path: root/drivers/gpu/drm/gma500/gtt.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2007, Intel Corporation.
 * All Rights Reserved.
 *
 * Authors: Thomas Hellstrom <thomas-at-tungstengraphics.com>
 *	    Alan Cox <alan@linux.intel.com>
 */

#include "gem.h" /* TODO: for struct psb_gem_object, see psb_gtt_restore() */
#include "psb_drv.h"


/*
 *	GTT resource allocator - manage page mappings in GTT space
 */

int psb_gtt_allocate_resource(struct drm_psb_private *pdev, struct resource *res,
			      const char *name, resource_size_t size, resource_size_t align,
			      bool stolen, u32 *offset)
{
	struct resource *root = pdev->gtt_mem;
	resource_size_t start, end;
	int ret;

	if (stolen) {
		/* The start of the GTT is backed by stolen pages. */
		start = root->start;
		end = root->start + pdev->gtt.stolen_size - 1;
	} else {
		/* The rest is backed by system pages. */
		start = root->start + pdev->gtt.stolen_size;
		end = root->end;
	}

	res->name = name;
	ret = allocate_resource(root, res, size, start, end, align, NULL, NULL);
	if (ret)
		return ret;
	*offset = res->start - root->start;

	return 0;
}

/**
 *	psb_gtt_mask_pte	-	generate GTT pte entry
 *	@pfn: page number to encode
 *	@type: type of memory in the GTT
 *
 *	Set the GTT entry for the appropriate memory type.
 */
static inline uint32_t psb_gtt_mask_pte(uint32_t pfn, int type)
{
	uint32_t mask = PSB_PTE_VALID;

	/* Ensure we explode rather than put an invalid low mapping of
	   a high mapping page into the gtt */
	BUG_ON(pfn & ~(0xFFFFFFFF >> PAGE_SHIFT));

	if (type & PSB_MMU_CACHED_MEMORY)
		mask |= PSB_PTE_CACHED;
	if (type & PSB_MMU_RO_MEMORY)
		mask |= PSB_PTE_RO;
	if (type & PSB_MMU_WO_MEMORY)
		mask |= PSB_PTE_WO;

	return (pfn << PAGE_SHIFT) | mask;
}

static u32 __iomem *psb_gtt_entry(struct drm_psb_private *pdev, const struct resource *res)
{
	unsigned long offset = res->start - pdev->gtt_mem->start;

	return pdev->gtt_map + (offset >> PAGE_SHIFT);
}

/* Acquires GTT mutex internally. */
void psb_gtt_insert_pages(struct drm_psb_private *pdev, const struct resource *res,
			  struct page **pages)
{
	resource_size_t npages, i;
	u32 __iomem *gtt_slot;
	u32 pte;

	mutex_lock(&pdev->gtt_mutex);

	/* Write our page entries into the GTT itself */

	npages = resource_size(res) >> PAGE_SHIFT;
	gtt_slot = psb_gtt_entry(pdev, res);

	for (i = 0; i < npages; ++i, ++gtt_slot) {
		pte = psb_gtt_mask_pte(page_to_pfn(pages[i]), PSB_MMU_CACHED_MEMORY);
		iowrite32(pte, gtt_slot);
	}

	/* Make sure all the entries are set before we return */
	ioread32(gtt_slot - 1);

	mutex_unlock(&pdev->gtt_mutex);
}

/* Acquires GTT mutex internally. */
void psb_gtt_remove_pages(struct drm_psb_private *pdev, const struct resource *res)
{
	resource_size_t npages, i;
	u32 __iomem *gtt_slot;
	u32 pte;

	mutex_lock(&pdev->gtt_mutex);

	/* Install scratch page for the resource */

	pte = psb_gtt_mask_pte(page_to_pfn(pdev->scratch_page), PSB_MMU_CACHED_MEMORY);

	npages = resource_size(res) >> PAGE_SHIFT;
	gtt_slot = psb_gtt_entry(pdev, res);

	for (i = 0; i < npages; ++i, ++gtt_slot)
		iowrite32(pte, gtt_slot);

	/* Make sure all the entries are set before we return */
	ioread32(gtt_slot - 1);

	mutex_unlock(&pdev->gtt_mutex);
}

void psb_gtt_fini(struct drm_device *dev)
{
	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
	struct pci_dev *pdev = to_pci_dev(dev->dev);

	iounmap(dev_priv->vram_addr);
	iounmap(dev_priv->gtt_map);

	pci_write_config_word(pdev, PSB_GMCH_CTRL, dev_priv->gmch_ctrl);
	PSB_WVDC32(dev_priv->pge_ctl, PSB_PGETBL_CTL);
	(void)PSB_RVDC32(PSB_PGETBL_CTL);

	mutex_destroy(&dev_priv->mmap_mutex);
	mutex_destroy(&dev_priv->gtt_mutex);
}

/* Clear GTT. Use a scratch page to avoid accidents or scribbles. */
static void psb_gtt_clear(struct drm_psb_private *pdev)
{
	resource_size_t pfn_base;
	unsigned long i;
	uint32_t pte;

	pfn_base = page_to_pfn(pdev->scratch_page);
	pte = psb_gtt_mask_pte(pfn_base, PSB_MMU_CACHED_MEMORY);

	for (i = 0; i < pdev->gtt.gtt_pages; ++i)
		iowrite32(pte, pdev->gtt_map + i);

	(void)ioread32(pdev->gtt_map + i - 1);
}

/* Insert vram stolen pages into the GTT. */
static void psb_gtt_populate_stolen(struct drm_psb_private *pdev)
{
	struct drm_device *dev = &pdev->dev;
	unsigned int pfn_base;
	unsigned int i, num_pages;
	uint32_t pte;

	pfn_base = pdev->stolen_base >> PAGE_SHIFT;
	num_pages = pdev->vram_stolen_size >> PAGE_SHIFT;

	drm_dbg(dev, "Set up %u stolen pages starting at 0x%08x, GTT offset %dK\n",
		num_pages, pfn_base << PAGE_SHIFT, 0);

	for (i = 0; i < num_pages; ++i) {
		pte = psb_gtt_mask_pte(pfn_base + i, PSB_MMU_CACHED_MEMORY);
		iowrite32(pte, pdev->gtt_map + i);
	}

	(void)ioread32(pdev->gtt_map + i - 1);
}

/* Re-insert all pinned GEM objects into GTT. */
static void psb_gtt_populate_resources(struct drm_psb_private *pdev)
{
	unsigned int restored = 0, total = 0, size = 0;
	struct resource *r = pdev->gtt_mem->child;
	struct drm_device *dev = &pdev->dev;
	struct psb_gem_object *pobj;

	while (r) {
		/*
		 * TODO: GTT restoration needs a refactoring, so that we don't have to touch
		 *       struct psb_gem_object here. The type represents a GEM object and is
		 *       not related to the GTT itself.
		 */
		pobj = container_of(r, struct psb_gem_object, resource);
		if (pobj->pages) {
			psb_gtt_insert_pages(pdev, &pobj->resource, pobj->pages);
			size += resource_size(&pobj->resource);
			++restored;
		}
		r = r->sibling;
		++total;
	}

	drm_dbg(dev, "Restored %u of %u gtt ranges (%u KB)", restored, total, (size / 1024));
}

int psb_gtt_init(struct drm_device *dev)
{
	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
	struct pci_dev *pdev = to_pci_dev(dev->dev);
	unsigned gtt_pages;
	unsigned long stolen_size, vram_stolen_size;
	struct psb_gtt *pg;
	int ret = 0;

	mutex_init(&dev_priv->gtt_mutex);
	mutex_init(&dev_priv->mmap_mutex);

	pg = &dev_priv->gtt;

	/* Enable the GTT */
	pci_read_config_word(pdev, PSB_GMCH_CTRL, &dev_priv->gmch_ctrl);
	pci_write_config_word(pdev, PSB_GMCH_CTRL,
			      dev_priv->gmch_ctrl | _PSB_GMCH_ENABLED);

	dev_priv->pge_ctl = PSB_RVDC32(PSB_PGETBL_CTL);
	PSB_WVDC32(dev_priv->pge_ctl | _PSB_PGETBL_ENABLED, PSB_PGETBL_CTL);
	(void) PSB_RVDC32(PSB_PGETBL_CTL);

	/* The root resource we allocate address space from */
	pg->gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;

	/*
	 *	The video mmu has a hw bug when accessing 0x0D0000000.
	 *	Make gatt start at 0x0e000,0000. This doesn't actually
	 *	matter for us but may do if the video acceleration ever
	 *	gets opened up.
	 */
	pg->mmu_gatt_start = 0xE0000000;

	pg->gtt_start = pci_resource_start(pdev, PSB_GTT_RESOURCE);
	gtt_pages = pci_resource_len(pdev, PSB_GTT_RESOURCE)
								>> PAGE_SHIFT;
	/* CDV doesn't report this. In which case the system has 64 gtt pages */
	if (pg->gtt_start == 0 || gtt_pages == 0) {
		dev_dbg(dev->dev, "GTT PCI BAR not initialized.\n");
		gtt_pages = 64;
		pg->gtt_start = dev_priv->pge_ctl;
	}

	pg->gatt_start = pci_resource_start(pdev, PSB_GATT_RESOURCE);
	pg->gatt_pages = pci_resource_len(pdev, PSB_GATT_RESOURCE)
								>> PAGE_SHIFT;
	dev_priv->gtt_mem = &pdev->resource[PSB_GATT_RESOURCE];

	if (pg->gatt_pages == 0 || pg->gatt_start == 0) {
		static struct resource fudge;	/* Preferably peppermint */
		/* This can occur on CDV systems. Fudge it in this case.
		   We really don't care what imaginary space is being allocated
		   at this point */
		dev_dbg(dev->dev, "GATT PCI BAR not initialized.\n");
		pg->gatt_start = 0x40000000;
		pg->gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
		/* This is a little confusing but in fact the GTT is providing
		   a view from the GPU into memory and not vice versa. As such
		   this is really allocating space that is not the same as the
		   CPU address space on CDV */
		fudge.start = 0x40000000;
		fudge.end = 0x40000000 + 128 * 1024 * 1024 - 1;
		fudge.name = "fudge";
		fudge.flags = IORESOURCE_MEM;
		dev_priv->gtt_mem = &fudge;
	}

	pci_read_config_dword(pdev, PSB_BSM, &dev_priv->stolen_base);
	vram_stolen_size = pg->gtt_phys_start - dev_priv->stolen_base
								- PAGE_SIZE;

	stolen_size = vram_stolen_size;

	dev_dbg(dev->dev, "Stolen memory base 0x%x, size %luK\n",
			dev_priv->stolen_base, vram_stolen_size / 1024);

	pg->gtt_pages = gtt_pages;
	pg->stolen_size = stolen_size;
	dev_priv->vram_stolen_size = vram_stolen_size;

	/*
	 *	Map the GTT and the stolen memory area
	 */
	dev_priv->gtt_map = ioremap(pg->gtt_phys_start, gtt_pages << PAGE_SHIFT);
	if (!dev_priv->gtt_map) {
		dev_err(dev->dev, "Failure to map gtt.\n");
		ret = -ENOMEM;
		goto err_gtt_disable;
	}

	dev_priv->vram_addr = ioremap_wc(dev_priv->stolen_base, stolen_size);
	if (!dev_priv->vram_addr) {
		dev_err(dev->dev, "Failure to map stolen base.\n");
		ret = -ENOMEM;
		goto err_iounmap;
	}

	psb_gtt_clear(dev_priv);
	psb_gtt_populate_stolen(dev_priv);

	return 0;

err_iounmap:
	iounmap(dev_priv->gtt_map);
err_gtt_disable:
	pci_write_config_word(pdev, PSB_GMCH_CTRL, dev_priv->gmch_ctrl);
	PSB_WVDC32(dev_priv->pge_ctl, PSB_PGETBL_CTL);
	(void)PSB_RVDC32(PSB_PGETBL_CTL);
	mutex_destroy(&dev_priv->mmap_mutex);
	mutex_destroy(&dev_priv->gtt_mutex);
	return ret;
}

static int psb_gtt_resume(struct drm_device *dev)
{
	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
	struct pci_dev *pdev = to_pci_dev(dev->dev);
	unsigned int gtt_pages;
	unsigned long stolen_size, vram_stolen_size;
	struct psb_gtt *pg;
	int ret = 0;

	pg = &dev_priv->gtt;

	/* Enable the GTT */
	pci_read_config_word(pdev, PSB_GMCH_CTRL, &dev_priv->gmch_ctrl);
	pci_write_config_word(pdev, PSB_GMCH_CTRL,
			      dev_priv->gmch_ctrl | _PSB_GMCH_ENABLED);

	dev_priv->pge_ctl = PSB_RVDC32(PSB_PGETBL_CTL);
	PSB_WVDC32(dev_priv->pge_ctl | _PSB_PGETBL_ENABLED, PSB_PGETBL_CTL);
	(void) PSB_RVDC32(PSB_PGETBL_CTL);

	/* The root resource we allocate address space from */
	pg->gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;

	/*
	 *	The video mmu has a hw bug when accessing 0x0D0000000.
	 *	Make gatt start at 0x0e000,0000. This doesn't actually
	 *	matter for us but may do if the video acceleration ever
	 *	gets opened up.
	 */
	pg->mmu_gatt_start = 0xE0000000;

	pg->gtt_start = pci_resource_start(pdev, PSB_GTT_RESOURCE);
	gtt_pages = pci_resource_len(pdev, PSB_GTT_RESOURCE) >> PAGE_SHIFT;
	/* CDV doesn't report this. In which case the system has 64 gtt pages */
	if (pg->gtt_start == 0 || gtt_pages == 0) {
		dev_dbg(dev->dev, "GTT PCI BAR not initialized.\n");
		gtt_pages = 64;
		pg->gtt_start = dev_priv->pge_ctl;
	}

	pg->gatt_start = pci_resource_start(pdev, PSB_GATT_RESOURCE);
	pg->gatt_pages = pci_resource_len(pdev, PSB_GATT_RESOURCE) >> PAGE_SHIFT;
	dev_priv->gtt_mem = &pdev->resource[PSB_GATT_RESOURCE];

	if (pg->gatt_pages == 0 || pg->gatt_start == 0) {
		static struct resource fudge;	/* Preferably peppermint */
		/*
		 * This can occur on CDV systems. Fudge it in this case. We
		 * really don't care what imaginary space is being allocated
		 * at this point.
		 */
		dev_dbg(dev->dev, "GATT PCI BAR not initialized.\n");
		pg->gatt_start = 0x40000000;
		pg->gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
		/*
		 * This is a little confusing but in fact the GTT is providing
		 * a view from the GPU into memory and not vice versa. As such
		 *  this is really allocating space that is not the same as the
		 *  CPU address space on CDV.
		 */
		fudge.start = 0x40000000;
		fudge.end = 0x40000000 + 128 * 1024 * 1024 - 1;
		fudge.name = "fudge";
		fudge.flags = IORESOURCE_MEM;
		dev_priv->gtt_mem = &fudge;
	}

	pci_read_config_dword(pdev, PSB_BSM, &dev_priv->stolen_base);
	vram_stolen_size = pg->gtt_phys_start - dev_priv->stolen_base - PAGE_SIZE;
	stolen_size = vram_stolen_size;

	dev_dbg(dev->dev, "Stolen memory base 0x%x, size %luK\n",
			dev_priv->stolen_base, vram_stolen_size / 1024);

	if ((gtt_pages != pg->gtt_pages) && (stolen_size != pg->stolen_size)) {
		dev_err(dev->dev, "GTT resume error.\n");
		ret = -EINVAL;
		goto err_gtt_disable;
	}

	pg->gtt_pages = gtt_pages;
	pg->stolen_size = stolen_size;
	dev_priv->vram_stolen_size = vram_stolen_size;

	psb_gtt_clear(dev_priv);
	psb_gtt_populate_stolen(dev_priv);

	return 0;

err_gtt_disable:
	pci_write_config_word(pdev, PSB_GMCH_CTRL, dev_priv->gmch_ctrl);
	PSB_WVDC32(dev_priv->pge_ctl, PSB_PGETBL_CTL);
	(void)PSB_RVDC32(PSB_PGETBL_CTL);
	return ret;
}

int psb_gtt_restore(struct drm_device *dev)
{
	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);

	psb_gtt_resume(dev);

	psb_gtt_populate_resources(dev_priv);

	return 0;
}