// SPDX-License-Identifier: MIT
/*
 * Copyright © 2019 Intel Corporation
 */

#include "i915_drv.h"
#include "i915_vma.h"
#include "intel_context.h"
#include "intel_engine_pm.h"
#include "intel_gpu_commands.h"
#include "intel_lrc.h"
#include "intel_lrc_reg.h"
#include "intel_ring.h"
#include "intel_sseu.h"

static int gen8_emit_rpcs_config(struct i915_request *rq,
                                 const struct intel_context *ce,
                                 const struct intel_sseu sseu)
{
        u64 offset;
        u32 *cs;

        cs = intel_ring_begin(rq, 4);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        offset = i915_ggtt_offset(ce->state) +
                 LRC_STATE_OFFSET + CTX_R_PWR_CLK_STATE * 4;

        *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
        *cs++ = lower_32_bits(offset);
        *cs++ = upper_32_bits(offset);
        *cs++ = intel_sseu_make_rpcs(rq->engine->gt, &sseu);

        intel_ring_advance(rq, cs);

        return 0;
}

static int
gen8_modify_rpcs(struct intel_context *ce, const struct intel_sseu sseu)
{
        struct i915_request *rq;
        int ret;

        lockdep_assert_held(&ce->pin_mutex);

        /*
         * If the context is not idle, we have to submit an ordered request to
         * modify its context image via the kernel context (writing to our own
         * image, or into the registers directory, does not stick). Pristine
         * and idle contexts will be configured on pinning.
         */
        if (!intel_context_pin_if_active(ce))
                return 0;

        rq = intel_engine_create_kernel_request(ce->engine);
        if (IS_ERR(rq)) {
                ret = PTR_ERR(rq);
                goto out_unpin;
        }

        /* Serialise with the remote context */
        ret = intel_context_prepare_remote_request(ce, rq);
        if (ret == 0)
                ret = gen8_emit_rpcs_config(rq, ce, sseu);

        i915_request_add(rq);
out_unpin:
        intel_context_unpin(ce);
        return ret;
}

int
intel_context_reconfigure_sseu(struct intel_context *ce,
                               const struct intel_sseu sseu)
{
        int ret;

        GEM_BUG_ON(GRAPHICS_VER(ce->engine->i915) < 8);

        ret = intel_context_lock_pinned(ce);
        if (ret)
                return ret;

        /* Nothing to do if unmodified. */
        if (!memcmp(&ce->sseu, &sseu, sizeof(sseu)))
                goto unlock;

        ret = gen8_modify_rpcs(ce, sseu);
        if (!ret)
                ce->sseu = sseu;

unlock:
        intel_context_unlock_pinned(ce);
        return ret;
}