[PATCH v4 0/5] Support trampoline for LoongArch

[Chenghao Duan]

v4:
1. Delete the #3 patch of version V3.

2. Add 5 NOP instructions in build_prologue().
   Reserve space for the move_imm + jirl instruction.

3. Differentiate between direct jumps and ftrace jumps of trampoline:
   direct jumps skip 5 instructions.
   ftrace jumps skip 2 instructions.

4. Remove the generation of BL jump instructions in emit_jump_and_link().
   After the trampoline ends, it will jump to the specified register.
   The BL instruction writes PC+4 to r1 instead of allowing the
   specification of rd.

-----------------------------------------------------------------------
Historical Version:
v3:
1. Patch 0003 adds EXECMEM_BPF memory type to the execmem subsystem.

2. Align the size calculated by arch_bpf_trampoline_size to page
boundaries.

3. Add the flush icache operation to larch_insn_text_copy.

4. Unify the implementation of bpf_arch_xxx into the patch
"0004-LoongArch-BPF-Add-bpf_arch_xxxxx-support-for-Loong.patch".

5. Change the patch order. Move the patch
"0002-LoongArch-BPF-Update-the-code-to-rename-validate_.patch" before
"0005-LoongArch-BPF-Add-bpf-trampoline-support-for-Loon.patch".

URL for version v3:
https://lore.kernel.org/all/20250709055029.723243-1-duanchenghao@xxxxxxxxxx/
---------
v2:
1. Change the fixmap in the instruction copy function to set_memory_xxx.

2. Change the implementation method of the following code.
	- arch_alloc_bpf_trampoline
	- arch_free_bpf_trampoline
	Use the BPF core's allocation and free functions.

	- bpf_arch_text_invalidate
	Operate with the function larch_insn_text_copy that carries
	memory attribute modifications.

3. Correct the incorrect code formatting.

URL for version v2:
https://lore.kernel.org/all/20250618105048.1510560-1-duanchenghao@xxxxxxxxxx/
---------
v1:
Support trampoline for LoongArch. The following feature tests have been
completed:
	1. fentry
	2. fexit
	3. fmod_ret

TODO: The support for the struct_ops feature will be provided in
subsequent patches.

URL for version v1:
https://lore.kernel.org/all/20250611035952.111182-1-duanchenghao@xxxxxxxxxx/
-----------------------------------------------------------------------

Chenghao Duan (4):
  LoongArch: Add larch_insn_gen_{beq,bne} helpers
  LoongArch: BPF: Update the code to rename validate_code to
    validate_ctx
  LoongArch: BPF: Add bpf_arch_xxxxx support for Loongarch
  LoongArch: BPF: Add bpf trampoline support for Loongarch

Tiezhu Yang (1):
  LoongArch: BPF: Add struct ops support for trampoline

 arch/loongarch/include/asm/inst.h |   3 +
 arch/loongarch/kernel/inst.c      |  60 ++++
 arch/loongarch/net/bpf_jit.c      | 521 +++++++++++++++++++++++++++++-
 arch/loongarch/net/bpf_jit.h      |   6 +
 4 files changed, 589 insertions(+), 1 deletion(-)

-- 
2.25.1