git: 0eaa57625d0f - main - linuxkpi: Add <linux/ascii85.h>

The branch main has been updated by dumbbell:

URL: https://cgit.FreeBSD.org/src/commit/?id=0eaa57625d0fbe9960eabbaaedd522acdf673648

commit 0eaa57625d0fbe9960eabbaaedd522acdf673648
Author:     Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
AuthorDate: 2026-03-09 19:04:12 +0000
Commit:     Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
CommitDate: 2026-04-06 19:28:11 +0000

    linuxkpi: Add <linux/ascii85.h>
    
    This is used by the i915 DRM driver for some time to log more details
    about a GPU error, but the code was commented out.
    
    Reviewed by:    emaste
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D56282
---
 sys/compat/linuxkpi/common/include/linux/ascii85.h | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/ascii85.h b/sys/compat/linuxkpi/common/include/linux/ascii85.h
new file mode 100644
index 000000000000..06777a130e41
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/ascii85.h
@@ -0,0 +1,46 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2026 The FreeBSD Foundation
+ */
+
+#ifndef	_LINUXKPI_LINUX_ASCII85_H_
+#define	_LINUXKPI_LINUX_ASCII85_H_
+
+#include <sys/param.h>
+
+#define	ASCII85_BUFSZ 6
+
+static inline long
+ascii85_encode_len(long in_len)
+{
+	long out_len;
+
+	out_len = howmany(in_len, 4);
+
+	return (out_len);
+}
+
+static inline const char *
+ascii85_encode(uint32_t in, char *out)
+{
+	int i;
+
+	if (in == 0) {
+		out[0] = 'z';
+		out[1] = '\0';
+		return (out);
+	}
+
+	for (i = ASCII85_BUFSZ - 2; i >= 0; i--) {
+		out[i] = in % 85;
+		out[i] += 33;
+
+		in /= 85;
+	}
+	out[ASCII85_BUFSZ - 1] = '\0';
+
+	return (out);
+}
+
+#endif /* _LINUXKPI_LINUX_ASCII85_H_ */