xtensa: add system call table generation support

The system call tables are in different format in all
architecture and it will be difficult to manually add,
modify or delete the syscall table entries in the res-
pective files. To make it easy by keeping a script and
which will generate the uapi header and syscall table
file. This change will also help to unify the implemen-
tation across all architectures.

The system call table generation script is added in
kernel/syscalls directory which contain the scripts to
generate both uapi header file and system call table
files. The syscall.tbl will be input for the scripts.

syscall.tbl contains the list of available system calls
along with system call number and corresponding entry
point. Add a new system call in this architecture will
be possible by adding new entry in the syscall.tbl file.

Adding a new table entry consisting of:
  	- System call number.
	- ABI.
	- System call name.
	- Entry point name.

syscallhdr.sh and syscalltbl.sh will generate uapi header
unistd_32.h and syscall_table.h files respectively. Both
.sh files will parse the content syscall.tbl to generate
the header and table files. unistd_32.h will be included
by uapi/asm/unistd.h and syscall_table.h is included by
kernel/syscall.c - the real system call table.

ARM, s390 and x86 architecuture does have similar support.
I leverage their implementation to come up with a generic
solution.

Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

4 files changed, 480 insertions, 0 deletions

diff --git a/arch/xtensa/kernel/syscalls/Makefile b/arch/xtensa/kernel/syscalls/Makefile
new file mode 100644
index 000000000000..659faefdcb1d
--- /dev/null
+++ b/arch/xtensa/kernel/syscalls/Makefile
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: GPL-2.0
+kapi := arch/$(SRCARCH)/include/generated/asm
+uapi := arch/$(SRCARCH)/include/generated/uapi/asm
+
+_dummy := $(shell [ -d '$(uapi)' ] || mkdir -p '$(uapi)')	\
+	  $(shell [ -d '$(kapi)' ] || mkdir -p '$(kapi)')
+
+syscall := $(srctree)/$(src)/syscall.tbl
+syshdr := $(srctree)/$(src)/syscallhdr.sh
+systbl := $(srctree)/$(src)/syscalltbl.sh
+
+quiet_cmd_syshdr = SYSHDR  $@
+      cmd_syshdr = $(CONFIG_SHELL) '$(syshdr)' '$<' '$@'	\
+		   '$(syshdr_abis_$(basetarget))'		\
+		   '$(syshdr_pfx_$(basetarget))'		\
+		   '$(syshdr_offset_$(basetarget))'
+
+quiet_cmd_systbl = SYSTBL  $@
+      cmd_systbl = $(CONFIG_SHELL) '$(systbl)' '$<' '$@'	\
+		   '$(systbl_abis_$(basetarget))'		\
+		   '$(systbl_abi_$(basetarget))'		\
+		   '$(systbl_offset_$(basetarget))'
+
+$(uapi)/unistd_32.h: $(syscall) $(syshdr)
+	$(call if_changed,syshdr)
+
+$(kapi)/syscall_table.h: $(syscall) $(systbl)
+	$(call if_changed,systbl)
+
+uapisyshdr-y		+= unistd_32.h
+kapisyshdr-y		+= syscall_table.h
+
+targets	+= $(uapisyshdr-y) $(kapisyshdr-y)
+
+PHONY += all
+all: $(addprefix $(uapi)/,$(uapisyshdr-y))
+all: $(addprefix $(kapi)/,$(kapisyshdr-y))
+	@:
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
new file mode 100644
index 000000000000..69cf91b03b26
--- /dev/null
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -0,0 +1,374 @@
+# SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+#
+# system call numbers and entry vectors for xtensa
+#
+# The format is:
+# <number> <abi> <name> <entry point>
+#
+# The <abi> is always "common" for this file
+#
+0	common	spill				sys_ni_syscall
+1	common	xtensa				sys_ni_syscall
+2	common	available4			sys_ni_syscall
+3	common	available5			sys_ni_syscall
+4	common	available6			sys_ni_syscall
+5	common	available7			sys_ni_syscall
+6	common	available8			sys_ni_syscall
+7	common	available9			sys_ni_syscall
+# File Operations
+8	common	open				sys_open
+9	common	close				sys_close
+10	common	dup				sys_dup
+11	common	dup2				sys_dup2
+12	common	read				sys_read
+13	common	write				sys_write
+14	common	select				sys_select
+15	common	lseek				sys_lseek
+16	common	poll				sys_poll
+17	common	_llseek				sys_llseek
+18	common	epoll_wait			sys_epoll_wait
+19	common	epoll_ctl			sys_epoll_ctl
+20	common	epoll_create			sys_epoll_create
+21	common	creat				sys_creat
+22	common	truncate			sys_truncate
+23	common	ftruncate			sys_ftruncate
+24	common	readv				sys_readv
+25	common	writev				sys_writev
+26	common	fsync				sys_fsync
+27	common	fdatasync			sys_fdatasync
+28	common	truncate64			sys_truncate64
+29	common	ftruncate64			sys_ftruncate64
+30	common	pread64				sys_pread64
+31	common	pwrite64			sys_pwrite64
+32	common	link				sys_link
+33	common	rename				sys_rename
+34	common	symlink				sys_symlink
+35	common	readlink			sys_readlink
+36	common	mknod				sys_mknod
+37	common	pipe				sys_pipe
+38	common	unlink				sys_unlink
+39	common	rmdir				sys_rmdir
+40	common	mkdir				sys_mkdir
+41	common	chdir				sys_chdir
+42	common	fchdir				sys_fchdir
+43	common	getcwd				sys_getcwd
+44	common	chmod				sys_chmod
+45	common	chown				sys_chown
+46	common	stat				sys_newstat
+47	common	stat64				sys_stat64
+48	common	lchown				sys_lchown
+49	common	lstat				sys_newlstat
+50	common	lstat64				sys_lstat64
+51	common	available51			sys_ni_syscall
+52	common	fchmod				sys_fchmod
+53	common	fchown				sys_fchown
+54	common	fstat				sys_newfstat
+55	common	fstat64				sys_fstat64
+56	common	flock				sys_flock
+57	common	access				sys_access
+58	common	umask				sys_umask
+59	common	getdents			sys_getdents
+60	common	getdents64			sys_getdents64
+61	common	fcntl64				sys_fcntl64
+62	common	fallocate			sys_fallocate
+63	common	fadvise64_64			xtensa_fadvise64_64
+64	common	utime				sys_utime
+65	common	utimes				sys_utimes
+66	common	ioctl				sys_ioctl
+67	common	fcntl				sys_fcntl
+68	common	setxattr			sys_setxattr
+69	common	getxattr			sys_getxattr
+70	common	listxattr			sys_listxattr
+71	common	removexattr			sys_removexattr
+72	common	lsetxattr			sys_lsetxattr
+73	common	lgetxattr			sys_lgetxattr
+74	common	llistxattr			sys_llistxattr
+75	common	lremovexattr			sys_lremovexattr
+76	common	fsetxattr			sys_fsetxattr
+77	common	fgetxattr			sys_fgetxattr
+78	common	flistxattr			sys_flistxattr
+79	common	fremovexattr			sys_fremovexattr
+# File Map / Shared Memory Operations
+80	common	mmap2				sys_mmap_pgoff
+81	common	munmap				sys_munmap
+82	common	mprotect			sys_mprotect
+83	common	brk				sys_brk
+84	common	mlock				sys_mlock
+85	common	munlock				sys_munlock
+86	common	mlockall			sys_mlockall
+87	common	munlockall			sys_munlockall
+88	common	mremap				sys_mremap
+89	common	msync				sys_msync
+90	common	mincore				sys_mincore
+91	common	madvise				sys_madvise
+92	common	shmget				sys_shmget
+93	common	shmat				xtensa_shmat
+94	common	shmctl				sys_shmctl
+95	common	shmdt				sys_shmdt
+# Socket Operations
+96	common	socket				sys_socket
+97	common	setsockopt			sys_setsockopt
+98	common	getsockopt			sys_getsockopt
+99	common	shutdown			sys_shutdown
+100	common	bind				sys_bind
+101	common	connect				sys_connect
+102	common	listen				sys_listen
+103	common	accept				sys_accept
+104	common	getsockname			sys_getsockname
+105	common	getpeername			sys_getpeername
+106	common	sendmsg				sys_sendmsg
+107	common	recvmsg				sys_recvmsg
+108	common	send				sys_send
+109	common	recv				sys_recv
+110	common	sendto				sys_sendto
+111	common	recvfrom			sys_recvfrom
+112	common	socketpair			sys_socketpair
+113	common	sendfile			sys_sendfile
+114	common	sendfile64			sys_sendfile64
+115	common	sendmmsg			sys_sendmmsg
+# Process Operations
+116	common	clone				sys_clone
+117	common	execve				sys_execve
+118	common	exit				sys_exit
+119	common	exit_group			sys_exit_group
+120	common	getpid				sys_getpid
+121	common	wait4				sys_wait4
+122	common	waitid				sys_waitid
+123	common	kill				sys_kill
+124	common	tkill				sys_tkill
+125	common	tgkill				sys_tgkill
+126	common	set_tid_address			sys_set_tid_address
+127	common	gettid				sys_gettid
+128	common	setsid				sys_setsid
+129	common	getsid				sys_getsid
+130	common	prctl				sys_prctl
+131	common	personality			sys_personality
+132	common	getpriority			sys_getpriority
+133	common	setpriority			sys_setpriority
+134	common	setitimer			sys_setitimer
+135	common	getitimer			sys_getitimer
+136	common	setuid				sys_setuid
+137	common	getuid				sys_getuid
+138	common	setgid				sys_setgid
+139	common	getgid				sys_getgid
+140	common	geteuid				sys_geteuid
+141	common	getegid				sys_getegid
+142	common	setreuid			sys_setreuid
+143	common	setregid			sys_setregid
+144	common	setresuid			sys_setresuid
+145	common	getresuid			sys_getresuid
+146	common	setresgid			sys_setresgid
+147	common	getresgid			sys_getresgid
+148	common	setpgid				sys_setpgid
+149	common	getpgid				sys_getpgid
+150	common	getppid				sys_getppid
+151	common	getpgrp				sys_getpgrp
+# 152 was set_thread_area
+152	common	reserved152			sys_ni_syscall
+# 153 was get_thread_area
+153	common	reserved153			sys_ni_syscall
+154	common	times				sys_times
+155	common	acct				sys_acct
+156	common	sched_setaffinity		sys_sched_setaffinity
+157	common	sched_getaffinity		sys_sched_getaffinity
+158	common	capget				sys_capget
+159	common	capset				sys_capset
+160	common	ptrace				sys_ptrace
+161	common	semtimedop			sys_semtimedop
+162	common	semget				sys_semget
+163	common	semop				sys_semop
+164	common	semctl				sys_semctl
+165	common	available165			sys_ni_syscall
+166	common	msgget				sys_msgget
+167	common	msgsnd				sys_msgsnd
+168	common	msgrcv				sys_msgrcv
+169	common	msgctl				sys_msgctl
+170	common	available170			sys_ni_syscall
+# File System
+171	common	umount2				sys_umount
+172	common	mount				sys_mount
+173	common	swapon				sys_swapon
+174	common	chroot				sys_chroot
+175	common	pivot_root			sys_pivot_root
+176	common	umount				sys_oldumount
+177	common	swapoff				sys_swapoff
+178	common	sync				sys_sync
+179	common	syncfs				sys_syncfs
+180	common	setfsuid			sys_setfsuid
+181	common	setfsgid			sys_setfsgid
+182	common	sysfs				sys_sysfs
+183	common	ustat				sys_ustat
+184	common	statfs				sys_statfs
+185	common	fstatfs				sys_fstatfs
+186	common	statfs64			sys_statfs64
+187	common	fstatfs64			sys_fstatfs64
+# System
+188	common	setrlimit			sys_setrlimit
+189	common	getrlimit			sys_getrlimit
+190	common	getrusage			sys_getrusage
+191	common	futex				sys_futex
+192	common	gettimeofday			sys_gettimeofday
+193	common	settimeofday			sys_settimeofday
+194	common	adjtimex			sys_adjtimex
+195	common	nanosleep			sys_nanosleep
+196	common	getgroups			sys_getgroups
+197	common	setgroups			sys_setgroups
+198	common	sethostname			sys_sethostname
+199	common	setdomainname			sys_setdomainname
+200	common	syslog				sys_syslog
+201	common	vhangup				sys_vhangup
+202	common	uselib				sys_uselib
+203	common	reboot				sys_reboot
+204	common	quotactl			sys_quotactl
+# 205 was old nfsservctl
+205	common	nfsservctl			sys_ni_syscall
+206	common	_sysctl				sys_sysctl
+207	common	bdflush				sys_bdflush
+208	common	uname				sys_newuname
+209	common	sysinfo				sys_sysinfo
+210	common	init_module			sys_init_module
+211	common	delete_module			sys_delete_module
+212	common	sched_setparam			sys_sched_setparam
+213	common	sched_getparam			sys_sched_getparam
+214	common	sched_setscheduler		sys_sched_setscheduler
+215	common	sched_getscheduler		sys_sched_getscheduler
+216	common	sched_get_priority_max		sys_sched_get_priority_max
+217	common	sched_get_priority_min		sys_sched_get_priority_min
+218	common	sched_rr_get_interval		sys_sched_rr_get_interval
+219	common	sched_yield			sys_sched_yield
+222	common	available222			sys_ni_syscall
+# Signal Handling
+223	common	restart_syscall			sys_restart_syscall
+224	common	sigaltstack			sys_sigaltstack
+225	common	rt_sigreturn			xtensa_rt_sigreturn
+226	common	rt_sigaction			sys_rt_sigaction
+227	common	rt_sigprocmask			sys_rt_sigprocmask
+228	common	rt_sigpending			sys_rt_sigpending
+229	common	rt_sigtimedwait			sys_rt_sigtimedwait
+230	common	rt_sigqueueinfo			sys_rt_sigqueueinfo
+231	common	rt_sigsuspend			sys_rt_sigsuspend
+# Message
+232	common	mq_open				sys_mq_open
+233	common	mq_unlink			sys_mq_unlink
+234	common	mq_timedsend			sys_mq_timedsend
+235	common	mq_timedreceive			sys_mq_timedreceive
+236	common	mq_notify			sys_mq_notify
+237	common	mq_getsetattr			sys_mq_getsetattr
+238	common	available238			sys_ni_syscall
+239	common	io_setup			sys_io_setup
+# IO
+240	common	io_destroy			sys_io_destroy
+241	common	io_submit			sys_io_submit
+242	common	io_getevents			sys_io_getevents
+243	common	io_cancel			sys_io_cancel
+244	common	clock_settime			sys_clock_settime
+245	common	clock_gettime			sys_clock_gettime
+246	common	clock_getres			sys_clock_getres
+247	common	clock_nanosleep			sys_clock_nanosleep
+# Timer
+248	common	timer_create			sys_timer_create
+249	common	timer_delete			sys_timer_delete
+250	common	timer_settime			sys_timer_settime
+251	common	timer_gettime			sys_timer_gettime
+252	common	timer_getoverrun		sys_timer_getoverrun
+# System
+253	common	reserved253			sys_ni_syscall
+254	common	lookup_dcookie			sys_lookup_dcookie
+255	common	available255			sys_ni_syscall
+256	common	add_key				sys_add_key
+257	common	request_key			sys_request_key
+258	common	keyctl				sys_keyctl
+259	common	available259			sys_ni_syscall
+260	common	readahead			sys_readahead
+261	common	remap_file_pages		sys_remap_file_pages
+262	common	migrate_pages			sys_migrate_pages
+263	common	mbind				sys_mbind
+264	common	get_mempolicy			sys_get_mempolicy
+265	common	set_mempolicy			sys_set_mempolicy
+266	common	unshare				sys_unshare
+267	common	move_pages			sys_move_pages
+268	common	splice				sys_splice
+269	common	tee				sys_tee
+270	common	vmsplice			sys_vmsplice
+271	common	available271			sys_ni_syscall
+272	common	pselect6			sys_pselect6
+273	common	ppoll				sys_ppoll
+274	common	epoll_pwait			sys_epoll_pwait
+275	common	epoll_create1			sys_epoll_create1
+276	common	inotify_init			sys_inotify_init
+277	common	inotify_add_watch		sys_inotify_add_watch
+278	common	inotify_rm_watch		sys_inotify_rm_watch
+279	common	inotify_init1			sys_inotify_init1
+280	common	getcpu				sys_getcpu
+281	common	kexec_load			sys_ni_syscall
+282	common	ioprio_set			sys_ioprio_set
+283	common	ioprio_get			sys_ioprio_get
+284	common	set_robust_list			sys_set_robust_list
+285	common	get_robust_list			sys_get_robust_list
+286	common	available286			sys_ni_syscall
+287	common	available287			sys_ni_syscall
+# Relative File Operations
+288	common	openat				sys_openat
+289	common	mkdirat				sys_mkdirat
+290	common	mknodat				sys_mknodat
+291	common	unlinkat			sys_unlinkat
+292	common	renameat			sys_renameat
+293	common	linkat				sys_linkat
+294	common	symlinkat			sys_symlinkat
+295	common	readlinkat			sys_readlinkat
+296	common	utimensat			sys_utimensat
+297	common	fchownat			sys_fchownat
+298	common	futimesat			sys_futimesat
+299	common	fstatat64			sys_fstatat64
+300	common	fchmodat			sys_fchmodat
+301	common	faccessat			sys_faccessat
+302	common	available302			sys_ni_syscall
+303	common	available303			sys_ni_syscall
+304	common	signalfd			sys_signalfd
+# 305 was timerfd
+306	common	eventfd				sys_eventfd
+307	common	recvmmsg			sys_recvmmsg
+308	common	setns				sys_setns
+309	common	signalfd4			sys_signalfd4
+310	common	dup3				sys_dup3
+311	common	pipe2				sys_pipe2
+312	common	timerfd_create			sys_timerfd_create
+313	common	timerfd_settime			sys_timerfd_settime
+314	common	timerfd_gettime			sys_timerfd_gettime
+315	common	available315			sys_ni_syscall
+316	common	eventfd2			sys_eventfd2
+317	common	preadv				sys_preadv
+318	common	pwritev				sys_pwritev
+319	common	available319			sys_ni_syscall
+320	common	fanotify_init			sys_fanotify_init
+321	common	fanotify_mark			sys_fanotify_mark
+322	common	process_vm_readv		sys_process_vm_readv
+323	common	process_vm_writev		sys_process_vm_writev
+324	common	name_to_handle_at		sys_name_to_handle_at
+325	common	open_by_handle_at		sys_open_by_handle_at
+326	common	sync_file_range2		sys_sync_file_range2
+327	common	perf_event_open			sys_perf_event_open
+328	common	rt_tgsigqueueinfo		sys_rt_tgsigqueueinfo
+329	common	clock_adjtime			sys_clock_adjtime
+330	common	prlimit64			sys_prlimit64
+331	common	kcmp				sys_kcmp
+332	common	finit_module			sys_finit_module
+333	common	accept4				sys_accept4
+334	common	sched_setattr			sys_sched_setattr
+335	common	sched_getattr			sys_sched_getattr
+336	common	renameat2			sys_renameat2
+337	common	seccomp				sys_seccomp
+338	common	getrandom			sys_getrandom
+339	common	memfd_create			sys_memfd_create
+340	common	bpf				sys_bpf
+341	common	execveat			sys_execveat
+342	common	userfaultfd			sys_userfaultfd
+343	common	membarrier			sys_membarrier
+344	common	mlock2				sys_mlock2
+345	common	copy_file_range			sys_copy_file_range
+346	common	preadv2				sys_preadv2
+347	common	pwritev2			sys_pwritev2
+348	common	pkey_mprotect			sys_pkey_mprotect
+349	common	pkey_alloc			sys_pkey_alloc
+350	common	pkey_free			sys_pkey_free
+351	common	statx				sys_statx
diff --git a/arch/xtensa/kernel/syscalls/syscallhdr.sh b/arch/xtensa/kernel/syscalls/syscallhdr.sh
new file mode 100644
index 000000000000..d37db641ca31
--- /dev/null
+++ b/arch/xtensa/kernel/syscalls/syscallhdr.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+in="$1"
+out="$2"
+my_abis=`echo "($3)" | tr ',' '|'`
+prefix="$4"
+offset="$5"
+
+fileguard=_UAPI_ASM_XTENSA_`basename "$out" | sed \
+	-e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' \
+	-e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g'`
+grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
+	printf "#ifndef %s\n" "${fileguard}"
+	printf "#define %s\n" "${fileguard}"
+	printf "\n"
+
+	nxt=0
+	while read nr abi name entry ; do
+		if [ -z "$offset" ]; then
+			printf "#define __NR_%s%s\t%s\n" \
+				"${prefix}" "${name}" "${nr}"
+		else
+			printf "#define __NR_%s%s\t(%s + %s)\n" \
+				"${prefix}" "${name}" "${offset}" "${nr}"
+		fi
+		nxt=$((nr+1))
+	done
+
+	printf "\n"
+	printf "#ifdef __KERNEL__\n"
+	printf "#define __NR_syscalls\t%s\n" "${nxt}"
+	printf "#endif\n"
+	printf "\n"
+	printf "#endif /* %s */" "${fileguard}"
+) > "$out"
diff --git a/arch/xtensa/kernel/syscalls/syscalltbl.sh b/arch/xtensa/kernel/syscalls/syscalltbl.sh
new file mode 100644
index 000000000000..85d78d9309ad
--- /dev/null
+++ b/arch/xtensa/kernel/syscalls/syscalltbl.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+in="$1"
+out="$2"
+my_abis=`echo "($3)" | tr ',' '|'`
+my_abi="$4"
+offset="$5"
+
+emit() {
+	t_nxt="$1"
+	t_nr="$2"
+	t_entry="$3"
+
+	while [ $t_nxt -lt $t_nr ]; do
+		printf "__SYSCALL(%s, sys_ni_syscall, )\n" "${t_nxt}"
+		t_nxt=$((t_nxt+1))
+	done
+	printf "__SYSCALL(%s, %s, )\n" "${t_nxt}" "${t_entry}"
+}
+
+grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
+	nxt=0
+	if [ -z "$offset" ]; then
+		offset=0
+	fi
+
+	while read nr abi name entry ; do
+		emit $((nxt+offset)) $((nr+offset)) $entry
+		nxt=$((nr+1))
+	done
+) > "$out"