LoongArch: Fix entry point in kernel image header

[ Upstream commit beb2800074c15362cf9f6c7301120910046d6556 ]

Currently kernel entry in head.S is in DMW address range, firmware is
instructed to ju

LoongArch: Fix entry point in kernel image header

[ Upstream commit beb2800074c15362cf9f6c7301120910046d6556 ]

Currently kernel entry in head.S is in DMW address range, firmware is
instructed to jump to this address after loading the kernel image.

However kernel should not make any assumption on firmware's DMW
setting, thus the entry point should be a physical address falls into
direct translation region.

Fix by converting entry address to physical and amend entry calculation
logic in libstub accordingly.

BTW, use ABSOLUTE() to calculate variables to make Clang/LLVM happy.

Cc: stable@vger.kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

efi/loongarch: Directly position the loaded image file

[ Upstream commit 174a0c565cea74a7811ff79fbee1b70247570ade ]

The use of the 'kernel_offset' variable to position the image file that
has been

efi/loongarch: Directly position the loaded image file

[ Upstream commit 174a0c565cea74a7811ff79fbee1b70247570ade ]

The use of the 'kernel_offset' variable to position the image file that
has been loaded by UEFI or GRUB is unnecessary, because we can directly
position the loaded image file through using the image_base field of the
efi_loaded_image struct provided by UEFI.

Replace kernel_offset with image_base to position the image file that has
been loaded by UEFI or GRUB.

Signed-off-by: Wang Yao <wangyao@lemote.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Stable-dep-of: beb2800074c1 ("LoongArch: Fix entry point in kernel image header")
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

vgacon: rework screen_info #ifdef checks

[ Upstream commit 8a736ddfc861b2a217c935c2f461a8004add8247 ]

On non-x86 architectures, the screen_info variable is generally only
used for the VGA console w

vgacon: rework screen_info #ifdef checks

[ Upstream commit 8a736ddfc861b2a217c935c2f461a8004add8247 ]

On non-x86 architectures, the screen_info variable is generally only
used for the VGA console where supported, and in some cases the EFI
framebuffer or vga16fb.

Now that we have a definite list of which architectures actually use it
for what, use consistent #ifdef checks so the global variable is only
defined when it is actually used on those architectures.

Loongarch and riscv have no support for vgacon or vga16fb, but
they support EFI firmware, so only that needs to be checked, and the
initialization can be removed because that is handled by EFI.
IA64 has both vgacon and EFI, though EFI apparently never uses
a framebuffer here.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Khalid Aziz <khalid@gonehiking.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231009211845.3136536-3-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: beb2800074c1 ("LoongArch: Fix entry point in kernel image header")
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

LoongArch: Fix multiple hardware watchpoint issues

commit 3eb2a8b23598e90fda43abb0f23cb267bd5018ba upstream.

In the current code, if multiple hardware breakpoints/watchpoints in
a user-space thread

LoongArch: Fix multiple hardware watchpoint issues

commit 3eb2a8b23598e90fda43abb0f23cb267bd5018ba upstream.

In the current code, if multiple hardware breakpoints/watchpoints in
a user-space thread, some of them will not be triggered.

When debugging the following code using gdb.

lihui@bogon:~$ cat test.c
#include <stdio.h>
int a = 0;
int main()
{
printf("start test\n");
a = 1;
printf("a = %d\n", a);
printf("end test\n");
return 0;
}
lihui@bogon:~$ gcc -g test.c -o test
lihui@bogon:~$ gdb test
...
(gdb) start
...
Temporary breakpoint 1, main () at test.c:5
5 printf("start test\n");
(gdb) watch a
Hardware watchpoint 2: a
(gdb) hbreak 8
Hardware assisted breakpoint 3 at 0x1200006ec: file test.c, line 8.
(gdb) c
Continuing.
start test
a = 1

Breakpoint 3, main () at test.c:8
8 printf("end test\n");
...

The first hardware watchpoint is not triggered, the root causes are:

1. In hw_breakpoint_control(), The FWPnCFG1.2.4/MWPnCFG1.2.4 register
settings are not distinguished. They should be set based on hardware
watchpoint functions (fetch or load/store operations).

2. In breakpoint_handler() and watchpoint_handler(), it doesn't identify
which watchpoint is triggered. So, all watchpoint-related perf_event
callbacks are called and siginfo is sent to the user space. This will
cause user-space unable to determine which watchpoint is triggered.
The kernel need to identity which watchpoint is triggered via MWPS/
FWPS registers, and then call the corresponding perf event callbacks
to report siginfo to the user-space.

Modify the relevant code to solve above issues.

All changes according to the LoongArch Reference Manual:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#control-and-status-registers-related-to-watchpoints

With this patch:

lihui@bogon:~$ gdb test
...
(gdb) start
...
Temporary breakpoint 1, main () at test.c:5
5 printf("start test\n");
(gdb) watch a
Hardware watchpoint 2: a
(gdb) hbreak 8
Hardware assisted breakpoint 3 at 0x1200006ec: file test.c, line 8.
(gdb) c
Continuing.
start test

Hardware watchpoint 2: a

Old value = 0
New value = 1
main () at test.c:7
7 printf("a = %d\n", a);
(gdb) c
Continuing.
a = 1

Breakpoint 3, main () at test.c:8
8 printf("end test\n");
(gdb) c
Continuing.
end test
[Inferior 1 (process 778) exited normally]

Cc: stable@vger.kernel.org
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

LoongArch: Trigger user-space watchpoints correctly

commit c8e57ab0995c5b443d3c81c8a36b588776dcd0c3 upstream.

In the current code, gdb can set the watchpoint successfully through
ptrace interface,

LoongArch: Trigger user-space watchpoints correctly

commit c8e57ab0995c5b443d3c81c8a36b588776dcd0c3 upstream.

In the current code, gdb can set the watchpoint successfully through
ptrace interface, but watchpoint will not be triggered.

When debugging the following code using gdb.

lihui@bogon:~$ cat test.c
#include <stdio.h>
int a = 0;
int main()
{
a = 1;
printf("a = %d\n", a);
return 0;
}
lihui@bogon:~$ gcc -g test.c -o test
lihui@bogon:~$ gdb test
...
(gdb) watch a
...
(gdb) r
...
a = 1
[Inferior 1 (process 4650) exited normally]

No watchpoints were triggered, the root causes are:

1. Kernel uses perf_event and hw_breakpoint framework to control
watchpoint, but the perf_event corresponding to watchpoint is
not enabled. So it needs to be enabled according to MWPnCFG3
or FWPnCFG3 PLV bit field in ptrace_hbp_set_ctrl(), and privilege
is set according to the monitored addr in hw_breakpoint_control().
Furthermore, add a judgment in ptrace_hbp_set_addr() to ensure
kernel-space addr cannot be monitored in user mode.

2. The global enable control for all watchpoints is the WE bit of
CSR.CRMD, and hardware sets the value to 0 when an exception is
triggered. When the ERTN instruction is executed to return, the
hardware restores the value of the PWE field of CSR.PRMD here.
So, before a thread containing watchpoints be scheduled, the PWE
field of CSR.PRMD needs to be set to 1. Add this modification in
hw_breakpoint_control().

All changes according to the LoongArch Reference Manual:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#control-and-status-registers-related-to-watchpoints
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#basic-control-and-status-registers

With this patch:

lihui@bogon:~$ gdb test
...
(gdb) watch a
Hardware watchpoint 1: a
(gdb) r
...
Hardware watchpoint 1: a

Old value = 0
New value = 1
main () at test.c:6
6 printf("a = %d\n", a);
(gdb) c
Continuing.
a = 1
[Inferior 1 (process 775) exited normally]

Cc: stable@vger.kernel.org
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

LoongArch: Fix watchpoint setting error

commit f63a47b34b140ed1ca39d7e4bd4f1cdc617fc316 upstream.

In the current code, when debugging the following code using gdb,
"invalid argument ..." message wi

LoongArch: Fix watchpoint setting error

commit f63a47b34b140ed1ca39d7e4bd4f1cdc617fc316 upstream.

In the current code, when debugging the following code using gdb,
"invalid argument ..." message will be displayed.

lihui@bogon:~$ cat test.c
#include <stdio.h>
int a = 0;
int main()
{
a = 1;
return 0;
}
lihui@bogon:~$ gcc -g test.c -o test
lihui@bogon:~$ gdb test
...
(gdb) watch a
Hardware watchpoint 1: a
(gdb) r
...
Invalid argument setting hardware debug registers

There are mainly two types of issues.

1. Some incorrect judgment condition existed in user_watch_state
argument parsing, causing -EINVAL to be returned.

When setting up a watchpoint, gdb uses the ptrace interface,
ptrace(PTRACE_SETREGSET, tid, NT_LOONGARCH_HW_WATCH, (void *) &iov)).
Register values in user_watch_state as follows:

addr[0] = 0x0, mask[0] = 0x0, ctrl[0] = 0x0
addr[1] = 0x0, mask[1] = 0x0, ctrl[1] = 0x0
addr[2] = 0x0, mask[2] = 0x0, ctrl[2] = 0x0
addr[3] = 0x0, mask[3] = 0x0, ctrl[3] = 0x0
addr[4] = 0x0, mask[4] = 0x0, ctrl[4] = 0x0
addr[5] = 0x0, mask[5] = 0x0, ctrl[5] = 0x0
addr[6] = 0x0, mask[6] = 0x0, ctrl[6] = 0x0
addr[7] = 0x12000803c, mask[7] = 0x0, ctrl[7] = 0x610

In arch_bp_generic_fields(), return -EINVAL when ctrl.len is
LOONGARCH_BREAKPOINT_LEN_8(0b00). So delete the incorrect judgment here.

In ptrace_hbp_fill_attr_ctrl(), when note_type is NT_LOONGARCH_HW_WATCH
and ctrl[0] == 0x0, if ((type & HW_BREAKPOINT_RW) != type) will return
-EINVAL. Here ctrl.type should be set based on note_type, and unnecessary
judgments can be removed.

2. The watchpoint argument was not set correctly due to unnecessary
offset and alignment_mask.

Modify ptrace_hbp_fill_attr_ctrl() and hw_breakpoint_arch_parse(), which
ensure the watchpont argument is set correctly.

All changes according to the LoongArch Reference Manual:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#control-and-status-registers-related-to-watchpoints

Cc: stable@vger.kernel.org
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

kprobe/ftrace: bail out if ftrace was killed

[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ]

If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, th

kprobe/ftrace: bail out if ftrace was killed

[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ]

If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, the ftrace_ops associated with the kprobes will be
freed, yet the kprobes will still be active, and when triggered, they
will use the freed memory, likely resulting in a page fault and panic.

This behavior can be reproduced quite easily, by creating a kprobe and
then triggering a ftrace_kill(). For simplicity, we can simulate an
ftrace error with a kernel module like [1]:

[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer

sudo perf probe --add commit_creds
sudo perf trace -e probe:commit_creds
# In another terminal
make
sudo insmod ftrace_killer.ko # calls ftrace_kill(), simulating bug
# Back to perf terminal
# ctrl-c
sudo perf probe --del commit_creds

After a short period, a page fault and panic would occur as the kprobe
continues to execute and uses the freed ftrace_ops. While ftrace_kill()
is supposed to be used only in extreme circumstances, it is invoked in
FTRACE_WARN_ON() and so there are many places where an unexpected bug
could be triggered, yet the system may continue operating, possibly
without the administrator noticing. If ftrace_kill() does not panic the
system, then we should do everything we can to continue operating,
rather than leave a ticking time bomb.

Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/

Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

LoongArch: Override higher address bits in JUMP_VIRT_ADDR

commit 1098efd299ffe9c8af818425338c7f6c4f930a98 upstream.

In JUMP_VIRT_ADDR we are performing an or calculation on address value
directly f

LoongArch: Override higher address bits in JUMP_VIRT_ADDR

commit 1098efd299ffe9c8af818425338c7f6c4f930a98 upstream.

In JUMP_VIRT_ADDR we are performing an or calculation on address value
directly from pcaddi.

This will only work if we are currently running from direct 1:1 mapping
addresses or firmware's DMW is configured exactly same as kernel. Still,
we should not rely on such assumption.

Fix by overriding higher bits in address comes from pcaddi, so we can
get rid of or operator.

Cc: stable@vger.kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

LoongArch: Add all CPUs enabled by fdt to NUMA node 0

commit 3de9c42d02a79a5e09bbee7a4421ddc00cfd5c6d upstream.

NUMA enabled kernel on FDT based machine fails to boot because CPUs
are all in NUMA_N

LoongArch: Add all CPUs enabled by fdt to NUMA node 0

commit 3de9c42d02a79a5e09bbee7a4421ddc00cfd5c6d upstream.

NUMA enabled kernel on FDT based machine fails to boot because CPUs
are all in NUMA_NO_NODE and mm subsystem won't accept that.

Fix by adding them to default NUMA node at FDT parsing phase and move
numa_add_cpu(0) to a later point.

Cc: stable@vger.kernel.org
Fixes: 88d4d957edc7 ("LoongArch: Add FDT booting support from efi system table")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

kbuild: unify vdso_install rules

[ Upstream commit 56769ba4b297a629148eb24d554aef72d1ddfd9e ]

Currently, there is no standard implementation for vdso_install,
leading to various issues:

1. Code d

kbuild: unify vdso_install rules

[ Upstream commit 56769ba4b297a629148eb24d554aef72d1ddfd9e ]

Currently, there is no standard implementation for vdso_install,
leading to various issues:

1. Code duplication

Many architectures duplicate similar code just for copying files
to the install destination.

Some architectures (arm, sparc, x86) create build-id symlinks,
introducing more code duplication.

2. Unintended updates of in-tree build artifacts

The vdso_install rule depends on the vdso files to install.
It may update in-tree build artifacts. This can be problematic,
as explained in commit 19514fc665ff ("arm, kbuild: make
"make install" not depend on vmlinux").

3. Broken code in some architectures

Makefile code is often copied from one architecture to another
without proper adaptation.

'make vdso_install' for parisc does not work.

'make vdso_install' for s390 installs vdso64, but not vdso32.

To address these problems, this commit introduces a generic vdso_install
rule.

Architectures that support vdso_install need to define vdso-install-y
in arch/*/Makefile. vdso-install-y lists the files to install.

For example, arch/x86/Makefile looks like this:

vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg
vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg
vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg
vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg

These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix,
if exists, stripped away.

vdso-install-y can optionally take the second field after the colon
separator. This is needed because some architectures install a vdso
file as a different base name.

The following is a snippet from arch/arm64/Makefile.

vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so

This will rename vdso.so.dbg to vdso32.so during installation. If such
architectures change their implementation so that the base names match,
this workaround will go away.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Guo Ren <guoren@kernel.org>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Stable-dep-of: fc2f5f10f9bc ("s390/vdso: Create .build-id links for unstripped vdso files")
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

LoongArch: Fix callchain parse error with kernel tracepoint events again

[ Upstream commit d6af2c76399f98444a5b4de96baf4b362d9f102b ]

With commit d3119bc985fb645 ("LoongArch: Fix callchain parse er

LoongArch: Fix callchain parse error with kernel tracepoint events again

[ Upstream commit d6af2c76399f98444a5b4de96baf4b362d9f102b ]

With commit d3119bc985fb645 ("LoongArch: Fix callchain parse error with
kernel tracepoint events"), perf can parse kernel callchain, but not
complete and sometimes maybe error. The reason is LoongArch's unwinders
(guess, prologue and orc) don't really need fp (i.e., regs[22]), and
they use sp (i.e., regs[3]) as the frame address rather than the current
stack pointer.

Fix that by removing the assignment of regs[22], and instead assign the
__builtin_frame_address(0) to regs[3].

Without fix:

Children Self Command Shared Object Symbol
........ ........ ............. ................. ................
33.91% 33.91% swapper [kernel.vmlinux] [k] __schedule
|
|--33.04%--__schedule
|
--0.87%--__arch_cpu_idle
__schedule

With this fix:

Children Self Command Shared Object Symbol
........ ........ ............. ................. ................
31.16% 31.16% swapper [kernel.vmlinux] [k] __schedule
|
|--20.63%--smpboot_entry
| cpu_startup_entry
| schedule_idle
| __schedule
|
--10.53%--start_kernel
cpu_startup_entry
schedule_idle
__schedule

Fixes: d3119bc985fb645 ("LoongArch: Fix callchain parse error with kernel tracepoint events")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

LoongArch: Lately init pmu after smp is online

[ Upstream commit f3334ebb8a2a1841c2824594dd992e66de19deb2 ]

There is an smp function call named reset_counters() to init PMU
registers of every CPU i

LoongArch: Lately init pmu after smp is online

[ Upstream commit f3334ebb8a2a1841c2824594dd992e66de19deb2 ]

There is an smp function call named reset_counters() to init PMU
registers of every CPU in PMU initialization state. It requires that all
CPUs are online. However there is an early_initcall() wrapper for the
PMU init funciton init_hw_perf_events(), so that pmu init funciton is
called in do_pre_smp_initcalls() which before function smp_init().
Function reset_counters() cannot work on other CPUs since they haven't
boot up still.

Here replace the wrapper early_initcall() with pure_initcall(), so that
the PMU init function is called after every cpu is online.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

LoongArch: Fix access error when read fault on a write-only VMA

commit efb44ff64c95340b06331fc48634b99efc9dd77c upstream.

As with most architectures, allow handling of read faults in VMAs that
have

LoongArch: Fix access error when read fault on a write-only VMA

commit efb44ff64c95340b06331fc48634b99efc9dd77c upstream.

As with most architectures, allow handling of read faults in VMAs that
have VM_WRITE but without VM_READ (WRITE implies READ).

Otherwise, reading before writing a write-only memory will error while
reading after writing everything is fine.

BTW, move the VM_EXEC judgement before VM_READ/VM_WRITE to make logic a
little clearer.

Cc: stable@vger.kernel.org
Fixes: 09cfefb7fa70c3af01 ("LoongArch: Add memory management")
Signed-off-by: Jiantao Shan <shanjiantao@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

LoongArch: Fix callchain parse error with kernel tracepoint events

commit d3119bc985fb645ad3b2a9cf9952c1d56d9daaa3 upstream.

In order to fix perf's callchain parse error for LoongArch, we implement

LoongArch: Fix callchain parse error with kernel tracepoint events

commit d3119bc985fb645ad3b2a9cf9952c1d56d9daaa3 upstream.

In order to fix perf's callchain parse error for LoongArch, we implement
perf_arch_fetch_caller_regs() which fills several necessary registers
used for callchain unwinding, including sp, fp, and era. This is similar
to the following commits.

commit b3eac0265bf6:
("arm: perf: Fix callchain parse error with kernel tracepoint events")

commit 5b09a094f2fb:
("arm64: perf: Fix callchain parse error with kernel tracepoint events")

commit 9a7e8ec0d4cc:
("riscv: perf: Fix callchain parse error with kernel tracepoint events")

Test with commands:

perf record -e sched:sched_switch -g --call-graph dwarf
perf report

Without this patch:

Children Self Command Shared Object Symbol
........ ........ ............. ................. ....................

43.41% 43.41% swapper [unknown] [k] 0000000000000000

10.94% 10.94% loong-container [unknown] [k] 0000000000000000
|
|--5.98%--0x12006ba38
|
|--2.56%--0x12006bb84
|
--2.40%--0x12006b6b8

With this patch, callchain can be parsed correctly:

Children Self Command Shared Object Symbol
........ ........ ............. ................. ....................

47.57% 47.57% swapper [kernel.vmlinux] [k] __schedule
|
---__schedule

26.76% 26.76% loong-container [kernel.vmlinux] [k] __schedule
|
|--13.78%--0x12006ba38
| |
| |--9.19%--__schedule
| |
| --4.59%--handle_syscall
| do_syscall
| sys_futex
| do_futex
| futex_wait
| futex_wait_queue_me
| hrtimer_start_range_ns
| __schedule
|
|--8.38%--0x12006bb84
| handle_syscall
| do_syscall
| sys_epoll_pwait
| do_epoll_wait
| schedule_hrtimeout_range_clock
| hrtimer_start_range_ns
| __schedule
|
--4.59%--0x12006b6b8
handle_syscall
do_syscall
sys_nanosleep
hrtimer_nanosleep
do_nanosleep
hrtimer_start_range_ns
__schedule

Cc: stable@vger.kernel.org
Fixes: b37042b2bb7cd751f0 ("LoongArch: Add perf events support")
Reported-by: Youling Tang <tangyouling@kylinos.cn>
Suggested-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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LoongArch/crypto: Clean up useless assignment operations

[ Upstream commit fea1c949f6ca5059e12de00d0483645debc5b206 ]

The LoongArch CRC32 hw acceleration is based on arch/mips/crypto/
crc32-mips.c.

LoongArch/crypto: Clean up useless assignment operations

[ Upstream commit fea1c949f6ca5059e12de00d0483645debc5b206 ]

The LoongArch CRC32 hw acceleration is based on arch/mips/crypto/
crc32-mips.c. While the MIPS code supports both MIPS32 and MIPS64,
but LoongArch32 lacks the CRC instruction. As a result, the line
"len -= sizeof(u32)" is unnecessary.

Removing it can make context code style more unified and improve
code readability.

Cc: stable@vger.kernel.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Suggested-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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LoongArch: Define the __io_aw() hook as mmiowb()

[ Upstream commit 9c68ece8b2a5c5ff9b2fcaea923dd73efeb174cd ]

Commit fb24ea52f78e0d595852e ("drivers: Remove explicit invocations of
mmiowb()") remov

LoongArch: Define the __io_aw() hook as mmiowb()

[ Upstream commit 9c68ece8b2a5c5ff9b2fcaea923dd73efeb174cd ]

Commit fb24ea52f78e0d595852e ("drivers: Remove explicit invocations of
mmiowb()") remove all mmiowb() in drivers, but it says:

"NOTE: mmiowb() has only ever guaranteed ordering in conjunction with
spin_unlock(). However, pairing each mmiowb() removal in this patch with
the corresponding call to spin_unlock() is not at all trivial, so there
is a small chance that this change may regress any drivers incorrectly
relying on mmiowb() to order MMIO writes between CPUs using lock-free
synchronisation."

The mmio in radeon_ring_commit() is protected by a mutex rather than a
spinlock, but in the mutex fastpath it behaves similar to spinlock. We
can add mmiowb() calls in the radeon driver but the maintainer says he
doesn't like such a workaround, and radeon is not the only example of
mutex protected mmio.

So we should extend the mmiowb tracking system from spinlock to mutex,
and maybe other locking primitives. This is not easy and error prone, so
we solve it in the architectural code, by simply defining the __io_aw()
hook as mmiowb(). And we no longer need to override queued_spin_unlock()
so use the generic definition.

Without this, we get such an error when run 'glxgears' on weak ordering
architectures such as LoongArch:

radeon 0000:04:00.0: ring 0 stalled for more than 10324msec
radeon 0000:04:00.0: ring 3 stalled for more than 10240msec
radeon 0000:04:00.0: GPU lockup (current fence id 0x000000000001f412 last fence id 0x000000000001f414 on ring 3)
radeon 0000:04:00.0: GPU lockup (current fence id 0x000000000000f940 last fence id 0x000000000000f941 on ring 0)
radeon 0000:04:00.0: scheduling IB failed (-35).
[drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35)
radeon 0000:04:00.0: scheduling IB failed (-35).
[drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35)
radeon 0000:04:00.0: scheduling IB failed (-35).
[drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35)
radeon 0000:04:00.0: scheduling IB failed (-35).
[drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35)
radeon 0000:04:00.0: scheduling IB failed (-35).
[drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35)
radeon 0000:04:00.0: scheduling IB failed (-35).
[drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35)
radeon 0000:04:00.0: scheduling IB failed (-35).
[drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35)

Link: https://lore.kernel.org/dri-devel/29df7e26-d7a8-4f67-b988-44353c4270ac@amd.com/T/#t
Link: https://lore.kernel.org/linux-arch/20240301130532.3953167-1-chenhuacai@loongson.cn/T/#t
Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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LoongArch: Change __my_cpu_offset definition to avoid mis-optimization

[ Upstream commit c87e12e0e8c1241410e758e181ca6bf23efa5b5b ]

From GCC commit 3f13154553f8546a ("df-scan: remove ad-hoc handlin

LoongArch: Change __my_cpu_offset definition to avoid mis-optimization

[ Upstream commit c87e12e0e8c1241410e758e181ca6bf23efa5b5b ]

From GCC commit 3f13154553f8546a ("df-scan: remove ad-hoc handling of
global regs in asms"), global registers will no longer be forced to add
to the def-use chain. Then current_thread_info(), current_stack_pointer
and __my_cpu_offset may be lifted out of the loop because they are no
longer treated as "volatile variables".

This optimization is still correct for the current_thread_info() and
current_stack_pointer usages because they are associated to a thread.
However it is wrong for __my_cpu_offset because it is associated to a
CPU rather than a thread: if the thread migrates to a different CPU in
the loop, __my_cpu_offset should be changed.

Change __my_cpu_offset definition to treat it as a "volatile variable",
in order to avoid such a mis-optimization.

Cc: stable@vger.kernel.org
Reported-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reported-by: Miao Wang <shankerwangmiao@gmail.com>
Signed-off-by: Xing Li <lixing@loongson.cn>
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
Signed-off-by: Rui Wang <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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