linux-stable.git/arch/loongarch/kernel/kdebugfs.c, branch linux-rolling-stable Linux kernel stable tree LoongArch: Add debugfs entries to switch SFB/TSO state 2025-01-26T13:49:59+00:00 Huacai Chen chenhuacai@loongson.cn 2025-01-26T13:49:59+00:00 04816c1507b46baccd17a4bc948440b3634d5d13 We need to switch SFB (Store Fill Buffer) and TSO (Total Store Order) state at runtime to debug memory management and KVM virtualization, so add two debugfs entries "sfb_state" and "tso_state" under the directory /sys/kernel/debug/loongarch. Query SFB: cat /sys/kernel/debug/loongarch/sfb_state Enable SFB: echo 1 > /sys/kernel/debug/loongarch/sfb_state Disable SFB: echo 0 > /sys/kernel/debug/loongarch/sfb_state Query TSO: cat /sys/kernel/debug/loongarch/tso_state Switch TSO: echo [TSO] > /sys/kernel/debug/loongarch/tso_state Available [TSO] states: 0 (No Load No Store) 1 (All Load No Store) 3 (Same Load No Store) 4 (No Load All Store) 5 (All Load All Store) 7 (Same Load All Store) Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
We need to switch SFB (Store Fill Buffer) and TSO (Total Store Order)
state at runtime to debug memory management and KVM virtualization, so
add two debugfs entries "sfb_state" and "tso_state" under the directory
/sys/kernel/debug/loongarch.

Query SFB:
cat /sys/kernel/debug/loongarch/sfb_state

Enable SFB:
echo 1 > /sys/kernel/debug/loongarch/sfb_state

Disable SFB:
echo 0 > /sys/kernel/debug/loongarch/sfb_state

Query TSO:
cat /sys/kernel/debug/loongarch/tso_state

Switch TSO:
echo [TSO] > /sys/kernel/debug/loongarch/tso_state

Available [TSO] states:
0 (No Load No Store)    1 (All Load No Store)   3 (Same Load No Store)
4 (No Load All Store)   5 (All Load All Store)  7 (Same Load All Store)

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>