lock for read. The
target_lock is held for write during initialization of the ->targets[]
array, but it is not held for write during cxl_port_setup_targets().

The ->target_lock() predates the introduction of @cxl_region_rwsem. That
semaphore protects changes to host-physical-address (HPA) decode which
is precisely what writes to a switch decoder's target list affects.

Replace ->target_lock with @cxl_region_rwsem.

Now the side-effect of snapshotting a unstable view of a decoder's
target list is likely benign so the Fixes: tag is presumptive.

Fixes: 27b3f8d138 ("cxl/region: Program target lists")
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:35:55 -08:00
Jim Harris
a2b2b30118 cxl/region: fix x9 interleave typo
[ Upstream commit c7ad3dc364 ]

CXL supports x3, x6 and x12 - not x9.

Fixes: 80d10a6cee ("cxl/region: Add interleave geometry attributes")
Signed-off-by: Jim Harris <jim.harris@samsung.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Link: https://lore.kernel.org/r/169904271254.204936.8580772404462743630.stgit@ubuntu
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:35:54 -08:00
Huang Ying
5a473e3208 cxl/port: Fix decoder initialization when nr_targets > interleave_ways
commit d6488fee66 upstream.

The decoder_populate_targets() helper walks all of the targets in a port
and makes sure they can be looked up in @target_map. Where @target_map
is a lookup table from target position to target id (corresponding to a
cxl_dport instance). However @target_map is only responsible for
conveying the active dport instances as indicated by interleave_ways.

When nr_targets > interleave_ways it results in
decoder_populate_targets() walking off the end of the valid entries in
@target_map. Given target_map is initialized to 0 it results in the
dport lookup failing if position 0 is not mapped to a dport with an id
of 0:

  cxl_port port3: Failed to populate active decoder targets
  cxl_port port3: Failed to add decoder
  cxl_port port3: Failed to add decoder3.0
  cxl_bus_probe: cxl_port port3: probe: -6

This bug also highlights that when the decoder's ->targets[] array is
written in cxl_port_setup_targets() it is missing a hold of the
targets_lock to synchronize against sysfs readers of the target list. A
fix for that is saved for a later patch.

Fixes: a5c2580216 ("cxl/bus: Populate the target list at decoder create")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Huang, Ying <ying.huang@intel.com>
[djbw: rewrite the changelog, find the Fixes: tag]
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25 15:35:47 -08:00
Alison Schofield
c897fb3da8 cxl/memdev: Hold region_rwsem during inject and clear poison ops
commit 0e33ac9c3f upstream.

Poison inject and clear are supported via debugfs where a privileged
user can inject and clear poison to a device physical address.

Commit 458ba8189c ("cxl: Add cxl_decoders_committed() helper")
added a lockdep assert that highlighted a gap in poison inject and
clear functions where holding the dpa_rwsem does not assure that a
a DPA is not added to a region.

The impact for inject and clear is that if the DPA address being
injected or cleared has been attached to a region, but not yet
committed, the dev_dbg() message intended to alert the debug user
that they are acting on a mapped address is not emitted. Also, the
cxl_poison trace event that serves as a log of the inject and clear
activity will not include region info.

Close this gap by snapshotting an unchangeable region state during
poison inject and clear operations. That means holding both the
region_rwsem and the dpa_rwsem during the inject and clear ops.

Fixes: d2fbc48658 ("cxl/memdev: Add support for the Inject Poison mailbox command")
Fixes: 9690b07748 ("cxl/memdev: Add support for the Clear Poison mailbox command")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/08721dc1df0a51e4e38fecd02425c3475912dfd5.1701041440.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-10 17:17:02 +01:00
Dave Jiang
0a460481df cxl/hdm: Fix a benign lockdep splat
commit 36a1c2ee50 upstream.

The new helper "cxl_num_decoders_committed()" added a lockdep assertion
to validate that port->commit_end is protected against modification.
That assertion fires in init_hdm_decoder() where it is initializing
port->commit_end. Given that it is both accessing and writing that
property it obstensibly needs the lock.

In practice, CXL decoder commit rules (must commit in order) and the
in-order discovery of device decoders makes the manipulation of
->commit_end in init_hdm_decoder() safe. However, rather than rely on
the subtle rules of CXL hardware, just make the implementation obviously
correct from a software perspective.

The Fixes: tag is only for cleaning up a lockdep splat, there is no
functional issue addressed by this fix.

Fixes: 458ba8189c ("cxl: Add cxl_decoders_committed() helper")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/170025232811.2147250.16376901801315194121.stgit@djiang5-mobl3
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-10 17:17:02 +01:00
Ira Weiny
5107937851 cxl/pmu: Ensure put_device on pmu devices
[ Upstream commit ef3d5cf9c5 ]

The following kmemleaks were detected when removing the cxl module
stack:

unreferenced object 0xffff88822616b800 (size 1024):
...
  backtrace:
    [<00000000bedc6f83>] kmalloc_trace+0x26/0x90
    [<00000000448d1afc>] devm_cxl_pmu_add+0x3a/0x110 [cxl_core]
    [<00000000ca3bfe16>] 0xffffffffa105213b
    [<00000000ba7f78dc>] local_pci_probe+0x41/0x90
    [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0
...
unreferenced object 0xffff8882260abcc0 (size 16):
...
  hex dump (first 16 bytes):
    70 6d 75 5f 6d 65 6d 30 2e 30 00 26 82 88 ff ff  pmu_mem0.0.&....
  backtrace:
...
    [<00000000152b5e98>] dev_set_name+0x43/0x50
    [<00000000c228798b>] devm_cxl_pmu_add+0x102/0x110 [cxl_core]
    [<00000000ca3bfe16>] 0xffffffffa105213b
    [<00000000ba7f78dc>] local_pci_probe+0x41/0x90
    [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0
...
unreferenced object 0xffff8882272af200 (size 256):
...
  backtrace:
    [<00000000bedc6f83>] kmalloc_trace+0x26/0x90
    [<00000000a14d1813>] device_add+0x4ea/0x890
    [<00000000a3f07b47>] devm_cxl_pmu_add+0xbe/0x110 [cxl_core]
    [<00000000ca3bfe16>] 0xffffffffa105213b
    [<00000000ba7f78dc>] local_pci_probe+0x41/0x90
    [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0
...

devm_cxl_pmu_add() correctly registers a device remove function but it
only calls device_del() which is only part of device unregistration.

Properly call device_unregister() to free up the memory associated with
the device.

Fixes: 1ad3f701c3 ("cxl/pci: Find and register CXL PMU devices")
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20231016-pmu-unregister-fix-v1-1-1e2eb2fa3c69@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-10 17:16:59 +01:00
Alison Schofield
4c269350e3 cxl/core: Always hold region_rwsem while reading poison lists
[ Upstream commit 5558b92e8d ]

A read of a device poison list is triggered via a sysfs attribute
and the results are logged as kernel trace events of type cxl_poison.
The work is managed by either: a) the region driver when one of more
regions map the device, or by b) the memdev driver when no regions
map the device.

In the case of a) the region driver holds the region_rwsem while
reading the poison by committed endpoint decoder mappings and for
any unmapped resources. This makes sure that the cxl_poison trace
event trace reports valid region info. (Region name, HPA, and UUID).

In the case of b) the memdev driver holds the dpa_rwsem preventing
new DPA resources from being attached to a region. However, it leaves
a gap between region attach and decoder commit actions. If a DPA in
the gap is in the poison list, the cxl_poison trace event will omit
the region info.

Close the gap by holding the region_rwsem and the dpa_rwsem when
reading poison per memdev. Since both methods now hold both locks,
down_read both from the caller. Doing so also addresses the lockdep
assert that found this issue:
Commit 458ba8189c ("cxl: Add cxl_decoders_committed() helper")

Fixes: f0832a5863 ("cxl/region: Provide region info to the cxl_poison trace event")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/08e8e7ec9a3413b91d51de39e385653494b1eed0.1701041440.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-10 17:16:58 +01:00
Dave Jiang
07f9a20b89 cxl: Add cxl_decoders_committed() helper
[ Upstream commit 458ba8189c ]

Add a helper to retrieve the number of decoders committed for the port.
Replace all the open coding of the calculation with the helper.

Link: https://lore.kernel.org/linux-cxl/651c98472dfed_ae7e729495@dwillia2-xfh.jf.intel.com.notmuch/
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jim Harris <jim.harris@samsung.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/169747906849.272156.1729290904857372335.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 5558b92e8d ("cxl/core: Always hold region_rwsem while reading poison lists")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-10 17:16:58 +01:00
Dan Williams
c1d2d08475 cxl/hdm: Fix dpa translation locking
commit 6f5c4eca48 upstream.

The helper, cxl_dpa_resource_start(), snapshots the dpa-address of an
endpoint-decoder after acquiring the cxl_dpa_rwsem. However, it is
sufficient to assert that cxl_dpa_rwsem is held rather than acquire it
in the helper. Otherwise, it triggers multiple lockdep reports:

1/ Tracing callbacks are in an atomic context that can not acquire sleeping
locks:

    BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1525
    in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1288, name: bash
    preempt_count: 2, expected: 0
    RCU nest depth: 0, expected: 0
    [..]
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc38 05/24/2023
    Call Trace:
     <TASK>
     dump_stack_lvl+0x71/0x90
     __might_resched+0x1b2/0x2c0
     down_read+0x1a/0x190
     cxl_dpa_resource_start+0x15/0x50 [cxl_core]
     cxl_trace_hpa+0x122/0x300 [cxl_core]
     trace_event_raw_event_cxl_poison+0x1c9/0x2d0 [cxl_core]

2/ The rwsem is already held in the inject poison path:

    WARNING: possible recursive locking detected
    6.7.0-rc2+ #12 Tainted: G        W  OE    N
    --------------------------------------------
    bash/1288 is trying to acquire lock:
    ffffffffc05f73d0 (cxl_dpa_rwsem){++++}-{3:3}, at: cxl_dpa_resource_start+0x15/0x50 [cxl_core]

    but task is already holding lock:
    ffffffffc05f73d0 (cxl_dpa_rwsem){++++}-{3:3}, at: cxl_inject_poison+0x7d/0x1e0 [cxl_core]
    [..]
    Call Trace:
     <TASK>
     dump_stack_lvl+0x71/0x90
     __might_resched+0x1b2/0x2c0
     down_read+0x1a/0x190
     cxl_dpa_resource_start+0x15/0x50 [cxl_core]
     cxl_trace_hpa+0x122/0x300 [cxl_core]
     trace_event_raw_event_cxl_poison+0x1c9/0x2d0 [cxl_core]
     __traceiter_cxl_poison+0x5c/0x80 [cxl_core]
     cxl_inject_poison+0x1bc/0x1e0 [cxl_core]

This appears to have been an issue since the initial implementation and
uncovered by the new cxl-poison.sh test [1]. That test is now passing with
these changes.

Fixes: 28a3ae4ff6 ("cxl/trace: Add an HPA to cxl_poison trace events")
Link: http://lore.kernel.org/r/e4f2716646918135ddbadf4146e92abb659de734.1700615159.git.alison.schofield@intel.com [1]
Cc: <stable@vger.kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20 17:02:01 +01:00
Dan Williams
6b2e428e67 cxl/port: Fix delete_endpoint() vs parent unregistration race
commit 8d2ad999ca upstream.

The CXL subsystem, at cxl_mem ->probe() time, establishes a lineage of
ports (struct cxl_port objects) between an endpoint and the root of a
CXL topology. Each port including the endpoint port is attached to the
cxl_port driver.

Given that setup, it follows that when either any port in that lineage
goes through a cxl_port ->remove() event, or the memdev goes through a
cxl_mem ->remove() event. The hierarchy below the removed port, or the
entire hierarchy if the memdev is removed needs to come down.

The delete_endpoint() callback is careful to check whether it is being
called to tear down the hierarchy, or if it is only being called to
teardown the memdev because an ancestor port is going through
->remove().

That care needs to take the device_lock() of the endpoint's parent.
Which requires 2 bugs to be fixed:

1/ A reference on the parent is needed to prevent use-after-free
   scenarios like this signature:

    BUG: spinlock bad magic on CPU#0, kworker/u56:0/11
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc38 05/24/2023
    Workqueue: cxl_port detach_memdev [cxl_core]
    RIP: 0010:spin_bug+0x65/0xa0
    Call Trace:
      do_raw_spin_lock+0x69/0xa0
     __mutex_lock+0x695/0xb80
     delete_endpoint+0xad/0x150 [cxl_core]
     devres_release_all+0xb8/0x110
     device_unbind_cleanup+0xe/0x70
     device_release_driver_internal+0x1d2/0x210
     detach_memdev+0x15/0x20 [cxl_core]
     process_one_work+0x1e3/0x4c0
     worker_thread+0x1dd/0x3d0

2/ In the case of RCH topologies, the parent device that needs to be
   locked is not always @port->dev as returned by cxl_mem_find_port(), use
   endpoint->dev.parent instead.

Fixes: 8dd2bc0f8e ("cxl/mem: Add the cxl_mem driver")
Cc: <stable@vger.kernel.org>
Reported-by: Robert Richter <rrichter@amd.com>
Closes: http://lore.kernel.org/r/20231018171713.1883517-2-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:20:07 +00:00
Jim Harris
8a9ab9037f cxl/region: Fix x1 root-decoder granularity calculations
commit 98a04c7ace upstream.

Root decoder granularity must match value from CFWMS, which may not
be the region's granularity for non-interleaved root decoders.

So when calculating granularities for host bridge decoders, use the
region's granularity instead of the root decoder's granularity to ensure
the correct granularities are set for the host bridge decoders and any
downstream switch decoders.

Test configuration is 1 host bridge * 2 switches * 2 endpoints per switch.

Region created with 2048 granularity using following command line:

cxl create-region -m -d decoder0.0 -w 4 mem0 mem2 mem1 mem3 \
		  -g 2048 -s 2048M

Use "cxl list -PDE | grep granularity" to get a view of the granularity
set at each level of the topology.

Before this patch:
        "interleave_granularity":2048,
        "interleave_granularity":2048,
    "interleave_granularity":512,
        "interleave_granularity":2048,
        "interleave_granularity":2048,
    "interleave_granularity":512,
"interleave_granularity":256,

After:
        "interleave_granularity":2048,
        "interleave_granularity":2048,
    "interleave_granularity":4096,
        "interleave_granularity":2048,
        "interleave_granularity":2048,
    "interleave_granularity":4096,
"interleave_granularity":2048,

Fixes: 27b3f8d138 ("cxl/region: Program target lists")
Cc: <stable@vger.kernel.org>
Signed-off-by: Jim Harris <jim.harris@samsung.com>
Link: https://lore.kernel.org/r/169824893473.1403938.16110924262989774582.stgit@bgt-140510-bm03.eng.stellus.in
[djbw: fixup the prebuilt cxl_test region]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:20:07 +00:00
Jim Harris
07ffcd8ec7 cxl/region: Do not try to cleanup after cxl_region_setup_targets() fails
commit 0718588c7a upstream.

Commit 5e42bcbc3f ("cxl/region: decrement ->nr_targets on error in
cxl_region_attach()") tried to avoid 'eiw' initialization errors when
->nr_targets exceeded 16, by just decrementing ->nr_targets when
cxl_region_setup_targets() failed.

Commit 86987c7662 ("cxl/region: Cleanup target list on attach error")
extended that cleanup to also clear cxled->pos and p->targets[pos]. The
initialization error was incidentally fixed separately by:
Commit 8d42854257 ("cxl/region: Fix port setup uninitialized variable
warnings") which was merged a few days after 5e42bcbc3f.

But now the original cleanup when cxl_region_setup_targets() fails
prevents endpoint and switch decoder resources from being reused:

1) the cleanup does not set the decoder's region to NULL, which results
   in future dpa_size_store() calls returning -EBUSY
2) the decoder is not properly freed, which results in future commit
   errors associated with the upstream switch

Now that the initialization errors were fixed separately, the proper
cleanup for this case is to just return immediately. Then the resources
associated with this target get cleanup up as normal when the failed
region is deleted.

The ->nr_targets decrement in the error case also helped prevent
a p->targets[] array overflow, so add a new check to prevent against
that overflow.

Tested by trying to create an invalid region for a 2 switch * 2 endpoint
topology, and then following up with creating a valid region.

Fixes: 5e42bcbc3f ("cxl/region: decrement ->nr_targets on error in cxl_region_attach()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Jim Harris <jim.harris@samsung.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/169703589120.1202031.14696100866518083806.stgit@bgt-140510-bm03.eng.stellus.in
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:20:06 +00:00
Dan Williams
6723e58d6f cxl/hdm: Remove broken error path
[ Upstream commit 5d09c63f11 ]

Dan reports that cxl_decoder_commit() potentially leaks a hold of
cxl_dpa_rwsem. The potential error case is a "should not" happen
scenario, turn it into a "can not" happen scenario by adding the error
check to cxl_port_setup_targets() where other setting validation occurs.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: http://lore.kernel.org/r/63295673-5d63-4919-b851-3b06d48734c0@moroto.mountain
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Fixes: 176baefb2e ("cxl/hdm: Commit decoder state to hardware")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:31 +01:00
Dan Williams
8b52796351 cxl/port: Fix @host confusion in cxl_dport_setup_regs()
[ Upstream commit 33d9c987bf ]

commit 5d2ffbe4b8 ("cxl/port: Store the downstream port's Component Register mappings in struct cxl_dport")

...moved the dport component registers from a raw component_reg_phys
passed in at dport instantiation time to a 'struct cxl_register_map'
populated with both the component register data *and* the "host" device
for mapping operations.

While typical CXL switch dports are mapped by their associated 'struct
cxl_port', an RCH host bridge dport registered by cxl_acpi needs to wait
until the cxl_mem driver makes the attachment to map the registers. This
is because there are no intervening 'struct cxl_port' instances between
the root cxl_port and the endpoint port in an RCH topology.

For now just mark the host as NULL in the RCH dport case until code that
needs to map the dport registers arrives.

This patch is not flagged for -stable since nothing in the current
driver uses the dport->comp_map.

Now, I am slightly uneasy that cxl_setup_comp_regs() sets map->host to a
wrong value and then cxl_dport_setup_regs() fixes it up, but the
alternatives I came up with are more messy. For example, adding an
@logdev to 'struct cxl_register_map' that the dev_printk()s can fall
back to when @host is NULL. I settled on "post-fixup+comment" since it
is only RCH dports that have this special case where register probing is
split between a host-bridge RCRB lookup and when cxl_mem_probe() does
the association of the cxl_memdev and endpoint port.

[moved rename of @comp_map to @reg_map into next patch]

Fixes: 5d2ffbe4b8 ("cxl/port: Store the downstream port's Component Register mappings in struct cxl_dport")
Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20231018171713.1883517-4-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:31 +01:00
Robert Richter
0fc37ec1b5 cxl/core/regs: Rename @dev to @host in struct cxl_register_map
[ Upstream commit dd22581f89 ]

The primary role of @dev is to host the mappings for devm operations.
@dev is too ambiguous as a name. I.e. when does @dev refer to the
'struct device *' instance that the registers belong, and when does
@dev refer to the 'struct device *' instance hosting the mapping for
devm operations?

Clarify the role of @dev in cxl_register_map by renaming it to @host.
Also, rename local variables to 'host' where map->host is used.

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/20231018171713.1883517-3-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 33d9c987bf ("cxl/port: Fix @host confusion in cxl_dport_setup_regs()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:31 +01:00
Li Zhijian
41f3c9f024 cxl/region: Fix cxl_region_rwsem lock held when returning to user space
[ Upstream commit 3531b27f1f ]

Fix a missed "goto out" to unlock on error to cleanup this splat:

    WARNING: lock held when returning to user space!
    6.6.0-rc3-lizhijian+ #213 Not tainted
    ------------------------------------------------
    cxl/673 is leaving the kernel with locks still held!
    1 lock held by cxl/673:
     #0: ffffffffa013b9d0 (cxl_region_rwsem){++++}-{3:3}, at: commit_store+0x7d/0x3e0 [cxl_core]

In terms of user visible impact of this bug for backports:

cxl_region_invalidate_memregion() on x86 invokes wbinvd which is a
problematic instruction for virtualized environments. So, on virtualized
x86, cxl_region_invalidate_memregion() returns an error. This failure
case got missed because CXL memory-expander device passthrough is not a
production use case, and emulation of CXL devices is typically limited
to kernel development builds with CONFIG_CXL_REGION_INVALIDATION_TEST=y,
that makes cxl_region_invalidate_memregion() succeed.

In other words, the expected exposure of this bug is limited to CXL
subsystem development environments using QEMU that neglected
CONFIG_CXL_REGION_INVALIDATION_TEST=y.

Fixes: d1257d098a ("cxl/region: Move cache invalidation before region teardown, and before setup")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20231025085450.2514906-1-lizhijian@fujitsu.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:31 +01:00
Alison Schofield
3cfdfce011 cxl/region: Use cxl_calc_interleave_pos() for auto-discovery
[ Upstream commit 0cf36a85c1 ]

For auto-discovered regions the driver must assign each target to
a valid position in the region interleave set based on the decoder
topology.

The current implementation fails to parse valid decode topologies,
as it does not consider the child offset into a parent port. The sort
put all targets of one port ahead of another port when an interleave
was expected, causing the region assembly to fail.

Replace the existing relative sort with cxl_calc_interleave_pos() that
finds the exact position in a region interleave for an endpoint based
on a walk up the ancestral tree from endpoint to root decoder.

cxl_calc_interleave_pos() was introduced in a prior patch, so the work
here is to use it in cxl_region_sort_targets().

Remove the obsoleted helper functions from the prior sort.

Testing passes on pre-production hardware with BIOS defined regions
that natively trigger this autodiscovery path of the region driver.
Testing passes a CXL unit test using the dev_dbg() calculation test
(see cxl_region_attach()) across an expanded set of region configs:
1, 1, 1+1, 1+1+1, 2, 2+2, 2+2+2, 2+2+2+2, 4, 4+4, where each number
represents the count of endpoints per host bridge.

Fixes: a32320b71f ("cxl/region: Add region autodiscovery")
Reported-by: Dmytro Adamenko <dmytro.adamenko@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jim Harris <jim.harris@samsung.com>
Link: https://lore.kernel.org/r/3946cc55ddc19678733eddc9de2c317749f43f3b.1698263080.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Alison Schofield
c6ffabc66d cxl/region: Calculate a target position in a region interleave
[ Upstream commit a3e00c964f ]

Introduce a calculation to find a target's position in a region
interleave. Perform a self-test of the calculation on user-defined
regions.

The region driver uses the kernel sort() function to put region
targets in relative order. Positions are assigned based on each
target's index in that sorted list. That relative sort doesn't
consider the offset of a port into its parent port which causes
some auto-discovered regions to fail creation. In one failure case,
a 2 + 2 config (2 host bridges each with 2 endpoints), the sort
puts all the targets of one port ahead of another port when they
were expected to be interleaved.

In preparation for repairing the autodiscovery region assembly,
introduce a new method for discovering a target position in the
region interleave.

cxl_calc_interleave_pos() adds a method to find the target position by
ascending from an endpoint to a root decoder. The calculation starts
with the endpoint's local position and position in the parent port. It
traverses towards the root decoder and examines both position and ways
in order to allow the position to be refined all the way to the root
decoder.

This calculation: position = position * parent_ways + parent_pos;
applied iteratively yields the correct position.

Include a self-test that exercises this new position calculation against
every successfully configured user-defined region.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/0ac32c75cf81dd8b86bf07d70ff139d33c2300bc.1698263080.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 0cf36a85c1 ("cxl/region: Use cxl_calc_interleave_pos() for auto-discovery")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Alison Schofield
c4255b9b0a cxl/region: Prepare the decoder match range helper for reuse
[ Upstream commit 1110581412 ]

match_decoder_by_range() and decoder_match_range() both determine
if an HPA range matches a decoder. The first does it for root
decoders and the second one operates on switch decoders.

Tidy these up with clear naming and make the switch helper more
like the root decoder helper in style and functionality. Make it
take the actual range, rather than an endpoint decoder from which
it extracts the range. Require an exact match on switch decoders,
because unlike a root decoder that maps an entire region, Linux
only supports 1:1 mapping of switch to endpoint decoders. Note that
root-decoders are a super-set of switch-decoders and the range they
cover is a super-set of a region, hence the use of range_contains() for
that case.

Aside from aesthetics and maintainability, this is in preparation
for reuse.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jim Harris <jim.harris@samsung.com>
Link: https://lore.kernel.org/r/011b1f498e1758bb8df17c5951be00bd8d489e3b.1698263080.git.alison.schofield@intel.com
[djbw: fixup root decoder vs switch decoder range checks]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 0cf36a85c1 ("cxl/region: Use cxl_calc_interleave_pos() for auto-discovery")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Dan Williams
0ca074f7d7 cxl/mem: Fix shutdown order
[ Upstream commit 88d3917f82 ]

Ira reports that removing cxl_mock_mem causes a crash with the following
trace:

 BUG: kernel NULL pointer dereference, address: 0000000000000044
 [..]
 RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core]
 [..]
 Call Trace:
  <TASK>
  cxl_region_detach+0xe8/0x210 [cxl_core]
  cxl_decoder_kill_region+0x27/0x40 [cxl_core]
  cxld_unregister+0x29/0x40 [cxl_core]
  devres_release_all+0xb8/0x110
  device_unbind_cleanup+0xe/0x70
  device_release_driver_internal+0x1d2/0x210
  bus_remove_device+0xd7/0x150
  device_del+0x155/0x3e0
  device_unregister+0x13/0x60
  devm_release_action+0x4d/0x90
  ? __pfx_unregister_port+0x10/0x10 [cxl_core]
  delete_endpoint+0x121/0x130 [cxl_core]
  devres_release_all+0xb8/0x110
  device_unbind_cleanup+0xe/0x70
  device_release_driver_internal+0x1d2/0x210
  bus_remove_device+0xd7/0x150
  device_del+0x155/0x3e0
  ? lock_release+0x142/0x290
  cdev_device_del+0x15/0x50
  cxl_memdev_unregister+0x54/0x70 [cxl_core]

This crash is due to the clearing out the cxl_memdev's driver context
(@cxlds) before the subsystem is done with it. This is ultimately due to
the region(s), that this memdev is a member, being torn down and expecting
to be able to de-reference @cxlds, like here:

static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
...
                if (cxlds->rcd)
                        goto endpoint_reset;
...

Fix it by keeping the driver context valid until memdev-device
unregistration, and subsequently the entire stack of related
dependencies, unwinds.

Fixes: 9cc238c7a5 ("cxl/pci: Introduce cdevm_file_operations")
Reported-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Dan Williams
d1d13a0934 cxl/memdev: Fix sanitize vs decoder setup locking
[ Upstream commit 3398183808 ]

The sanitize operation is destructive and the expectation is that the
device is unmapped while in progress. The current implementation does a
lockless check for decoders being active, but then does nothing to
prevent decoders from racing to be committed. Introduce state tracking
to resolve this race.

This incidentally cleans up unpriveleged userspace from triggering mmio
read cycles by spinning on reading the 'security/state' attribute. Which
at a minimum is a waste since the kernel state machine can cache the
completion result.

Lastly cxl_mem_sanitize() was mistakenly marked EXPORT_SYMBOL() in the
original implementation, but an export was never required.

Fixes: 0c36b6ad43 ("cxl/mbox: Add sanitization handling machinery")
Cc: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Dan Williams
d4e21e7b94 cxl/pci: Fix sanitize notifier setup
[ Upstream commit 5f2da19714 ]

Fix a race condition between the mailbox-background command interrupt
firing and the security-state sysfs attribute being removed.

The race is difficult to see due to the awkward placement of the
sanitize-notifier setup code and the multiple places the teardown calls
are made, cxl_memdev_security_init() and cxl_memdev_security_shutdown().

Unify setup in one place, cxl_sanitize_setup_notifier(). Arrange for
the paired cxl_sanitize_teardown_notifier() to safely quiet the notifier
and let the cxl_memdev + irq be unregistered later in the flow.

Note: The special wrinkle of the sanitize notifier is that it interacts
with interrupts, which are enabled early in the flow, and it interacts
with memdev sysfs which is not initialized until late in the flow. Hence
why this setup routine takes an @cxlmd argument, and not just @mds.

This fix is also needed as a preparation fix for a memdev unregistration
crash.

Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Closes: http://lore.kernel.org/r/20230929100316.00004546@Huawei.com
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Fixes: 0c36b6ad43 ("cxl/mbox: Add sanitization handling machinery")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Dan Williams
22c9bb1ed1 cxl/pci: Clarify devm host for memdev relative setup
[ Upstream commit f29a824b0b ]

It is all too easy to get confused about @dev usage in the CXL driver
stack. Before adding a new cxl_pci_probe() setup operation that has a
devm lifetime dependent on @cxlds->dev binding, but also references
@cxlmd->dev, and prints messages, rework the devm_cxl_add_memdev() and
cxl_memdev_setup_fw_upload() function signatures to make this
distinction explicit. I.e. pass in the devm context as an @host argument
rather than infer it from other objects.

This is in preparation for adding a devm_cxl_sanitize_setup_notifier().

Note the whitespace fixup near the change of the devm_cxl_add_memdev()
signature. That uncaught typo originated in the patch that added
cxl_memdev_security_init().

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 5f2da19714 ("cxl/pci: Fix sanitize notifier setup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Dan Williams
c57d7ce488 cxl/pci: Remove inconsistent usage of dev_err_probe()
[ Upstream commit 2627c995c1 ]

If dev_err_probe() is to be used it should at least be used consistently
within the same function. It is also worth questioning whether
every potential -ENOMEM needs an explicit error message.

Remove the cxl_setup_fw_upload() error prints for what are rare /
hardware-independent failures.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 5f2da19714 ("cxl/pci: Fix sanitize notifier setup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Dan Williams
e8347a1ce0 cxl/pci: Cleanup 'sanitize' to always poll
[ Upstream commit e30a106558 ]

In preparation for fixing the init/teardown of the 'sanitize' workqueue
and sysfs notification mechanism, arrange for cxl_mbox_sanitize_work()
to be the single location where the sysfs attribute is notified. With
that change there is no distinction between polled mode and interrupt
mode. All the interrupt does is accelerate the polling interval.

The change to check for "mds->security.sanitize_node" under the lock is
there to ensure that the interrupt, the work routine and the
setup/teardown code can all have a consistent view of the registered
notifier and the workqueue state. I.e. the expectation is that the
interrupt is live past the point that the sanitize sysfs attribute is
published, and it may race teardown, so it must be consulted under a
lock. Given that new locking requirement, cxl_pci_mbox_irq() is moved
from hard to thread irq context.

Lastly, some opportunistic replacements of
"queue_delayed_work(system_wq, ...)", which is just open coded
schedule_delayed_work(), are included.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 5f2da19714 ("cxl/pci: Fix sanitize notifier setup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Dan Williams
f5355d4e48 cxl/pci: Remove unnecessary device reference management in sanitize work
[ Upstream commit 76fe8713dd ]

Given that any particular put_device() could be the final put of the
device, the fact that there are usages of cxlds->dev after
put_device(cxlds->dev) is a red flag. Drop the reference counting since
the device is pinned by being registered and will not be unregistered
without triggering the driver + workqueue to shutdown.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Stable-dep-of: 5f2da19714 ("cxl/pci: Fix sanitize notifier setup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:30 +01:00
Kees Cook
c66650d297 cxl/acpi: Annotate struct cxl_cxims_data with __counted_by
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct cxl_cxims_data.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-cxl@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230922175319.work.096-kees@kernel.org
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-22 14:31:04 -07:00
Dan Williams
a76b62518e cxl/port: Fix cxl_test register enumeration regression
The cxl_test unit test environment models a CXL topology for
sysfs/user-ABI regression testing. It uses interface mocking via the
"--wrap=" linker option to redirect cxl_core routines that parse
hardware registers with versions that just publish objects, like
devm_cxl_enumerate_decoders().

Starting with:

Commit 19ab69a60e ("cxl/port: Store the port's Component Register mappings in struct cxl_port")

...port register enumeration is moved into devm_cxl_add_port(). This
conflicts with the "cxl_test avoids emulating registers stance" so
either the port code needs to be refactored (too violent), or modified
so that register enumeration is skipped on "fake" cxl_test ports
(annoying, but straightforward).

This conflict has happened previously and the "check for platform
device" workaround to avoid instrusive refactoring was deployed in those
scenarios. In general, refactoring should only benefit production code,
test code needs to remain minimally instrusive to the greatest extent
possible.

This was missed previously because it may sometimes just cause warning
messages to be emitted, but it can also cause test failures. The
backport to -stable is only nice to have for clean cxl_test runs.

Fixes: 19ab69a60e ("cxl/port: Store the port's Component Register mappings in struct cxl_port")
Cc: stable@vger.kernel.org
Reported-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/169476525052.1013896.6235102957693675187.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-22 14:28:42 -07:00
Alison Schofield
18f35dc931 cxl/region: Refactor granularity select in cxl_port_setup_targets()
In cxl_port_setup_targets() the region driver validates the
configuration of auto-discovered region decoders, as well
as decoders the driver is preparing to program.

The existing calculations use the encoded interleave granularity
value to create an interleave granularity that properly fans out
when routing an x1 interleave to a greater than x1 interleave.

That all worked well, until this config came along:
Host Bridge: 2 way at 256 granularity
    Switch Decoder_A:	1 way at 512
        Endpoint_X:	2 way at 256
    Switch Decoder_B:	1 way at 512
        Endpoint_Y:	2 way at 256

When the Host Bridge interleave is greater than 1 and the root
decoder interleave is exactly 1, the region driver needs to
consider the number of targets in the region when calculating
the expected granularity.

While examining the existing logic, and trying to cover the case
above, a couple of simplifications appeared, hence this proposed
refactoring.

The first simplification is to apply the logic to the nominal
values and use the existing helper function granularity_to_eig() to
translate the desired granularity to the encoded form. This means
the comment and code regarding setting address bits is discarded.
Although that logic is not wrong, it adds a level of complexity that
is not required in the granularity selection. The eig and eiw are
indeed part of the routing instructions programmed into the decoders.
Up-level the discussion to nominal ways and granularity for clearer
analysis.

The second simplification reduces the logic to a single granularity
calculation that works for all cases. The new calculation doesn't
care if parent_iw => 1 because parent_iw is used as a multiplier.

The refactor cleans up a useless assignment of eiw made after the
iw is already calculated.

Regression testing included an examination of all of the ways and
granularity selections made during a run of the cxl_test unit tests.
There were no differences in selections before and after this patch.

Fixes: ("27b3f8d13830 cxl/region: Program target lists")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230822180928.117596-1-alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-14 20:47:42 -07:00
Alison Schofield
9e4edf1a21 cxl/region: Match auto-discovered region decoders by HPA range
Currently, when the region driver attaches a region to a port, it
selects the ports next available decoder to program.

With the addition of auto-discovered regions, a port decoder has
already been programmed so grabbing the next available decoder can
be a mismatch when there is more than one region using the port.

The failure appears like this with CXL DEBUG enabled:

[] cxl_core:alloc_region_ref:754: cxl region0: endpoint9: HPA order violation region0:[mem 0x14780000000-0x1478fffffff flags 0x200] vs [mem 0x880000000-0x185fffffff flags 0x200]
[] cxl_core:cxl_port_attach_region:972: cxl region0: endpoint9: failed to allocate region reference

When CXL DEBUG is not enabled, there is no failure message. The region
just never materializes. Users can suspect this issue if they know their
firmware has programmed decoders so that more than one region is using
a port. Note that the problem may appear intermittently, ie not on
every reboot.

Add a matching method for auto-discovered regions that finds a decoder
based on an HPA range. The decoder range must exactly match the region
resource parameter.

Fixes: a32320b71f ("cxl/region: Add region autodiscovery")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230905211007.256385-1-alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-14 20:46:12 -07:00
Ira Weiny
d2f7060588 cxl/mbox: Fix CEL logic for poison and security commands
The following debug output was observed while testing CXL

cxl_core:cxl_walk_cel:721: cxl_mock_mem cxl_mem.0: Opcode 0x4300 unsupported by driver

opcode 0x4300 (Get Poison) is supported by the driver and the mock
device supports it.  The logic should be checking that the opcode is
both not poison and not security.

Fix the logic to allow poison and security commands.

Fixes: ad64f5952c ("cxl/memdev: Only show sanitize sysfs files when supported")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230903-cxl-cel-fix-v1-1-e260c9467be3@intel.com
[cleanup cxl_walk_cel() to centralized "enabled" checks]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-14 13:48:49 -07:00
Smita Koralahalli
55b8ff06a0 cxl/pci: Replace host_bridge->native_aer with pcie_aer_is_native()
Use pcie_aer_is_native() to determine the native AER ownership as the
usage of host_bride->native_aer does not cover command line override of
AER ownership.

Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230823234305.27333-4-Smita.KoralahalliChannabasappa@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-11 15:24:30 -07:00
Smita Koralahalli
0339dc39a5 cxl/pci: Fix appropriate checking for _OSC while handling CXL RAS registers
cxl_pci fails to unmask CXL protocol errors when CXL memory error reporting
is not granted native control. Given that CXL memory error reporting uses
the event interface and protocol errors use AER, unmask protocol errors
based only on the native AER setting. Without this change end user
deployments will fail to report protocol errors in the case where native
memory error handling is not granted to Linux.

Also, return zero instead of an error code to not block the communication
with the cxl device when in native memory error reporting mode.

Fixes: 248529edc8 ("cxl: add RAS status unmasking for CXL")
Cc: <stable@vger.kernel.org>
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Reviewed-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230823234305.27333-2-Smita.KoralahalliChannabasappa@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-11 15:23:20 -07:00
Davidlohr Bueso
ad64f5952c cxl/memdev: Only show sanitize sysfs files when supported
If the device does not support Sanitize or Secure Erase commands,
hide the respective sysfs interfaces such that the operation can
never be attempted.

In order to be generic, keep track of the enabled security commands
found in the CEL - the driver does not support Security Passthrough.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/20230726051940.3570-4-dave@stgolabs.net
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-07-28 13:16:54 -06:00
Davidlohr Bueso
3de8cd2242 cxl/memdev: Document security state in kern-doc
... as is the case with all members of struct cxl_memdev_state.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/20230726051940.3570-3-dave@stgolabs.net
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-07-28 13:16:54 -06:00
Breno Leitao
91019b5bc7 cxl/acpi: Return 'rc' instead of '0' in cxl_parse_cfmws()
Driver initialization returned success (return 0) even if the
initialization (cxl_decoder_add() or acpi_table_parse_cedt()) failed.

Return the error instead of swallowing it.

Fixes: f4ce1f766f ("cxl/acpi: Convert CFMWS parsing to ACPI sub-table helpers")
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230714093146.2253438-2-leitao@debian.org
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-07-18 11:55:09 -06:00
Breno Leitao
4cf67d3cc9 cxl/acpi: Fix a use-after-free in cxl_parse_cfmws()
KASAN and KFENCE detected an user-after-free in the CXL driver. This
happens in the cxl_decoder_add() fail path. KASAN prints the following
error:

   BUG: KASAN: slab-use-after-free in cxl_parse_cfmws (drivers/cxl/acpi.c:299)

This happens in cxl_parse_cfmws(), where put_device() is called,
releasing cxld, which is accessed later.

Use the local variables in the dev_err() instead of pointing to the
released memory. Since the dev_err() is printing a resource, change the open
coded print format to use the %pr format specifier.

Fixes: e50fe01e1f ("cxl/core: Drop ->platform_res attribute for root decoders")
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230714093146.2253438-1-leitao@debian.org
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-07-18 11:55:02 -06:00
Dan Carpenter
95c6bff72b cxl/mem: Fix a double shift bug
The CXL_FW_CANCEL macro is used with set/test_bit() so it should be a
bit number and not the shifted value.  The original code is the
equivalent of using BIT(BIT(0)) so it's 0x2 instead of 0x1.  This has
no effect on runtime because it's done consistently and nothing else
was using the 0x2 bit.

Fixes: 9521875bbe ("cxl: add a firmware update mechanism using the sysfs firmware loader")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/a11b0c78-4717-4f4e-90be-f47f300d607c@moroto.mountain
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-07-14 14:33:21 -06:00
Arnd Bergmann
9171dfcda4 cxl: fix CONFIG_FW_LOADER dependency
When FW_LOADER is disabled, cxl fails to link:

arm-linux-gnueabi-ld: drivers/cxl/core/memdev.o: in function `cxl_memdev_setup_fw_upload':
memdev.c:(.text+0x90e): undefined reference to `firmware_upload_register'
memdev.c:(.text+0x93c): undefined reference to `firmware_upload_unregister'

In order to use the firmware_upload_register() function, both FW_LOADER
and FW_UPLOAD have to be enabled, which is a bit confusing. In addition,
the dependency is on the wrong symbol, as the caller is part of the
cxl_core.ko module, not the cxl_mem.ko module.

Fixes: 9521875bbe ("cxl: add a firmware update mechanism using the sysfs firmware loader")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230703112928.332321-1-arnd@kernel.org
Reviewed-by: Xiao Yang <yangx.jy@fujitsu.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-07-14 14:32:22 -06:00
Yang Li
fe77cc2e5a cxl: Fix one kernel-doc comment
Fix a merge error that updated the argument to cxl_mem_get_fw_info() but
not the kernel-doc.

drivers/cxl/core/memdev.c:678: warning: Function parameter or member
'mds' not described in 'cxl_mem_get_fw_info'
drivers/cxl/core/memdev.c:678: warning: Excess function parameter
'cxlds' description in 'cxl_mem_get_fw_info'

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230629021118.102744-1-yang.lee@linux.alibaba.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-29 16:03:58 -07:00
Davidlohr Bueso
71baec7b85 cxl/pci: Use correct flag for sanitize polling
This is a bogus value, left behind from a previous version.

Fixes: 0c36b6ad43 ("cxl/mbox: Add sanitization handling machinery")
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/7q3vcjqidtmxmys4n34g6b3mygvhaen7yikzxanpz56lw43fz7@7subbtbfkmyx
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-27 15:51:40 -07:00
Dan Williams
0c0df63177 Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxl
Pick up the first half of the RCH error handling series. The back half
needs some fixups for test regressions. Small conflicts with the PMU
work around register enumeration and setup helpers.
2023-06-25 18:56:13 -07:00
Dan Williams
d2f9fe6953 Merge branch 'for-6.5/cxl-perf' into for-6.5/cxl
Pick up initial support for the CXL 3.0 performance monitoring
definition. Small conflicts with the firmware update work as they both
placed their init code in the same location.
2023-06-25 17:53:18 -07:00
Jonathan Cameron
5d7107c727 perf: CXL Performance Monitoring Unit driver
CXL rev 3.0 introduces a standard performance monitoring hardware
block to CXL. Instances are discovered using CXL Register Locator DVSEC
entries. Each CXL component may have multiple PMUs.

This initial driver supports a subset of types of counter.
It supports counters that are either fixed or configurable, but requires
that they support the ability to freeze and write value whilst frozen.

Development done with QEMU model which will be posted shortly.

Example:

$ perf stat -a -e cxl_pmu_mem0.0/h2d_req_snpcur/ -e cxl_pmu_mem0.0/h2d_req_snpdata/ -e cxl_pmu_mem0.0/clock_ticks/ sleep 1

Performance counter stats for 'system wide':

96,757,023,244,321      cxl_pmu_mem0.0/h2d_req_snpcur/
96,757,023,244,365      cxl_pmu_mem0.0/h2d_req_snpdata/
193,514,046,488,653      cxl_pmu_mem0.0/clock_ticks/

       1.090539600 seconds time elapsed

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230526095824.16336-5-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 17:47:09 -07:00