drivers/gpu/drm/nouveau/nouveau_mem.c

/*
 * Copyright (C) The Weather Channel, Inc.  2002.  All Rights Reserved.
 * Copyright 2005 Stephane Marchesin
 *
 * The Weather Channel (TM) funded Tungsten Graphics to develop the
 * initial release of the Radeon 8500 driver under the XFree86 license.
 * This notice must be preserved.
 *
 * 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 AND/OR THEIR SUPPLIERS 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:
 *    Keith Whitwell <keith@tungstengraphics.com>
 */


#include "drmP.h"
#include "drm.h"
#include "drm_sarea.h"

#include "nouveau_drv.h"
#include "nouveau_pm.h"

/*
 * NV10-NV40 tiling helpers
 */

static void
nv10_mem_set_region_tiling(struct drm_device *dev, int i, uint32_t addr,
			   uint32_t size, uint32_t pitch)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct nouveau_fifo_engine *pfifo = &dev_priv->engine.fifo;
	struct nouveau_fb_engine *pfb = &dev_priv->engine.fb;
	struct nouveau_pgraph_engine *pgraph = &dev_priv->engine.graph;
	struct nouveau_tile_reg *tile = &dev_priv->tile[i];

	tile->addr = addr;
	tile->size = size;
	tile->used = !!pitch;
	nouveau_fence_unref((void **)&tile->fence);

	pfifo->reassign(dev, false);
	pfifo->cache_pull(dev, false);

	nouveau_wait_for_idle(dev);

	pgraph->set_region_tiling(dev, i, addr, size, pitch);
	pfb->set_region_tiling(dev, i, addr, size, pitch);

	pfifo->cache_pull(dev, true);
	pfifo->reassign(dev, true);
}

struct nouveau_tile_reg *
nv10_mem_set_tiling(struct drm_device *dev, uint32_t addr, uint32_t size,
		    uint32_t pitch)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct nouveau_fb_engine *pfb = &dev_priv->engine.fb;
	struct nouveau_tile_reg *found = NULL;
	unsigned long i, flags;

	spin_lock_irqsave(&dev_priv->context_switch_lock, flags);

	for (i = 0; i < pfb->num_tiles; i++) {
		struct nouveau_tile_reg *tile = &dev_priv->tile[i];

		if (tile->used)
			/* Tile region in use. */
			continue;

		if (tile->fence &&
		    !nouveau_fence_signalled(tile->fence, NULL))
			/* Pending tile region. */
			continue;

		if (max(tile->addr, addr) <
		    min(tile->addr + tile->size, addr + size))
			/* Kill an intersecting tile region. */
			nv10_mem_set_region_tiling(dev, i, 0, 0, 0);

		if (pitch && !found) {
			/* Free tile region. */
			nv10_mem_set_region_tiling(dev, i, addr, size, pitch);
			found = tile;
		}
	}

	spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);

	return found;
}

void
nv10_mem_expire_tiling(struct drm_device *dev, struct nouveau_tile_reg *tile,
		       struct nouveau_fence *fence)
{
	if (fence) {
		/* Mark it as pending. */
		tile->fence = fence;
		nouveau_fence_ref(fence);
	}

	tile->used = false;
}

/*
 * NV50 VM helpers
 */
int
nv50_mem_vm_bind_linear(struct drm_device *dev, uint64_t virt, uint32_t size,
			uint32_t flags, uint64_t phys)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct nouveau_gpuobj *pgt;
	unsigned block;
	int i;

	virt = ((virt - dev_priv->vm_vram_base) >> 16) << 1;
	size = (size >> 16) << 1;

	phys |= ((uint64_t)flags << 32);
	phys |= 1;
	if (dev_priv->vram_sys_base) {
		phys += dev_priv->vram_sys_base;
		phys |= 0x30;
	}

	while (size) {
		unsigned offset_h = upper_32_bits(phys);
		unsigned offset_l = lower_32_bits(phys);
		unsigned pte, end;

		for (i = 7; i >= 0; i--) {
			block = 1 << (i + 1);
			if (size >= block && !(virt & (block - 1)))
				break;
		}
		offset_l |= (i << 7);

		phys += block << 15;
		size -= block;

		while (block) {
			pgt = dev_priv->vm_vram_pt[virt >> 14];
			pte = virt & 0x3ffe;

			end = pte + block;
			if (end > 16384)
				end = 16384;
			block -= (end - pte);
			virt  += (end - pte);

			while (pte < end) {
				nv_wo32(pgt, (pte * 4) + 0, offset_l);
				nv_wo32(pgt, (pte * 4) + 4, offset_h);
				pte += 2;
			}
		}
	}

	dev_priv->engine.instmem.flush(dev);
	dev_priv->engine.fifo.tlb_flush(dev);
	dev_priv->engine.graph.tlb_flush(dev);
	nv50_vm_flush(dev, 6);
	return 0;
}

void
nv50_mem_vm_unbind(struct drm_device *dev, uint64_t virt, uint32_t size)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct nouveau_gpuobj *pgt;
	unsigned pages, pte, end;

	virt -= dev_priv->vm_vram_base;
	pages = (size >> 16) << 1;

	while (pages) {
		pgt = dev_priv->vm_vram_pt[virt >> 29];
		pte = (virt & 0x1ffe0000ULL) >> 15;

		end = pte + pages;
		if (end > 16384)
			end = 16384;
		pages -= (end - pte);
		virt  += (end - pte) << 15;

		while (pte < end) {
			nv_wo32(pgt, (pte * 4), 0);
			pte++;
		}
	}

	dev_priv->engine.instmem.flush(dev);
	dev_priv->engine.fifo.tlb_flush(dev);
	dev_priv->engine.graph.tlb_flush(dev);
	nv50_vm_flush(dev, 6);
}

/*
 * Cleanup everything
 */
void
nouveau_mem_vram_fini(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;

	nouveau_bo_unpin(dev_priv->vga_ram);
	nouveau_bo_ref(NULL, &dev_priv->vga_ram);

	ttm_bo_device_release(&dev_priv->ttm.bdev);

	nouveau_ttm_global_release(dev_priv);

	if (dev_priv->fb_mtrr >= 0) {
		drm_mtrr_del(dev_priv->fb_mtrr,
			     pci_resource_start(dev->pdev, 1),
			     pci_resource_len(dev->pdev, 1), DRM_MTRR_WC);
		dev_priv->fb_mtrr = -1;
	}
}

void
nouveau_mem_gart_fini(struct drm_device *dev)
{
	nouveau_sgdma_takedown(dev);

	if (drm_core_has_AGP(dev) && dev->agp) {
		struct drm_agp_mem *entry, *tempe;

		/* Remove AGP resources, but leave dev->agp
		   intact until drv_cleanup is called. */
		list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
			if (entry->bound)
				drm_unbind_agp(entry->memory);
			drm_free_agp(entry->memory, entry->pages);
			kfree(entry);
		}
		INIT_LIST_HEAD(&dev->agp->memory);

		if (dev->agp->acquired)
			drm_agp_release(dev);

		dev->agp->acquired = 0;
		dev->agp->enabled = 0;
	}
}

static uint32_t
nouveau_mem_detect_nv04(struct drm_device *dev)
{
	uint32_t boot0 = nv_rd32(dev, NV04_PFB_BOOT_0);

	if (boot0 & 0x00000100)
		return (((boot0 >> 12) & 0xf) * 2 + 2) * 1024 * 1024;

	switch (boot0 & NV04_PFB_BOOT_0_RAM_AMOUNT) {
	case NV04_PFB_BOOT_0_RAM_AMOUNT_32MB:
		return 32 * 1024 * 1024;
	case NV04_PFB_BOOT_0_RAM_AMOUNT_16MB:
		return 16 * 1024 * 1024;
	case NV04_PFB_BOOT_0_RAM_AMOUNT_8MB:
		return 8 * 1024 * 1024;
	case NV04_PFB_BOOT_0_RAM_AMOUNT_4MB:
		return 4 * 1024 * 1024;
	}

	return 0;
}

static uint32_t
nouveau_mem_detect_nforce(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct pci_dev *bridge;
	uint32_t mem;

	bridge = pci_get_bus_and_slot(0, PCI_DEVFN(0, 1));
	if (!bridge) {
		NV_ERROR(dev, "no bridge device\n");
		return 0;
	}

	if (dev_priv->flags & NV_NFORCE) {
		pci_read_config_dword(bridge, 0x7C, &mem);
		return (uint64_t)(((mem >> 6) & 31) + 1)*1024*1024;
	} else
	if (dev_priv->flags & NV_NFORCE2) {
		pci_read_config_dword(bridge, 0x84, &mem);
		return (uint64_t)(((mem >> 4) & 127) + 1)*1024*1024;
	}

	NV_ERROR(dev, "impossible!\n");
	return 0;
}

static void
nv50_vram_preinit(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	int i, parts, colbits, rowbitsa, rowbitsb, banks;
	u64 rowsize, predicted;
	u32 r0, r4, rt, ru;

	r0 = nv_rd32(dev, 0x100200);
	r4 = nv_rd32(dev, 0x100204);
	rt = nv_rd32(dev, 0x100250);
	ru = nv_rd32(dev, 0x001540);
	NV_DEBUG(dev, "memcfg 0x%08x 0x%08x 0x%08x 0x%08x\n", r0, r4, rt, ru);

	for (i = 0, parts = 0; i < 8; i++) {
		if (ru & (0x00010000 << i))
			parts++;
	}

	colbits  =  (r4 & 0x0000f000) >> 12;
	rowbitsa = ((r4 & 0x000f0000) >> 16) + 8;
	rowbitsb = ((r4 & 0x00f00000) >> 20) + 8;
	banks    = ((r4 & 0x01000000) ? 8 : 4);

	rowsize = parts * banks * (1 << colbits) * 8;
	predicted = rowsize << rowbitsa;
	if (r0 & 0x00000004)
		predicted += rowsize << rowbitsb;

	if (predicted != dev_priv->vram_size) {
		NV_WARN(dev, "memory controller reports %dMiB VRAM\n",
			(u32)(dev_priv->vram_size >> 20));
		NV_WARN(dev, "we calculated %dMiB VRAM\n",
			(u32)(predicted >> 20));
	}

	dev_priv->vram_rblock_size = rowsize >> 12;
	if (rt & 1)
		dev_priv->vram_rblock_size *= 3;

	NV_DEBUG(dev, "rblock %lld bytes\n",
		 (u64)dev_priv->vram_rblock_size << 12);
}

static void
nvaa_vram_preinit(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;

	/* To our knowledge, there's no large scale reordering of pages
	 * that occurs on IGP chipsets.
	 */
	dev_priv->vram_rblock_size = 1;
}

static int
nouveau_mem_detect(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;

	if (dev_priv->card_type == NV_04) {
		dev_priv->vram_size = nouveau_mem_detect_nv04(dev);
	} else
	if (dev_priv->flags & (NV_NFORCE | NV_NFORCE2)) {
		dev_priv->vram_size = nouveau_mem_detect_nforce(dev);
	} else
	if (dev_priv->card_type < NV_50) {
		dev_priv->vram_size  = nv_rd32(dev, NV04_PFB_FIFO_DATA);
		dev_priv->vram_size &= NV10_PFB_FIFO_DATA_RAM_AMOUNT_MB_MASK;
	} else
	if (dev_priv->card_type < NV_C0) {
		dev_priv->vram_size = nv_rd32(dev, NV04_PFB_FIFO_DATA);
		dev_priv->vram_size |= (dev_priv->vram_size & 0xff) << 32;
		dev_priv->vram_size &= 0xffffffff00ll;

		switch (dev_priv->chipset) {
		case 0xaa:
		case 0xac:
		case 0xaf:
			dev_priv->vram_sys_base = nv_rd32(dev, 0x100e10);
			dev_priv->vram_sys_base <<= 12;
			nvaa_vram_preinit(dev);
			break;
		default:
			nv50_vram_preinit(dev);
			break;
		}
	} else {
		dev_priv->vram_size  = nv_rd32(dev, 0x10f20c) << 20;
		dev_priv->vram_size *= nv_rd32(dev, 0x121c74);
	}

	NV_INFO(dev, "Detected %dMiB VRAM\n", (int)(dev_priv->vram_size >> 20));
	if (dev_priv->vram_sys_base) {
		NV_INFO(dev, "Stolen system memory at: 0x%010llx\n",
			dev_priv->vram_sys_base);
	}

	if (dev_priv->vram_size)
		return 0;
	return -ENOMEM;
}

#if __OS_HAS_AGP
static unsigned long
get_agp_mode(struct drm_device *dev, unsigned long mode)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;

	/*
	 * FW seems to be broken on nv18, it makes the card lock up
	 * randomly.
	 */
	if (dev_priv->chipset == 0x18)
		mode &= ~PCI_AGP_COMMAND_FW;

	/*
	 * AGP mode set in the command line.
	 */
	if (nouveau_agpmode > 0) {
		bool agpv3 = mode & 0x8;
		int rate = agpv3 ? nouveau_agpmode / 4 : nouveau_agpmode;

		mode = (mode & ~0x7) | (rate & 0x7);
	}

	return mode;
}
#endif

int
nouveau_mem_reset_agp(struct drm_device *dev)
{
#if __OS_HAS_AGP
	uint32_t saved_pci_nv_1, pmc_enable;
	int ret;

	/* First of all, disable fast writes, otherwise if it's
	 * already enabled in the AGP bridge and we disable the card's
	 * AGP controller we might be locking ourselves out of it. */
	if ((nv_rd32(dev, NV04_PBUS_PCI_NV_19) |
	     dev->agp->mode) & PCI_AGP_COMMAND_FW) {
		struct drm_agp_info info;
		struct drm_agp_mode mode;

		ret = drm_agp_info(dev, &info);
		if (ret)
			return ret;

		mode.mode = get_agp_mode(dev, info.mode) & ~PCI_AGP_COMMAND_FW;
		ret = drm_agp_enable(dev, mode);
		if (ret)
			return ret;
	}

	saved_pci_nv_1 = nv_rd32(dev, NV04_PBUS_PCI_NV_1);

	/* clear busmaster bit */
	nv_wr32(dev, NV04_PBUS_PCI_NV_1, saved_pci_nv_1 & ~0x4);
	/* disable AGP */
	nv_wr32(dev, NV04_PBUS_PCI_NV_19, 0);

	/* power cycle pgraph, if enabled */
	pmc_enable = nv_rd32(dev, NV03_PMC_ENABLE);
	if (pmc_enable & NV_PMC_ENABLE_PGRAPH) {
		nv_wr32(dev, NV03_PMC_ENABLE,
				pmc_enable & ~NV_PMC_ENABLE_PGRAPH);
		nv_wr32(dev, NV03_PMC_ENABLE, nv_rd32(dev, NV03_PMC_ENABLE) |
				NV_PMC_ENABLE_PGRAPH);
	}

	/* and restore (gives effect of resetting AGP) */
	nv_wr32(dev, NV04_PBUS_PCI_NV_1, saved_pci_nv_1);
#endif

	return 0;
}

int
nouveau_mem_init_agp(struct drm_device *dev)
{
#if __OS_HAS_AGP
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct drm_agp_info info;
	struct drm_agp_mode mode;
	int ret;

	if (!dev->agp->acquired) {
		ret = drm_agp_acquire(dev);
		if (ret) {
			NV_ERROR(dev, "Unable to acquire AGP: %d\n", ret);
			return ret;
		}
	}

	nouveau_mem_reset_agp(dev);

	ret = drm_agp_info(dev, &info);
	if (ret) {
		NV_ERROR(dev, "Unable to get AGP info: %d\n", ret);
		return ret;
	}

	/* see agp.h for the AGPSTAT_* modes available */
	mode.mode = get_agp_mode(dev, info.mode);
	ret = drm_agp_enable(dev, mode);
	if (ret) {
		NV_ERROR(dev, "Unable to enable AGP: %d\n", ret);
		return ret;
	}

	dev_priv->gart_info.type	= NOUVEAU_GART_AGP;
	dev_priv->gart_info.aper_base	= info.aperture_base;
	dev_priv->gart_info.aper_size	= info.aperture_size;
#endif
	return 0;
}

int
nouveau_mem_vram_init(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct ttm_bo_device *bdev = &dev_priv->ttm.bdev;
	int ret, dma_bits;

	if (dev_priv->card_type >= NV_50 &&
	    pci_dma_supported(dev->pdev, DMA_BIT_MASK(40)))
		dma_bits = 40;
	else
		dma_bits = 32;

	ret = pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(dma_bits));
	if (ret)
		return ret;

	ret = nouveau_mem_detect(dev);
	if (ret)
		return ret;

	dev_priv->fb_phys = pci_resource_start(dev->pdev, 1);

	ret = nouveau_ttm_global_init(dev_priv);
	if (ret)
		return ret;

	ret = ttm_bo_device_init(&dev_priv->ttm.bdev,
				 dev_priv->ttm.bo_global_ref.ref.object,
				 &nouveau_bo_driver, DRM_FILE_PAGE_OFFSET,
				 dma_bits <= 32 ? true : false);
	if (ret) {
		NV_ERROR(dev, "Error initialising bo driver: %d\n", ret);
		return ret;
	}

	dev_priv->fb_available_size = dev_priv->vram_size;
	dev_priv->fb_mappable_pages = dev_priv->fb_available_size;
	if (dev_priv->fb_mappable_pages > pci_resource_len(dev->pdev, 1))
		dev_priv->fb_mappable_pages =
			pci_resource_len(dev->pdev, 1);
	dev_priv->fb_mappable_pages >>= PAGE_SHIFT;

	/* reserve space at end of VRAM for PRAMIN */
	if (dev_priv->chipset == 0x40 || dev_priv->chipset == 0x47 ||
	    dev_priv->chipset == 0x49 || dev_priv->chipset == 0x4b)
		dev_priv->ramin_rsvd_vram = (2 * 1024 * 1024);
	else
	if (dev_priv->card_type >= NV_40)
		dev_priv->ramin_rsvd_vram = (1 * 1024 * 1024);
	else
		dev_priv->ramin_rsvd_vram = (512 * 1024);

	dev_priv->fb_available_size -= dev_priv->ramin_rsvd_vram;
	dev_priv->fb_aper_free = dev_priv->fb_available_size;

	/* mappable vram */
	ret = ttm_bo_init_mm(bdev, TTM_PL_VRAM,
			     dev_priv->fb_available_size >> PAGE_SHIFT);
	if (ret) {
		NV_ERROR(dev, "Failed VRAM mm init: %d\n", ret);
		return ret;
	}

	ret = nouveau_bo_new(dev, NULL, 256*1024, 0, TTM_PL_FLAG_VRAM,
			     0, 0, true, true, &dev_priv->vga_ram);
	if (ret == 0)
		ret = nouveau_bo_pin(dev_priv->vga_ram, TTM_PL_FLAG_VRAM);
	if (ret) {
		NV_WARN(dev, "failed to reserve VGA memory\n");
		nouveau_bo_ref(NULL, &dev_priv->vga_ram);
	}

	dev_priv->fb_mtrr = drm_mtrr_add(pci_resource_start(dev->pdev, 1),
					 pci_resource_len(dev->pdev, 1),
					 DRM_MTRR_WC);
	return 0;
}

int
nouveau_mem_gart_init(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct ttm_bo_device *bdev = &dev_priv->ttm.bdev;
	int ret;

	dev_priv->gart_info.type = NOUVEAU_GART_NONE;

#if !defined(__powerpc__) && !defined(__ia64__)
	if (drm_device_is_agp(dev) && dev->agp && nouveau_agpmode) {
		ret = nouveau_mem_init_agp(dev);
		if (ret)
			NV_ERROR(dev, "Error initialising AGP: %d\n", ret);
	}
#endif

	if (dev_priv->gart_info.type == NOUVEAU_GART_NONE) {
		ret = nouveau_sgdma_init(dev);
		if (ret) {
			NV_ERROR(dev, "Error initialising PCI(E): %d\n", ret);
			return ret;
		}
	}

	NV_INFO(dev, "%d MiB GART (aperture)\n",
		(int)(dev_priv->gart_info.aper_size >> 20));
	dev_priv->gart_info.aper_free = dev_priv->gart_info.aper_size;

	ret = ttm_bo_init_mm(bdev, TTM_PL_TT,
			     dev_priv->gart_info.aper_size >> PAGE_SHIFT);
	if (ret) {
		NV_ERROR(dev, "Failed TT mm init: %d\n", ret);
		return ret;
	}

	return 0;
}

void
nouveau_mem_timing_init(struct drm_device *dev)
{
	/* cards < NVC0 only */
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct nouveau_pm_engine *pm = &dev_priv->engine.pm;
	struct nouveau_pm_memtimings *memtimings = &pm->memtimings;
	struct nvbios *bios = &dev_priv->vbios;
	struct bit_entry P;
	u8 tUNK_0, tUNK_1, tUNK_2;
	u8 tRP;		/* Byte 3 */
	u8 tRAS;	/* Byte 5 */
	u8 tRFC;	/* Byte 7 */
	u8 tRC;		/* Byte 9 */
	u8 tUNK_10, tUNK_11, tUNK_12, tUNK_13, tUNK_14;
	u8 tUNK_18, tUNK_19, tUNK_20, tUNK_21;
	u8 *mem = NULL, *entry;
	int i, recordlen, entries;

	if (bios->type == NVBIOS_BIT) {
		if (bit_table(dev, 'P', &P))
			return;

		if (P.version == 1)
			mem = ROMPTR(bios, P.data[4]);
		else
		if (P.version == 2)
			mem = ROMPTR(bios, P.data[8]);
		else {
			NV_WARN(dev, "unknown mem for BIT P %d\n", P.version);
		}
	} else {
		NV_DEBUG(dev, "BMP version too old for memory\n");
		return;
	}

	if (!mem) {
		NV_DEBUG(dev, "memory timing table pointer invalid\n");
		return;
	}

	if (mem[0] != 0x10) {
		NV_WARN(dev, "memory timing table 0x%02x unknown\n", mem[0]);
		return;
	}

	/* validate record length */
	entries   = mem[2];
	recordlen = mem[3];
	if (recordlen < 15) {
		NV_ERROR(dev, "mem timing table length unknown: %d\n", mem[3]);
		return;
	}

	/* parse vbios entries into common format */
	memtimings->timing =
		kcalloc(entries, sizeof(*memtimings->timing), GFP_KERNEL);
	if (!memtimings->timing)
		return;

	entry = mem + mem[1];
	for (i = 0; i < entries; i++, entry += recordlen) {
		struct nouveau_pm_memtiming *timing = &pm->memtimings.timing[i];
		if (entry[0] == 0)
			continue;

		tUNK_18 = 1;
		tUNK_19 = 1;
		tUNK_20 = 0;
		tUNK_21 = 0;
		switch (min(recordlen, 22)) {
		case 22:
			tUNK_21 = entry[21];
		case 21:
			tUNK_20 = entry[20];
		case 20:
			tUNK_19 = entry[19];
		case 19:
			tUNK_18 = entry[18];
		default:
			tUNK_0  = entry[0];
			tUNK_1  = entry[1];
			tUNK_2  = entry[2];
			tRP     = entry[3];
			tRAS    = entry[5];
			tRFC    = entry[7];
			tRC     = entry[9];
			tUNK_10 = entry[10];
			tUNK_11 = entry[11];
			tUNK_12 = entry[12];
			tUNK_13 = entry[13];
			tUNK_14 = entry[14];
			break;
		}

		timing->reg_100220 = (tRC << 24 | tRFC << 16 | tRAS << 8 | tRP);

		/* XXX: I don't trust the -1's and +1's... they must come
		 *      from somewhere! */
		timing->reg_100224 = ((tUNK_0 + tUNK_19 + 1) << 24 |
				      tUNK_18 << 16 |
				      (tUNK_1 + tUNK_19 + 1) << 8 |
				      (tUNK_2 - 1));

		timing->reg_100228 = (tUNK_12 << 16 | tUNK_11 << 8 | tUNK_10);
		if(recordlen > 19) {
			timing->reg_100228 += (tUNK_19 - 1) << 24;
		}/* I cannot back-up this else-statement right now
			 else {
			timing->reg_100228 += tUNK_12 << 24;
		}*/

		/* XXX: reg_10022c */
		timing->reg_10022c = tUNK_2 - 1;

		timing->reg_100230 = (tUNK_20 << 24 | tUNK_21 << 16 |
				      tUNK_13 << 8  | tUNK_13);

		/* XXX: +6? */
		timing->reg_100234 = (tRAS << 24 | (tUNK_19 + 6) << 8 | tRC);
		timing->reg_100234 += max(tUNK_10,tUNK_11) << 16;

		/* XXX; reg_100238, reg_10023c
		 * reg: 0x00??????
		 * reg_10023c:
		 *      0 for pre-NV50 cards
		 *      0x????0202 for NV50+ cards (empirical evidence) */
		if(dev_priv->card_type >= NV_50) {
			timing->reg_10023c = 0x202;
		}

		NV_DEBUG(dev, "Entry %d: 220: %08x %08x %08x %08x\n", i,
			 timing->reg_100220, timing->reg_100224,
			 timing->reg_100228, timing->reg_10022c);
		NV_DEBUG(dev, "         230: %08x %08x %08x %08x\n",
			 timing->reg_100230, timing->reg_100234,
			 timing->reg_100238, timing->reg_10023c);
	}

	memtimings->nr_timing  = entries;
	memtimings->supported = true;
}

void
nouveau_mem_timing_fini(struct drm_device *dev)
{
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	struct nouveau_pm_memtimings *mem = &dev_priv->engine.pm.memtimings;

	kfree(mem->timing);
}