path: root/drivers/gpu/drm/msm/msm_gem.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 */

#include <linux/spinlock.h>
#include <linux/shmem_fs.h>
#include <linux/dma-buf.h>
#include <linux/pfn_t.h>

#include "msm_drv.h"
#include "msm_fence.h"
#include "msm_gem.h"
#include "msm_gpu.h"
#include "msm_mmu.h"

static void msm_gem_vunmap_locked(struct drm_gem_object *obj);


static dma_addr_t physaddr(struct drm_gem_object *obj)
{
	struct msm_gem_object *msm_obj = to_msm_bo(obj);
	struct msm_drm_private *priv = obj->dev->dev_private;
	return (((dma_addr_t)msm_obj->vram_node->start) << PAGE_SHIFT) +
			priv->vram.paddr;
}

static bool use_pages(struct drm_gem_object *obj)
{
	struct msm_gem_object *msm_obj = to_msm_bo(obj);
	return !msm_obj->vram_node;
}

/* allocate pages from VRAM carveout, used when no IOMMU: */
static struct page **get_pages_vram(struct drm_gem_object *obj, int npages)
{
	struct msm_gem_object *msm_obj = to_msm_bo(obj);
	struct msm_drm_private *priv = obj->dev->dev_private;
	dma_addr_t paddr;
	struct page **p;
	int ret, i;

	p = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
	if (!p)
		return ERR_PTR(-ENOMEM);

	spin_lock(&priv->vram.lock);
	ret = drm_mm_insert_node(&priv->vram.mm, msm_obj->vram_node, npages);
	spin_unlock(&priv->vram.lock);
	if (ret) {
		kvfree(p);
		return ERR_PTR(ret);
	}

	paddr = physaddr(obj);
	for (i = 0; i < npages; i++) {
		p[i] = phys_to_page(paddr);
		paddr += PAGE_SIZE;
	}

	return p;
}

static struct page **get_pages(struct drm_gem_object *obj)
{
	struct msm_gem_object *msm_obj = to_msm_bo(obj);

	if (!msm_obj->pages) {
		struct drm_device *dev = obj->dev;
		struct page **p;
		int npages = obj->size >> PAGE_SHIFT;

		if (use_pages(obj))
			p = drm_gem_get_pages(obj);
		else
			p = get_pages_vram(obj, npages);

		if (IS_ERR(p)) {
			DRM_DEV_ERROR(dev->dev, "could not get pages: %ld\n",
					PTR_ERR(p));
			return p;
		}

		msm_obj->pages = p;

		msm_obj->sgt = drm_prime_pages_to_sg(p, npages);
		if (IS_ERR(msm_obj->sgt)) {
			void *ptr = ERR_CAST(msm_obj->sgt);

			DRM_DEV_ERROR(dev->dev, "failed to allocate sgt\n");
			msm_obj->sgt = NULL;
			return ptr;
		}

		/* For non-cached buffers, ensure the new pages are clean
		 * because display controller, GPU, etc. are not coherent:
		 */
		if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
			dma_map_sg(dev->dev, msm_obj->sgt->sgl,
					msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
	}

	return msm_obj->pages;
}

static void put_pages_vram(struct drm_gem_object *obj)
{
	struct msm_gem_object *msm_obj = to_msm_bo(obj);
	struct msm_drm_private *priv = obj->dev->dev_private;

	spin_lock(&priv->vram.lock);
	drm_mm_remove_node(msm_obj->vram_node);
	spin_unlock(&priv->vram.lock);

	kvfree(msm_obj