/*
 * Copyright (c) 2017, NVIDIA Corporation.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <uapi/linux/nvgpu.h>

#include <nvgpu/types.h>

#include <nvgpu/hw/gk20a/hw_pbdma_gk20a.h>

#include "gk20a/ce2_gk20a.h"
#include "gk20a/gk20a.h"
#include "channel.h"

static inline int gk20a_get_valid_launch_flags(struct gk20a *g, int launch_flags)
{
	/* there is no local memory available,
	don't allow local memory related CE flags */
	if (!g->mm.vidmem.size) {
		launch_flags &= ~(NVGPU_CE_SRC_LOCATION_LOCAL_FB |
			NVGPU_CE_DST_LOCATION_LOCAL_FB);
	}
	return launch_flags;
}

int gk20a_ce_execute_ops(struct gk20a *g,
		u32 ce_ctx_id,
		u64 src_buf,
		u64 dst_buf,
		u64 size,
		unsigned int payload,
		int launch_flags,
		int request_operation,
		struct gk20a_fence *gk20a_fence_in,
		u32 submit_flags,
		struct gk20a_fence **gk20a_fence_out)
{
	int ret = -EPERM;
	struct gk20a_ce_app *ce_app = &g->ce_app;
	struct gk20a_gpu_ctx *ce_ctx, *ce_ctx_save;
	bool found = false;
	u32 *cmd_buf_cpu_va;
	u64 cmd_buf_gpu_va = 0;
	u32 methodSize;
	u32 cmd_buf_read_offset;
	u32 fence_index;
	u32 dma_copy_class;
	struct nvgpu_gpfifo gpfifo;
	struct nvgpu_fence fence = {0,0};
	struct gk20a_fence *ce_cmd_buf_fence_out = NULL;

	if (!ce_app->initialised ||ce_app->app_state != NVGPU_CE_ACTIVE)
		goto end;

	nvgpu_mutex_acquire(&ce_app->app_mutex);

	nvgpu_list_for_each_entry_safe(ce_ctx, ce_ctx_save,
			&ce_app->allocated_contexts, gk20a_gpu_ctx, list) {
		if (ce_ctx->ctx_id == ce_ctx_id) {
			found = true;
			break;
		}
	}

	nvgpu_mutex_release(&ce_app->app_mutex);

	if (!found) {
		ret = -EINVAL;
		goto end;
	}

	if (ce_ctx->gpu_ctx_state != NVGPU_CE_GPU_CTX_ALLOCATED) {
		ret = -ENODEV;
		goto end;
	}

	nvgpu_mutex_acquire(&ce_ctx->gpu_ctx_mutex);

	ce_ctx->cmd_buf_read_queue_offset %= ce_ctx->cmd_buf_end_queue_offset;

	cmd_buf_read_offset = (ce_ctx->cmd_buf_read_queue_offset *
			(NVGPU_CE_MAX_COMMAND_BUFF_SIZE_PER_KICKOFF / sizeof(u32)));

	/* at end of command buffer has gk20a_fence for command buffer sync */
	fence_index = (cmd_buf_read_offset +
			((NVGPU_CE_MAX_COMMAND_BUFF_SIZE_PER_KICKOFF / sizeof(u32)) -
			(NVGPU_CE_MAX_COMMAND_BUFF_SIZE_FOR_TRACING / sizeof(u32))));

	if (sizeof(struct gk20a_fence *) > NVGPU_CE_MAX_COMMAND_BUFF_SIZE_FOR_TRACING) {
		ret = -ENOMEM;
		goto noop;
	}

	cmd_buf_cpu_va = (u32 *)ce_ctx->cmd_buf_mem.cpu_va;

	/* 0 is treated as invalid pre-sync */
	if (cmd_buf_cpu_va[fence_index]) {
		struct gk20a_fence * ce_cmd_buf_fence_in = NULL;

		memcpy((void *)&ce_cmd_buf_fence_in,
				(void *)(cmd_buf_cpu_va + fence_index),
				sizeof(struct gk20a_fence *));
		ret = gk20a_fence_wait(g, ce_cmd_buf_fence_in,
				       gk20a_get_gr_idle_timeout(g));

		gk20a_fence_put(ce_cmd_buf_fence_in);
		/* Reset the stored last pre-sync */
		memset((void *)(cmd_buf_cpu_va + fence_index),
				0,
				NVGPU_CE_MAX_COMMAND_BUFF_SIZE_FOR_TRACING);
		if (ret)
			goto noop;
	}

	cmd_buf_gpu_va = (ce_ctx->cmd_buf_mem.gpu_va + (u64)(cmd_buf_read_offset *sizeof(u32)));

	dma_copy_class = g->ops.get_litter_value(g, GPU_LIT_DMA_COPY_CLASS);
	methodSize = gk20a_ce_prepare_submit(src_buf,
					dst_buf,
					size,
					&cmd_buf_cpu_va[cmd_buf_read_offset],
					NVGPU_CE_MAX_COMMAND_BUFF_SIZE_PER_KICKOFF,
					payload,
					gk20a_get_valid_launch_flags(g, launch_flags),
					request_operation,
					dma_copy_class,
					gk20a_fence_in);

	if (methodSize) {
		/* TODO: Remove CPU pre-fence wait */
		if (gk20a_fence_in) {
			ret = gk20a_fence_wait(g, gk20a_fence_in,
					       gk20a_get_gr_idle_timeout(g));
			gk20a_fence_put(gk20a_fence_in);
			if (ret)
				goto noop;
		}

		/* store the element into gpfifo */
		gpfifo.entry0 =
			u64_lo32(cmd_buf_gpu_va);
		gpfifo.entry1 =
			(u64_hi32(cmd_buf_gpu_va) |
			pbdma_gp_entry1_length_f(methodSize));

		/* take always the postfence as it is needed for protecting the ce context */
		submit_flags |= NVGPU_SUBMIT_GPFIFO_FLAGS_FENCE_GET;

		nvgpu_smp_wmb();

		ret = gk20a_submit_channel_gpfifo(ce_ctx->ch, &gpfifo, NULL,
					1, submit_flags, &fence,
					&ce_cmd_buf_fence_out, false, NULL);

		if (!ret) {
			memcpy((void *)(cmd_buf_cpu_va + fence_index),
					(void *)&ce_cmd_buf_fence_out,
					sizeof(struct gk20a_fence *));

			if (gk20a_fence_out) {
				gk20a_fence_get(ce_cmd_buf_fence_out);
				*gk20a_fence_out = ce_cmd_buf_fence_out;
			}

			/* Next available command buffer queue Index */
			++ce_ctx->cmd_buf_read_queue_offset;
		}
	} else {
		ret = -ENOMEM;
	}
noop:
	nvgpu_mutex_release(&ce_ctx->gpu_ctx_mutex);
end:
	return ret;
}