lib/crypto/x86/sha1-ni-asm.S

Source file repositories/reference/linux-study-clean/lib/crypto/x86/sha1-ni-asm.S

File Facts

System
Linux kernel
Corpus path
lib/crypto/x86/sha1-ni-asm.S
Extension
.S
Size
4987 bytes
Lines
153
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: lib
Status
atlas-only

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/linkage.h>

#define STATE_PTR	%rdi	/* 1st arg */
#define DATA_PTR	%rsi	/* 2nd arg */
#define NUM_BLKS	%rdx	/* 3rd arg */

#define ABCD		%xmm0
#define E0		%xmm1	/* Need two E's b/c they ping pong */
#define E1		%xmm2
#define MSG0		%xmm3
#define MSG1		%xmm4
#define MSG2		%xmm5
#define MSG3		%xmm6
#define SHUF_MASK	%xmm7
#define ABCD_SAVED	%xmm8
#define E0_SAVED	%xmm9

.macro do_4rounds	i, m0, m1, m2, m3, e0, e1
.if \i < 16
	movdqu		\i*4(DATA_PTR), \m0
	pshufb		SHUF_MASK, \m0
.endif
.if \i == 0
	paddd		\m0, \e0
.else
	sha1nexte	\m0, \e0
.endif
	movdqa		ABCD, \e1
.if \i >= 12 && \i < 76
	sha1msg2	\m0, \m1
.endif
	sha1rnds4	$\i / 20, \e0, ABCD
.if \i >= 4 && \i < 68
	sha1msg1	\m0, \m3
.endif
.if \i >= 8 && \i < 72
	pxor		\m0, \m2
.endif
.endm

/*
 * Intel SHA Extensions optimized implementation of a SHA-1 block function
 *
 * This function takes a pointer to the current SHA-1 state, a pointer to the
 * input data, and the number of 64-byte blocks to process.  The number of
 * blocks to process is assumed to be nonzero.  Once all blocks have been
 * processed, the state is updated with the new state.  This function only
 * processes complete blocks.  State initialization, buffering of partial
 * blocks, and digest finalization are expected to be handled elsewhere.
 *
 * void sha1_ni_transform(struct sha1_block_state *state,
 *			  const u8 *data, size_t nblocks)
 */
.text
SYM_FUNC_START(sha1_ni_transform)

	/* Load the initial state from STATE_PTR. */
	pxor		E0, E0
	pinsrd		$3, 16(STATE_PTR), E0
	movdqu		(STATE_PTR), ABCD
	pshufd		$0x1B, ABCD, ABCD

	movdqa		PSHUFFLE_BYTE_FLIP_MASK(%rip), SHUF_MASK

.Lnext_block:
	/* Save the state for addition after the rounds. */
	movdqa		E0, E0_SAVED
	movdqa		ABCD, ABCD_SAVED

.irp i, 0, 16, 32, 48, 64

Annotation

Implementation Notes