// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2024 Institute of Software, CAS.
 * Author: Chunyan Zhang <zhangchunyan@iscas.ac.cn>
 */

#include <linux/raid/pq.h>
#include "rvv.h"

static void __raid6_2data_recov_rvv(int bytes, u8 *p, u8 *q, u8 *dp,
                                    u8 *dq, const u8 *pbmul,
                                    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-- ) {
         *      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]
                 */
                asm volatile (".option          push\n"
                              ".option          arch,+v\n"
                              "vle8.v           v0, (%[vx])\n"
                              "vle8.v           v2, (%[dq])\n"
                              "vxor.vv          v0, v0, v2\n"
                              "vsrl.vi          v1, v0, 4\n"
                              "vand.vi          v0, v0, 0xf\n"
                              "vle8.v           v4, (%[qm0])\n"
                              "vle8.v           v5, (%[qm1])\n"
                              "vrgather.vv      v10, v4, v0\n"
                              "vrgather.vv      v11, v5, v1\n"
                              "vxor.vv          v0, v10, v11\n"
                              "vle8.v           v1, (%[vy])\n"
                              "vxor.vv          v1, v0, v1\n"
                              "vse8.v           v0, (%[dq])\n"
                              "vse8.v           v1, (%[vy])\n"
                              ".option          pop\n"
                              : :
                              [vx]"r"(q),
                              [vy]"r"(p),
                              [dq]"r"(dq),
                              [qm0]"r"(qmul),
                              [qm1]"r"(qmul + 16)
                              :);

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

static void raid6_2data_recov_rvv(int disks, size_t bytes, int faila,
                                  int failb, void **ptrs)
{
        u8 *p, *q, *dp, *dq;
        const u8 *pbmul;        /* P multiplier table for B data */
        const u8 *qmul;         /* Q multiplier table (for both) */

        p = (u8 *)ptrs[disks - 2];
        q = (u8 *)ptrs[disks - 1];

        /*
         * Compute syndrome with zero for the missing data pages
         * Use the dead data pages as temporary storage for
         * delta p and delta q
         */
        dp = (u8 *)ptrs[faila];
        ptrs[faila] = raid6_get_zero_page();
        ptrs[disks - 2] = dp;
        dq = (u8 *)ptrs[failb];
        ptrs[failb] = raid6_get_zero_page();
        ptrs[disks - 1] = dq;

        raid6_call.gen_syndrome(disks, bytes, ptrs);

        /* Restore pointer table */
        ptrs[faila]     = dp;
        ptrs[failb]     = dq;
        ptrs[disks - 2] = p;
        ptrs[disks - 1] = q;

        /* Now, pick the proper data tables */
        pbmul = raid6_vgfmul[raid6_gfexi[failb - faila]];
        qmul  = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila] ^
                                         raid6_gfexp[failb]]];

        kernel_vector_begin();
        __raid6_2data_recov_rvv(bytes, p, q, dp, dq, pbmul, qmul);
        kernel_vector_end();
}

static void raid6_datap_recov_rvv(int disks, size_t bytes, int faila,
                                  void **ptrs)
{
        u8 *p, *q, *dq;
        const u8 *qmul;         /* Q multiplier table */

        p = (u8 *)ptrs[disks - 2];
        q = (u8 *)ptrs[disks - 1];

        /*
         * Compute syndrome with zero for the missing data page
         * Use the dead data page as temporary storage for delta q
         */
        dq = (u8 *)ptrs[faila];
        ptrs[faila] = raid6_get_zero_page();
        ptrs[disks - 1] = dq;

        raid6_call.gen_syndrome(disks, bytes, ptrs);

        /* Restore pointer table */
        ptrs[faila]     = dq;
        ptrs[disks - 1] = q;

        /* Now, pick the proper data tables */
        qmul = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila]]];

        kernel_vector_begin();
        __raid6_datap_recov_rvv(bytes, p, q, dq, qmul);
        kernel_vector_end();
}

const struct raid6_recov_calls raid6_recov_rvv = {
        .data2          = raid6_2data_recov_rvv,
        .datap          = raid6_datap_recov_rvv,
        .valid          = rvv_has_vector,
        .name           = "rvv",
        .priority       = 1,
};