i915/src/i915_gem_stolen.c

/*
 * Copyright © 2008-2013 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *    Chris Wilson <chris@chris-wilson.co.uk>
 *
 */

/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 */

#include "drmP.h"
#include "i915_drm.h"
#include "i915_drv.h"

/*
 * The BIOS typically reserves some of the system's memory for the exclusive
 * use of the integrated graphics. This memory is no longer available for
 * use by the OS and so the user finds that his system has less memory
 * available than he put in. We refer to this memory as stolen.
 *
 * The BIOS will allocate its framebuffer from the stolen memory. Our
 * goal is try to reuse that object for our own fbcon which must always
 * be available for panics. Anything else we can reuse the stolen memory
 * for is a boon.
 */

static unsigned long i915_stolen_to_physical(struct drm_device *dev)
{
    struct pci_dev *pdev = dev->pdev;
    u32 base;

    /* On the machines I have tested the Graphics Base of Stolen Memory
     * is unreliable, so on those compute the base by subtracting the
     * stolen memory from the Top of Low Usable DRAM which is where the
     * BIOS places the graphics stolen memory.
     *
     * On gen2, the layout is slightly different with the Graphics Segment
     * immediately following Top of Memory (or Top of Usable DRAM). Note
     * it appears that TOUD is only reported by 865g, so we just use the
     * top of memory as determined by the e820 probe.
     *
     * XXX gen2 requires an unavailable symbol and 945gm fails with
     * its value of TOLUD.
     */
    base = 0;
    if (IS_VALLEYVIEW(dev)) {
        pci_read_config_dword(dev->pdev, 0x5c, &base);
        base &= ~((1<<20) - 1);
    } else if (INTEL_INFO(dev)->gen >= 6) {
        /* Read Base Data of Stolen Memory Register (BDSM) directly.
         * Note that there is also a MCHBAR miror at 0x1080c0 or
         * we could use device 2:0x5c instead.
        */
        pci_read_config_dword(pdev, 0xB0, &base);
        base &= ~4095; /* lower bits used for locking register */
    } else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
        /* Read Graphics Base of Stolen Memory directly */
        pci_read_config_dword(pdev, 0xA4, &base);
#if 0
    } else if (IS_GEN3(dev)) {
        u8 val;
        /* Stolen is immediately below Top of Low Usable DRAM */
        pci_read_config_byte(pdev, 0x9c, &val);
        base = val >> 3 << 27;
        base -= dev_priv->mm.gtt->stolen_size;
    } else {
        /* Stolen is immediately above Top of Memory */
        base = max_low_pfn_mapped << PAGE_SHIFT;
#endif
    }

    return base;
}

static int i915_setup_compression(struct drm_device *dev, int size)
{
    struct drm_i915_private *dev_priv = dev->dev_private;
    struct drm_mm_node *compressed_fb, *compressed_llb;

    /* Try to over-allocate to reduce reallocations and fragmentation */
    compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
                       size <<= 1, 4096, 0);
    if (!compressed_fb)
        compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
                           size >>= 1, 4096, 0);
    if (compressed_fb)
        compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
    if (!compressed_fb)
        goto err;

    if (HAS_PCH_SPLIT(dev))
        I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
    else if (IS_GM45(dev)) {
        I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
    } else {
        compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
                            4096, 4096, 0);
        if (compressed_llb)
            compressed_llb = drm_mm_get_block(compressed_llb,
                              4096, 4096);
        if (!compressed_llb)
            goto err_fb;

        dev_priv->compressed_llb = compressed_llb;

        I915_WRITE(FBC_CFB_BASE,
               dev_priv->mm.stolen_base + compressed_fb->start);
        I915_WRITE(FBC_LL_BASE,
               dev_priv->mm.stolen_base + compressed_llb->start);
    }

    dev_priv->compressed_fb = compressed_fb;
    dev_priv->cfb_size = size;

    DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
              size);

    return 0;

err_fb:
    drm_mm_put_block(compressed_fb);
err:
    return -ENOSPC;
}

int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
{
    struct drm_i915_private *dev_priv = dev->dev_private;

    if (!drm_mm_initialized(&dev_priv->mm.stolen))
        return -ENODEV;

    if (size < dev_priv->cfb_size)
        return 0;

    /* Release any current block */
    i915_gem_stolen_cleanup_compression(dev);

    return i915_setup_compression(dev, size);
}

void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
{
    struct drm_i915_private *dev_priv = dev->dev_private;

    if (dev_priv->cfb_size == 0)
        return;

    if (dev_priv->compressed_fb)
        drm_mm_put_block(dev_priv->compressed_fb);

    if (dev_priv->compressed_llb)
        drm_mm_put_block(dev_priv->compressed_llb);

    dev_priv->cfb_size = 0;
}

void i915_gem_cleanup_stolen(struct drm_device *dev)
{
    struct drm_i915_private *dev_priv = dev->dev_private;

    if (!drm_mm_initialized(&dev_priv->mm.stolen))
        return;

    i915_gem_stolen_cleanup_compression(dev);
    drm_mm_takedown(&dev_priv->mm.stolen);
}

int i915_gem_init_stolen(struct drm_device *dev)
{
    struct drm_i915_private *dev_priv = dev->dev_private;
    int bios_reserved = 0;

    dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
    if (dev_priv->mm.stolen_base == 0)
        return 0;

    DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
              dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);

    if (IS_VALLEYVIEW(dev))
        bios_reserved = 1024*1024; /* top 1M on VLV/BYT */

    /* Basic memrange allocator for stolen space */
    drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
            bios_reserved);

    return 0;
}

#if 0
static struct sg_table *
i915_pages_create_for_stolen(struct drm_device *dev,
                 u32 offset, u32 size)
{
    struct drm_i915_private *dev_priv = dev->dev_private;
    caddr_t *page_list;

    DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
    BUG_ON(offset > dev_priv->gtt.stolen_size - size);

    /* We hide that we have no struct page backing our stolen object
     * by wrapping the contiguous physical allocation with a fake
     * dma mapping in a single scatterlist.
     */

    page_list = kmem_zalloc(btop(size) * sizeof(caddr_t), KM_SLEEP);
    st = kmalloc(sizeof(*st), GFP_KERNEL);
    if (st == NULL)
        return NULL;

    if (sg_alloc_table(st, 1, GFP_KERNEL)) {
        kfree(st);
        return NULL;
    }

    sg = st->sgl;
    sg->offset = offset;
    sg->length = size;

    sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
    sg_dma_len(sg) = size;

    return st;
}
#endif

static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
{
    BUG();
    return -EINVAL;
}

static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
{
    /* Should only be called during free */
}

static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
    .get_pages = i915_gem_object_get_pages_stolen,
    .put_pages = i915_gem_object_put_pages_stolen,
};


static struct drm_i915_gem_object *
_i915_gem_object_create_stolen(struct drm_device *dev,
                   struct drm_mm_node *stolen)
{
#if 0
    struct drm_i915_gem_object *obj;

    obj = i915_gem_object_alloc(dev);
    if (obj == NULL)
        return NULL;

    if (drm_gem_private_object_init(dev, &obj->base, stolen->size))
        goto cleanup;

    i915_gem_object_init(obj, &i915_gem_object_stolen_ops);

    obj->page_list = i915_pages_create_for_stolen(dev,
                          stolen->start, stolen->size);
    if (obj->pages == NULL)
        goto cleanup;

    obj->has_dma_mapping = true;
    i915_gem_object_pin_pages(obj);
    obj->stolen = stolen;

    obj->base.write_domain = I915_GEM_DOMAIN_GTT;
    obj->base.read_domains = I915_GEM_DOMAIN_GTT;
    obj->cache_level = I915_CACHE_NONE;

    return obj;

cleanup:
    i915_gem_object_free(obj);
#endif
    return NULL;
}


struct drm_i915_gem_object *
i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
{
    DRM_DEBUG_KMS("Not support stolen object yet");
    return NULL;
#if 0
    struct drm_i915_private *dev_priv = dev->dev_private;
    struct drm_i915_gem_object *obj;
    struct drm_mm_node *stolen;

    if (!drm_mm_initialized(&dev_priv->mm.stolen))
        return NULL;

    DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
    if (size == 0)
        return NULL;

    stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
    if (stolen)
        stolen = drm_mm_get_block(stolen, size, 4096);
    if (stolen == NULL)
        return NULL;

    obj = _i915_gem_object_create_stolen(dev, stolen);
    if (obj)
        return obj;

    drm_mm_put_block(stolen);
    return NULL;
#endif
}

struct drm_i915_gem_object *
i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
                           u32 stolen_offset,
                           u32 gtt_offset,
                           u32 size)
{
    struct drm_i915_private *dev_priv = dev->dev_private;
    struct drm_i915_gem_object *obj;
    struct drm_mm_node *stolen;

    if (!drm_mm_initialized(&dev_priv->mm.stolen))
        return NULL;

    DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
            stolen_offset, gtt_offset, size);

    /* KISS and expect everything to be page-aligned */
    BUG_ON(stolen_offset & 4095);
    BUG_ON(size & 4095);

    if (size == 0)
        return NULL;

    stolen = drm_mm_create_block(&dev_priv->mm.stolen,
                     stolen_offset, size,
                     false);
    if (stolen == NULL) {
        DRM_DEBUG_KMS("failed to allocate stolen space\n");
        return NULL;
    }

    obj = _i915_gem_object_create_stolen(dev, stolen);
    if (obj == NULL) {
        DRM_DEBUG_KMS("failed to allocate stolen object\n");
        drm_mm_put_block(stolen);
        return NULL;
    }

    /* Some objects just need physical mem from stolen space */
    if (gtt_offset == 0xffffffff)
        return obj;

    /* To simplify the initialisation sequence between KMS and GTT,
     * we allow construction of the stolen object prior to
     * setting up the GTT space. The actual reservation will occur
     * later.
     */
    if (drm_mm_initialized(&dev_priv->mm.gtt_space)) {
        obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
                             gtt_offset, size,
                             false);
        if (obj->gtt_space == NULL) {
            DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
            drm_gem_object_unreference(&obj->base);
            return NULL;
        }
    } else
        obj->gtt_space = I915_GTT_RESERVED;

    obj->gtt_offset = gtt_offset;
    obj->has_global_gtt_mapping = 1;

    list_add_tail(&obj->global_list, &dev_priv->mm.bound_list, (caddr_t)obj);
    list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list, (caddr_t)obj);

    return obj;
}

void
i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
{
    if (obj->stolen) {
        drm_mm_put_block(obj->stolen);
        obj->stolen = NULL;
    }
}