drm: Implement linux/io-mapping.h

[dragonfly.git] / sys / dev / drm / i915 / i915_drv.c

/* i915_drv.c -- i830,i845,i855,i865,i915 driver -*- linux-c -*-
 */
/*
 *
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 *
 * 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, sub license, 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS 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.
 *
 */

#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include <drm/drm_pciids.h>
#include "intel_drv.h"

/*		 "Specify LVDS channel mode "
		 "(0=probe BIOS [default], 1=single-channel, 2=dual-channel)" */
int i915_lvds_channel_mode __read_mostly = 0;
TUNABLE_INT("drm.i915.lvds_channel_mode", &i915_lvds_channel_mode);

int i915_disable_power_well __read_mostly = 1;
module_param_named(disable_power_well, i915_disable_power_well, int, 0600);
MODULE_PARM_DESC(disable_power_well,
		 "Disable the power well when possible (default: true)");

bool i915_enable_hangcheck __read_mostly = true;
module_param_named(enable_hangcheck, i915_enable_hangcheck, bool, 0644);
MODULE_PARM_DESC(enable_hangcheck,
		"Periodically check GPU activity for detecting hangs. "
		"WARNING: Disabling this can cause system wide hangs. "
		"(default: true)");

int i915_enable_ips __read_mostly = 1;
module_param_named(enable_ips, i915_enable_ips, int, 0600);
MODULE_PARM_DESC(enable_ips, "Enable IPS (default: true)");

static struct drm_driver driver;

#define INTEL_VGA_DEVICE(id, info) {		\
	.class = PCI_BASE_CLASS_DISPLAY << 16,	\
	.class_mask = 0xff0000,			\
	.vendor = 0x8086,			\
	.device = id,				\
	.subvendor = PCI_ANY_ID,		\
	.subdevice = PCI_ANY_ID,		\
	.driver_data = (unsigned long) info }

#define INTEL_QUANTA_VGA_DEVICE(info) {		\
	.class = PCI_BASE_CLASS_DISPLAY << 16,	\
	.class_mask = 0xff0000,			\
	.vendor = 0x8086,			\
	.device = 0x16a,			\
	.subvendor = 0x152d,			\
	.subdevice = 0x8990,			\
	.driver_data = (unsigned long) info }


static const struct intel_device_info intel_i830_info = {
	.gen = 2, .is_mobile = 1, .cursor_needs_physical = 1, .num_pipes = 2,
	.has_overlay = 1, .overlay_needs_physical = 1,
};

static const struct intel_device_info intel_845g_info = {
	.gen = 2, .num_pipes = 1,
	.has_overlay = 1, .overlay_needs_physical = 1,
};

static const struct intel_device_info intel_i85x_info = {
	.gen = 2, .is_i85x = 1, .is_mobile = 1, .num_pipes = 2,
	.cursor_needs_physical = 1,
	.has_overlay = 1, .overlay_needs_physical = 1,
};

static const struct intel_device_info intel_i865g_info = {
	.gen = 2, .num_pipes = 1,
	.has_overlay = 1, .overlay_needs_physical = 1,
};

static const struct intel_device_info intel_i915g_info = {
	.gen = 3, .is_i915g = 1, .cursor_needs_physical = 1, .num_pipes = 2,
	.has_overlay = 1, .overlay_needs_physical = 1,
};
static const struct intel_device_info intel_i915gm_info = {
	.gen = 3, .is_mobile = 1, .num_pipes = 2,
	.cursor_needs_physical = 1,
	.has_overlay = 1, .overlay_needs_physical = 1,
	.supports_tv = 1,
};
static const struct intel_device_info intel_i945g_info = {
	.gen = 3, .has_hotplug = 1, .cursor_needs_physical = 1, .num_pipes = 2,
	.has_overlay = 1, .overlay_needs_physical = 1,
};
static const struct intel_device_info intel_i945gm_info = {
	.gen = 3, .is_i945gm = 1, .is_mobile = 1, .num_pipes = 2,
	.has_hotplug = 1, .cursor_needs_physical = 1,
	.has_overlay = 1, .overlay_needs_physical = 1,
	.supports_tv = 1,
};

static const struct intel_device_info intel_i965g_info = {
	.gen = 4, .is_broadwater = 1, .num_pipes = 2,
	.has_hotplug = 1,
	.has_overlay = 1,
};

static const struct intel_device_info intel_i965gm_info = {
	.gen = 4, .is_crestline = 1, .num_pipes = 2,
	.is_mobile = 1, .has_fbc = 1, .has_hotplug = 1,
	.has_overlay = 1,
	.supports_tv = 1,
};

static const struct intel_device_info intel_g33_info = {
	.gen = 3, .is_g33 = 1, .num_pipes = 2,
	.need_gfx_hws = 1, .has_hotplug = 1,
	.has_overlay = 1,
};

static const struct intel_device_info intel_g45_info = {
	.gen = 4, .is_g4x = 1, .need_gfx_hws = 1, .num_pipes = 2,
	.has_pipe_cxsr = 1, .has_hotplug = 1,
	.has_bsd_ring = 1,
};

static const struct intel_device_info intel_gm45_info = {
	.gen = 4, .is_g4x = 1, .num_pipes = 2,
	.is_mobile = 1, .need_gfx_hws = 1, .has_fbc = 1,
	.has_pipe_cxsr = 1, .has_hotplug = 1,
	.supports_tv = 1,
	.has_bsd_ring = 1,
};

static const struct intel_device_info intel_pineview_info = {
	.gen = 3, .is_g33 = 1, .is_pineview = 1, .is_mobile = 1, .num_pipes = 2,
	.need_gfx_hws = 1, .has_hotplug = 1,
	.has_overlay = 1,
};

static const struct intel_device_info intel_ironlake_d_info = {
	.gen = 5, .num_pipes = 2,
	.need_gfx_hws = 1, .has_hotplug = 1,
	.has_bsd_ring = 1,
};

static const struct intel_device_info intel_ironlake_m_info = {
	.gen = 5, .is_mobile = 1, .num_pipes = 2,
	.need_gfx_hws = 1, .has_hotplug = 1,
	.has_fbc = 1,
	.has_bsd_ring = 1,
};

static const struct intel_device_info intel_sandybridge_d_info = {
	.gen = 6, .num_pipes = 2,
	.need_gfx_hws = 1, .has_hotplug = 1,
	.has_bsd_ring = 1,
	.has_blt_ring = 1,
	.has_llc = 1,
	.has_force_wake = 1,
};

static const struct intel_device_info intel_sandybridge_m_info = {
	.gen = 6, .is_mobile = 1, .num_pipes = 2,
	.need_gfx_hws = 1, .has_hotplug = 1,
	.has_fbc = 1,
	.has_bsd_ring = 1,
	.has_blt_ring = 1,
	.has_llc = 1,
	.has_force_wake = 1,
};

#define GEN7_FEATURES  \
	.gen = 7, .num_pipes = 3, \
	.need_gfx_hws = 1, .has_hotplug = 1, \
	.has_bsd_ring = 1, \
	.has_blt_ring = 1, \
	.has_llc = 1, \
	.has_force_wake = 1

static const struct intel_device_info intel_ivybridge_d_info = {
	GEN7_FEATURES,
	.is_ivybridge = 1,
};

static const struct intel_device_info intel_ivybridge_m_info = {
	GEN7_FEATURES,
	.is_ivybridge = 1,
	.is_mobile = 1,
	.has_fbc = 1,
};

static const struct intel_device_info intel_ivybridge_q_info = {
	GEN7_FEATURES,
	.is_ivybridge = 1,
	.num_pipes = 0, /* legal, last one wins */
};

static const struct intel_device_info intel_valleyview_m_info = {
	GEN7_FEATURES,
	.is_mobile = 1,
	.num_pipes = 2,
	.is_valleyview = 1,
	.display_mmio_offset = VLV_DISPLAY_BASE,
	.has_llc = 0, /* legal, last one wins */
};

static const struct intel_device_info intel_valleyview_d_info = {
	GEN7_FEATURES,
	.num_pipes = 2,
	.is_valleyview = 1,
	.display_mmio_offset = VLV_DISPLAY_BASE,
	.has_llc = 0, /* legal, last one wins */
};

static const struct intel_device_info intel_haswell_d_info = {
	GEN7_FEATURES,
	.is_haswell = 1,
	.has_ddi = 1,
	.has_fpga_dbg = 1,
	.has_vebox_ring = 1,
};

static const struct intel_device_info intel_haswell_m_info = {
	GEN7_FEATURES,
	.is_haswell = 1,
	.is_mobile = 1,
	.has_ddi = 1,
	.has_fpga_dbg = 1,
	.has_fbc = 1,
	.has_vebox_ring = 1,
};

static const struct pci_device_id pciidlist[] = {		/* aka */
	INTEL_VGA_DEVICE(0x3577, &intel_i830_info),		/* I830_M */
	INTEL_VGA_DEVICE(0x2562, &intel_845g_info),		/* 845_G */
	INTEL_VGA_DEVICE(0x3582, &intel_i85x_info),		/* I855_GM */
	INTEL_VGA_DEVICE(0x358e, &intel_i85x_info),
	INTEL_VGA_DEVICE(0x2572, &intel_i865g_info),		/* I865_G */
	INTEL_VGA_DEVICE(0x2582, &intel_i915g_info),		/* I915_G */
	INTEL_VGA_DEVICE(0x258a, &intel_i915g_info),		/* E7221_G */
	INTEL_VGA_DEVICE(0x2592, &intel_i915gm_info),		/* I915_GM */
	INTEL_VGA_DEVICE(0x2772, &intel_i945g_info),		/* I945_G */
	INTEL_VGA_DEVICE(0x27a2, &intel_i945gm_info),		/* I945_GM */
	INTEL_VGA_DEVICE(0x27ae, &intel_i945gm_info),		/* I945_GME */
	INTEL_VGA_DEVICE(0x2972, &intel_i965g_info),		/* I946_GZ */
	INTEL_VGA_DEVICE(0x2982, &intel_i965g_info),		/* G35_G */
	INTEL_VGA_DEVICE(0x2992, &intel_i965g_info),		/* I965_Q */
	INTEL_VGA_DEVICE(0x29a2, &intel_i965g_info),		/* I965_G */
	INTEL_VGA_DEVICE(0x29b2, &intel_g33_info),		/* Q35_G */
	INTEL_VGA_DEVICE(0x29c2, &intel_g33_info),		/* G33_G */
	INTEL_VGA_DEVICE(0x29d2, &intel_g33_info),		/* Q33_G */
	INTEL_VGA_DEVICE(0x2a02, &intel_i965gm_info),		/* I965_GM */
	INTEL_VGA_DEVICE(0x2a12, &intel_i965gm_info),		/* I965_GME */
	INTEL_VGA_DEVICE(0x2a42, &intel_gm45_info),		/* GM45_G */
	INTEL_VGA_DEVICE(0x2e02, &intel_g45_info),		/* IGD_E_G */
	INTEL_VGA_DEVICE(0x2e12, &intel_g45_info),		/* Q45_G */
	INTEL_VGA_DEVICE(0x2e22, &intel_g45_info),		/* G45_G */
	INTEL_VGA_DEVICE(0x2e32, &intel_g45_info),		/* G41_G */
	INTEL_VGA_DEVICE(0x2e42, &intel_g45_info),		/* B43_G */
	INTEL_VGA_DEVICE(0x2e92, &intel_g45_info),		/* B43_G.1 */
	INTEL_VGA_DEVICE(0xa001, &intel_pineview_info),
	INTEL_VGA_DEVICE(0xa011, &intel_pineview_info),
	INTEL_VGA_DEVICE(0x0042, &intel_ironlake_d_info),
	INTEL_VGA_DEVICE(0x0046, &intel_ironlake_m_info),
	INTEL_VGA_DEVICE(0x0102, &intel_sandybridge_d_info),
	INTEL_VGA_DEVICE(0x0112, &intel_sandybridge_d_info),
	INTEL_VGA_DEVICE(0x0122, &intel_sandybridge_d_info),
	INTEL_VGA_DEVICE(0x0106, &intel_sandybridge_m_info),
	INTEL_VGA_DEVICE(0x0116, &intel_sandybridge_m_info),
	INTEL_VGA_DEVICE(0x0126, &intel_sandybridge_m_info),
	INTEL_VGA_DEVICE(0x010A, &intel_sandybridge_d_info),
	INTEL_VGA_DEVICE(0x0156, &intel_ivybridge_m_info), /* GT1 mobile */
	INTEL_VGA_DEVICE(0x0166, &intel_ivybridge_m_info), /* GT2 mobile */
	INTEL_VGA_DEVICE(0x0152, &intel_ivybridge_d_info), /* GT1 desktop */
	INTEL_VGA_DEVICE(0x0162, &intel_ivybridge_d_info), /* GT2 desktop */
	INTEL_VGA_DEVICE(0x015a, &intel_ivybridge_d_info), /* GT1 server */
	INTEL_VGA_DEVICE(0x016a, &intel_ivybridge_d_info), /* GT2 server */
	INTEL_VGA_DEVICE(0x0402, &intel_haswell_d_info), /* GT1 desktop */
	INTEL_VGA_DEVICE(0x0412, &intel_haswell_d_info), /* GT2 desktop */
	INTEL_VGA_DEVICE(0x0422, &intel_haswell_d_info), /* GT3 desktop */
	INTEL_VGA_DEVICE(0x040a, &intel_haswell_d_info), /* GT1 server */
	INTEL_VGA_DEVICE(0x041a, &intel_haswell_d_info), /* GT2 server */
	INTEL_VGA_DEVICE(0x042a, &intel_haswell_d_info), /* GT3 server */
	INTEL_VGA_DEVICE(0x0406, &intel_haswell_m_info), /* GT1 mobile */
	INTEL_VGA_DEVICE(0x0416, &intel_haswell_m_info), /* GT2 mobile */
	INTEL_VGA_DEVICE(0x0426, &intel_haswell_m_info), /* GT2 mobile */
	INTEL_VGA_DEVICE(0x040B, &intel_haswell_d_info), /* GT1 reserved */
	INTEL_VGA_DEVICE(0x041B, &intel_haswell_d_info), /* GT2 reserved */
	INTEL_VGA_DEVICE(0x042B, &intel_haswell_d_info), /* GT3 reserved */
	INTEL_VGA_DEVICE(0x040E, &intel_haswell_d_info), /* GT1 reserved */
	INTEL_VGA_DEVICE(0x041E, &intel_haswell_d_info), /* GT2 reserved */
	INTEL_VGA_DEVICE(0x042E, &intel_haswell_d_info), /* GT3 reserved */
	INTEL_VGA_DEVICE(0x0C02, &intel_haswell_d_info), /* SDV GT1 desktop */
	INTEL_VGA_DEVICE(0x0C12, &intel_haswell_d_info), /* SDV GT2 desktop */
	INTEL_VGA_DEVICE(0x0C22, &intel_haswell_d_info), /* SDV GT3 desktop */
	INTEL_VGA_DEVICE(0x0C0A, &intel_haswell_d_info), /* SDV GT1 server */
	INTEL_VGA_DEVICE(0x0C1A, &intel_haswell_d_info), /* SDV GT2 server */
	INTEL_VGA_DEVICE(0x0C2A, &intel_haswell_d_info), /* SDV GT3 server */
	INTEL_VGA_DEVICE(0x0C06, &intel_haswell_m_info), /* SDV GT1 mobile */
	INTEL_VGA_DEVICE(0x0C16, &intel_haswell_m_info), /* SDV GT2 mobile */
	INTEL_VGA_DEVICE(0x0C26, &intel_haswell_m_info), /* SDV GT3 mobile */
	INTEL_VGA_DEVICE(0x0C0B, &intel_haswell_d_info), /* SDV GT1 reserved */
	INTEL_VGA_DEVICE(0x0C1B, &intel_haswell_d_info), /* SDV GT2 reserved */
	INTEL_VGA_DEVICE(0x0C2B, &intel_haswell_d_info), /* SDV GT3 reserved */
	INTEL_VGA_DEVICE(0x0C0E, &intel_haswell_d_info), /* SDV GT1 reserved */
	INTEL_VGA_DEVICE(0x0C1E, &intel_haswell_d_info), /* SDV GT2 reserved */
	INTEL_VGA_DEVICE(0x0C2E, &intel_haswell_d_info), /* SDV GT3 reserved */
	INTEL_VGA_DEVICE(0x0A02, &intel_haswell_d_info), /* ULT GT1 desktop */
	INTEL_VGA_DEVICE(0x0A12, &intel_haswell_d_info), /* ULT GT2 desktop */
	INTEL_VGA_DEVICE(0x0A22, &intel_haswell_d_info), /* ULT GT3 desktop */
	INTEL_VGA_DEVICE(0x0A0A, &intel_haswell_d_info), /* ULT GT1 server */
	INTEL_VGA_DEVICE(0x0A1A, &intel_haswell_d_info), /* ULT GT2 server */
	INTEL_VGA_DEVICE(0x0A2A, &intel_haswell_d_info), /* ULT GT3 server */
	INTEL_VGA_DEVICE(0x0A06, &intel_haswell_m_info), /* ULT GT1 mobile */
	INTEL_VGA_DEVICE(0x0A16, &intel_haswell_m_info), /* ULT GT2 mobile */
	INTEL_VGA_DEVICE(0x0A26, &intel_haswell_m_info), /* ULT GT3 mobile */
	INTEL_VGA_DEVICE(0x0A0B, &intel_haswell_d_info), /* ULT GT1 reserved */
	INTEL_VGA_DEVICE(0x0A1B, &intel_haswell_d_info), /* ULT GT2 reserved */
	INTEL_VGA_DEVICE(0x0A2B, &intel_haswell_d_info), /* ULT GT3 reserved */
	INTEL_VGA_DEVICE(0x0A0E, &intel_haswell_m_info), /* ULT GT1 reserved */
	INTEL_VGA_DEVICE(0x0A1E, &intel_haswell_m_info), /* ULT GT2 reserved */
	INTEL_VGA_DEVICE(0x0A2E, &intel_haswell_m_info), /* ULT GT3 reserved */
	INTEL_VGA_DEVICE(0x0D02, &intel_haswell_d_info), /* CRW GT1 desktop */
	INTEL_VGA_DEVICE(0x0D12, &intel_haswell_d_info), /* CRW GT2 desktop */
	INTEL_VGA_DEVICE(0x0D22, &intel_haswell_d_info), /* CRW GT3 desktop */
	INTEL_VGA_DEVICE(0x0D0A, &intel_haswell_d_info), /* CRW GT1 server */
	INTEL_VGA_DEVICE(0x0D1A, &intel_haswell_d_info), /* CRW GT2 server */
	INTEL_VGA_DEVICE(0x0D2A, &intel_haswell_d_info), /* CRW GT3 server */
	INTEL_VGA_DEVICE(0x0D06, &intel_haswell_m_info), /* CRW GT1 mobile */
	INTEL_VGA_DEVICE(0x0D16, &intel_haswell_m_info), /* CRW GT2 mobile */
	INTEL_VGA_DEVICE(0x0D26, &intel_haswell_m_info), /* CRW GT3 mobile */
	INTEL_VGA_DEVICE(0x0D0B, &intel_haswell_d_info), /* CRW GT1 reserved */
	INTEL_VGA_DEVICE(0x0D1B, &intel_haswell_d_info), /* CRW GT2 reserved */
	INTEL_VGA_DEVICE(0x0D2B, &intel_haswell_d_info), /* CRW GT3 reserved */
	INTEL_VGA_DEVICE(0x0D0E, &intel_haswell_d_info), /* CRW GT1 reserved */
	INTEL_VGA_DEVICE(0x0D1E, &intel_haswell_d_info), /* CRW GT2 reserved */
	INTEL_VGA_DEVICE(0x0D2E, &intel_haswell_d_info), /* CRW GT3 reserved */
	INTEL_VGA_DEVICE(0x0f30, &intel_valleyview_m_info),
	INTEL_VGA_DEVICE(0x0f31, &intel_valleyview_m_info),
	INTEL_VGA_DEVICE(0x0f32, &intel_valleyview_m_info),
	INTEL_VGA_DEVICE(0x0f33, &intel_valleyview_m_info),
	INTEL_VGA_DEVICE(0x0157, &intel_valleyview_m_info),
	INTEL_VGA_DEVICE(0x0155, &intel_valleyview_d_info),
	{0, 0}
};

#define	PCI_VENDOR_INTEL	0x8086

void intel_detect_pch(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	device_t pch;

	/* In all current cases, num_pipes is equivalent to the PCH_NOP setting
	 * (which really amounts to a PCH but no South Display).
	 */
	if (INTEL_INFO(dev)->num_pipes == 0) {
		dev_priv->pch_type = PCH_NOP;
		return;
	}

	/*
	 * The reason to probe ISA bridge instead of Dev31:Fun0 is to
	 * make graphics device passthrough work easy for VMM, that only
	 * need to expose ISA bridge to let driver know the real hardware
	 * underneath. This is a requirement from virtualization team.
	 */
	pch = pci_find_class(PCIC_BRIDGE, PCIS_BRIDGE_ISA);
	if (pch) {
		if (pci_get_vendor(pch) == PCI_VENDOR_INTEL) {
			unsigned short id;
			id = pci_get_device(pch) & INTEL_PCH_DEVICE_ID_MASK;
			dev_priv->pch_id = id;

			if (id == INTEL_PCH_IBX_DEVICE_ID_TYPE) {
				dev_priv->pch_type = PCH_IBX;
				DRM_DEBUG_KMS("Found Ibex Peak PCH\n");
				WARN_ON(!IS_GEN5(dev));
			} else if (id == INTEL_PCH_CPT_DEVICE_ID_TYPE) {
				dev_priv->pch_type = PCH_CPT;
				DRM_DEBUG_KMS("Found CougarPoint PCH\n");
				WARN_ON(!(IS_GEN6(dev) || IS_IVYBRIDGE(dev)));
			} else if (id == INTEL_PCH_PPT_DEVICE_ID_TYPE) {
				/* PantherPoint is CPT compatible */
				dev_priv->pch_type = PCH_CPT;
				DRM_DEBUG_KMS("Found PatherPoint PCH\n");
				WARN_ON(!(IS_GEN6(dev) || IS_IVYBRIDGE(dev)));
			} else if (id == INTEL_PCH_LPT_DEVICE_ID_TYPE) {
				dev_priv->pch_type = PCH_LPT;
				DRM_DEBUG_KMS("Found LynxPoint PCH\n");
				WARN_ON(!IS_HASWELL(dev));
				WARN_ON(IS_ULT(dev));
			} else if (id == INTEL_PCH_LPT_LP_DEVICE_ID_TYPE) {
				dev_priv->pch_type = PCH_LPT;
				DRM_DEBUG_KMS("Found LynxPoint LP PCH\n");
				WARN_ON(!IS_HASWELL(dev));
				WARN_ON(!IS_ULT(dev));
			}
		}
#if 0
		pci_dev_put(pch);
#endif
	}
}

bool i915_semaphore_is_enabled(struct drm_device *dev)
{
	if (INTEL_INFO(dev)->gen < 6)
		return 0;

	if (i915_semaphores >= 0)
		return i915_semaphores;

#ifdef CONFIG_INTEL_IOMMU
	/* Enable semaphores on SNB when IO remapping is off */
	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)
		return false;
#endif

	return 1;
}

static int i915_drm_freeze(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_crtc *crtc;

	/* ignore lid events during suspend */
	mutex_lock(&dev_priv->modeset_restore_lock);
	dev_priv->modeset_restore = MODESET_SUSPENDED;
	mutex_unlock(&dev_priv->modeset_restore_lock);

	intel_set_power_well(dev, true);

	drm_kms_helper_poll_disable(dev);

#if 0
	pci_save_state(dev->pdev);
#endif

	/* If KMS is active, we do the leavevt stuff here */
	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
		int error = i915_gem_idle(dev);
		if (error) {
			dev_err(dev->pdev->dev,
				"GEM idle failed, resume might fail\n");
			return error;
		}

		cancel_delayed_work_sync(&dev_priv->rps.delayed_resume_work);

		drm_irq_uninstall(dev);
		dev_priv->enable_hotplug_processing = false;
		/*
		 * Disable CRTCs directly since we want to preserve sw state
		 * for _thaw.
		 */
		list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
			dev_priv->display.crtc_disable(crtc);

		intel_modeset_suspend_hw(dev);
	}

	i915_save_state(dev);

	intel_opregion_fini(dev);

#if 0
	console_lock();
	intel_fbdev_set_suspend(dev, FBINFO_STATE_SUSPENDED);
	console_unlock();
#endif

	return 0;
}

static int
i915_suspend(device_t kdev)
{
	struct drm_device *dev;
	int error;

	dev = device_get_softc(kdev);
	if (dev == NULL || dev->dev_private == NULL) {
		DRM_ERROR("DRM not initialized, aborting suspend.\n");
		return -ENODEV;
	}

	DRM_DEBUG_KMS("starting suspend\n");
	error = i915_drm_freeze(dev);
	if (error)
		return (error);

	error = bus_generic_suspend(kdev);
	DRM_DEBUG_KMS("finished suspend %d\n", error);
	return (error);
}

#if 0
void intel_console_resume(struct work_struct *work)
{
	struct drm_i915_private *dev_priv =
		container_of(work, struct drm_i915_private,
			     console_resume_work);
	struct drm_device *dev = dev_priv->dev;

	console_lock();
	intel_fbdev_set_suspend(dev, FBINFO_STATE_RUNNING);
	console_unlock();
}
#endif

static void intel_resume_hotplug(struct drm_device *dev)
{
	struct drm_mode_config *mode_config = &dev->mode_config;
	struct intel_encoder *encoder;

	mutex_lock(&mode_config->mutex);
	DRM_DEBUG_KMS("running encoder hotplug functions\n");

	list_for_each_entry(encoder, &mode_config->encoder_list, base.head)
		if (encoder->hot_plug)
			encoder->hot_plug(encoder);

	mutex_unlock(&mode_config->mutex);

	/* Just fire off a uevent and let userspace tell us what to do */
	drm_helper_hpd_irq_event(dev);
}

static int __i915_drm_thaw(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	int error = 0;

	i915_restore_state(dev);
	intel_opregion_setup(dev);

	/* KMS EnterVT equivalent */
	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
		intel_init_pch_refclk(dev);

		mutex_lock(&dev->struct_mutex);
		dev_priv->mm.suspended = 0;

		error = i915_gem_init_hw(dev);
		mutex_unlock(&dev->struct_mutex);

		/* We need working interrupts for modeset enabling ... */
		drm_irq_install(dev);

		intel_modeset_init_hw(dev);

		drm_modeset_lock_all(dev);
		intel_modeset_setup_hw_state(dev, true);
		drm_modeset_unlock_all(dev);

		/*
		 * ... but also need to make sure that hotplug processing
		 * doesn't cause havoc. Like in the driver load code we don't
		 * bother with the tiny race here where we might loose hotplug
		 * notifications.
		 * */
		intel_hpd_init(dev);
		dev_priv->enable_hotplug_processing = true;
		/* Config may have changed between suspend and resume */
		intel_resume_hotplug(dev);
	}

	intel_opregion_init(dev);

	/*
	 * The console lock can be pretty contented on resume due
	 * to all the printk activity.  Try to keep it out of the hot
	 * path of resume if possible.
	 */
#if 0
	if (console_trylock()) {
		intel_fbdev_set_suspend(dev, FBINFO_STATE_RUNNING);
		console_unlock();
	} else {
		schedule_work(&dev_priv->console_resume_work);
	}
#endif

	mutex_lock(&dev_priv->modeset_restore_lock);
	dev_priv->modeset_restore = MODESET_DONE;
	mutex_unlock(&dev_priv->modeset_restore_lock);
	return error;
}

static int i915_drm_thaw(struct drm_device *dev)
{
	int error = 0;

	intel_gt_sanitize(dev);

	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
		mutex_lock(&dev->struct_mutex);
		i915_gem_restore_gtt_mappings(dev);
		mutex_unlock(&dev->struct_mutex);
	}

	__i915_drm_thaw(dev);

	return error;
}

static int
i915_resume(device_t kdev)
{
	struct drm_device *dev = device_get_softc(kdev);
	struct drm_i915_private *dev_priv = dev->dev_private;
	int ret;

#if 0
	if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
		return 0;

	if (pci_enable_device(dev->pdev))
		return -EIO;

	pci_set_master(dev->pdev);
#endif

	intel_gt_sanitize(dev);

	/*
	 * Platforms with opregion should have sane BIOS, older ones (gen3 and
	 * earlier) need this since the BIOS might clear all our scratch PTEs.
	 */
	if (drm_core_check_feature(dev, DRIVER_MODESET) &&
	    !dev_priv->opregion.header) {
		mutex_lock(&dev->struct_mutex);
		i915_gem_restore_gtt_mappings(dev);
		mutex_unlock(&dev->struct_mutex);
	}

	ret = -i915_drm_thaw(dev);
	if (ret)
		return ret;

	ret = bus_generic_resume(kdev);
	if (ret)
		return ret;

	drm_kms_helper_poll_enable(dev);
	return 0;
}

/* XXX Hack for the old *BSD drm code base
 * The device id field is set at probe time */
static drm_pci_id_list_t i915_attach_list[] = {
	{0x8086, 0, 0, "Intel i915 GPU"},
	{0, 0, 0, NULL}
};

int i915_modeset;

/* static int __init i915_init(void) */
static int
i915_attach(device_t kdev)
{
	struct drm_device *dev;

	dev = device_get_softc(kdev);

	driver.num_ioctls = i915_max_ioctl;

	if (i915_modeset == 1)
		driver.driver_features |= DRIVER_MODESET;

	dev->driver = &driver;
	return (drm_attach(kdev, i915_attach_list));
}

const struct intel_device_info *
i915_get_device_id(int device)
{
	const struct pci_device_id *did;

	for (did = &pciidlist[0]; did->device != 0; did++) {
		if (did->device != device)
			continue;
		return (struct intel_device_info *)did->driver_data;
	}
	return (NULL);
}

extern devclass_t drm_devclass;

int intel_iommu_enabled = 0;
TUNABLE_INT("drm.i915.intel_iommu_enabled", &intel_iommu_enabled);

int i915_semaphores = -1;
TUNABLE_INT("drm.i915.semaphores", &i915_semaphores);
static int i915_try_reset = 1;
TUNABLE_INT("drm.i915.try_reset", &i915_try_reset);
unsigned int i915_lvds_downclock = 0;
TUNABLE_INT("drm.i915.lvds_downclock", &i915_lvds_downclock);
int i915_vbt_sdvo_panel_type = -1;
TUNABLE_INT("drm.i915.vbt_sdvo_panel_type", &i915_vbt_sdvo_panel_type);
unsigned int i915_powersave = 1;
TUNABLE_INT("drm.i915.powersave", &i915_powersave);
int i915_enable_fbc = 0;
TUNABLE_INT("drm.i915.enable_fbc", &i915_enable_fbc);
int i915_enable_rc6 = 0;
TUNABLE_INT("drm.i915.enable_rc6", &i915_enable_rc6);
int i915_panel_use_ssc = -1;
TUNABLE_INT("drm.i915.panel_use_ssc", &i915_panel_use_ssc);
int i915_panel_ignore_lid = 0;
TUNABLE_INT("drm.i915.panel_ignore_lid", &i915_panel_ignore_lid);
int i915_modeset = 1;
TUNABLE_INT("drm.i915.modeset", &i915_modeset);
int i915_enable_ppgtt = -1;
TUNABLE_INT("drm.i915.enable_ppgtt", &i915_enable_ppgtt);

static int i8xx_do_reset(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (IS_I85X(dev))
		return -ENODEV;

	I915_WRITE(D_STATE, I915_READ(D_STATE) | DSTATE_GFX_RESET_I830);
	POSTING_READ(D_STATE);

	if (IS_I830(dev) || IS_845G(dev)) {
		I915_WRITE(DEBUG_RESET_I830,
			   DEBUG_RESET_DISPLAY |
			   DEBUG_RESET_RENDER |
			   DEBUG_RESET_FULL);
		POSTING_READ(DEBUG_RESET_I830);
		msleep(1);

		I915_WRITE(DEBUG_RESET_I830, 0);
		POSTING_READ(DEBUG_RESET_I830);
	}

	msleep(1);

	I915_WRITE(D_STATE, I915_READ(D_STATE) & ~DSTATE_GFX_RESET_I830);
	POSTING_READ(D_STATE);

	return 0;
}

static int i965_reset_complete(struct drm_device *dev)
{
	u8 gdrst;
	pci_read_config_byte(dev->pdev, I965_GDRST, &gdrst);
	return (gdrst & GRDOM_RESET_ENABLE) == 0;
}

static int i965_do_reset(struct drm_device *dev)
{
	int ret;
	u8 gdrst;

	/*
	 * Set the domains we want to reset (GRDOM/bits 2 and 3) as
	 * well as the reset bit (GR/bit 0).  Setting the GR bit
	 * triggers the reset; when done, the hardware will clear it.
	 */
	pci_read_config_byte(dev->pdev, I965_GDRST, &gdrst);
	pci_write_config_byte(dev->pdev, I965_GDRST,
			      gdrst | GRDOM_RENDER |
			      GRDOM_RESET_ENABLE);
	ret =  wait_for(i965_reset_complete(dev), 500);
	if (ret)
		return ret;

	/* We can't reset render&media without also resetting display ... */
	pci_read_config_byte(dev->pdev, I965_GDRST, &gdrst);
	pci_write_config_byte(dev->pdev, I965_GDRST,
			      gdrst | GRDOM_MEDIA |
			      GRDOM_RESET_ENABLE);

	return wait_for(i965_reset_complete(dev), 500);
}

static int ironlake_do_reset(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	u32 gdrst;
	int ret;

	gdrst = I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR);
	gdrst &= ~GRDOM_MASK;
	I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
		   gdrst | GRDOM_RENDER | GRDOM_RESET_ENABLE);
	ret = wait_for(I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) & 0x1, 500);
	if (ret)
		return ret;

	/* We can't reset render&media without also resetting display ... */
	gdrst = I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR);
	gdrst &= ~GRDOM_MASK;
	I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
		   gdrst | GRDOM_MEDIA | GRDOM_RESET_ENABLE);
	return wait_for(I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) & 0x1, 500);
}

static int gen6_do_reset(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	int ret;

	dev_priv = dev->dev_private;

	/* Hold gt_lock across reset to prevent any register access
	 * with forcewake not set correctly
	 */
	lockmgr(&dev_priv->gt_lock, LK_EXCLUSIVE);

	/* Reset the chip */

	/* GEN6_GDRST is not in the gt power well, no need to check
	 * for fifo space for the write or forcewake the chip for
	 * the read
	 */
	I915_WRITE_NOTRACE(GEN6_GDRST, GEN6_GRDOM_FULL);

	/* Spin waiting for the device to ack the reset request */
	ret = wait_for((I915_READ_NOTRACE(GEN6_GDRST) & GEN6_GRDOM_FULL) == 0, 500);

	/* If reset with a user forcewake, try to restore, otherwise turn it off */
	if (dev_priv->forcewake_count)
		dev_priv->gt.force_wake_get(dev_priv);
	else
		dev_priv->gt.force_wake_put(dev_priv);

	/* Restore fifo count */
	dev_priv->gt_fifo_count = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);

	lockmgr(&dev_priv->gt_lock, LK_RELEASE);
	return ret;
}

int intel_gpu_reset(struct drm_device *dev)
{
	switch (INTEL_INFO(dev)->gen) {
	case 7:
	case 6: return gen6_do_reset(dev);
	case 5: return ironlake_do_reset(dev);
	case 4: return i965_do_reset(dev);
	case 2: return i8xx_do_reset(dev);
	default: return -ENODEV;
	}
}

/**
 * i915_reset - reset chip after a hang
 * @dev: drm device to reset
 *
 * Reset the chip.  Useful if a hang is detected. Returns zero on successful
 * reset or otherwise an error code.
 *
 * Procedure is fairly simple:
 *   - reset the chip using the reset reg
 *   - re-init context state
 *   - re-init hardware status page
 *   - re-init ring buffer
 *   - re-init interrupt state
 *   - re-init display
 */
int i915_reset(struct drm_device *dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	bool simulated;
	int ret;

	if (!i915_try_reset)
		return 0;

	mutex_lock(&dev->struct_mutex);

	i915_gem_reset(dev);

	simulated = dev_priv->gpu_error.stop_rings != 0;

	if (!simulated && get_seconds() - dev_priv->gpu_error.last_reset < 5) {
		DRM_ERROR("GPU hanging too fast, declaring wedged!\n");
		ret = -ENODEV;
	} else {
		ret = intel_gpu_reset(dev);

		/* Also reset the gpu hangman. */
		if (simulated) {
			DRM_INFO("Simulated gpu hang, resetting stop_rings\n");
			dev_priv->gpu_error.stop_rings = 0;
			if (ret == -ENODEV) {
				DRM_ERROR("Reset not implemented, but ignoring "
					  "error for simulated gpu hangs\n");
				ret = 0;
			}
		} else
			dev_priv->gpu_error.last_reset = get_seconds();
	}
	if (ret) {
		DRM_ERROR("Failed to reset chip.\n");
		mutex_unlock(&dev->struct_mutex);
		return ret;
	}

	/* Ok, now get things going again... */

	/*
	 * Everything depends on having the GTT running, so we need to start
	 * there.  Fortunately we don't need to do this unless we reset the
	 * chip at a PCI level.
	 *
	 * Next we need to restore the context, but we don't use those
	 * yet either...
	 *
	 * Ring buffer needs to be re-initialized in the KMS case, or if X
	 * was running at the time of the reset (i.e. we weren't VT
	 * switched away).
	 */
	if (drm_core_check_feature(dev, DRIVER_MODESET) ||
			!dev_priv->mm.suspended) {
		struct intel_ring_buffer *ring;
		int i;

		dev_priv->mm.suspended = 0;

		i915_gem_init_swizzling(dev);

		for_each_ring(ring, dev_priv, i)
			ring->init(ring);

		i915_gem_context_init(dev);
		if (dev_priv->mm.aliasing_ppgtt) {
			ret = dev_priv->mm.aliasing_ppgtt->enable(dev);
			if (ret)
				i915_gem_cleanup_aliasing_ppgtt(dev);
		}

		/*
		 * It would make sense to re-init all the other hw state, at
		 * least the rps/rc6/emon init done within modeset_init_hw. For
		 * some unknown reason, this blows up my ilk, so don't.
		 */

		mutex_unlock(&dev->struct_mutex);

		drm_irq_uninstall(dev);
		drm_irq_install(dev);
		intel_hpd_init(dev);
	} else {
		mutex_unlock(&dev->struct_mutex);
	}

	return 0;
}

static int
i915_pci_probe(device_t kdev)
{
	int device, i = 0;

	if (pci_get_class(kdev) != PCIC_DISPLAY)
		return ENXIO;

	if (pci_get_vendor(kdev) != PCI_VENDOR_INTEL)
		return ENXIO;

	device = pci_get_device(kdev);

	for (i = 0; pciidlist[i].device != 0; i++) {
		if (pciidlist[i].device == device) {
			i915_attach_list[0].device = device;
			return 0;
		}
	}

	return ENXIO;
}

static struct drm_driver driver = {
	.driver_features =   DRIVER_USE_AGP | DRIVER_REQUIRE_AGP |
	    DRIVER_USE_MTRR | DRIVER_HAVE_IRQ | DRIVER_LOCKLESS_IRQ |
	    DRIVER_GEM /*| DRIVER_MODESET*/,

	.buf_priv_size	= sizeof(drm_i915_private_t),
	.load		= i915_driver_load,
	.open		= i915_driver_open,
	.unload		= i915_driver_unload,
	.preclose	= i915_driver_preclose,
	.lastclose	= i915_driver_lastclose,
	.postclose	= i915_driver_postclose,
	.device_is_agp	= i915_driver_device_is_agp,
	.gem_init_object = i915_gem_init_object,
	.gem_free_object = i915_gem_free_object,
	.gem_pager_ops	= &i915_gem_pager_ops,
	.dumb_create	= i915_gem_dumb_create,
	.dumb_map_offset = i915_gem_mmap_gtt,
	.dumb_destroy	= i915_gem_dumb_destroy,

	.ioctls		= i915_ioctls,

	.name		= DRIVER_NAME,
	.desc		= DRIVER_DESC,
	.date		= DRIVER_DATE,
	.major		= DRIVER_MAJOR,
	.minor		= DRIVER_MINOR,
	.patchlevel	= DRIVER_PATCHLEVEL,
};

static device_method_t i915_methods[] = {
	/* Device interface */
	DEVMETHOD(device_probe,		i915_pci_probe),
	DEVMETHOD(device_attach,	i915_attach),
	DEVMETHOD(device_suspend,	i915_suspend),
	DEVMETHOD(device_resume,	i915_resume),
	DEVMETHOD(device_detach,	drm_release),
	DEVMETHOD_END
};

static driver_t i915_driver = {
	"drm",
	i915_methods,
	sizeof(struct drm_device)
};

DRIVER_MODULE_ORDERED(i915kms, vgapci, i915_driver, drm_devclass, 0, 0,
    SI_ORDER_ANY);
MODULE_DEPEND(i915kms, drm, 1, 1, 1);
MODULE_DEPEND(i915kms, agp, 1, 1, 1);
MODULE_DEPEND(i915kms, iicbus, 1, 1, 1);
MODULE_DEPEND(i915kms, iic, 1, 1, 1);
MODULE_DEPEND(i915kms, iicbb, 1, 1, 1);

/* We give fast paths for the really cool registers */
#define NEEDS_FORCE_WAKE(dev_priv, reg) \
	((HAS_FORCE_WAKE((dev_priv)->dev)) && \
	 ((reg) < 0x40000) &&            \
	 ((reg) != FORCEWAKE))
static void
ilk_dummy_write(struct drm_i915_private *dev_priv)
{
	/* WaIssueDummyWriteToWakeupFromRC6:ilk Issue a dummy write to wake up
	 * the chip from rc6 before touching it for real. MI_MODE is masked,
	 * hence harmless to write 0 into. */
	I915_WRITE_NOTRACE(MI_MODE, 0);
}

static void
hsw_unclaimed_reg_clear(struct drm_i915_private *dev_priv, u32 reg)
{
	if (HAS_FPGA_DBG_UNCLAIMED(dev_priv->dev) &&
	    (I915_READ_NOTRACE(FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) {
		DRM_ERROR("Unknown unclaimed register before writing to %x\n",
			  reg);
		I915_WRITE_NOTRACE(FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
	}
}

static void
hsw_unclaimed_reg_check(struct drm_i915_private *dev_priv, u32 reg)
{
	if (HAS_FPGA_DBG_UNCLAIMED(dev_priv->dev) &&
	    (I915_READ_NOTRACE(FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) {
		DRM_ERROR("Unclaimed write to %x\n", reg);
		I915_WRITE_NOTRACE(FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
	}
}

#define __i915_read(x, y) \
u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \
	u##x val = 0; \
	lockmgr(&dev_priv->gt_lock, LK_EXCLUSIVE); \
	if (IS_GEN5(dev_priv->dev)) \
		ilk_dummy_write(dev_priv); \
	if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
		if (dev_priv->forcewake_count == 0) \
			dev_priv->gt.force_wake_get(dev_priv); \
		val = DRM_READ##y(dev_priv->mmio_map, reg);	\
		if (dev_priv->forcewake_count == 0) \
			dev_priv->gt.force_wake_put(dev_priv); \
	} else { \
		val = DRM_READ##y(dev_priv->mmio_map, reg);	\
	} \
	lockmgr(&dev_priv->gt_lock, LK_RELEASE); \
	trace_i915_reg_rw(false, reg, val, sizeof(val)); \
	return val; \
}

__i915_read(8, 8)
__i915_read(16, 16)
__i915_read(32, 32)
__i915_read(64, 64)
#undef __i915_read

#define __i915_write(x, y) \
void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val) { \
	u32 __fifo_ret = 0; \
	trace_i915_reg_rw(true, reg, val, sizeof(val)); \
	lockmgr(&dev_priv->gt_lock, LK_EXCLUSIVE); \
	if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
		__fifo_ret = __gen6_gt_wait_for_fifo(dev_priv); \
	} \
	if (IS_GEN5(dev_priv->dev)) \
		ilk_dummy_write(dev_priv); \
	hsw_unclaimed_reg_clear(dev_priv, reg); \
	DRM_WRITE##y(dev_priv->mmio_map, reg, val); \
	if (unlikely(__fifo_ret)) { \
		gen6_gt_check_fifodbg(dev_priv); \
	} \
	hsw_unclaimed_reg_check(dev_priv, reg); \
	lockmgr(&dev_priv->gt_lock, LK_RELEASE); \
}

__i915_write(8, 8)
__i915_write(16, 16)
__i915_write(32, 32)
__i915_write(64, 64)
#undef __i915_write

static const struct register_whitelist {
	uint64_t offset;
	uint32_t size;
	uint32_t gen_bitmask; /* support gens, 0x10 for 4, 0x30 for 4 and 5, etc. */
} whitelist[] = {
	{ RING_TIMESTAMP(RENDER_RING_BASE), 8, 0xF0 },
};

int i915_reg_read_ioctl(struct drm_device *dev,
			void *data, struct drm_file *file)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_i915_reg_read *reg = data;
	struct register_whitelist const *entry = whitelist;
	int i;

	for (i = 0; i < ARRAY_SIZE(whitelist); i++, entry++) {
		if (entry->offset == reg->offset &&
		    (1 << INTEL_INFO(dev)->gen & entry->gen_bitmask))
			break;
	}

	if (i == ARRAY_SIZE(whitelist))
		return -EINVAL;

	switch (entry->size) {
	case 8:
		reg->val = I915_READ64(reg->offset);
		break;
	case 4:
		reg->val = I915_READ(reg->offset);
		break;
	case 2:
		reg->val = I915_READ16(reg->offset);
		break;
	case 1:
		reg->val = I915_READ8(reg->offset);
		break;
	default:
		WARN_ON(1);
		return -EINVAL;
	}

	return 0;
}