[PATCH V3 10/11] bpf: manual updates for eBPF

["Jose E. Marchesi" <jose dot marchesi at oracle dot com>]

gcc/ChangeLog:

	* doc/invoke.texi (Option Summary): Cover eBPF.
	(eBPF Options): New section.
	* doc/extend.texi (BPF Built-in Functions): Likewise.
	(BPF Kernel Helpers): Likewise.
---
 gcc/ChangeLog       |   7 +++
 gcc/doc/extend.texi | 171 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 gcc/doc/invoke.texi |  37 ++++++++++++
 3 files changed, 215 insertions(+)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 235be99abcb..65ea5ce238c 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -13603,6 +13603,8 @@ instructions, but allow the compiler to schedule those calls.
 * ARM ARMv8-M Security Extensions::
 * AVR Built-in Functions::
 * Blackfin Built-in Functions::
+* BPF Built-in Functions::
+* BPF Kernel Helpers::
 * FR-V Built-in Functions::
 * MIPS DSP Built-in Functions::
 * MIPS Paired-Single Support::
@@ -14600,6 +14602,175 @@ void __builtin_bfin_csync (void)
 void __builtin_bfin_ssync (void)
 @end smallexample
 
+@node BPF Built-in Functions
+@subsection BPF Built-in Functions
+
+The following built-in functions are available for eBPF targets.
+
+@deftypefn {Built-in Function} unsigned long long __builtin_bpf_load_byte (unsigned long long @var{offset})
+Load a byte from the @code{struct sk_buff} packet data pointed by the register @code{%r6} and return it.
+@end deftypefn
+
+@deftypefn {Built-in Function} unsigned long long __builtin_bpf_load_half (unsigned long long @var{offset})
+Load 16-bits from the @code{struct sk_buff} packet data pointed by the register @code{%r6} and return it.
+@end deftypefn
+
+@deftypefn {Built-in Function} unsigned long long __builtin_bpf_load_word (unsigned long long @var{offset})
+Load 32-bits from the @code{struct sk_buff} packet data pointed by the register @code{%r6} and return it.
+@end deftypefn
+
+@node BPF Kernel Helpers
+@subsection BPF Kernel Helpers
+
+These built-in functions are available for calling kernel helpers, and
+they are available depending on the kernel version selected as the
+CPU.
+
+Rather than using the built-ins directly, it is preferred for programs
+to include @file{bpf-helpers.h} and use the wrappers defined there.
+
+For a full description of what the helpers do, the arguments they
+take, and the returned value, see the
+@file{linux/include/uapi/linux/bpf.h} in a Linux source tree.
+
+@smallexample
+void *__builtin_bpf_helper_map_lookup_elem (void *map, void *key)
+int   __builtin_bpf_helper_map_update_elem (void *map, void *key,
+                                            void *value,
+                                            unsigned long long flags)
+int   __builtin_bpf_helper_map_delete_elem (void *map, const void *key)
+int   __builtin_bpf_helper_map_push_elem (void *map, const void *value,
+                                          unsigned long long flags)
+int   __builtin_bpf_helper_map_pop_elem (void *map, void *value)
+int   __builtin_bpf_helper_map_peek_elem (void *map, void *value)
+int __builtin_bpf_helper_clone_redirect (void *skb,
+                                         unsigned int ifindex,
+                                         unsigned long long flags)
+int __builtin_bpf_helper_skb_get_tunnel_key (void *ctx, void *key, int size, int flags)
+int __builtin_bpf_helper_skb_set_tunnel_key (void *ctx, void *key, int size, int flags)
+int __builtin_bpf_helper_skb_get_tunnel_opt (void *ctx, void *md, int size)
+int __builtin_bpf_helper_skb_set_tunnel_opt (void *ctx, void *md, int size)
+int __builtin_bpf_helper_skb_get_xfrm_state (void *ctx, int index, void *state,
+				     int size, int flags)
+static unsigned long long __builtin_bpf_helper_skb_cgroup_id (void *ctx)
+static unsigned long long __builtin_bpf_helper_skb_ancestor_cgroup_id
+                                         (void *ctx, int level)
+int __builtin_bpf_helper_skb_vlan_push (void *ctx, __be16 vlan_proto, __u16 vlan_tci)
+int __builtin_bpf_helper_skb_vlan_pop (void *ctx)
+int __builtin_bpf_helper_skb_ecn_set_ce (void *ctx)
+
+int __builtin_bpf_helper_skb_load_bytes (void *ctx, int off, void *to, int len)
+int __builtin_bpf_helper_skb_load_bytes_relative (void *ctx, int off, void *to, int len, __u32 start_header)
+int __builtin_bpf_helper_skb_store_bytes (void *ctx, int off, void *from, int len, int flags)
+int __builtin_bpf_helper_skb_under_cgroup (void *ctx, void *map, int index)
+int __builtin_bpf_helper_skb_change_head (void *, int len, int flags)
+int __builtin_bpf_helper_skb_pull_data (void *, int len)
+int __builtin_bpf_helper_skb_change_proto (void *ctx, __be16 proto, __u64 flags)
+int __builtin_bpf_helper_skb_change_type (void *ctx, __u32 type)
+int __builtin_bpf_helper_skb_change_tail (void *ctx, __u32 len, __u64 flags)
+int __builtin_bpf_helper_skb_adjust_room (void *ctx, __s32 len_diff, __u32 mode,
+    				  unsigned long long flags)
+@end smallexample
+
+Other helpers:
+
+@smallexample
+int __builtin_bpf_helper_probe_read (void *dst, unsigned int size, void *src)
+unsigned long long __builtin_bpf_helper_ktime_get_ns (void)
+int __builtin_bpf_helper_trace_printk (const char *fmt, unsigned int fmt_size, ...)
+void __builtin_bpf_helper_tail_call (void *ctx, void *prog_array_map, unsigned int index)
+unsigned int __builtin_bpf_helper_get_smp_processor_id (void)
+unsigned long long __builtin_bpf_helper_get_current_pid_tgid (void)
+unsigned long long __builtin_bpf_helper_get_current_uid_gid (void)
+int __builtin_bpf_helper_get_current_comm (void *buf, unsigned int size_of_buf)
+unsigned long long __builtin_bpf_helper_perf_event_read (void *map, unsigned long long flags)
+
+int __builtin_bpf_helper_redirect (unsigned int ifindex, unsigned long long flags)
+int __builtin_bpf_helper_redirect_map (void *map, unsigned int key, unsigned long long flags)
+int __builtin_bpf_helper_perf_event_output (void *ctx,void *map, unsigned long long flags, void *data, unsigned long long size)
+int __builtin_bpf_helper_get_stackid (void *ctx, void *map, unsigned long long flags)
+int __builtin_bpf_helper_probe_write_user (void *dst, const void *src, unsigned int len)
+int __builtin_bpf_helper_current_task_under_cgroup (void *map, unsigned int index)
+
+static unsigned long long __builtin_bpf_helper_get_prandom_u32 (void)
+int __builtin_bpf_helper_xdp_adjust_head (void *ctx, int offset)
+int __builtin_bpf_helper_xdp_adjust_meta (void *ctx, int offset)
+int __builtin_bpf_helper_get_socket_cookie (void *ctx)
+int __builtin_bpf_helper_setsockopt (void *ctx, int level, int optname, void *optval,
+			     int optlen)
+int __builtin_bpf_helper_getsockopt (void *ctx, int level, int optname, void *optval,
+			     int optlen)
+int __builtin_bpf_helper_sock_ops_cb_flags_set (void *ctx, int flags)
+int __builtin_bpf_helper_sk_redirect_map (void *ctx, void *map, int key, int flags)
+int __builtin_bpf_helper_sk_redirect_hash (void *ctx, void *map, void *key, int flags)
+int __builtin_bpf_helper_sock_map_update (void *map, void *key, void *value,
+				  unsigned long long flags)
+int __builtin_bpf_helper_sock_hash_update (void *map, void *key, void *value,
+				   unsigned long long flags)
+int __builtin_bpf_helper_perf_event_read_value (void *map, unsigned long long flags,
+					void *buf, unsigned int buf_size)
+int __builtin_bpf_helper_perf_prog_read_value (void *ctx, void *buf,
+				       unsigned int buf_size)
+
+int __builtin_bpf_helper_override_return (void *ctx, unsigned long rc)
+int __builtin_bpf_helper_msg_redirect_map (void *ctx, void *map, int key, int flags)
+int __builtin_bpf_helper_msg_redirect_hash (void *ctx,
+				    void *map, void *key, int flags)
+int __builtin_bpf_helper_msg_apply_bytes (void *ctx, int len)
+int __builtin_bpf_helper_msg_cork_bytes (void *ctx, int len)
+int __builtin_bpf_helper_msg_pull_data (void *ctx, int start, int end, int flags)
+int __builtin_bpf_helper_msg_push_data (void *ctx, int start, int end, int flags)
+int __builtin_bpf_helper_msg_pop_data (void *ctx, int start, int cut, int flags)
+int __builtin_bpf_helper_bind (void *ctx, void *addr, int addr_len)
+int __builtin_bpf_helper_xdp_adjust_tail (void *ctx, int offset)
+int __builtin_bpf_helper_sk_select_reuseport (void *ctx, void *map, void *key, __u32 flags)
+int __builtin_bpf_helper_get_stack (void *ctx, void *buf, int size, int flags)
+int __builtin_bpf_helper_fib_lookup (void *ctx, struct bpf_fib_lookup *params,
+			     int plen, __u32 flags)
+
+int __builtin_bpf_helper_lwt_push_encap (void *ctx, unsigned int type, void *hdr,
+				 unsigned int len)
+int __builtin_bpf_helper_lwt_seg6_store_bytes (void *ctx, unsigned int offset,
+				       void *from, unsigned int len)
+int __builtin_bpf_helper_lwt_seg6_action (void *ctx, unsigned int action, void *param,
+				  unsigned int param_len)
+int __builtin_bpf_helper_lwt_seg6_adjust_srh (void *ctx, unsigned int offset,
+				      unsigned int len)
+int __builtin_bpf_helper_rc_repeat (void *ctx)
+int __builtin_bpf_helper_rc_keydown (void *ctx, unsigned int protocol,
+			     unsigned long long scancode, unsigned int toggle)
+static unsigned long long __builtin_bpf_helper_get_current_cgroup_id (void)
+static void *__builtin_bpf_helper_get_local_storage (void *map, unsigned long long flags)
+static struct bpf_sock *__builtin_bpf_helper_sk_lookup_tcp (void *ctx, void *tuple, int size, unsigned long long netns_id, unsigned long long flags)
+static struct bpf_sock *__builtin_bpf_helper_sk_lookup_udp (void *ctx, void *tuple, int size, unsigned long long netns_id, unsigned long long flags)
+int __builtin_bpf_helper_sk_release (struct bpf_sock *sk)
+int __builtin_bpf_helper_rc_pointer_rel (void *ctx, int rel_x, int rel_y)
+static void __builtin_bpf_helper_spin_lock (struct bpf_spin_lock *lock)
+static void __builtin_bpf_helper_spin_unlock (struct bpf_spin_lock *lock)
+
+static struct bpf_sock *__builtin_bpf_helper_sk_fullsock (struct bpf_sock *sk)
+static struct bpf_tcp_sock *__builtin_bpf_helper_tcp_sock (struct bpf_sock *sk)
+static struct bpf_sock *__builtin_bpf_helper_get_listener_sock (struct bpf_sock *sk)
+
+int __builtin_bpf_helper_l3_csum_replace (void *ctx, int off, int from, int to, int flags)
+int __builtin_bpf_helper_l4_csum_replace (void *ctx, int off, int from, int to, int flags)
+int __builtin_bpf_helper_csum_diff (void *from, int from_size, void *to, int to_size, int seed)
+
+static unsigned int __builtin_bpf_helper_get_cgroup_classid (void *ctx)
+static unsigned int __builtin_bpf_helper_get_route_realm (void *ctx)
+static unsigned int __builtin_bpf_helper_get_hash_recalc (void *ctx)
+static unsigned long long __builtin_bpf_helper_get_current_task (void *ctx)
+
+static long long __builtin_bpf_helper_csum_update (void *ctx, __u32 csum)
+static void __builtin_bpf_helper_set_hash_invalid (void *ctx)
+int __builtin_bpf_helper_get_numa_node_id (void)
+int __builtin_bpf_helper_probe_read_str (void *ctx, __u32 size,
+				 const void *unsafe_ptr)
+static unsigned int __builtin_bpf_helper_get_socket_uid (void *ctx)
+static unsigned int __builtin_bpf_helper_set_hash (void *ctx, __u32 hash)
+@end smallexample
+
+
 @node FR-V Built-in Functions
 @subsection FR-V Built-in Functions
 
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 549e043c67c..f0279ded218 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -800,6 +800,10 @@ Objective-C and Objective-C++ Dialects}.
 -msmall-text  -mlarge-text @gol
 -mmemory-latency=@var{time}}
 
+@emph{eBPF Options}
+@gccoptlist{-mbig-endian -mlittle-endian -mkernel=@var{version}
+-mframe-limit=@var{bytes}}
+
 @emph{FR30 Options}
 @gccoptlist{-msmall-model  -mno-lsim}
 
@@ -15660,6 +15664,7 @@ platform.
 * C-SKY Options::
 * Darwin Options::
 * DEC Alpha Options::
+* eBPF Options::
 * FR30 Options::
 * FT32 Options::
 * FRV Options::
@@ -19780,6 +19785,38 @@ Note that L3 is only valid for EV5.
 @end table
 @end table
 
+@node eBPF Options
+@subsection eBPF Options
+@cindex eBPF Options
+
+@table @gcctabopt
+@item -mframe-limit=@var{bytes}
+This specifies the hard limit for frame sizes, in bytes.  Currently,
+the value that can be specified should be less or equal than
+@samp{32767}.  Defaults to whatever limit is imposed by the version of
+the Linux kernel targeted.
+
+@item -mkernel=@var{version}
+@opindex mkernel
+This specifies the minimum version of the kernel that will run the
+compiled program.  GCC uses this version to determine which
+instructions to use, what kernel helpers to allow, etc.  Currently,
+@var{version} can be one of @samp{4.0}, @samp{4.1}, @samp{4.2},
+@samp{4.3}, @samp{4.4}, @samp{4.5}, @samp{4.6}, @samp{4.7},
+@samp{4.8}, @samp{4.9}, @samp{4.10}, @samp{4.11}, @samp{4.12},
+@samp{4.13}, @samp{4.14}, @samp{4.15}, @samp{4.16}, @samp{4.17},
+@samp{4.18}, @samp{4.19}, @samp{4.20}, @samp{5.0}, @samp{5.1},
+@samp{5.2}, @samp{latest} and @samp{native}.
+
+@item -mbig-endian
+@opindex mbig-endian
+Generate code for a big-endian target.
+
+@item -mlittle-endian
+@opindex mlittle-endian
+Generate code for a little-endian target.  This is the default.
+@end table
+
 @node FR30 Options
 @subsection FR30 Options
 @cindex FR30 Options
-- 
2.11.0