PCI: loongson: Fix supported link speeds for Loongson 3c19/3c29 PCIe devices proper dynamic speed negotiation. #2
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AydenMeng
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series steppings Older steppings of the Loongson 3C6000 series incorrectly report the supported link speeds on their PCIe bridges (device IDs 3c19, 3c29) as only 2.5 GT/s, despite the upstream bus supporting speeds from 2.5 GT/s up to 16 GT/s. As a result, certain PCIe devices would be incorrectly probed as a Gen1- only, even if higher link speeds are supported, harming performance and prevents dynamic link speed functionality from being enabled in drivers such as amdgpu. Manually override the `supported_speeds` field for affected PCIe bridges with those found on the upstream bus to correctly reflect the supported link speeds. Tested-by: Lain "Fearyncess" Yang <[email protected]> Reviewed-by: Mingcong Bai <[email protected]> Signed-off-by: Ayden Meng <[email protected]>
MingcongBai
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Jun 4, 2025
KexyBiscuit
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Add a compile-time check that `*$ptr` is of the type of `$type->$($f)*`. Rename those placeholders for clarity. Given the incorrect usage: > diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs > index 8d978c8..6a7089149878 100644 > --- a/rust/kernel/rbtree.rs > +++ b/rust/kernel/rbtree.rs > @@ -329,7 +329,7 @@ fn raw_entry(&mut self, key: &K) -> RawEntry<'_, K, V> { > while !(*child_field_of_parent).is_null() { > let curr = *child_field_of_parent; > // SAFETY: All links fields we create are in a `Node<K, V>`. > - let node = unsafe { container_of!(curr, Node<K, V>, links) }; > + let node = unsafe { container_of!(curr, Node<K, V>, key) }; > > // SAFETY: `node` is a non-null node so it is valid by the type invariants. > match key.cmp(unsafe { &(*node).key }) { this patch produces the compilation error: > error[E0308]: mismatched types > --> rust/kernel/lib.rs:220:45 > | > 220 | $crate::assert_same_type(field_ptr, (&raw const (*container_ptr).$($fields)*).cast_mut()); > | ------------------------ --------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*mut rb_node`, found `*mut K` > | | | > | | expected all arguments to be this `*mut bindings::rb_node` type because they need to match the type of this parameter > | arguments to this function are incorrect > | > ::: rust/kernel/rbtree.rs:270:6 > | > 270 | impl<K, V> RBTree<K, V> > | - found this type parameter > ... > 332 | let node = unsafe { container_of!(curr, Node<K, V>, key) }; > | ------------------------------------ in this macro invocation > | > = note: expected raw pointer `*mut bindings::rb_node` > found raw pointer `*mut K` > note: function defined here > --> rust/kernel/lib.rs:227:8 > | > 227 | pub fn assert_same_type<T>(_: T, _: T) {} > | ^^^^^^^^^^^^^^^^ - ---- ---- this parameter needs to match the `*mut bindings::rb_node` type of parameter #1 > | | | > | | parameter #2 needs to match the `*mut bindings::rb_node` type of this parameter > | parameter #1 and parameter #2 both reference this parameter `T` > = note: this error originates in the macro `container_of` (in Nightly builds, run with -Z macro-backtrace for more info) [ We decided to go with a variation of v1 [1] that became v4, since it seems like the obvious approach, the error messages seem good enough and the debug performance should be fine, given the kernel is always built with -O2. In the future, we may want to make the helper non-hidden, with proper documentation, for others to use. [1] https://lore.kernel.org/rust-for-linux/CANiq72kQWNfSV0KK6qs6oJt+aGdgY=hXg=wJcmK3zYcokY1LNw@mail.gmail.com/ - Miguel ] Suggested-by: Alice Ryhl <[email protected]> Link: https://lore.kernel.org/all/CAH5fLgh6gmqGBhPMi2SKn7mCmMWfOSiS0WP5wBuGPYh9ZTAiww@mail.gmail.com/ Signed-off-by: Tamir Duberstein <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Added intra-doc link. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>
KexyBiscuit
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Jun 9, 2025
Batch #2 of next window Signed-off-by: Nishanth Menon <[email protected]>
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Jun 10, 2025
Some architectures (e.g. arm64) only support memory hotplug operations on a restricted set of physical addresses. This applies even when we are faking some CXL fixed memory windows for the purposes of cxl_test. That range can be queried with mhp_get_pluggable_range(true). Use the minimum of that the top of that range and iomem_resource.end to establish the 64GiB region used by cxl_test. From thread #2 which was related to the issue in #1. [ dj: Add CONFIG_MEMORY_HOTPLUG config check, from Alison ] Link: https://lore.kernel.org/linux-cxl/[email protected]/ #2 Reported-by: Itaru Kitayama <[email protected]> Closes: pmem/ndctl#278 #1 Reviewed-by: Dan Williams <[email protected]> Tested-by: Itaru Kitayama <[email protected] <mailto:[email protected]> Tested-by: Marc Herbert <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Dave Jiang <[email protected]>
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Jun 12, 2025
pert script tests fails with segmentation fault as below:
92: perf script tests:
--- start ---
test child forked, pid 103769
DB test
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.012 MB /tmp/perf-test-script.7rbftEpOzX/perf.data (9 samples) ]
/usr/libexec/perf-core/tests/shell/script.sh: line 35:
103780 Segmentation fault (core dumped)
perf script -i "${perfdatafile}" -s "${db_test}"
--- Cleaning up ---
---- end(-1) ----
92: perf script tests : FAILED!
Backtrace pointed to :
#0 0x0000000010247dd0 in maps.machine ()
#1 0x00000000101d178c in db_export.sample ()
#2 0x00000000103412c8 in python_process_event ()
#3 0x000000001004eb28 in process_sample_event ()
#4 0x000000001024fcd0 in machines.deliver_event ()
#5 0x000000001025005c in perf_session.deliver_event ()
torvalds#6 0x00000000102568b0 in __ordered_events__flush.part.0 ()
torvalds#7 0x0000000010251618 in perf_session.process_events ()
torvalds#8 0x0000000010053620 in cmd_script ()
torvalds#9 0x00000000100b5a28 in run_builtin ()
torvalds#10 0x00000000100b5f94 in handle_internal_command ()
torvalds#11 0x0000000010011114 in main ()
Further investigation reveals that this occurs in the `perf script tests`,
because it uses `db_test.py` script. This script sets `perf_db_export_mode = True`.
With `perf_db_export_mode` enabled, if a sample originates from a hypervisor,
perf doesn't set maps for "[H]" sample in the code. Consequently, `al->maps` remains NULL
when `maps__machine(al->maps)` is called from `db_export__sample`.
As al->maps can be NULL in case of Hypervisor samples , use thread->maps
because even for Hypervisor sample, machine should exist.
If we don't have machine for some reason, return -1 to avoid segmentation fault.
Reported-by: Disha Goel <[email protected]>
Signed-off-by: Aditya Bodkhe <[email protected]>
Reviewed-by: Adrian Hunter <[email protected]>
Tested-by: Disha Goel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: Adrian Hunter <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
KexyBiscuit
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Jun 12, 2025
Some architectures (e.g. arm64) only support memory hotplug operations on a restricted set of physical addresses. This applies even when we are faking some CXL fixed memory windows for the purposes of cxl_test. That range can be queried with mhp_get_pluggable_range(true). Use the minimum of that the top of that range and iomem_resource.end to establish the 64GiB region used by cxl_test. From thread #2 which was related to the issue in #1. [ dj: Add CONFIG_MEMORY_HOTPLUG config check, from Alison ] Link: https://lore.kernel.org/linux-cxl/[email protected]/ #2 Reported-by: Itaru Kitayama <[email protected]> Closes: pmem/ndctl#278 #1 Reviewed-by: Dan Williams <[email protected]> Tested-by: Itaru Kitayama <[email protected] <mailto:[email protected]> Tested-by: Marc Herbert <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Dave Jiang <[email protected]>
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The "Supported Link Speeds" field reported by Loongson PCIe devices 3c19 and 3c29 is incorrect, which prevents the AMDGPU driver (and potentially others) from correctly detecting the dynamic link speed capabilities of the device. As a result, the PCIe card is incorrectly identified as a GEN1-only device, even when higher speeds are supported.
This patch manually overrides the
supported_speedsfield for these devices to reflect the actual supported link speeds.Tested-by: Lain "Fearyncess" Yang [email protected]