riscv: convert to generic syscall table

The uapi/asm/unistd_{32,64}.h and asm/syscall_table_{32,64}.h headers can
now be generated from scripts/syscall.tbl, which makes this consistent
with the other architectures that have their own syscall.tbl.

riscv has two extra system call that gets added to scripts/syscall.tbl.

The newstat and rlimit entries in the syscall_abis_64 line are for system
calls that were part of the generic ABI when riscv64 got added but are
no longer enabled by default for new architectures. Both riscv32 and
riscv64 also implement memfd_secret, which is optional for all
architectures.

Unlike all the other 32-bit architectures, the time32 and stat64
sets of syscalls are not enabled on riscv32.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index 504f8b7e72d412be222ef4fc48c173b177f4f171..5c589770f2a8232c793ca7bb8ff8dc3d570ff694 100644 (file)
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -1,4 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
+syscall-y += syscall_table_32.h
+syscall-y += syscall_table_64.h
+
 generic-y += early_ioremap.h
 generic-y += flat.h
 generic-y += kvm_para.h

diff --git a/arch/riscv/include/asm/syscall_table.h b/arch/riscv/include/asm/syscall_table.h
new file mode 100644 (file)
index 0000000..0c2d617
--- /dev/null
+++ b/arch/riscv/include/asm/syscall_table.h
@@ -0,0 +1,7 @@
+#include <asm/bitsperlong.h>
+
+#if __BITS_PER_LONG == 64
+#include <asm/syscall_table_64.h>
+#else
+#include <asm/syscall_table_32.h>
+#endif

diff --git a/arch/riscv/include/asm/unistd.h b/arch/riscv/include/asm/unistd.h
index 221630bdbd0778a664710783d0489a74e7b490ea..e6d904fa67c5ea88b3de01003e5f64fcdb0e8fd3 100644 (file)
--- a/arch/riscv/include/asm/unistd.h
+++ b/arch/riscv/include/asm/unistd.h
@@ -3,11 +3,6 @@
  * Copyright (C) 2012 Regents of the University of California
  */
 
-/*
- * There is explicitly no include guard here because this file is expected to
- * be included multiple times.
- */
-
 #define __ARCH_WANT_SYS_CLONE
 
 #ifdef CONFIG_COMPAT
@@ -21,6 +16,14 @@
 #define __ARCH_WANT_COMPAT_FADVISE64_64
 #endif
 
+#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
+#define __ARCH_WANT_NEW_STAT
+#define __ARCH_WANT_SET_GET_RLIMIT
+#endif /* __LP64__ */
+
+#define __ARCH_WANT_MEMFD_SECRET
+
+
 #include <uapi/asm/unistd.h>
 
 #define NR_syscalls (__NR_syscalls)

diff --git a/arch/riscv/include/uapi/asm/Kbuild b/arch/riscv/include/uapi/asm/Kbuild
index f66554cd5c4518cf919abf321ce9137e8b2be59d..89ac01faa5aef5f35837b8c4acc583082c30db53 100644 (file)
--- a/arch/riscv/include/uapi/asm/Kbuild
+++ b/arch/riscv/include/uapi/asm/Kbuild
@@ -1 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
+syscall-y += unistd_32.h
+syscall-y += unistd_64.h

diff --git a/arch/riscv/include/uapi/asm/unistd.h b/arch/riscv/include/uapi/asm/unistd.h
index 328520defc1389ae9faeca8914ef61447350a644..81896bbbf727f525b069a56ed143fb2c0ee179aa 100644 (file)
--- a/arch/riscv/include/uapi/asm/unistd.h
+++ b/arch/riscv/include/uapi/asm/unistd.h
@@ -14,40 +14,10 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
+#include <asm/bitsperlong.h>
 
-#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
-#define __ARCH_WANT_NEW_STAT
-#define __ARCH_WANT_SET_GET_RLIMIT
-#endif /* __LP64__ */
-
-#define __ARCH_WANT_MEMFD_SECRET
-
-#include <asm-generic/unistd.h>
-
-/*
- * Allows the instruction cache to be flushed from userspace.  Despite RISC-V
- * having a direct 'fence.i' instruction available to userspace (which we
- * can't trap!), that's not actually viable when running on Linux because the
- * kernel might schedule a process on another hart.  There is no way for
- * userspace to handle this without invoking the kernel (as it doesn't know the
- * thread->hart mappings), so we've defined a RISC-V specific system call to
- * flush the instruction cache.
- *
- * __NR_riscv_flush_icache is defined to flush the instruction cache over an
- * address range, with the flush applying to either all threads or just the
- * caller.  We don't currently do anything with the address range, that's just
- * in there for forwards compatibility.
- */
-#ifndef __NR_riscv_flush_icache
-#define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15)
-#endif
-__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache)
-
-/*
- * Allows userspace to query the kernel for CPU architecture and
- * microarchitecture details across a given set of CPUs.
- */
-#ifndef __NR_riscv_hwprobe
-#define __NR_riscv_hwprobe (__NR_arch_specific_syscall + 14)
+#if __BITS_PER_LONG == 64
+#include <asm/unistd_64.h>
+#else
+#include <asm/unistd_32.h>
 #endif
-__SYSCALL(__NR_riscv_hwprobe, sys_riscv_hwprobe)

diff --git a/arch/riscv/kernel/Makefile.syscalls b/arch/riscv/kernel/Makefile.syscalls
new file mode 100644 (file)
index 0000000..52087a0
--- /dev/null
+++ b/arch/riscv/kernel/Makefile.syscalls
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+syscall_abis_32 += riscv memfd_secret
+syscall_abis_64 += riscv newstat rlimit memfd_secret

diff --git a/arch/riscv/kernel/compat_syscall_table.c b/arch/riscv/kernel/compat_syscall_table.c
index ad7f2d712f5fd070b3e4d8687a8b8d147f17162c..e884c069e88fdb5a6abeedd29059cb908681e124 100644 (file)
--- a/arch/riscv/kernel/compat_syscall_table.c
+++ b/arch/riscv/kernel/compat_syscall_table.c
@@ -8,9 +8,11 @@
 #include <asm-generic/syscalls.h>
 #include <asm/syscall.h>
 
+#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
+
 #undef __SYSCALL
 #define __SYSCALL(nr, call)    asmlinkage long __riscv_##call(const struct pt_regs *);
-#include <asm/unistd.h>
+#include <asm/syscall_table_32.h>
 
 #undef __SYSCALL
 #define __SYSCALL(nr, call)      [nr] = __riscv_##call,
@@ -19,5 +21,5 @@ asmlinkage long compat_sys_rt_sigreturn(void);
 
 void * const compat_sys_call_table[__NR_syscalls] = {
        [0 ... __NR_syscalls - 1] = __riscv_sys_ni_syscall,
-#include <asm/unistd.h>
+#include <asm/syscall_table_32.h>
 };

diff --git a/arch/riscv/kernel/syscall_table.c b/arch/riscv/kernel/syscall_table.c
index dda91376490340c111e84f937495c6c35d5b63ee..6f1a36cb0f3f91aca3f3c77eef77107626589650 100644 (file)
--- a/arch/riscv/kernel/syscall_table.c
+++ b/arch/riscv/kernel/syscall_table.c
@@ -9,14 +9,16 @@
 #include <asm-generic/syscalls.h>
 #include <asm/syscall.h>
 
+#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
+
 #undef __SYSCALL
 #define __SYSCALL(nr, call)    asmlinkage long __riscv_##call(const struct pt_regs *);
-#include <asm/unistd.h>
+#include <asm/syscall_table.h>
 
 #undef __SYSCALL
 #define __SYSCALL(nr, call)    [nr] = __riscv_##call,
 
 void * const sys_call_table[__NR_syscalls] = {
        [0 ... __NR_syscalls - 1] = __riscv_sys_ni_syscall,
-#include <asm/unistd.h>
+#include <asm/syscall_table.h>
 };

diff --git a/scripts/syscall.tbl b/scripts/syscall.tbl
index 28329c00bf688f4c73c15810baa50423b2f0413f..797e20ea99a2d53cf01def5802cd648a9db2f0ba 100644 (file)
--- a/scripts/syscall.tbl
+++ b/scripts/syscall.tbl
@@ -301,6 +301,9 @@
 
 244    or1k    or1k_atomic                     sys_or1k_atomic
 
+258    riscv   riscv_hwprobe                   sys_riscv_hwprobe
+259    riscv   riscv_flush_icache              sys_riscv_flush_icache
+
 260    time32  wait4                           sys_wait4                       compat_sys_wait4
 260    64      wait4                           sys_wait4
 261    common  prlimit64                       sys_prlimit64