lib/raid/raid6/riscv/recov_rvv.c

Source file repositories/reference/linux-study-clean/lib/raid/raid6/riscv/recov_rvv.c

File Facts

System
Linux kernel
Corpus path
lib/raid/raid6/riscv/recov_rvv.c
Extension
.c
Size
5412 bytes
Lines
223
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

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

* while ( bytes-- ) {
	 *	uint8_t px, qx, db;
	 *
	 *	px	  = *p ^ *dp;
	 *	qx	  = qmul[*q ^ *dq];
	 *	*dq++ = db = pbmul[px] ^ qx;
	 *	*dp++ = db ^ px;
	 *	p++; q++;
	 * }
	 */
	while (bytes) {
		/*
		 * v0:px, v1:dp,
		 * v2:qx, v3:dq,
		 * v4:vx, v5:vy,
		 * v6:qm0, v7:qm1,
		 * v8:pm0, v9:pm1,
		 * v14:p/qm[vx], v15:p/qm[vy]
		 */
		asm volatile (".option		push\n"
			      ".option		arch,+v\n"
			      "vle8.v		v0, (%[px])\n"
			      "vle8.v		v1, (%[dp])\n"
			      "vxor.vv		v0, v0, v1\n"
			      "vle8.v		v2, (%[qx])\n"
			      "vle8.v		v3, (%[dq])\n"
			      "vxor.vv		v4, v2, v3\n"
			      "vsrl.vi		v5, v4, 4\n"
			      "vand.vi		v4, v4, 0xf\n"
			      "vle8.v		v6, (%[qm0])\n"
			      "vle8.v		v7, (%[qm1])\n"
			      "vrgather.vv	v14, v6, v4\n" /* v14 = qm[vx] */
			      "vrgather.vv	v15, v7, v5\n" /* v15 = qm[vy] */
			      "vxor.vv		v2, v14, v15\n" /* v2 = qmul[*q ^ *dq] */

			      "vsrl.vi		v5, v0, 4\n"
			      "vand.vi		v4, v0, 0xf\n"
			      "vle8.v		v8, (%[pm0])\n"
			      "vle8.v		v9, (%[pm1])\n"
			      "vrgather.vv	v14, v8, v4\n" /* v14 = pm[vx] */
			      "vrgather.vv	v15, v9, v5\n" /* v15 = pm[vy] */
			      "vxor.vv		v4, v14, v15\n" /* v4 = pbmul[px] */
			      "vxor.vv		v3, v4, v2\n" /* v3 = db = pbmul[px] ^ qx */
			      "vxor.vv		v1, v3, v0\n" /* v1 = db ^ px; */
			      "vse8.v		v3, (%[dq])\n"
			      "vse8.v		v1, (%[dp])\n"
			      ".option		pop\n"
			      : :
			      [px]"r"(p),
			      [dp]"r"(dp),
			      [qx]"r"(q),
			      [dq]"r"(dq),
			      [qm0]"r"(qmul),
			      [qm1]"r"(qmul + 16),
			      [pm0]"r"(pbmul),
			      [pm1]"r"(pbmul + 16)
			      :);

		bytes -= 16;
		p += 16;
		q += 16;
		dp += 16;
		dq += 16;
	}
}

static void __raid6_datap_recov_rvv(int bytes, u8 *p, u8 *q,
				    u8 *dq, const u8 *qmul)
{
	asm volatile (".option	push\n"
		      ".option	arch,+v\n"
		      "vsetvli	x0, %[avl], e8, m1, ta, ma\n"
		      ".option	pop\n"
		      : :
		      [avl]"r"(16)
	);

	/*
	 * while (bytes--) {
	 *  *p++ ^= *dq = qmul[*q ^ *dq];
	 *  q++; dq++;
	 * }
	 */
	while (bytes) {
		/*
		 * v0:vx, v1:vy,
		 * v2:dq, v3:p,
		 * v4:qm0, v5:qm1,
		 * v10:m[vx], v11:m[vy]
		 */

Annotation

Implementation Notes