lib/debugfs: Support new generic ABI for CRC capture

The kernel has now a new debugfs ABI that can also allow capturing frame
CRCs for drivers other than i915.

Add alternative codepaths so the new ABI is used if the kernel is recent
enough, and fall back to the legacy ABI if not.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Robert Foss <robert.foss@collabora.com>

2 files changed, 143 insertions, 51 deletions

diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
index 9142e3f7..3d92c6a1 100644
--- a/lib/igt_debugfs.c
+++ b/lib/igt_debugfs.c
@@ -25,6 +25,7 @@
 #include <inttypes.h>
 #include <sys/stat.h>
 #include <sys/mount.h>
+#include <dirent.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -291,25 +292,23 @@ char *igt_crc_to_string(igt_crc_t *crc)
 {
 	char buf[128];
 
-	igt_assert_eq(crc->n_words, 5);
-
 	sprintf(buf, "%08x %08x %08x %08x %08x", crc->crc[0],
 		crc->crc[1], crc->crc[2], crc->crc[3], crc->crc[4]);
 
 	return strdup(buf);
 }
 
+#define MAX_CRC_ENTRIES 10
+#define MAX_LINE_LEN (10 + 11 * MAX_CRC_ENTRIES + 1)
+
 /* (6 fields, 8 chars each, space separated (5) + '\n') */
-#define PIPE_CRC_LINE_LEN       (6 * 8 + 5 + 1)
-/* account for \'0' */
-#define PIPE_CRC_BUFFER_LEN     (PIPE_CRC_LINE_LEN + 1)
+#define LEGACY_LINE_LEN       (6 * 8 + 5 + 1)
 
 struct _igt_pipe_crc {
 	int ctl_fd;
 	int crc_fd;
-	int line_len;
-	int buffer_len;
 	int flags;
+	bool is_legacy;
 
 	enum pipe pipe;
 	enum intel_pipe_crc_source source;
@@ -340,13 +339,26 @@ static bool igt_pipe_crc_do_start(igt_pipe_crc_t *pipe_crc)
 	/* Stop first just to make sure we don't have lingering state left. */
 	igt_pipe_crc_stop(pipe_crc);
 
-	sprintf(buf, "pipe %s %s", kmstest_pipe_name(pipe_crc->pipe),
-		pipe_crc_source_name(pipe_crc->source));
+	if (pipe_crc->is_legacy)
+		sprintf(buf, "pipe %s %s", kmstest_pipe_name(pipe_crc->pipe),
+			pipe_crc_source_name(pipe_crc->source));
+	else
+		sprintf(buf, "%s", pipe_crc_source_name(pipe_crc->source));
+
 	errno = 0;
 	igt_assert_eq(write(pipe_crc->ctl_fd, buf, strlen(buf)), strlen(buf));
 	if (errno != 0)
 		return false;
 
+	if (!pipe_crc->is_legacy) {
+		sprintf(buf, "crtc-%d/crc/data", pipe_crc->pipe);
+		errno = 0;
+		pipe_crc->crc_fd = igt_debugfs_open(buf, pipe_crc->flags);
+		if (pipe_crc->crc_fd == -1 && errno == EINVAL)
+			return false;
+		igt_assert_eq(errno, 0);
+	}
+
 	return true;
 }
 
@@ -360,15 +372,45 @@ static void igt_pipe_crc_pipe_off(int fd, enum pipe pipe)
 
 static void igt_pipe_crc_reset(void)
 {
+	igt_debugfs_t *debugfs = __igt_debugfs_singleton();
 	int fd;
+	struct dirent *dirent;
+	char buf[128];
+	const char *cmd = "none";
+	bool done = false;
+	DIR *dir;
+
+	dir = opendir(debugfs->dri_path);
+	if (dir) {
+		while ((dirent = readdir(dir))) {
+			if (strcmp(dirent->d_name, "crtc-") != 0)
+				continue;
+
+			sprintf(buf, "%s/%s/crc/control", debugfs->dri_path,
+				dirent->d_name);
+			fd = open(buf, O_WRONLY);
+			if (fd == -1)
+				continue;
+
+			igt_assert_eq(write(fd, cmd, strlen(cmd)), strlen(cmd));
+			done = true;
+
+			close(fd);
+		}
+		closedir(dir);
+	}
 
-	fd = igt_debugfs_open("i915_display_crc_ctl", O_WRONLY);
+	if (done)
+		return;
 
-	igt_pipe_crc_pipe_off(fd, PIPE_A);
-	igt_pipe_crc_pipe_off(fd, PIPE_B);
-	igt_pipe_crc_pipe_off(fd, PIPE_C);
+	fd = igt_debugfs_open("i915_display_crc_ctl", O_WRONLY);
+	if (fd != -1) {
+		igt_pipe_crc_pipe_off(fd, PIPE_A);
+		igt_pipe_crc_pipe_off(fd, PIPE_B);
+		igt_pipe_crc_pipe_off(fd, PIPE_C);
 
-	close(fd);
+		close(fd);
+	}
 }
 
 static void pipe_crc_exit_handler(int sig)
@@ -390,13 +432,16 @@ void igt_require_pipe_crc(void)
 	size_t written;
 	int ret;
 
-	ctl = igt_debugfs_fopen("i915_display_crc_ctl", "r+");
-	igt_require_f(ctl,
-		      "No display_crc_ctl found, kernel too old\n");
-	written = fwrite(cmd, 1, strlen(cmd), ctl);
-	ret = fflush(ctl);
-	igt_require_f((written == strlen(cmd) && ret == 0) || errno != ENODEV,
-		      "CRCs not supported on this platform\n");
+	ctl = igt_debugfs_fopen("crtc-0/crc/control", "r+");
+	if (!ctl) {
+		ctl = igt_debugfs_fopen("i915_display_crc_ctl", "r+");
+		igt_require_f(ctl,
+			      "No display_crc_ctl found, kernel too old\n");
+		written = fwrite(cmd, 1, strlen(cmd), ctl);
+		ret = fflush(ctl);
+		igt_require_f((written == strlen(cmd) && ret == 0) || errno != ENODEV,
+			      "CRCs not supported on this platform\n");
+	}
 
 	fclose(ctl);
 }
@@ -411,15 +456,25 @@ pipe_crc_new(enum pipe pipe, enum intel_pipe_crc_source source, int flags)
 
 	pipe_crc = calloc(1, sizeof(struct _igt_pipe_crc));
 
-	pipe_crc->ctl_fd = igt_debugfs_open("i915_display_crc_ctl", O_WRONLY);
-	igt_assert(pipe_crc->ctl_fd != -1);
+	sprintf(buf, "crtc-%d/crc/control", pipe);
+	pipe_crc->ctl_fd = igt_debugfs_open(buf, O_WRONLY);
+	if (pipe_crc->ctl_fd == -1) {
+		pipe_crc->ctl_fd = igt_debugfs_open("i915_display_crc_ctl",
+						    O_WRONLY);
+		igt_assert(pipe_crc->ctl_fd != -1);
+		pipe_crc->is_legacy = true;
+	}
 
-	sprintf(buf, "i915_pipe_%s_crc", kmstest_pipe_name(pipe));
-	pipe_crc->crc_fd = igt_debugfs_open(buf, flags);
-	igt_assert(pipe_crc->crc_fd != -1);
+	if (pipe_crc->is_legacy) {
+		sprintf(buf, "i915_pipe_%s_crc", kmstest_pipe_name(pipe));
+		pipe_crc->crc_fd = igt_debugfs_open(buf, flags);
+		igt_assert(pipe_crc->crc_fd != -1);
+		igt_debug("Using legacy frame CRC ABI\n");
+	} else {
+		pipe_crc->crc_fd = -1;
+		igt_debug("Using generic frame CRC ABI\n");
+	}
 
-	pipe_crc->line_len = PIPE_CRC_LINE_LEN;
-	pipe_crc->buffer_len = PIPE_CRC_BUFFER_LEN;
 	pipe_crc->pipe = pipe;
 	pipe_crc->source = source;
 	pipe_crc->flags = flags;
@@ -479,34 +534,59 @@ void igt_pipe_crc_free(igt_pipe_crc_t *pipe_crc)
 	free(pipe_crc);
 }
 
-static bool pipe_crc_init_from_string(igt_crc_t *crc, const char *line)
+static bool pipe_crc_init_from_string(igt_pipe_crc_t *pipe_crc, igt_crc_t *crc,
+				      const char *line)
 {
-	int n;
+	int n, i;
+	const char *buf;
 
-	crc->n_words = 5;
-	n = sscanf(line, "%8u %8x %8x %8x %8x %8x", &crc->frame, &crc->crc[0],
-		   &crc->crc[1], &crc->crc[2], &crc->crc[3], &crc->crc[4]);
-	return n == 6;
+	if (pipe_crc->is_legacy) {
+		crc->has_valid_frame = true;
+		crc->n_words = 5;
+		n = sscanf(line, "%8u %8x %8x %8x %8x %8x", &crc->frame,
+			   &crc->crc[0], &crc->crc[1], &crc->crc[2],
+			   &crc->crc[3], &crc->crc[4]);
+		return n == 6;
+	}
+
+	if (strncmp(line, "XXXXXXXXXX", 10) == 0)
+		crc->has_valid_frame = false;
+	else {
+		crc->has_valid_frame = true;
+		crc->frame = strtoul(line, NULL, 16);
+	}
+
+	buf = line + 10;
+	for (i = 0; *buf != '\n'; i++, buf += 11)
+		crc->crc[i] = strtoul(buf, NULL, 16);
+
+	crc->n_words = i;
+
+	return true;
 }
 
 static int read_crc(igt_pipe_crc_t *pipe_crc, igt_crc_t *out)
 {
 	ssize_t bytes_read;
-	char buf[pipe_crc->buffer_len];
+	char buf[MAX_LINE_LEN + 1];
+	size_t read_len;
+
+	if (pipe_crc->is_legacy)
+		read_len = LEGACY_LINE_LEN;
+	else
+		read_len = MAX_LINE_LEN;
 
 	igt_set_timeout(5, "CRC reading");
-	bytes_read = read(pipe_crc->crc_fd, &buf, pipe_crc->line_len);
+	bytes_read = read(pipe_crc->crc_fd, &buf, read_len);
 	igt_reset_timeout();
 
 	if (bytes_read < 0 && errno == EAGAIN) {
 		igt_assert(pipe_crc->flags & O_NONBLOCK);
 		bytes_read = 0;
-	} else {
-		igt_assert_eq(bytes_read, pipe_crc->line_len);
 	}
 	buf[bytes_read] = '\0';
 
-	if (bytes_read && !pipe_crc_init_from_string(out, buf))
+	if (bytes_read && !pipe_crc_init_from_string(pipe_crc, out, buf))
 		return -EINVAL;
 
 	return bytes_read;
@@ -530,15 +610,18 @@ void igt_pipe_crc_start(igt_pipe_crc_t *pipe_crc)
 
 	igt_assert(igt_pipe_crc_do_start(pipe_crc));
 
-	/*
-	 * For some no yet identified reason, the first CRC is bonkers. So
-	 * let's just wait for the next vblank and read out the buggy result.
-	 *
-	 * On CHV sometimes the second CRC is bonkers as well, so don't trust
-	 * that one either.
-	 */
-	read_one_crc(pipe_crc, &crc);
-	read_one_crc(pipe_crc, &crc);
+	if (pipe_crc->is_legacy) {
+		/*
+		 * For some no yet identified reason, the first CRC is
+		 * bonkers. So let's just wait for the next vblank and read
+		 * out the buggy result.
+		 *
+		 * On CHV sometimes the second CRC is bonkers as well, so
+		 * don't trust that one either.
+		 */
+		read_one_crc(pipe_crc, &crc);
+		read_one_crc(pipe_crc, &crc);
+	}
 }
 
 /**
@@ -551,8 +634,15 @@ void igt_pipe_crc_stop(igt_pipe_crc_t *pipe_crc)
 {
 	char buf[32];
 
-	sprintf(buf, "pipe %s none", kmstest_pipe_name(pipe_crc->pipe));
-	igt_assert_eq(write(pipe_crc->ctl_fd, buf, strlen(buf)), strlen(buf));
+	if (pipe_crc->is_legacy) {
+		sprintf(buf, "pipe %s none",
+			kmstest_pipe_name(pipe_crc->pipe));
+		igt_assert_eq(write(pipe_crc->ctl_fd, buf, strlen(buf)),
+			      strlen(buf));
+	} else {
+		close(pipe_crc->crc_fd);
+		pipe_crc->crc_fd = -1;
+	}
 }
 
 /**
diff --git a/lib/igt_debugfs.h b/lib/igt_debugfs.h
index fb189322..4c6572cd 100644
--- a/lib/igt_debugfs.h
+++ b/lib/igt_debugfs.h
@@ -62,6 +62,7 @@ bool igt_debugfs_search(const char *filename, const char *substring);
  */
 typedef struct _igt_pipe_crc igt_pipe_crc_t;
 
+#define DRM_MAX_CRC_NR 10
 /**
  * igt_crc_t:
  * @frame: frame number of the capture CRC
@@ -73,8 +74,9 @@ typedef struct _igt_pipe_crc igt_pipe_crc_t;
  */
 typedef struct {
 	uint32_t frame;
+	bool has_valid_frame;
 	int n_words;
-	uint32_t crc[5];
+	uint32_t crc[DRM_MAX_CRC_NR];
 } igt_crc_t;
 
 /**