gma500: introduce the GTT and MMU handling logic

This fits alongside the GEM support to manage our resources on the card
itself. It's not actually clear we need to configure the MMU at all.
Further research is needed before removing it entirely. For now we suck it
in (slightly abused) from the old semi-free driver.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 500 insertions, 0 deletions

diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
new file mode 100644
index 0000000..461ead2
--- /dev/null
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -0,0 +1,500 @@
+/*
+ * Copyright (c) 2007, Intel 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Authors: Thomas Hellstrom <thomas-at-tungstengraphics.com>
+ *	    Alan Cox <alan@linux.intel.com>
+ */
+
+#include <drm/drmP.h>
+#include "psb_drv.h"
+
+
+/*
+ *	GTT resource allocator - manage page mappings in GTT space
+ */
+
+/**
+ *	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;
+
+	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;
+}
+
+/**
+ *	psb_gtt_entry		-	find the GTT entries for a gtt_range
+ *	@dev: our DRM device
+ *	@r: our GTT range
+ *
+ *	Given a gtt_range object return the GTT offset of the page table
+ *	entries for this gtt_range
+ */
+u32 *psb_gtt_entry(struct drm_device *dev, struct gtt_range *r)
+{
+	struct drm_psb_private *dev_priv = dev->dev_private;
+	unsigned long offset;
+
+	offset = r->resource.start - dev_priv->gtt_mem->start;
+
+	return dev_priv->gtt_map + (offset >> PAGE_SHIFT);
+}
+
+/**
+ *	psb_gtt_insert	-	put an object into the GTT
+ *	@dev: our DRM device
+ *	@r: our GTT range
+ *
+ *	Take our preallocated GTT range and insert the GEM object into
+ *	the GTT.
+ *
+ *	FIXME: gtt lock ?
+ */
+static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r)
+{
+	u32 *gtt_slot, pte;
+	struct page **pages;
+	int i;
+
+	if (r->pages == NULL) {
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	WARN_ON(r->stolen);	/* refcount these maybe ? */
+
+	gtt_slot = psb_gtt_entry(dev, r);
+	pages = r->pages;
+
+	/* Make sure changes are visible to the GPU */
+	set_pages_array_uc(pages, r->npage);
+
+	/* Write our page entries into the GTT itself */
+	for (i = 0; i < r->npage; i++) {
+		pte = psb_gtt_mask_pte(page_to_pfn(*pages++), 0/*type*/);
+		iowrite32(pte, gtt_slot++);
+	}
+	/* Make sure all the entries are set before we return */
+	ioread32(gtt_slot - 1);
+	return 0;
+}
+
+/**
+ *	psb_gtt_remove	-	remove an object from the GTT
+ *	@dev: our DRM device
+ *	@r: our GTT range
+ *
+ *	Remove a preallocated GTT range from the GTT. Overwrite all the
+ *	page table entries with the dummy page
+ */
+
+static void psb_gtt_remove(struct drm_device *dev, struct gtt_range *r)
+{
+	struct drm_psb_private *dev_priv = dev->dev_private;
+	u32 *gtt_slot, pte;
+	int i;
+
+	WARN_ON(r->stolen);
+
+	gtt_slot = psb_gtt_entry(dev, r);
+	pte = psb_gtt_mask_pte(page_to_pfn(dev_priv->scratch_page), 0);
+
+	for (i = 0; i < r->npage; i++)
+		iowrite32(pte, gtt_slot++);
+	ioread32(gtt_slot - 1);
+	set_pages_array_wb(r->pages, r->npage);
+}
+
+/**
+ *	psb_gtt_attach_pages	-	attach and pin GEM pages
+ *	@gt: the gtt range
+ *
+ *	Pin and build an in kernel list of the pages that back our GEM object.
+ *	While we hold this the pages cannot be swapped out
+ */
+static int psb_gtt_attach_pages(struct gtt_range *gt)
+{
+	struct inode *inode;
+	struct address_space *mapping;
+	int i;
+	struct page *p;
+	int pages = gt->gem.size / PAGE_SIZE;
+
+	WARN_ON(gt->pages);
+
+	/* This is the shared memory object that backs the GEM resource */
+	inode = gt->gem.filp->f_path.dentry->d_inode;
+	mapping = inode->i_mapping;
+
+	gt->pages = kmalloc(pages * sizeof(struct page *), GFP_KERNEL);
+	if (gt->pages == NULL)
+		return -ENOMEM;
+	gt->npage = pages;
+
+	for (i = 0; i < pages; i++) {
+		/* FIXME: review flags later */
+		p = read_cache_page_gfp(mapping, i,
+					__GFP_COLD | GFP_KERNEL);
+		if (IS_ERR(p))
+			goto err;
+		gt->pages[i] = p;
+	}
+	return 0;
+
+err:
+	while (i--)
+		page_cache_release(gt->pages[i]);
+	kfree(gt->pages);
+	gt->pages = NULL;
+	return PTR_ERR(p);
+}
+
+/**
+ *	psb_gtt_detach_pages	-	attach and pin GEM pages
+ *	@gt: the gtt range
+ *
+ *	Undo the effect of psb_gtt_attach_pages. At this point the pages
+ *	must have been removed from the GTT as they could now be paged out
+ *	and move bus address.
+ */
+static void psb_gtt_detach_pages(struct gtt_range *gt)
+{
+	int i;
+	for (i = 0; i < gt->npage; i++) {
+		/* FIXME: do we need to force dirty */
+		set_page_dirty(gt->pages[i]);
+		page_cache_release(gt->pages[i]);
+	}
+	kfree(gt->pages);
+	gt->pages = NULL;
+}
+
+/**
+ *	psb_gtt_pin		-	pin pages into the GTT
+ *	@gt: range to pin
+ *
+ *	Pin a set of pages into the GTT. The pins are refcounted so that
+ *	multiple pins need multiple unpins to undo.
+ *
+ *	Non GEM backed objects treat this as a no-op as they are always GTT
+ *	backed objects.
+ */
+int psb_gtt_pin(struct gtt_range *gt)
+{
+	int ret = 0;
+	struct drm_device *dev = gt->gem.dev;
+	struct drm_psb_private *dev_priv = dev->dev_private;
+
+	mutex_lock(&dev_priv->gtt_mutex);
+
+	if (gt->in_gart == 0 && gt->stolen == 0) {
+		ret = psb_gtt_attach_pages(gt);
+		if (ret < 0)
+			goto out;
+		ret = psb_gtt_insert(dev, gt);
+		if (ret < 0) {
+			psb_gtt_detach_pages(gt);
+			goto out;
+		}
+	}
+	gt->in_gart++;
+out:
+	mutex_unlock(&dev_priv->gtt_mutex);
+	return ret;
+}
+
+/**
+ *	psb_gtt_unpin		-	Drop a GTT pin requirement
+ *	@gt: range to pin
+ *
+ *	Undoes the effect of psb_gtt_pin. On the last drop the GEM object
+ *	will be removed from the GTT which will also drop the page references
+ *	and allow the VM to clean up or page stuff.
+ *
+ *	Non GEM backed objects treat this as a no-op as they are always GTT
+ *	backed objects.
+ */
+void psb_gtt_unpin(struct gtt_range *gt)
+{
+	struct drm_device *dev = gt->gem.dev;
+	struct drm_psb_private *dev_priv = dev->dev_private;
+
+	mutex_lock(&dev_priv->gtt_mutex);
+
+	WARN_ON(!gt->in_gart);
+
+	gt->in_gart--;
+	if (gt->in_gart == 0 && gt->stolen == 0) {
+		psb_gtt_remove(dev, gt);
+		psb_gtt_detach_pages(gt);
+	}
+	mutex_unlock(&dev_priv->gtt_mutex);
+}
+
+/*
+ *	GTT resource allocator - allocate and manage GTT address space
+ */
+
+/**
+ *	psb_gtt_alloc_range	-	allocate GTT address space
+ *	@dev: Our DRM device
+ *	@len: length (bytes) of address space required
+ *	@name: resource name
+ *	@backed: resource should be backed by stolen pages
+ *
+ *	Ask the kernel core to find us a suitable range of addresses
+ *	to use for a GTT mapping.
+ *
+ *	Returns a gtt_range structure describing the object, or NULL on
+ *	error. On successful return the resource is both allocated and marked
+ *	as in use.
+ */
+struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
+						const char *name, int backed)
+{
+	struct drm_psb_private *dev_priv = dev->dev_private;
+	struct gtt_range *gt;
+	struct resource *r = dev_priv->gtt_mem;
+	int ret;
+	unsigned long start, end;
+
+	if (backed) {
+		/* The start of the GTT is the stolen pages */
+		start = r->start;
+		end = r->start + dev_priv->gtt.stolen_size - 1;
+	} else {
+		/* The rest we will use for GEM backed objects */
+		start = r->start + dev_priv->gtt.stolen_size;
+		end = r->end;
+	}
+
+	gt = kzalloc(sizeof(struct gtt_range), GFP_KERNEL);
+	if (gt == NULL)
+		return NULL;
+	gt->resource.name = name;
+	gt->stolen = backed;
+	gt->in_gart = backed;
+	/* Ensure this is set for non GEM objects */
+	gt->gem.dev = dev;
+	ret = allocate_resource(dev_priv->gtt_mem, &gt->resource,
+				len, start, end, PAGE_SIZE, NULL, NULL);
+	if (ret == 0) {
+		gt->offset = gt->resource.start - r->start;
+		return gt;
+	}
+	kfree(gt);
+	return NULL;
+}
+
+/**
+ *	psb_gtt_free_range	-	release GTT address space
+ *	@dev: our DRM device
+ *	@gt: a mapping created with psb_gtt_alloc_range
+ *
+ *	Release a resource that was allocated with psb_gtt_alloc_range. If the
+ *	object has been pinned by mmap users we clean this up here currently.
+ */
+void psb_gtt_free_range(struct drm_device *dev, struct gtt_range *gt)
+{
+	/* Undo the mmap pin if we are destroying the object */
+	if (gt->mmapping) {
+		psb_gtt_unpin(gt);
+		gt->mmapping = 0;
+	}
+	WARN_ON(gt->in_gart && !gt->stolen);
+	release_resource(&gt->resource);
+	kfree(gt);
+}
+
+void psb_gtt_alloc(struct drm_device *dev)
+{
+	struct drm_psb_private *dev_priv = dev->dev_private;
+	init_rwsem(&dev_priv->gtt.sem);
+}
+
+void psb_gtt_takedown(struct drm_device *dev)
+{
+	struct drm_psb_private *dev_priv = dev->dev_private;
+
+	if (dev_priv->gtt_map) {
+		iounmap(dev_priv->gtt_map);
+		dev_priv->gtt_map = NULL;
+	}
+	if (dev_priv->gtt_initialized) {
+		pci_write_config_word(dev->pdev, PSB_GMCH_CTRL,
+				      dev_priv->gmch_ctrl);
+		PSB_WVDC32(dev_priv->pge_ctl, PSB_PGETBL_CTL);
+		(void) PSB_RVDC32(PSB_PGETBL_CTL);
+	}
+	if (dev_priv->vram_addr)
+		iounmap(dev_priv->gtt_map);
+}
+
+int psb_gtt_init(struct drm_device *dev, int resume)
+{
+	struct drm_psb_private *dev_priv = dev->dev_private;
+	unsigned gtt_pages;
+	unsigned long stolen_size, vram_stolen_size;
+	unsigned i, num_pages;
+	unsigned pfn_base;
+	uint32_t vram_pages;
+	uint32_t dvmt_mode = 0;
+	struct psb_gtt *pg;
+
+	int ret = 0;
+	uint32_t pte;
+
+	mutex_init(&dev_priv->gtt_mutex);
+
+	psb_gtt_alloc(dev);
+	pg = &dev_priv->gtt;
+
+	/* Enable the GTT */
+	pci_read_config_word(dev->pdev, PSB_GMCH_CTRL, &dev_priv->gmch_ctrl);
+	pci_write_config_word(dev->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 */
+	dev_priv->gtt_initialized = 1;
+
+	pg->gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;
+
+	/*
+	 *	FIXME: video mmu has hw bug to access 0x0D0000000,
+	 *	then make gatt start at 0x0e000,0000
+	 */
+	pg->mmu_gatt_start = 0xE0000000;
+
+	pg->gtt_start = pci_resource_start(dev->pdev, PSB_GTT_RESOURCE);
+	gtt_pages = pci_resource_len(dev->pdev, PSB_GTT_RESOURCE)
+								>> PAGE_SHIFT;
+	/* CDV workaround */
+	if (pg->gtt_start == 0 || gtt_pages == 0) {
+		dev_err(dev->dev, "GTT PCI BAR not initialized.\n");
+		gtt_pages = 64;
+		pg->gtt_start = dev_priv->pge_ctl;
+	}
+
+	pg->gatt_start = pci_resource_start(dev->pdev, PSB_GATT_RESOURCE);
+	pg->gatt_pages = pci_resource_len(dev->pdev, PSB_GATT_RESOURCE)
+								>> PAGE_SHIFT;
+	dev_priv->gtt_mem = &dev->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 SDV systems. Fudge it in this case.
+		   We really don't care what imaginary space is being allocated
+		   at this point */
+		dev_err(dev->dev, "GATT PCI BAR not initialized.\n");
+		pg->gatt_start = 0x40000000;
+		pg->gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
+		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(dev->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;
+
+	printk(KERN_INFO "Stolen memory information\n");
+	printk(KERN_INFO "       base in RAM: 0x%x\n", dev_priv->stolen_base);
+	printk(KERN_INFO "       size: %luK, calculated by (GTT RAM base) - (Stolen base), seems wrong\n",
+		vram_stolen_size/1024);
+	dvmt_mode = (dev_priv->gmch_ctrl >> 4) & 0x7;
+	printk(KERN_INFO "      the correct size should be: %dM(dvmt mode=%d)\n",
+		(dvmt_mode == 1) ? 1 : (2 << (dvmt_mode - 1)), dvmt_mode);
+
+	if (resume && (gtt_pages != pg->gtt_pages) &&
+	    (stolen_size != pg->stolen_size)) {
+		dev_err(dev->dev, "GTT resume error.\n");
+		ret = -EINVAL;
+		goto out_err;
+	}
+
+	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_nocache(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 out_err;
+	}
+
+	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 out_err;
+	}
+
+	/*
+	 * Insert vram stolen pages into the GTT
+	 */
+
+	pfn_base = dev_priv->stolen_base >> PAGE_SHIFT;
+	vram_pages = num_pages = vram_stolen_size >> PAGE_SHIFT;
+	printk(KERN_INFO"Set up %d 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, 0);
+		iowrite32(pte, dev_priv->gtt_map + i);
+	}
+
+	/*
+	 * Init rest of GTT to the scratch page to avoid accidents or scribbles
+	 */
+
+	pfn_base = page_to_pfn(dev_priv->scratch_page);
+	pte = psb_gtt_mask_pte(pfn_base, 0);
+	for (; i < gtt_pages; ++i)
+		iowrite32(pte, dev_priv->gtt_map + i);
+
+	(void) ioread32(dev_priv->gtt_map + i - 1);
+	return 0;
+
+out_err:
+	psb_gtt_takedown(dev);
+	return ret;
+}