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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2017-09-29 12:24:10 +0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2017-09-29 12:24:10 +0300
commitcf09e3c904bf424f8b6a8203958e09bf7d9bcbc0 (patch)
tree5e9936b3de36aa222b52a9bca366a43d98730ffd /include/linux/tnum.h
parentd5426f4c2ebac8cf05de43988c3fccddbee13d28 (diff)
parente19b205be43d11bff638cad4487008c48d21c103 (diff)
downloadlinux-cf09e3c904bf424f8b6a8203958e09bf7d9bcbc0.tar.xz
Merge tag 'v4.14-rc2' into patchwork
Linux 4.14-rc2 * tag 'v4.14-rc2': (12066 commits) Linux 4.14-rc2 tpm: ibmvtpm: simplify crq initialization and document crq format tpm: replace msleep() with usleep_range() in TPM 1.2/2.0 generic drivers Documentation: tpm: add powered-while-suspended binding documentation tpm: tpm_crb: constify acpi_device_id. tpm: vtpm: constify vio_device_id security: fix description of values returned by cap_inode_need_killpriv x86/asm: Fix inline asm call constraints for Clang objtool: Handle another GCC stack pointer adjustment bug inet: fix improper empty comparison net: use inet6_rcv_saddr to compare sockets net: set tb->fast_sk_family net: orphan frags on stand-alone ptype in dev_queue_xmit_nit MAINTAINERS: update git tree locations for ieee802154 subsystem SMB3: Don't ignore O_SYNC/O_DSYNC and O_DIRECT flags SMB3: handle new statx fields arch: remove unused *_segments() macros/functions parisc: Unbreak bootloader due to gcc-7 optimizations parisc: Reintroduce option to gzip-compress the kernel apparmor: fix apparmorfs DAC access permissions ...
Diffstat (limited to 'include/linux/tnum.h')
-rw-r--r--include/linux/tnum.h81
1 files changed, 81 insertions, 0 deletions
diff --git a/include/linux/tnum.h b/include/linux/tnum.h
new file mode 100644
index 000000000000..0d2d3da46139
--- /dev/null
+++ b/include/linux/tnum.h
@@ -0,0 +1,81 @@
+/* tnum: tracked (or tristate) numbers
+ *
+ * A tnum tracks knowledge about the bits of a value. Each bit can be either
+ * known (0 or 1), or unknown (x). Arithmetic operations on tnums will
+ * propagate the unknown bits such that the tnum result represents all the
+ * possible results for possible values of the operands.
+ */
+#include <linux/types.h>
+
+struct tnum {
+ u64 value;
+ u64 mask;
+};
+
+/* Constructors */
+/* Represent a known constant as a tnum. */
+struct tnum tnum_const(u64 value);
+/* A completely unknown value */
+extern const struct tnum tnum_unknown;
+/* A value that's unknown except that @min <= value <= @max */
+struct tnum tnum_range(u64 min, u64 max);
+
+/* Arithmetic and logical ops */
+/* Shift a tnum left (by a fixed shift) */
+struct tnum tnum_lshift(struct tnum a, u8 shift);
+/* Shift a tnum right (by a fixed shift) */
+struct tnum tnum_rshift(struct tnum a, u8 shift);
+/* Add two tnums, return @a + @b */
+struct tnum tnum_add(struct tnum a, struct tnum b);
+/* Subtract two tnums, return @a - @b */
+struct tnum tnum_sub(struct tnum a, struct tnum b);
+/* Bitwise-AND, return @a & @b */
+struct tnum tnum_and(struct tnum a, struct tnum b);
+/* Bitwise-OR, return @a | @b */
+struct tnum tnum_or(struct tnum a, struct tnum b);
+/* Bitwise-XOR, return @a ^ @b */
+struct tnum tnum_xor(struct tnum a, struct tnum b);
+/* Multiply two tnums, return @a * @b */
+struct tnum tnum_mul(struct tnum a, struct tnum b);
+
+/* Return a tnum representing numbers satisfying both @a and @b */
+struct tnum tnum_intersect(struct tnum a, struct tnum b);
+
+/* Return @a with all but the lowest @size bytes cleared */
+struct tnum tnum_cast(struct tnum a, u8 size);
+
+/* Returns true if @a is a known constant */
+static inline bool tnum_is_const(struct tnum a)
+{
+ return !a.mask;
+}
+
+/* Returns true if @a == tnum_const(@b) */
+static inline bool tnum_equals_const(struct tnum a, u64 b)
+{
+ return tnum_is_const(a) && a.value == b;
+}
+
+/* Returns true if @a is completely unknown */
+static inline bool tnum_is_unknown(struct tnum a)
+{
+ return !~a.mask;
+}
+
+/* Returns true if @a is known to be a multiple of @size.
+ * @size must be a power of two.
+ */
+bool tnum_is_aligned(struct tnum a, u64 size);
+
+/* Returns true if @b represents a subset of @a. */
+bool tnum_in(struct tnum a, struct tnum b);
+
+/* Formatting functions. These have snprintf-like semantics: they will write
+ * up to @size bytes (including the terminating NUL byte), and return the number
+ * of bytes (excluding the terminating NUL) which would have been written had
+ * sufficient space been available. (Thus tnum_sbin always returns 64.)
+ */
+/* Format a tnum as a pair of hex numbers (value; mask) */
+int tnum_strn(char *str, size_t size, struct tnum a);
+/* Format a tnum as tristate binary expansion */
+int tnum_sbin(char *str, size_t size, struct tnum a);