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authorJani Nikula <jani.nikula@intel.com>2024-08-01 13:06:09 +0300
committerJani Nikula <jani.nikula@intel.com>2024-08-01 13:06:09 +0300
commit3663e2c4bc45fcdc71931fcbfcbfbf9b71f55c83 (patch)
tree3927fa90c7faa89131fcf2e789ca9de97a65dc5f /include/vdso/getrandom.h
parent688c43dd6ca9e0cd0568868aefca5b041695c3f4 (diff)
parent8400291e289ee6b2bf9779ff1c83a291501f017b (diff)
downloadlwn-3663e2c4bc45fcdc71931fcbfcbfbf9b71f55c83.tar.gz
lwn-3663e2c4bc45fcdc71931fcbfcbfbf9b71f55c83.zip
Merge drm/drm-next into drm-intel-next
Sync with v6.11-rc1 in general, and specifically get the new BACKLIGHT_POWER_ constants for power states. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'include/vdso/getrandom.h')
-rw-r--r--include/vdso/getrandom.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/include/vdso/getrandom.h b/include/vdso/getrandom.h
new file mode 100644
index 000000000000..a8b7c14b0ae0
--- /dev/null
+++ b/include/vdso/getrandom.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#ifndef _VDSO_GETRANDOM_H
+#define _VDSO_GETRANDOM_H
+
+#include <linux/types.h>
+
+#define CHACHA_KEY_SIZE 32
+#define CHACHA_BLOCK_SIZE 64
+
+/**
+ * struct vgetrandom_state - State used by vDSO getrandom().
+ *
+ * @batch: One and a half ChaCha20 blocks of buffered RNG output.
+ *
+ * @key: Key to be used for generating next batch.
+ *
+ * @batch_key: Union of the prior two members, which is exactly two full
+ * ChaCha20 blocks in size, so that @batch and @key can be filled
+ * together.
+ *
+ * @generation: Snapshot of @rng_info->generation in the vDSO data page at
+ * the time @key was generated.
+ *
+ * @pos: Offset into @batch of the next available random byte.
+ *
+ * @in_use: Reentrancy guard for reusing a state within the same thread
+ * due to signal handlers.
+ */
+struct vgetrandom_state {
+ union {
+ struct {
+ u8 batch[CHACHA_BLOCK_SIZE * 3 / 2];
+ u32 key[CHACHA_KEY_SIZE / sizeof(u32)];
+ };
+ u8 batch_key[CHACHA_BLOCK_SIZE * 2];
+ };
+ u64 generation;
+ u8 pos;
+ bool in_use;
+};
+
+#endif /* _VDSO_GETRANDOM_H */