[PATCH V4 09/14] LoongArch: Adjust system call for 32BIT/64BIT

Huacai Chen
2025-11-27T15:55:39Z

Adjust system call for both 32BIT and 64BIT, including: add the uapi
unistd_{32,64}.h and syscall_table_{32,64}.h inclusion, add sys_mmap2()
definition, change the system call entry routines, etc.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
arch/loongarch/include/asm/Kbuild | 1 +
arch/loongarch/include/uapi/asm/Kbuild | 1 +
arch/loongarch/include/uapi/asm/unistd.h | 6 ++++++
arch/loongarch/kernel/Makefile.syscalls | 1 +
arch/loongarch/kernel/entry.S | 22 +++++++++++-----------
arch/loongarch/kernel/syscall.c | 13 +++++++++++++
6 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/arch/loongarch/include/asm/Kbuild b/arch/loongarch/include/asm/Kbuild
index b04d2cef935f..9034b583a88a 100644
--- a/arch/loongarch/include/asm/Kbuild
+++ b/arch/loongarch/include/asm/Kbuild
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
+syscall-y += syscall_table_32.h
syscall-y += syscall_table_64.h
generated-y += orc_hash.h

diff --git a/arch/loongarch/include/uapi/asm/Kbuild b/arch/loongarch/include/uapi/asm/Kbuild
index 517761419999..89ac01faa5ae 100644
--- a/arch/loongarch/include/uapi/asm/Kbuild
+++ b/arch/loongarch/include/uapi/asm/Kbuild
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
+syscall-y += unistd_32.h
syscall-y += unistd_64.h
diff --git a/arch/loongarch/include/uapi/asm/unistd.h b/arch/loongarch/include/uapi/asm/unistd.h
index 1f01980f9c94..e19c7f2f9f87 100644
--- a/arch/loongarch/include/uapi/asm/unistd.h
+++ b/arch/loongarch/include/uapi/asm/unistd.h
@@ -1,3 +1,9 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */

+#include <asm/bitsperlong.h>
+
+#if __BITS_PER_LONG == 32
+#include <asm/unistd_32.h>
+#else
#include <asm/unistd_64.h>
+#endif
diff --git a/arch/loongarch/kernel/Makefile.syscalls b/arch/loongarch/kernel/Makefile.syscalls
index ab7d9baa2915..cd46c2b69c7f 100644
--- a/arch/loongarch/kernel/Makefile.syscalls
+++ b/arch/loongarch/kernel/Makefile.syscalls
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0

# No special ABIs on loongarch so far
+syscall_abis_32 +=
syscall_abis_64 +=
diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S
index 47e1db9a1ce4..b53d333a7c42 100644
--- a/arch/loongarch/kernel/entry.S
+++ b/arch/loongarch/kernel/entry.S
@@ -23,24 +23,24 @@ SYM_CODE_START(handle_syscall)
UNWIND_HINT_UNDEFINED
csrrd t0, PERCPU_BASE_KS
la.pcrel t1, kernelsp
- add.d t1, t1, t0
+ PTR_ADD t1, t1, t0
move t2, sp
- ld.d sp, t1, 0
+ PTR_L sp, t1, 0

- addi.d sp, sp, -PT_SIZE
+ PTR_ADDI sp, sp, -PT_SIZE
cfi_st t2, PT_R3
cfi_rel_offset sp, PT_R3
- st.d zero, sp, PT_R0
+ LONG_S zero, sp, PT_R0
csrrd t2, LOONGARCH_CSR_PRMD
- st.d t2, sp, PT_PRMD
+ LONG_S t2, sp, PT_PRMD
csrrd t2, LOONGARCH_CSR_CRMD
- st.d t2, sp, PT_CRMD
+ LONG_S t2, sp, PT_CRMD
csrrd t2, LOONGARCH_CSR_EUEN
- st.d t2, sp, PT_EUEN
+ LONG_S t2, sp, PT_EUEN
csrrd t2, LOONGARCH_CSR_ECFG
- st.d t2, sp, PT_ECFG
+ LONG_S t2, sp, PT_ECFG
csrrd t2, LOONGARCH_CSR_ESTAT
- st.d t2, sp, PT_ESTAT
+ LONG_S t2, sp, PT_ESTAT
cfi_st ra, PT_R1
cfi_st a0, PT_R4
cfi_st a1, PT_R5
@@ -51,7 +51,7 @@ SYM_CODE_START(handle_syscall)
cfi_st a6, PT_R10
cfi_st a7, PT_R11
csrrd ra, LOONGARCH_CSR_ERA
- st.d ra, sp, PT_ERA
+ LONG_S ra, sp, PT_ERA
cfi_rel_offset ra, PT_ERA

cfi_st tp, PT_R2
@@ -67,7 +67,7 @@ SYM_CODE_START(handle_syscall)
#endif

move u0, t0
- li.d tp, ~_THREAD_MASK
+ LONG_LI tp, ~_THREAD_MASK
and tp, tp, sp

move a0, sp
diff --git a/arch/loongarch/kernel/syscall.c b/arch/loongarch/kernel/syscall.c
index ab94eb5ce039..1249d82c1cd0 100644
--- a/arch/loongarch/kernel/syscall.c
+++ b/arch/loongarch/kernel/syscall.c
@@ -34,9 +34,22 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long,
return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
}

+SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len, unsigned long,
+ prot, unsigned long, flags, unsigned long, fd, unsigned long, offset)
+{
+ if (offset & (~PAGE_MASK >> 12))
+ return -EINVAL;
+
+ return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> (PAGE_SHIFT - 12));
+}
+
void *sys_call_table[__NR_syscalls] = {
[0 ... __NR_syscalls - 1] = sys_ni_syscall,
+#ifdef CONFIG_32BIT
+#include <asm/syscall_table_32.h>
+#else
#include <asm/syscall_table_64.h>
+#endif
};

typedef long (*sys_call_fn)(unsigned long, unsigned long,
--
2.47.3