// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2015-2018 Etnaviv Project
 */

#include <linux/kernel.h>

#include "etnaviv_gem.h"
#include "etnaviv_gpu.h"

#include "cmdstream.xml.h"

#define EXTRACT(val, field) (((val) & field##__MASK) >> field##__SHIFT)

struct etna_validation_state {
        struct etnaviv_gpu *gpu;
        const struct drm_etnaviv_gem_submit_reloc *relocs;
        unsigned int num_relocs;
        u32 *start;
};

static const struct {
        u16 offset;
        u16 size;
} etnaviv_sensitive_states[] __initconst = {
#define ST(start, num) { (start) >> 2, (num) }
        /* 2D */
        ST(0x1200, 1),
        ST(0x1228, 1),
        ST(0x1238, 1),
        ST(0x1284, 1),
        ST(0x128c, 1),
        ST(0x1304, 1),
        ST(0x1310, 1),
        ST(0x1318, 1),
        ST(0x12800, 4),
        ST(0x128a0, 4),
        ST(0x128c0, 4),
        ST(0x12970, 4),
        ST(0x12a00, 8),
        ST(0x12b40, 8),
        ST(0x12b80, 8),
        ST(0x12ce0, 8),
        /* 3D */
        ST(0x0644, 1),
        ST(0x064c, 1),
        ST(0x0680, 8),
        ST(0x086c, 1),
        ST(0x1028, 1),
        ST(0x1410, 1),
        ST(0x1430, 1),
        ST(0x1458, 1),
        ST(0x1460, 8),
        ST(0x1480, 8),
        ST(0x1500, 8),
        ST(0x1520, 8),
        ST(0x1540, 8),
        ST(0x1608, 1),
        ST(0x1610, 1),
        ST(0x1658, 1),
        ST(0x165c, 1),
        ST(0x1664, 1),
        ST(0x1668, 1),
        ST(0x16a4, 1),
        ST(0x16c0, 8),
        ST(0x16e0, 8),
        ST(0x1740, 8),
        ST(0x17c0, 8),
        ST(0x17e0, 8),
        ST(0x2400, 14 * 16),
        ST(0x3824, 1),
        ST(0x10800, 32 * 16),
        ST(0x14600, 16),
        ST(0x14800, 8 * 8),
#undef ST
};

#define ETNAVIV_STATES_SIZE (VIV_FE_LOAD_STATE_HEADER_OFFSET__MASK + 1u)
static DECLARE_BITMAP(etnaviv_states, ETNAVIV_STATES_SIZE);

void __init etnaviv_validate_init(void)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(etnaviv_sensitive_states); i++)
                bitmap_set(etnaviv_states, etnaviv_sensitive_states[i].offset,
                           etnaviv_sensitive_states[i].size);
}

static void etnaviv_warn_if_non_sensitive(struct etna_validation_state *state,
        unsigned int buf_offset, unsigned int state_addr)
{
        if (state->num_relocs && state->relocs->submit_offset < buf_offset) {
                dev_warn_once(state->gpu->dev,
                              "%s: relocation for non-sensitive state 0x%x at offset %u\n",
                              __func__, state_addr,
                              state->relocs->submit_offset);
                while (state->num_relocs &&
                       state->relocs->submit_offset < buf_offset) {
                        state->relocs++;
                        state->num_relocs--;
                }
        }
}

static bool etnaviv_validate_load_state(struct etna_validation_state *state,
        u32 *ptr, unsigned int state_offset, unsigned int num)
{
        unsigned int size = min(ETNAVIV_STATES_SIZE, state_offset + num);
        unsigned int st_offset = state_offset, buf_offset;

        for_each_set_bit_from(st_offset, etnaviv_states, size) {
                buf_offset = (ptr - state->start +
                              st_offset - state_offset) * 4;

                etnaviv_warn_if_non_sensitive(state, buf_offset, st_offset * 4);
                if (state->num_relocs &&
                    state->relocs->submit_offset == buf_offset) {
                        state->relocs++;
                        state->num_relocs--;
                        continue;
                }

                dev_warn_ratelimited(state->gpu->dev,
                                     "%s: load state touches restricted state 0x%x at offset %u\n",
                                     __func__, st_offset * 4, buf_offset);
                return false;
        }

        if (state->num_relocs) {
                buf_offset = (ptr - state->start + num) * 4;
                etnaviv_warn_if_non_sensitive(state, buf_offset, st_offset * 4 +
                                              state->relocs->submit_offset -
                                              buf_offset);
        }

        return true;
}

static uint8_t cmd_length[32] = {
        [FE_OPCODE_DRAW_PRIMITIVES] = 4,
        [FE_OPCODE_DRAW_INDEXED_PRIMITIVES] = 6,
        [FE_OPCODE_DRAW_INSTANCED] = 4,
        [FE_OPCODE_NOP] = 2,
        [FE_OPCODE_STALL] = 2,
};

bool etnaviv_cmd_validate_one(struct etnaviv_gpu *gpu, u32 *stream,
                              unsigned int size,
                              struct drm_etnaviv_gem_submit_reloc *relocs,
                              unsigned int reloc_size)
{
        struct etna_validation_state state;
        u32 *buf = stream;
        u32 *end = buf + size;

        state.gpu = gpu;
        state.relocs = relocs;
        state.num_relocs = reloc_size;
        state.start = stream;

        while (buf < end) {
                u32 cmd = *buf;
                unsigned int len, n, off;
                unsigned int op = cmd >> 27;

                switch (op) {
                case FE_OPCODE_LOAD_STATE:
                        n = EXTRACT(cmd, VIV_FE_LOAD_STATE_HEADER_COUNT);
                        len = ALIGN(1 + n, 2);
                        if (buf + len > end)
                                break;

                        off = EXTRACT(cmd, VIV_FE_LOAD_STATE_HEADER_OFFSET);
                        if (!etnaviv_validate_load_state(&state, buf + 1,
                                                         off, n))
                                return false;
                        break;

                case FE_OPCODE_DRAW_2D:
                        n = EXTRACT(cmd, VIV_FE_DRAW_2D_HEADER_COUNT);
                        if (n == 0)
                                n = 256;
                        len = 2 + n * 2;
                        break;

                default:
                        len = cmd_length[op];
                        if (len == 0) {
                                dev_err(gpu->dev, "%s: op %u not permitted at offset %tu\n",
                                        __func__, op, buf - state.start);
                                return false;
                        }
                        break;
                }

                buf += len;
        }

        if (buf > end) {
                dev_err(gpu->dev, "%s: commands overflow end of buffer: %tu > %u\n",
                        __func__, buf - state.start, size);
                return false;
        }

        return true;
}