Add the bpf_sock_ops_enable_tx_tstamp kfunc to allow BPF programs to
selectively enable TX timestamping on a skb during tcp_sendmsg().
For example, BPF program will limit tracking X numbers of packets
and then will stop there instead of tracing all the sendmsgs of
matched flow all along. It would be helpful for users who cannot
afford to calculate latencies from every sendmsg call probably
due to the performance or storage space consideration.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-12-kerneljasonxing@gmail.com
This patch introduces a new callback in tcp_tx_timestamp() to correlate
tcp_sendmsg timestamp with timestamps from other tx timestamping
callbacks (e.g., SND/SW/ACK).
Without this patch, BPF program wouldn't know which timestamps belong
to which flow because of no socket lock protection. This new callback
is inserted in tcp_tx_timestamp() to address this issue because
tcp_tx_timestamp() still owns the same socket lock with
tcp_sendmsg_locked() in the meanwhile tcp_tx_timestamp() initializes
the timestamping related fields for the skb, especially tskey. The
tskey is the bridge to do the correlation.
For TCP, BPF program hooks the beginning of tcp_sendmsg_locked() and
then stores the sendmsg timestamp at the bpf_sk_storage, correlating
this timestamp with its tskey that are later used in other sending
timestamping callbacks.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-11-kerneljasonxing@gmail.com
Support the ACK case for bpf timestamping.
Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_ACK_CB. This
callback will occur at the same timestamping point as the user
space's SCM_TSTAMP_ACK. The BPF program can use it to get the
same SCM_TSTAMP_ACK timestamp without modifying the user-space
application.
This patch extends txstamp_ack to two bits: 1 stands for
SO_TIMESTAMPING mode, 2 bpf extension.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-10-kerneljasonxing@gmail.com
Support hw SCM_TSTAMP_SND case for bpf timestamping.
Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SND_HW_CB. This
callback will occur at the same timestamping point as the user
space's hardware SCM_TSTAMP_SND. The BPF program can use it to
get the same SCM_TSTAMP_SND timestamp without modifying the
user-space application.
To avoid increasing the code complexity, replace SKBTX_HW_TSTAMP
with SKBTX_HW_TSTAMP_NOBPF instead of changing numerous callers
from driver side using SKBTX_HW_TSTAMP. The new definition of
SKBTX_HW_TSTAMP means the combination tests of socket timestamping
and bpf timestamping. After this patch, drivers can work under the
bpf timestamping.
Considering some drivers don't assign the skb with hardware
timestamp, this patch does the assignment and then BPF program
can acquire the hwstamp from skb directly.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-9-kerneljasonxing@gmail.com
Support sw SCM_TSTAMP_SND case for bpf timestamping.
Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SND_SW_CB. This
callback will occur at the same timestamping point as the user
space's software SCM_TSTAMP_SND. The BPF program can use it to
get the same SCM_TSTAMP_SND timestamp without modifying the
user-space application.
Based on this patch, BPF program will get the software
timestamp when the driver is ready to send the skb. In the
sebsequent patch, the hardware timestamp will be supported.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-8-kerneljasonxing@gmail.com
Support SCM_TSTAMP_SCHED case for bpf timestamping.
Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SCHED_CB. This
callback will occur at the same timestamping point as the user
space's SCM_TSTAMP_SCHED. The BPF program can use it to get the
same SCM_TSTAMP_SCHED timestamp without modifying the user-space
application.
A new SKBTX_BPF flag is added to mark skb_shinfo(skb)->tx_flags,
ensuring that the new BPF timestamping and the current user
space's SO_TIMESTAMPING do not interfere with each other.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-7-kerneljasonxing@gmail.com
No functional changes here. Only add test to see if the orig_skb
matches the usage of application SO_TIMESTAMPING.
In this series, bpf timestamping and previous socket timestamping
are implemented in the same function __skb_tstamp_tx(). To test
the socket enables socket timestamping feature, this function
skb_tstamp_tx_report_so_timestamping() is added.
In the next patch, another check for bpf timestamping feature
will be introduced just like the above report function, namely,
skb_tstamp_tx_report_bpf_timestamping(). Then users will be able
to know the socket enables either or both of features.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-6-kerneljasonxing@gmail.com
New TX timestamping sock_ops callbacks will be added in the
subsequent patch. Some of the existing BPF helpers will not
be safe to be used in the TX timestamping callbacks.
The bpf_sock_ops_setsockopt, bpf_sock_ops_getsockopt, and
bpf_sock_ops_cb_flags_set require owning the sock lock. TX
timestamping callbacks will not own the lock.
The bpf_sock_ops_load_hdr_opt needs the skb->data pointing
to the TCP header. This will not be true in the TX timestamping
callbacks.
At the beginning of these helpers, this patch checks the
bpf_sock->op to ensure these helpers are used by the existing
sock_ops callbacks only.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250220072940.99994-5-kerneljasonxing@gmail.com
The subsequent patch will implement BPF TX timestamping. It will
call the sockops BPF program without holding the sock lock.
This breaks the current assumption that all sock ops programs will
hold the sock lock. The sock's fields of the uapi's bpf_sock_ops
requires this assumption.
To address this, a new "u8 is_locked_tcp_sock;" field is added. This
patch sets it in the current sock_ops callbacks. The "is_fullsock"
test is then replaced by the "is_locked_tcp_sock" test during
sock_ops_convert_ctx_access().
The new TX timestamping callbacks added in the subsequent patch will
not have this set. This will prevent unsafe access from the new
timestamping callbacks.
Potentially, we could allow read-only access. However, this would
require identifying which callback is read-safe-only and also requires
additional BPF instruction rewrites in the covert_ctx. Since the BPF
program can always read everything from a socket (e.g., by using
bpf_core_cast), this patch keeps it simple and disables all read
and write access to any socket fields through the bpf_sock_ops
UAPI from the new TX timestamping callback.
Moreover, note that some of the fields in bpf_sock_ops are specific
to tcp_sock, and sock_ops currently only supports tcp_sock. In
the future, UDP timestamping will be added, which will also break
this assumption. The same idea used in this patch will be reused.
Considering that the current sock_ops only supports tcp_sock, the
variable is named is_locked_"tcp"_sock.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250220072940.99994-4-kerneljasonxing@gmail.com
This patch introduces a new bpf_skops_tx_timestamping() function
that prepares the "struct bpf_sock_ops" ctx and then executes the
sockops BPF program.
The subsequent patch will utilize bpf_skops_tx_timestamping() at
the existing TX timestamping kernel callbacks (__sk_tstamp_tx
specifically) to call the sockops BPF program. Later, four callback
points to report information to user space based on this patch will
be introduced.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250220072940.99994-3-kerneljasonxing@gmail.com
Some applications don't want to wait for too long because the
time of retransmission increases exponentially and can reach more
than 10 seconds, for example. Eric implements the core logic
on supporting rto max feature in the stack previously. Based on that,
we can support it for BPF use.
This patch reuses the same logic of TCP_RTO_MAX_MS in do_tcp_setsockopt()
and do_tcp_getsockopt(). BPF program can call bpf_{set/get}sockopt()
to set/get the maximum value of RTO.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250219081333.56378-2-kerneljasonxing@gmail.com
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter, wireless and bluetooth.
Kalle Valo steps down after serving as the WiFi driver maintainer for
over a decade.
Current release - fix to a fix:
- vsock: orphan socket after transport release, avoid null-deref
- Bluetooth: L2CAP: fix corrupted list in hci_chan_del
Current release - regressions:
- eth:
- stmmac: correct Rx buffer layout when SPH is enabled
- iavf: fix a locking bug in an error path
- rxrpc: fix alteration of headers whilst zerocopy pending
- s390/qeth: move netif_napi_add_tx() and napi_enable() from under BH
- Revert "netfilter: flowtable: teardown flow if cached mtu is stale"
Current release - new code bugs:
- rxrpc: fix ipv6 path MTU discovery, only ipv4 worked
- pse-pd: fix deadlock in current limit functions
Previous releases - regressions:
- rtnetlink: fix netns refleak with rtnl_setlink()
- wifi: brcmfmac: use random seed flag for BCM4355 and BCM4364
firmware
Previous releases - always broken:
- add missing RCU protection of struct net throughout the stack
- can: rockchip: bail out if skb cannot be allocated
- eth: ti: am65-cpsw: base XDP support fixes
Misc:
- ethtool: tsconfig: update the format of hwtstamp flags, changes the
uAPI but this uAPI was not in any release yet"
* tag 'net-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits)
net: pse-pd: Fix deadlock in current limit functions
rxrpc: Fix ipv6 path MTU discovery
Reapply "net: skb: introduce and use a single page frag cache"
s390/qeth: move netif_napi_add_tx() and napi_enable() from under BH
mlxsw: Add return value check for mlxsw_sp_port_get_stats_raw()
ipv6: mcast: add RCU protection to mld_newpack()
team: better TEAM_OPTION_TYPE_STRING validation
Bluetooth: L2CAP: Fix corrupted list in hci_chan_del
Bluetooth: btintel_pcie: Fix a potential race condition
Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd
net: ethernet: ti: am65_cpsw: fix tx_cleanup for XDP case
net: ethernet: ti: am65-cpsw: fix RX & TX statistics for XDP_TX case
net: ethernet: ti: am65-cpsw: fix memleak in certain XDP cases
vsock/test: Add test for SO_LINGER null ptr deref
vsock: Orphan socket after transport release
MAINTAINERS: Add sctp headers to the general netdev entry
Revert "netfilter: flowtable: teardown flow if cached mtu is stale"
iavf: Fix a locking bug in an error path
rxrpc: Fix alteration of headers whilst zerocopy pending
net: phylink: make configuring clock-stop dependent on MAC support
...
Pull btrfs fixes from David Sterba:
- fix stale page cache after race between readahead and direct IO write
- fix hole expansion when writing at an offset beyond EOF, the range
will not be zeroed
- use proper way to calculate offsets in folio ranges
* tag 'for-6.14-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix hole expansion when writing at an offset beyond EOF
btrfs: fix stale page cache after race between readahead and direct IO write
btrfs: fix two misuses of folio_shift()
Pull bcachefs fixes from Kent Overstreet:
"Just small stuff.
As a general announcement, on disk format is now frozen in my master
branch - future on disk format changes will be optional, not required.
- More fixes for going read-only: the previous fix was insufficient,
but with more work on ordering journal reclaim flushing (and a
btree node accounting fix so we don't split until we have to) the
tiering_replication test now consistently goes read-only in less
than a second.
- fix for fsck when we have reflink pointers to missing indirect
extents
- some transaction restart handling fixes from Alan; the "Pass
_orig_restart_count to trans_was_restarted" likely fixes some rare
undefined behaviour heisenbugs"
* tag 'bcachefs-2025-02-12' of git://evilpiepirate.org/bcachefs:
bcachefs: Reuse transaction
bcachefs: Pass _orig_restart_count to trans_was_restarted
bcachefs: CONFIG_BCACHEFS_INJECT_TRANSACTION_RESTARTS
bcachefs: Fix want_new_bset() so we write until the end of the btree node
bcachefs: Split out journal pins by btree level
bcachefs: Fix use after free
bcachefs: Fix marking reflink pointers to missing indirect extents
Fix a deadlock in pse_pi_get_current_limit and pse_pi_set_current_limit
caused by consecutive mutex_lock calls. One in the function itself and
another in pse_pi_get_voltage.
Resolve the issue by using the unlocked version of pse_pi_get_voltage
instead.
Fixes: e0a5e2bba3 ("net: pse-pd: Use power limit at driver side instead of current limit")
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20250212151751.1515008-1-kory.maincent@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Luiz Augusto von Dentz says:
====================
bluetooth pull request for net:
- btintel_pcie: Fix a potential race condition
- L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd
- L2CAP: Fix corrupted list in hci_chan_del
* tag 'for-net-2025-02-13' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
Bluetooth: L2CAP: Fix corrupted list in hci_chan_del
Bluetooth: btintel_pcie: Fix a potential race condition
Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd
====================
Link: https://patch.msgid.link/20250213162446.617632-1-luiz.dentz@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following batch contains one revert for:
1) Revert flowtable entry teardown cycle when skbuff exceeds mtu to
deal with DF flag unset scenarios. This is reverts a patch coming
in the previous merge window (available in 6.14-rc releases).
* tag 'nf-25-02-13' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
Revert "netfilter: flowtable: teardown flow if cached mtu is stale"
====================
Link: https://patch.msgid.link/20250213100502.3983-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull LoongArch fixes from Huacai Chen:
"Fix bugs about idle, kernel_page_present(), IP checksum and KVM, plus
some trival cleanups"
* tag 'loongarch-fixes-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
LoongArch: KVM: Set host with kernel mode when switch to VM mode
LoongArch: KVM: Remove duplicated cache attribute setting
LoongArch: KVM: Fix typo issue about GCFG feature detection
LoongArch: csum: Fix OoB access in IP checksum code for negative lengths
LoongArch: Remove the deprecated notifier hook mechanism
LoongArch: Use str_yes_no() helper function for /proc/cpuinfo
LoongArch: Fix kernel_page_present() for KPRANGE/XKPRANGE
LoongArch: Fix idle VS timer enqueue
Pull x86 platform driver fixes from Ilpo Järvinen:
- thinkpad_acpi:
- Fix registration of tpacpi platform driver
- Support fan speed in ticks per revolution (Thinkpad X120e)
- Support V9 DYTC profiles (new Thinkpad AMD platforms)
- int3472: Handle GPIO "enable" vs "reset" variation (ov7251)
* tag 'platform-drivers-x86-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
platform/x86: thinkpad_acpi: Fix registration of tpacpi platform driver
platform/x86: int3472: Call "reset" GPIO "enable" for INT347E
platform/x86: int3472: Use correct type for "polarity", call it gpio_flags
platform/x86: thinkpad_acpi: Support for V9 DYTC platform profiles
platform/x86: thinkpad_acpi: Fix invalid fan speed on ThinkPad X120e
mld_newpack() can be called without RTNL or RCU being held.
Note that we no longer can use sock_alloc_send_skb() because
ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep.
Instead use alloc_skb() and charge the net->ipv6.igmp_sk
socket under RCU protection.
Fixes: b8ad0cbc58 ("[NETNS][IPV6] mcast - handle several network namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250212141021.1663666-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On HCI_OP_RESET command, firmware raises alive interrupt. Driver needs
to wait for this before sending other command. This patch fixes the potential
miss of alive interrupt due to which HCI_OP_RESET can timeout.
Expected flow:
If tx command is HCI_OP_RESET,
1. set data->gp0_received = false
2. send HCI_OP_RESET
3. wait for alive interrupt
Actual flow having potential race:
If tx command is HCI_OP_RESET,
1. send HCI_OP_RESET
1a. Firmware raises alive interrupt here and in ISR
data->gp0_received is set to true
2. set data->gp0_received = false
3. wait for alive interrupt
Signed-off-by: Kiran K <kiran.k@intel.com>
Fixes: 05c200c8f0 ("Bluetooth: btintel_pcie: Add handshake between driver and firmware")
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Closes: https://patchwork.kernel.org/project/bluetooth/patch/20241001104451.626964-1-kiran.k@intel.com/
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
For successful XDP_TX and XDP_REDIRECT cases, the packet was received
successfully so update RX statistics. Use original received
packet length for that.
TX packets statistics are incremented on TX completion so don't
update it while TX queueing.
If xdp_convert_buff_to_frame() fails, increment tx_dropped.
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Fixes: 8acacc40f7 ("net: ethernet: ti: am65-cpsw: Add minimal XDP support")
Link: https://patch.msgid.link/20250210-am65-cpsw-xdp-fixes-v1-2-ec6b1f7f1aca@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If the XDP program doesn't result in XDP_PASS then we leak the
memory allocated by am65_cpsw_build_skb().
It is pointless to allocate SKB memory before running the XDP
program as we would be wasting CPU cycles for cases other than XDP_PASS.
Move the SKB allocation after evaluating the XDP program result.
This fixes the memleak. A performance boost is seen for XDP_DROP test.
XDP_DROP test:
Before: 460256 rx/s 0 err/s
After: 784130 rx/s 0 err/s
Fixes: 8acacc40f7 ("net: ethernet: ti: am65-cpsw: Add minimal XDP support")
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Link: https://patch.msgid.link/20250210-am65-cpsw-xdp-fixes-v1-1-ec6b1f7f1aca@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Now for dwmac-loongson {tx,rx}_fifo_size are uninitialised, which means
zero. This means dwmac-loongson doesn't support changing MTU because in
stmmac_change_mtu() it requires the fifo size be no less than MTU. Thus,
set the correct tx_fifo_size and rx_fifo_size for it (16KB multiplied by
queue counts).
Here {tx,rx}_fifo_size is initialised with the initial value (also the
maximum value) of {tx,rx}_queues_to_use. So it will keep as 16KB if we
don't change the queue count, and will be larger than 16KB if we change
(decrease) the queue count. However stmmac_change_mtu() still work well
with current logic (MTU cannot be larger than 16KB for stmmac).
Note: the Fixes tag picked here is the oldest commit and key commit of
the dwmac-loongson series "stmmac: Add Loongson platform support".
Acked-by: Yanteng Si <si.yanteng@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Chong Qiao <qiaochong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://patch.msgid.link/20250210134328.2755328-1-chenhuacai@loongson.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
PRMD register is only meaningful on the beginning stage of exception
entry, and it is overwritten with nested irq or exception.
When CPU runs in VM mode, interrupt need be enabled on host. And the
mode for host had better be kernel mode rather than random or user mode.
When VM is running, the running mode with top command comes from CRMD
register, and running mode should be kernel mode since kernel function
is executing with perf command. It needs be consistent with both top and
perf command.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Cache attribute comes from GPA->HPA secondary mmu page table and is
configured when kvm is enabled. It is the same for all VMs, so remove
duplicated cache attribute setting on vCPU context switch.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This is typo issue and misusage about GCFG feature macro. The code
is wrong, only that it does not cause obvious problem since GCFG is
set again on vCPU context switch.
Fixes: 0d0df3c99d ("LoongArch: KVM: Implement kvm hardware enable, disable interface")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Commit 69e3a6aa6b ("LoongArch: Add checksum optimization for 64-bit
system") would cause an undefined shift and an out-of-bounds read.
Commit 8bd795fedb ("arm64: csum: Fix OoB access in IP checksum code
for negative lengths") fixes the same issue on ARM64.
Fixes: 69e3a6aa6b ("LoongArch: Add checksum optimization for 64-bit system")
Co-developed-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The notifier hook mechanism in proc and cpuinfo is actually unnecessary
for LoongArch because it's not used anywhere.
It was originally added to the MIPS code in commit d6d3c9afaa ("MIPS:
MT: proc: Add support for printing VPE and TC ids"), and LoongArch then
inherited it.
But as the kernel code stands now, this notifier hook mechanism doesn't
really make sense for either LoongArch or MIPS.
In addition, the seq_file forward declaration needs to be moved to its
proper place, as only the show_ipi_list() function in smp.c requires it.
Co-developed-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
