From: Bobby Eshleman <bobbyeshleman@meta.com>

Add -A flag to ncdevmem to set autorelease mode.

Add tests for the SO_DEVMEM_AUTORELEASE socket option:

New tests include:
   - check_sockopt_autorelease_default: Verifies default value is 0
   - check_sockopt_autorelease_set_0: Tests setting to 0 and reading
     back
   - check_sockopt_autorelease_set_1: Tests toggling from 0 to 1
   - check_sockopt_autorelease_invalid: Tests invalid value (2) returns
     EINVAL
   - check_autorelease_disabled: Tests ncdevmem in manual token release
     mode
   - check_autorelease_enabled: Tests ncdevmem in autorelease mode

All check_sockopt tests gracefully skip with KsftSkipEx if
SO_DEVMEM_AUTORELEASE is not supported by the kernel.

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/drivers/net/hw/devmem.py  | 115 +++++++++++++++++++++-
 tools/testing/selftests/drivers/net/hw/ncdevmem.c |  20 +++-
 2 files changed, 133 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/devmem.py b/tools/testing/selftests/drivers/net/hw/devmem.py
index 45c2d49d55b6..29ec179d651f 100755
--- a/tools/testing/selftests/drivers/net/hw/devmem.py
+++ b/tools/testing/selftests/drivers/net/hw/devmem.py
@@ -1,6 +1,9 @@
 #!/usr/bin/env python3
 # SPDX-License-Identifier: GPL-2.0
 
+import socket
+import errno
+
 from os import path
 from lib.py import ksft_run, ksft_exit
 from lib.py import ksft_eq, KsftSkipEx
@@ -63,12 +66,122 @@ def check_tx_chunks(cfg) -> None:
     ksft_eq(socat.stdout.strip(), "hello\nworld")
 
 
+@ksft_disruptive
+def check_autorelease_disabled(cfg) -> None:
+    """Test RX with autorelease disabled (requires manual token release in ncdevmem)"""
+    require_devmem(cfg)
+
+    port = rand_port()
+    socat = f"socat -u - TCP{cfg.addr_ipver}:{cfg.baddr}:{port},bind={cfg.remote_baddr}:{port}"
+    listen_cmd = f"{cfg.bin_local} -l -f {cfg.ifname} -s {cfg.addr} -p {port} -c {cfg.remote_addr} -v 7 -A 0"
+
+    with bkg(listen_cmd, exit_wait=True) as ncdevmem:
+        wait_port_listen(port)
+        cmd(f"yes $(echo -e \x01\x02\x03\x04\x05\x06) | \
+            head -c 1K | {socat}", host=cfg.remote, shell=True)
+
+    ksft_eq(ncdevmem.ret, 0)
+
+
+@ksft_disruptive
+def check_autorelease_enabled(cfg) -> None:
+    """Test RX with autorelease enabled (requires token autorelease in ncdevmem)"""
+    require_devmem(cfg)
+
+    port = rand_port()
+    socat = f"socat -u - TCP{cfg.addr_ipver}:{cfg.baddr}:{port},bind={cfg.remote_baddr}:{port}"
+    listen_cmd = f"{cfg.bin_local} -l -f {cfg.ifname} -s {cfg.addr} -p {port} -c {cfg.remote_addr} -v 7 -A 1"
+
+    with bkg(listen_cmd, exit_wait=True) as ncdevmem:
+        wait_port_listen(port)
+        cmd(f"yes $(echo -e \x01\x02\x03\x04\x05\x06) | \
+            head -c 1K | {socat}", host=cfg.remote, shell=True)
+
+    ksft_eq(ncdevmem.ret, 0)
+
+
+def check_sockopt_autorelease_default(cfg) -> None:
+    """Test that SO_DEVMEM_AUTORELEASE default is 0"""
+    SO_DEVMEM_AUTORELEASE = 85
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    try:
+        val = sock.getsockopt(socket.SOL_SOCKET, SO_DEVMEM_AUTORELEASE)
+        ksft_eq(val, 0, "Default autorelease should be 0")
+    except OSError as e:
+        if e.errno == errno.ENOPROTOOPT:
+            raise KsftSkipEx("SO_DEVMEM_AUTORELEASE not supported")
+        raise
+    finally:
+        sock.close()
+
+
+def check_sockopt_autorelease_set_0(cfg) -> None:
+    """Test setting SO_DEVMEM_AUTORELEASE to 0"""
+    SO_DEVMEM_AUTORELEASE = 85
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    try:
+        sock.setsockopt(socket.SOL_SOCKET, SO_DEVMEM_AUTORELEASE, 0)
+        val = sock.getsockopt(socket.SOL_SOCKET, SO_DEVMEM_AUTORELEASE)
+        ksft_eq(val, 0, "Autorelease should be 0 after setting")
+    except OSError as e:
+        if e.errno == errno.ENOPROTOOPT:
+            raise KsftSkipEx("SO_DEVMEM_AUTORELEASE not supported")
+        raise
+    finally:
+        sock.close()
+
+
+def check_sockopt_autorelease_set_1(cfg) -> None:
+    """Test setting SO_DEVMEM_AUTORELEASE to 1"""
+    SO_DEVMEM_AUTORELEASE = 85
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    try:
+        # First set to 0
+        sock.setsockopt(socket.SOL_SOCKET, SO_DEVMEM_AUTORELEASE, 0)
+        # Then set back to 1
+        sock.setsockopt(socket.SOL_SOCKET, SO_DEVMEM_AUTORELEASE, 1)
+        val = sock.getsockopt(socket.SOL_SOCKET, SO_DEVMEM_AUTORELEASE)
+        ksft_eq(val, 1, "Autorelease should be 1 after setting")
+    except OSError as e:
+        if e.errno == errno.ENOPROTOOPT:
+            raise KsftSkipEx("SO_DEVMEM_AUTORELEASE not supported")
+        raise
+    finally:
+        sock.close()
+
+
+def check_sockopt_autorelease_invalid(cfg) -> None:
+    """Test that SO_DEVMEM_AUTORELEASE rejects invalid values"""
+    SO_DEVMEM_AUTORELEASE = 85
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    try:
+        try:
+            sock.setsockopt(socket.SOL_SOCKET, SO_DEVMEM_AUTORELEASE, 2)
+            raise Exception("setsockopt should have failed with EINVAL")
+        except OSError as e:
+            if e.errno == errno.ENOPROTOOPT:
+                raise KsftSkipEx("SO_DEVMEM_AUTORELEASE not supported")
+            ksft_eq(e.errno, errno.EINVAL, "Should fail with EINVAL for invalid value")
+    finally:
+        sock.close()
+
+
 def main() -> None:
     with NetDrvEpEnv(__file__) as cfg:
         cfg.bin_local = path.abspath(path.dirname(__file__) + "/ncdevmem")
         cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
 
-        ksft_run([check_rx, check_tx, check_tx_chunks],
+        ksft_run([check_rx, check_tx, check_tx_chunks,
+                  check_autorelease_enabled,
+                  check_autorelease_disabled,
+                  check_sockopt_autorelease_default,
+                  check_sockopt_autorelease_set_0,
+                  check_sockopt_autorelease_set_1,
+                  check_sockopt_autorelease_invalid],
                  args=(cfg, ))
     ksft_exit()
 
diff --git a/tools/testing/selftests/drivers/net/hw/ncdevmem.c b/tools/testing/selftests/drivers/net/hw/ncdevmem.c
index 3288ed04ce08..34d608d07bec 100644
--- a/tools/testing/selftests/drivers/net/hw/ncdevmem.c
+++ b/tools/testing/selftests/drivers/net/hw/ncdevmem.c
@@ -83,6 +83,10 @@
 #define MSG_SOCK_DEVMEM 0x2000000
 #endif
 
+#ifndef SO_DEVMEM_AUTORELEASE
+#define SO_DEVMEM_AUTORELEASE 85
+#endif
+
 #define MAX_IOV 1024
 
 static size_t max_chunk;
@@ -97,6 +101,7 @@ static unsigned int ifindex;
 static unsigned int dmabuf_id;
 static uint32_t tx_dmabuf_id;
 static int waittime_ms = 500;
+static int autorelease = -1;
 
 /* System state loaded by current_config_load() */
 #define MAX_FLOWS	8
@@ -890,6 +895,16 @@ static int do_server(struct memory_buffer *mem)
 	if (enable_reuseaddr(socket_fd))
 		goto err_close_socket;
 
+	if (autorelease >= 0) {
+		ret = setsockopt(socket_fd, SOL_SOCKET, SO_DEVMEM_AUTORELEASE,
+				 &autorelease, sizeof(autorelease));
+		if (ret) {
+			pr_err("SO_DEVMEM_AUTORELEASE failed");
+			goto err_close_socket;
+		}
+		fprintf(stderr, "Set SO_DEVMEM_AUTORELEASE to %d\n", autorelease);
+	}
+
 	fprintf(stderr, "binding to address %s:%d\n", server_ip,
 		ntohs(server_sin.sin6_port));
 
@@ -1397,7 +1412,7 @@ int main(int argc, char *argv[])
 	int is_server = 0, opt;
 	int ret, err = 1;
 
-	while ((opt = getopt(argc, argv, "ls:c:p:v:q:t:f:z:")) != -1) {
+	while ((opt = getopt(argc, argv, "ls:c:p:v:q:t:f:z:A:")) != -1) {
 		switch (opt) {
 		case 'l':
 			is_server = 1;
@@ -1426,6 +1441,9 @@ int main(int argc, char *argv[])
 		case 'z':
 			max_chunk = atoi(optarg);
 			break;
+		case 'A':
+			autorelease = atoi(optarg);
+			break;
 		case '?':
 			fprintf(stderr, "unknown option: %c\n", optopt);
 			break;

-- 
2.47.3