/* SPDX-License-Identifier: MIT */
/*
 * Copyright © 2023 Intel Corporation
 */

#include <linux/fb.h>

#include <drm/drm_print.h>

#include "gem/i915_gem_lmem.h"

#include "i915_drv.h"
#include "intel_fbdev_fb.h"

u32 intel_fbdev_fb_pitch_align(u32 stride)
{
        return ALIGN(stride, 64);
}

struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size)
{
        struct drm_i915_private *dev_priv = to_i915(drm);
        struct drm_i915_gem_object *obj;

        obj = ERR_PTR(-ENODEV);
        if (HAS_LMEM(dev_priv)) {
                obj = i915_gem_object_create_lmem(dev_priv, size,
                                                  I915_BO_ALLOC_CONTIGUOUS |
                                                  I915_BO_ALLOC_USER);
        } else {
                /*
                 * If the FB is too big, just don't use it since fbdev is not very
                 * important and we should probably use that space with FBC or other
                 * features.
                 *
                 * Also skip stolen on MTL as Wa_22018444074 mitigation.
                 */
                if (!IS_METEORLAKE(dev_priv) && size * 2 < dev_priv->dsm.usable_size)
                        obj = i915_gem_object_create_stolen(dev_priv, size);
                if (IS_ERR(obj))
                        obj = i915_gem_object_create_shmem(dev_priv, size);
        }

        if (IS_ERR(obj)) {
                drm_err(drm, "failed to allocate framebuffer (%pe)\n", obj);
                return ERR_PTR(-ENOMEM);
        }

        return &obj->base;
}

void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj)
{
        drm_gem_object_put(obj);
}

int intel_fbdev_fb_fill_info(struct drm_device *drm, struct fb_info *info,
                             struct drm_gem_object *_obj, struct i915_vma *vma)
{
        struct drm_i915_private *i915 = to_i915(drm);
        struct drm_i915_gem_object *obj = to_intel_bo(_obj);
        struct i915_gem_ww_ctx ww;
        void __iomem *vaddr;
        int ret;

        if (i915_gem_object_is_lmem(obj)) {
                struct intel_memory_region *mem = obj->mm.region;

                /* Use fbdev's framebuffer from lmem for discrete */
                info->fix.smem_start =
                        (unsigned long)(mem->io.start +
                                        i915_gem_object_get_dma_address(obj, 0) -
                                        mem->region.start);
                info->fix.smem_len = obj->base.size;
        } else {
                struct i915_ggtt *ggtt = to_gt(i915)->ggtt;

                /* Our framebuffer is the entirety of fbdev's system memory */
                info->fix.smem_start =
                        (unsigned long)(ggtt->gmadr.start + i915_ggtt_offset(vma));
                info->fix.smem_len = vma->size;
        }

        for_i915_gem_ww(&ww, ret, false) {
                ret = i915_gem_object_lock(vma->obj, &ww);

                if (ret)
                        continue;

                vaddr = i915_vma_pin_iomap(vma);
                if (IS_ERR(vaddr)) {
                        drm_err(drm,
                                "Failed to remap framebuffer into virtual memory (%pe)\n", vaddr);
                        ret = PTR_ERR(vaddr);
                        continue;
                }
        }

        if (ret)
                return ret;

        info->screen_base = vaddr;
        info->screen_size = intel_bo_to_drm_bo(obj)->size;

        return 0;
}