/*
 * Copyright © 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.
 */

#include "i915_drv.h"
#include "intel_drv.h"
#include "i915_vgpu.h"

#include <linux/pm_runtime.h>

#define FORCEWAKE_ACK_TIMEOUT_MS 2

#define __raw_i915_read8(dev_priv__, reg__) readb((dev_priv__)->regs + (reg__))
#define __raw_i915_write8(dev_priv__, reg__, val__) writeb(val__, (dev_priv__)->regs + (reg__))

#define __raw_i915_read16(dev_priv__, reg__) readw((dev_priv__)->regs + (reg__))
#define __raw_i915_write16(dev_priv__, reg__, val__) writew(val__, (dev_priv__)->regs + (reg__))

#define __raw_i915_read32(dev_priv__, reg__) readl((dev_priv__)->regs + (reg__))
#define __raw_i915_write32(dev_priv__, reg__, val__) writel(val__, (dev_priv__)->regs + (reg__))

#define __raw_i915_read64(dev_priv__, reg__) readq((dev_priv__)->regs + (reg__))
#define __raw_i915_write64(dev_priv__, reg__, val__) writeq(val__, (dev_priv__)->regs + (reg__))

#define __raw_posting_read(dev_priv__, reg__) (void)__raw_i915_read32(dev_priv__, reg__)

static const char * const forcewake_domain_names[] = {
        "render",
        "blitter",
        "media",
};

const char *
intel_uncore_forcewake_domain_to_str(const enum forcewake_domain_id id)
{
        BUILD_BUG_ON((sizeof(forcewake_domain_names)/sizeof(const char *)) !=
                     FW_DOMAIN_ID_COUNT);

        if (id >= 0 && id < FW_DOMAIN_ID_COUNT)
                return forcewake_domain_names[id];

        WARN_ON(id);

        return "unknown";
}

static void
assert_device_not_suspended(struct drm_i915_private *dev_priv)
{
        WARN_ONCE(HAS_RUNTIME_PM(dev_priv->dev) && dev_priv->pm.suspended,
                  "Device suspended\n");
}

static inline void
fw_domain_reset(const struct intel_uncore_forcewake_domain *d)
{
        WARN_ON(d->reg_set == 0);
        __raw_i915_write32(d->i915, d->reg_set, d->val_reset);
}

static inline void
fw_domain_arm_timer(struct intel_uncore_forcewake_domain *d)
{
        mod_timer_pinned(&d->timer, jiffies + 1);
}

static inline void
fw_domain_wait_ack_clear(const struct intel_uncore_forcewake_domain *d)
{
        if (wait_for_atomic((__raw_i915_read32(d->i915, d->reg_ack) &
                             FORCEWAKE_KERNEL) == 0,
                            FORCEWAKE_ACK_TIMEOUT_MS))
                DRM_ERROR("%s: timed out waiting for forcewake ack to clear.\n",
                          intel_uncore_forcewake_domain_to_str(d->id));
}

static inline void
fw_domain_get(const struct intel_uncore_forcewake_domain *d)
{
        __raw_i915_write32(d->i915, d->reg_set, d->val_set);
}

static inline void
fw_domain_wait_ack(const struct intel_uncore_forcewake_domain *d)
{
        if (wait_for_atomic((__raw_i915_read32(d->i915, d->reg_ack) &
                             FORCEWAKE_KERNEL),
                            FORCEWAKE_ACK_TIMEOUT_MS))
                DRM_ERROR("%s: timed out waiting for forcewake ack request.\n",
                          intel_uncore_forcewake_domain_to_str(d->id));
}

static inline void
fw_domain_put(const struct intel_uncore_forcewake_domain *d)
{
        __raw_i915_write32(d->i915, d->reg_set, d->val_clear);
}

static inline void
fw_domain_posting_read(const struct intel_uncore_forcewake_domain *d)
{
        /* something from same cacheline, but not from the set register */
        if (d->reg_post)
                __raw_posting_read(d->i915, d->reg_post);
}

static void
fw_domains_get(struct drm_i915_private *dev_priv, enum forcewake_domains fw_domains)
{
        struct intel_uncore_forcewake_domain *d;
        enum forcewake_domain_id id;

        for_each_fw_domain_mask(d, fw_domains, dev_priv, id) {
                fw_domain_wait_ack_clear(d);
                fw_domain_get(d);
                fw_domain_wait_ack(d);
        }
}

static void
fw_domains_put(struct drm_i915_private *dev_priv, enum forcewake_domains fw_domains)
{
        struct intel_uncore_forcewake_domain *d;
        enum forcewake_domain_id id;

        for_each_fw_domain_mask(d, fw_domains, dev_priv, id) {
                fw_domain_put(d);
                fw_domain_posting_read(d);
        }
}

static void
fw_domains_posting_read(struct drm_i915_private *dev_priv)
{
        struct intel_uncore_forcewake_domain *d;
        enum forcewake_domain_id id;

        /* No need to do for all, just do for first found */
        for_each_fw_domain(d, dev_priv, id) {
                fw_domain_posting_read(d);
                break;
        }
}

static void
fw_domains_reset(struct drm_i915_private *dev_priv, enum forcewake_domains fw_domains)
{
        struct intel_uncore_forcewake_domain *d;
        enum forcewake_domain_id id;

        if (dev_priv->uncore.fw_domains == 0)
                return;

        for_each_fw_domain_mask(d, fw_domains, dev_priv, id)
                fw_domain_reset(d);

        fw_domains_posting_read(dev_priv);
}

static void __gen6_gt_wait_for_thread_c0(struct drm_i915_private *dev_priv)
{
        /* w/a for a sporadic read returning 0 by waiting for the GT
         * thread to wake up.
         */
        if (wait_for_atomic_us((__raw_i915_read32(dev_priv, GEN6_GT_THREAD_STATUS_REG) &
                                GEN6_GT_THREAD_STATUS_CORE_MASK) == 0, 500))
                DRM_ERROR("GT thread status wait timed out\n");
}

static void fw_domains_get_with_thread_status(struct drm_i915_private *dev_priv,
                                              enum forcewake_domains fw_domains)
{
        fw_domains_get(dev_priv, fw_domains);

        /* WaRsForcewakeWaitTC0:snb,ivb,hsw,bdw,vlv */
        __gen6_gt_wait_for_thread_c0(dev_priv);
}

static void gen6_gt_check_fifodbg(struct drm_i915_private *dev_priv)
{
        u32 gtfifodbg;

        gtfifodbg = __raw_i915_read32(dev_priv, GTFIFODBG);
        if (WARN(gtfifodbg, "GT wake FIFO error 0x%x\n", gtfifodbg))
                __raw_i915_write32(dev_priv, GTFIFODBG, gtfifodbg);
}

static void fw_domains_put_with_fifo(struct drm_i915_private *dev_priv,
                                     enum forcewake_domains fw_domains)
{
        fw_domains_put(dev_priv, fw_domains);
        gen6_gt_check_fifodbg(dev_priv);
}

static inline u32 fifo_free_entries(struct drm_i915_private *dev_priv)
{
        u32 count = __raw_i915_read32(dev_priv, GTFIFOCTL);

        return count & GT_FIFO_FREE_ENTRIES_MASK;
}

static int __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
{
        int ret = 0;

        /* On VLV, FIFO will be shared by both SW and HW.
         * So, we need to read the FREE_ENTRIES everytime */
        if (IS_VALLEYVIEW(dev_priv->dev))
                dev_priv->uncore.fifo_count = fifo_free_entries(dev_priv);

        if (dev_priv->uncore.fifo_count < GT_FIFO_NUM_RESERVED_ENTRIES) {
                int loop = 500;
                u32 fifo = fifo_free_entries(dev_priv);

                while (fifo <= GT_FIFO_NUM_RESERVED_ENTRIES && loop--) {
                        udelay(10);
                        fifo = fifo_free_entries(dev_priv);
                }
                if (WARN_ON(loop < 0 && fifo <= GT_FIFO_NUM_RESERVED_ENTRIES))
                        ++ret;
                dev_priv->uncore.fifo_count = fifo;
        }
        dev_priv->uncore.fifo_count--;

        return ret;
}

static void intel_uncore_fw_release_timer(unsigned long arg)
{
        struct intel_uncore_forcewake_domain *domain = (void *)arg;
        unsigned long irqflags;

        assert_device_not_suspended(domain->i915);

        spin_lock_irqsave(&domain->i915->uncore.lock, irqflags);
        if (WARN_ON(domain->wake_count == 0))
                domain->wake_count++;

        if (--domain->wake_count == 0)
                domain->i915->uncore.funcs.force_wake_put(domain->i915,
                                                          1 << domain->id);

        spin_unlock_irqrestore(&domain->i915->uncore.lock, irqflags);
}

void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;
        struct intel_uncore_forcewake_domain *domain;
        int retry_count = 100;
        enum forcewake_domain_id id;
        enum forcewake_domains fw = 0, active_domains;

        /* Hold uncore.lock across reset to prevent any register access
         * with forcewake not set correctly. Wait until all pending
         * timers are run before holding.
         */
        while (1) {
                active_domains = 0;

                for_each_fw_domain(domain, dev_priv, id) {
                        if (del_timer_sync(&domain->timer) == 0)
                                continue;

                        intel_uncore_fw_release_timer((unsigned long)domain);
                }

                spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);

                for_each_fw_domain(domain, dev_priv, id) {
                        if (timer_pending(&domain->timer))
                                active_domains |= (1 << id);
                }

                if (active_domains == 0)
                        break;

                if (--retry_count == 0) {
                        DRM_ERROR("Timed out waiting for forcewake timers to finish\n");
                        break;
                }

                spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
                cond_resched();
        }

        WARN_ON(active_domains);

        for_each_fw_domain(domain, dev_priv, id)
                if (domain->wake_count)
                        fw |= 1 << id;

        if (fw)
                dev_priv->uncore.funcs.force_wake_put(dev_priv, fw);

        fw_domains_reset(dev_priv, FORCEWAKE_ALL);

        if (restore) { /* If reset with a user forcewake, try to restore */
                if (fw)
                        dev_priv->uncore.funcs.force_wake_get(dev_priv, fw);

                if (IS_GEN6(dev) || IS_GEN7(dev))
                        dev_priv->uncore.fifo_count =
                                fifo_free_entries(dev_priv);
        }

        if (!restore)
                assert_forcewakes_inactive(dev_priv);

        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
}

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

        if ((IS_HASWELL(dev) || IS_BROADWELL(dev) ||
             INTEL_INFO(dev)->gen >= 9) &&
            (__raw_i915_read32(dev_priv, HSW_EDRAM_PRESENT) & EDRAM_ENABLED)) {
                /* The docs do not explain exactly how the calculation can be
                 * made. It is somewhat guessable, but for now, it's always
                 * 128MB.
                 * NB: We can't write IDICR yet because we do not have gt funcs
                 * set up */
                dev_priv->ellc_size = 128;
                DRM_INFO("Found %zuMB of eLLC\n", dev_priv->ellc_size);
        }
}

static void __intel_uncore_early_sanitize(struct drm_device *dev,
                                          bool restore_forcewake)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (HAS_FPGA_DBG_UNCLAIMED(dev))
                __raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);

        /* clear out old GT FIFO errors */
        if (IS_GEN6(dev) || IS_GEN7(dev))
                __raw_i915_write32(dev_priv, GTFIFODBG,
                                   __raw_i915_read32(dev_priv, GTFIFODBG));

        /* WaDisableShadowRegForCpd:chv */
        if (IS_CHERRYVIEW(dev)) {
                __raw_i915_write32(dev_priv, GTFIFOCTL,
                                   __raw_i915_read32(dev_priv, GTFIFOCTL) |
                                   GT_FIFO_CTL_BLOCK_ALL_POLICY_STALL |
                                   GT_FIFO_CTL_RC6_POLICY_STALL);
        }

        intel_uncore_forcewake_reset(dev, restore_forcewake);
}

void intel_uncore_early_sanitize(struct drm_device *dev, bool restore_forcewake)
{
        __intel_uncore_early_sanitize(dev, restore_forcewake);
        i915_check_and_clear_faults(dev);
}

void intel_uncore_sanitize(struct drm_device *dev)
{
        /* BIOS often leaves RC6 enabled, but disable it for hw init */
        intel_disable_gt_powersave(dev);
}

/**
 * intel_uncore_forcewake_get - grab forcewake domain references
 * @dev_priv: i915 device instance
 * @fw_domains: forcewake domains to get reference on
 *
 * This function can be used get GT's forcewake domain references.
 * Normal register access will handle the forcewake domains automatically.
 * However if some sequence requires the GT to not power down a particular
 * forcewake domains this function should be called at the beginning of the
 * sequence. And subsequently the reference should be dropped by symmetric
 * call to intel_unforce_forcewake_put(). Usually caller wants all the domains
 * to be kept awake so the @fw_domains would be then FORCEWAKE_ALL.
 */
void intel_uncore_forcewake_get(struct drm_i915_private *dev_priv,
                                enum forcewake_domains fw_domains)
{
        unsigned long irqflags;
        struct intel_uncore_forcewake_domain *domain;
        enum forcewake_domain_id id;

        if (!dev_priv->uncore.funcs.force_wake_get)
                return;

        WARN_ON(dev_priv->pm.suspended);

        fw_domains &= dev_priv->uncore.fw_domains;

        spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);

        for_each_fw_domain_mask(domain, fw_domains, dev_priv, id) {
                if (domain->wake_count++)
                        fw_domains &= ~(1 << id);
        }

        if (fw_domains)
                dev_priv->uncore.funcs.force_wake_get(dev_priv, fw_domains);

        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
}

/**
 * intel_uncore_forcewake_put - release a forcewake domain reference
 * @dev_priv: i915 device instance
 * @fw_domains: forcewake domains to put references
 *
 * This function drops the device-level forcewakes for specified
 * domains obtained by intel_uncore_forcewake_get().
 */
void intel_uncore_forcewake_put(struct drm_i915_private *dev_priv,
                                enum forcewake_domains fw_domains)
{
        unsigned long irqflags;
        struct intel_uncore_forcewake_domain *domain;
        enum forcewake_domain_id id;

        if (!dev_priv->uncore.funcs.force_wake_put)
                return;

        fw_domains &= dev_priv->uncore.fw_domains;

        spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);

        for_each_fw_domain_mask(domain, fw_domains, dev_priv, id) {
                if (WARN_ON(domain->wake_count == 0))
                        continue;

                if (--domain->wake_count)
                        continue;

                domain->wake_count++;
                fw_domain_arm_timer(domain);
        }

        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
}

void assert_forcewakes_inactive(struct drm_i915_private *dev_priv)
{
        struct intel_uncore_forcewake_domain *domain;
        enum forcewake_domain_id id;

        if (!dev_priv->uncore.funcs.force_wake_get)
                return;

        for_each_fw_domain(domain, dev_priv, id)
                WARN_ON(domain->wake_count);
}

/* We give fast paths for the really cool registers */
#define NEEDS_FORCE_WAKE(dev_priv, reg) \
         ((reg) < 0x40000 && (reg) != FORCEWAKE)

#define REG_RANGE(reg, start, end) ((reg) >= (start) && (reg) < (end))

#define FORCEWAKE_VLV_RENDER_RANGE_OFFSET(reg) \
        (REG_RANGE((reg), 0x2000, 0x4000) || \
         REG_RANGE((reg), 0x5000, 0x8000) || \
         REG_RANGE((reg), 0xB000, 0x12000) || \
         REG_RANGE((reg), 0x2E000, 0x30000))

#define FORCEWAKE_VLV_MEDIA_RANGE_OFFSET(reg) \
        (REG_RANGE((reg), 0x12000, 0x14000) || \
         REG_RANGE((reg), 0x22000, 0x24000) || \
         REG_RANGE((reg), 0x30000, 0x40000))

#define FORCEWAKE_CHV_RENDER_RANGE_OFFSET(reg) \
        (REG_RANGE((reg), 0x2000, 0x4000) || \
         REG_RANGE((reg), 0x5200, 0x8000) || \
         REG_RANGE((reg), 0x8300, 0x8500) || \
         REG_RANGE((reg), 0xB000, 0xB480) || \
         REG_RANGE((reg), 0xE000, 0xE800))

#define FORCEWAKE_CHV_MEDIA_RANGE_OFFSET(reg) \
        (REG_RANGE((reg), 0x8800, 0x8900) || \
         REG_RANGE((reg), 0xD000, 0xD800) || \
         REG_RANGE((reg), 0x12000, 0x14000) || \
         REG_RANGE((reg), 0x1A000, 0x1C000) || \
         REG_RANGE((reg), 0x1E800, 0x1EA00) || \
         REG_RANGE((reg), 0x30000, 0x38000))

#define FORCEWAKE_CHV_COMMON_RANGE_OFFSET(reg) \
        (REG_RANGE((reg), 0x4000, 0x5000) || \
         REG_RANGE((reg), 0x8000, 0x8300) || \
         REG_RANGE((reg), 0x8500, 0x8600) || \
         REG_RANGE((reg), 0x9000, 0xB000) || \
         REG_RANGE((reg), 0xF000, 0x10000))

#define FORCEWAKE_GEN9_UNCORE_RANGE_OFFSET(reg) \
        REG_RANGE((reg), 0xB00,  0x2000)

#define FORCEWAKE_GEN9_RENDER_RANGE_OFFSET(reg) \
        (REG_RANGE((reg), 0x2000, 0x2700) || \
         REG_RANGE((reg), 0x3000, 0x4000) || \
         REG_RANGE((reg), 0x5200, 0x8000) || \
         REG_RANGE((reg), 0x8140, 0x8160) || \
         REG_RANGE((reg), 0x8300, 0x8500) || \
         REG_RANGE((reg), 0x8C00, 0x8D00) || \
         REG_RANGE((reg), 0xB000, 0xB480) || \
         REG_RANGE((reg), 0xE000, 0xE900) || \
         REG_RANGE((reg), 0x24400, 0x24800))

#define FORCEWAKE_GEN9_MEDIA_RANGE_OFFSET(reg) \
        (REG_RANGE((reg), 0x8130, 0x8140) || \
         REG_RANGE((reg), 0x8800, 0x8A00) || \
         REG_RANGE((reg), 0xD000, 0xD800) || \
         REG_RANGE((reg), 0x12000, 0x14000) || \
         REG_RANGE((reg), 0x1A000, 0x1EA00) || \
         REG_RANGE((reg), 0x30000, 0x40000))

#define FORCEWAKE_GEN9_COMMON_RANGE_OFFSET(reg) \
        REG_RANGE((reg), 0x9400, 0x9800)

#define FORCEWAKE_GEN9_BLITTER_RANGE_OFFSET(reg) \
        ((reg) < 0x40000 &&\
         !FORCEWAKE_GEN9_UNCORE_RANGE_OFFSET(reg) && \
         !FORCEWAKE_GEN9_RENDER_RANGE_OFFSET(reg) && \
         !FORCEWAKE_GEN9_MEDIA_RANGE_OFFSET(reg) && \
         !FORCEWAKE_GEN9_COMMON_RANGE_OFFSET(reg))

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. */
        __raw_i915_write32(dev_priv, MI_MODE, 0);
}

static void
hsw_unclaimed_reg_debug(struct drm_i915_private *dev_priv, u32 reg, bool read,
                        bool before)
{
        const char *op = read ? "reading" : "writing to";
        const char *when = before ? "before" : "after";

        if (!i915.mmio_debug)
                return;

        if (__raw_i915_read32(dev_priv, FPGA_DBG) & FPGA_DBG_RM_NOCLAIM) {
                WARN(1, "Unclaimed register detected %s %s register 0x%x\n",
                     when, op, reg);
                __raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
                i915.mmio_debug--; /* Only report the first N failures */
        }
}

static void
hsw_unclaimed_reg_detect(struct drm_i915_private *dev_priv)
{
        static bool mmio_debug_once = true;

        if (i915.mmio_debug || !mmio_debug_once)
                return;

        if (__raw_i915_read32(dev_priv, FPGA_DBG) & FPGA_DBG_RM_NOCLAIM) {
                DRM_DEBUG("Unclaimed register detected, "
                          "enabling oneshot unclaimed register reporting. "
                          "Please use i915.mmio_debug=N for more information.\n");
                __raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
                i915.mmio_debug = mmio_debug_once--;
        }
}

#define GEN2_READ_HEADER(x) \
        u##x val = 0; \
        assert_device_not_suspended(dev_priv);

#define GEN2_READ_FOOTER \
        trace_i915_reg_rw(false, reg, val, sizeof(val), trace); \
        return val

#define __gen2_read(x) \
static u##x \
gen2_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
        GEN2_READ_HEADER(x); \
        val = __raw_i915_read##x(dev_priv, reg); \
        GEN2_READ_FOOTER; \
}

#define __gen5_read(x) \
static u##x \
gen5_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
        GEN2_READ_HEADER(x); \
        ilk_dummy_write(dev_priv); \
        val = __raw_i915_read##x(dev_priv, reg); \
        GEN2_READ_FOOTER; \
}

__gen5_read(8)
__gen5_read(16)
__gen5_read(32)
__gen5_read(64)
__gen2_read(8)
__gen2_read(16)
__gen2_read(32)
__gen2_read(64)

#undef __gen5_read
#undef __gen2_read

#undef GEN2_READ_FOOTER
#undef GEN2_READ_HEADER

#define GEN6_READ_HEADER(x) \
        unsigned long irqflags; \
        u##x val = 0; \
        assert_device_not_suspended(dev_priv); \
        spin_lock_irqsave(&dev_priv->uncore.lock, irqflags)

#define GEN6_READ_FOOTER \
        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags); \
        trace_i915_reg_rw(false, reg, val, sizeof(val), trace); \
        return val

static inline void __force_wake_get(struct drm_i915_private *dev_priv,
                                    enum forcewake_domains fw_domains)
{
        struct intel_uncore_forcewake_domain *domain;
        enum forcewake_domain_id id;

        if (WARN_ON(!fw_domains))
                return;

        /* Ideally GCC would be constant-fold and eliminate this loop */
        for_each_fw_domain_mask(domain, fw_domains, dev_priv, id) {
                if (domain->wake_count) {
                        fw_domains &= ~(1 << id);
                        continue;
                }

                domain->wake_count++;
                fw_domain_arm_timer(domain);
        }

        if (fw_domains)
                dev_priv->uncore.funcs.force_wake_get(dev_priv, fw_domains);
}

#define __vgpu_read(x) \
static u##x \
vgpu_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
        GEN6_READ_HEADER(x); \
        val = __raw_i915_read##x(dev_priv, reg); \
        GEN6_READ_FOOTER; \
}

#define __gen6_read(x) \
static u##x \
gen6_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
        GEN6_READ_HEADER(x); \
        hsw_unclaimed_reg_debug(dev_priv, reg, true, true); \
        if (NEEDS_FORCE_WAKE((dev_priv), (reg))) \
                __force_wake_get(dev_priv, FORCEWAKE_RENDER); \
        val = __raw_i915_read##x(dev_priv, reg); \
        hsw_unclaimed_reg_debug(dev_priv, reg, true, false); \
        GEN6_READ_FOOTER; \
}

#define __vlv_read(x) \
static u##x \
vlv_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
        GEN6_READ_HEADER(x); \
        if (FORCEWAKE_VLV_RENDER_RANGE_OFFSET(reg)) \
                __force_wake_get(dev_priv, FORCEWAKE_RENDER); \
        else if (FORCEWAKE_VLV_MEDIA_RANGE_OFFSET(reg)) \
                __force_wake_get(dev_priv, FORCEWAKE_MEDIA); \
        val = __raw_i915_read##x(dev_priv, reg); \
        GEN6_READ_FOOTER; \
}

#define __chv_read(x) \
static u##x \
chv_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
        GEN6_READ_HEADER(x); \
        if (FORCEWAKE_CHV_RENDER_RANGE_OFFSET(reg)) \
                __force_wake_get(dev_priv, FORCEWAKE_RENDER); \
        else if (FORCEWAKE_CHV_MEDIA_RANGE_OFFSET(reg)) \
                __force_wake_get(dev_priv, FORCEWAKE_MEDIA); \
        else if (FORCEWAKE_CHV_COMMON_RANGE_OFFSET(reg)) \
                __force_wake_get(dev_priv, \
                                 FORCEWAKE_RENDER | FORCEWAKE_MEDIA); \
        val = __raw_i915_read##x(dev_priv, reg); \
        GEN6_READ_FOOTER; \
}

#define SKL_NEEDS_FORCE_WAKE(dev_priv, reg)     \
         ((reg) < 0x40000 && !FORCEWAKE_GEN9_UNCORE_RANGE_OFFSET(reg))

#define __gen9_read(x) \
static u##x \
gen9_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
        enum forcewake_domains fw_engine; \
        GEN6_READ_HEADER(x); \
        if (!SKL_NEEDS_FORCE_WAKE((dev_priv), (reg)))   \
                fw_engine = 0; \
        else if (FORCEWAKE_GEN9_RENDER_RANGE_OFFSET(reg))       \
                fw_engine = FORCEWAKE_RENDER; \
        else if (FORCEWAKE_GEN9_MEDIA_RANGE_OFFSET(reg)) \
                fw_engine = FORCEWAKE_MEDIA; \
        else if (FORCEWAKE_GEN9_COMMON_RANGE_OFFSET(reg)) \
                fw_engine = FORCEWAKE_RENDER | FORCEWAKE_MEDIA; \
        else \
                fw_engine = FORCEWAKE_BLITTER; \
        if (fw_engine) \
                __force_wake_get(dev_priv, fw_engine); \
        val = __raw_i915_read##x(dev_priv, reg); \
        GEN6_READ_FOOTER; \
}

__vgpu_read(8)
__vgpu_read(16)
__vgpu_read(32)
__vgpu_read(64)
__gen9_read(8)
__gen9_read(16)
__gen9_read(32)
__gen9_read(64)
__chv_read(8)
__chv_read(16)
__chv_read(32)
__chv_read(64)
__vlv_read(8)
__vlv_read(16)
__vlv_read(32)
__vlv_read(64)
__gen6_read(8)
__gen6_read(16)
__gen6_read(32)
__gen6_read(64)

#undef __gen9_read
#undef __chv_read
#undef __vlv_read
#undef __gen6_read
#undef __vgpu_read
#undef GEN6_READ_FOOTER
#undef GEN6_READ_HEADER

#define GEN2_WRITE_HEADER \
        trace_i915_reg_rw(true, reg, val, sizeof(val), trace); \
        assert_device_not_suspended(dev_priv); \

#define GEN2_WRITE_FOOTER

#define __gen2_write(x) \
static void \
gen2_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
        GEN2_WRITE_HEADER; \
        __raw_i915_write##x(dev_priv, reg, val); \
        GEN2_WRITE_FOOTER; \
}

#define __gen5_write(x) \
static void \
gen5_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
        GEN2_WRITE_HEADER; \
        ilk_dummy_write(dev_priv); \
        __raw_i915_write##x(dev_priv, reg, val); \
        GEN2_WRITE_FOOTER; \
}

__gen5_write(8)
__gen5_write(16)
__gen5_write(32)
__gen5_write(64)
__gen2_write(8)
__gen2_write(16)
__gen2_write(32)
__gen2_write(64)

#undef __gen5_write
#undef __gen2_write

#undef GEN2_WRITE_FOOTER
#undef GEN2_WRITE_HEADER

#define GEN6_WRITE_HEADER \
        unsigned long irqflags; \
        trace_i915_reg_rw(true, reg, val, sizeof(val), trace); \
        assert_device_not_suspended(dev_priv); \
        spin_lock_irqsave(&dev_priv->uncore.lock, irqflags)

#define GEN6_WRITE_FOOTER \
        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags)

#define __gen6_write(x) \
static void \
gen6_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
        u32 __fifo_ret = 0; \
        GEN6_WRITE_HEADER; \
        if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
                __fifo_ret = __gen6_gt_wait_for_fifo(dev_priv); \
        } \
        __raw_i915_write##x(dev_priv, reg, val); \
        if (unlikely(__fifo_ret)) { \
                gen6_gt_check_fifodbg(dev_priv); \
        } \
        GEN6_WRITE_FOOTER; \
}

#define __hsw_write(x) \
static void \
hsw_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
        u32 __fifo_ret = 0; \
        GEN6_WRITE_HEADER; \
        if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
                __fifo_ret = __gen6_gt_wait_for_fifo(dev_priv); \
        } \
        hsw_unclaimed_reg_debug(dev_priv, reg, false, true); \
        __raw_i915_write##x(dev_priv, reg, val); \
        if (unlikely(__fifo_ret)) { \
                gen6_gt_check_fifodbg(dev_priv); \
        } \
        hsw_unclaimed_reg_debug(dev_priv, reg, false, false); \
        hsw_unclaimed_reg_detect(dev_priv); \
        GEN6_WRITE_FOOTER; \
}

#define __vgpu_write(x) \
static void vgpu_write##x(struct drm_i915_private *dev_priv, \
                          off_t reg, u##x val, bool trace) { \
        GEN6_WRITE_HEADER; \
        __raw_i915_write##x(dev_priv, reg, val); \
        GEN6_WRITE_FOOTER; \
}

static const u32 gen8_shadowed_regs[] = {
        FORCEWAKE_MT,
        GEN6_RPNSWREQ,
        GEN6_RC_VIDEO_FREQ,
        RING_TAIL(RENDER_RING_BASE),
        RING_TAIL(GEN6_BSD_RING_BASE),
        RING_TAIL(VEBOX_RING_BASE),
        RING_TAIL(BLT_RING_BASE),
        /* TODO: Other registers are not yet used */
};

static bool is_gen8_shadowed(struct drm_i915_private *dev_priv, u32 reg)
{
        int i;
        for (i = 0; i < ARRAY_SIZE(gen8_shadowed_regs); i++)
                if (reg == gen8_shadowed_regs[i])
                        return true;

        return false;
}

#define __gen8_write(x) \
static void \
gen8_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
        GEN6_WRITE_HEADER; \
        hsw_unclaimed_reg_debug(dev_priv, reg, false, true); \
        if (reg < 0x40000 && !is_gen8_shadowed(dev_priv, reg)) \
                __force_wake_get(dev_priv, FORCEWAKE_RENDER); \
        __raw_i915_write##x(dev_priv, reg, val); \
        hsw_unclaimed_reg_debug(dev_priv, reg, false, false); \
        hsw_unclaimed_reg_detect(dev_priv); \
        GEN6_WRITE_FOOTER; \
}

#define __chv_write(x) \
static void \
chv_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
        bool shadowed = is_gen8_shadowed(dev_priv, reg); \
        GEN6_WRITE_HEADER; \
        if (!shadowed) { \
                if (FORCEWAKE_CHV_RENDER_RANGE_OFFSET(reg)) \
                        __force_wake_get(dev_priv, FORCEWAKE_RENDER); \
                else if (FORCEWAKE_CHV_MEDIA_RANGE_OFFSET(reg)) \
                        __force_wake_get(dev_priv, FORCEWAKE_MEDIA); \
                else if (FORCEWAKE_CHV_COMMON_RANGE_OFFSET(reg)) \
                        __force_wake_get(dev_priv, FORCEWAKE_RENDER | FORCEWAKE_MEDIA); \
        } \
        __raw_i915_write##x(dev_priv, reg, val); \
        GEN6_WRITE_FOOTER; \
}

static const u32 gen9_shadowed_regs[] = {
        RING_TAIL(RENDER_RING_BASE),
        RING_TAIL(GEN6_BSD_RING_BASE),
        RING_TAIL(VEBOX_RING_BASE),
        RING_TAIL(BLT_RING_BASE),
        FORCEWAKE_BLITTER_GEN9,
        FORCEWAKE_RENDER_GEN9,
        FORCEWAKE_MEDIA_GEN9,
        GEN6_RPNSWREQ,
        GEN6_RC_VIDEO_FREQ,
        /* TODO: Other registers are not yet used */
};

static bool is_gen9_shadowed(struct drm_i915_private *dev_priv, u32 reg)
{
        int i;
        for (i = 0; i < ARRAY_SIZE(gen9_shadowed_regs); i++)
                if (reg == gen9_shadowed_regs[i])
                        return true;

        return false;
}

#define __gen9_write(x) \
static void \
gen9_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, \
                bool trace) { \
        enum forcewake_domains fw_engine; \
        GEN6_WRITE_HEADER; \
        if (!SKL_NEEDS_FORCE_WAKE((dev_priv), (reg)) || \
            is_gen9_shadowed(dev_priv, reg)) \
                fw_engine = 0; \
        else if (FORCEWAKE_GEN9_RENDER_RANGE_OFFSET(reg)) \
                fw_engine = FORCEWAKE_RENDER; \
        else if (FORCEWAKE_GEN9_MEDIA_RANGE_OFFSET(reg)) \
                fw_engine = FORCEWAKE_MEDIA; \
        else if (FORCEWAKE_GEN9_COMMON_RANGE_OFFSET(reg)) \
                fw_engine = FORCEWAKE_RENDER | FORCEWAKE_MEDIA; \
        else \
                fw_engine = FORCEWAKE_BLITTER; \
        if (fw_engine) \
                __force_wake_get(dev_priv, fw_engine); \
        __raw_i915_write##x(dev_priv, reg, val); \
        GEN6_WRITE_FOOTER; \
}

__gen9_write(8)
__gen9_write(16)
__gen9_write(32)
__gen9_write(64)
__chv_write(8)
__chv_write(16)
__chv_write(32)
__chv_write(64)
__gen8_write(8)
__gen8_write(16)
__gen8_write(32)
__gen8_write(64)
__hsw_write(8)
__hsw_write(16)
__hsw_write(32)
__hsw_write(64)
__gen6_write(8)
__gen6_write(16)
__gen6_write(32)
__gen6_write(64)
__vgpu_write(8)
__vgpu_write(16)
__vgpu_write(32)
__vgpu_write(64)

#undef __gen9_write
#undef __chv_write
#undef __gen8_write
#undef __hsw_write
#undef __gen6_write
#undef __vgpu_write
#undef GEN6_WRITE_FOOTER
#undef GEN6_WRITE_HEADER

#define ASSIGN_WRITE_MMIO_VFUNCS(x) \
do { \
        dev_priv->uncore.funcs.mmio_writeb = x##_write8; \
        dev_priv->uncore.funcs.mmio_writew = x##_write16; \
        dev_priv->uncore.funcs.mmio_writel = x##_write32; \
        dev_priv->uncore.funcs.mmio_writeq = x##_write64; \
} while (0)

#define ASSIGN_READ_MMIO_VFUNCS(x) \
do { \
        dev_priv->uncore.funcs.mmio_readb = x##_read8; \
        dev_priv->uncore.funcs.mmio_readw = x##_read16; \
        dev_priv->uncore.funcs.mmio_readl = x##_read32; \
        dev_priv->uncore.funcs.mmio_readq = x##_read64; \
} while (0)


static void fw_domain_init(struct drm_i915_private *dev_priv,

                           enum forcewake_domain_id domain_id,
                           u32 reg_set, u32 reg_ack)
{
        struct intel_uncore_forcewake_domain *d;

        if (WARN_ON(domain_id >= FW_DOMAIN_ID_COUNT))
                return;

        d = &dev_priv->uncore.fw_domain[domain_id];

        WARN_ON(d->wake_count);

        d->wake_count = 0;
        d->reg_set = reg_set;
        d->reg_ack = reg_ack;

        if (IS_GEN6(dev_priv)) {
                d->val_reset = 0;
                d->val_set = FORCEWAKE_KERNEL;
                d->val_clear = 0;
        } else {
                /* WaRsClearFWBitsAtReset:bdw,skl */
                d->val_reset = _MASKED_BIT_DISABLE(0xffff);
                d->val_set = _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL);
                d->val_clear = _MASKED_BIT_DISABLE(FORCEWAKE_KERNEL);
        }

        if (IS_VALLEYVIEW(dev_priv))
                d->reg_post = FORCEWAKE_ACK_VLV;
        else if (IS_GEN6(dev_priv) || IS_GEN7(dev_priv) || IS_GEN8(dev_priv))
                d->reg_post = ECOBUS;
        else
                d->reg_post = 0;

        d->i915 = dev_priv;
        d->id = domain_id;

        setup_timer(&d->timer, intel_uncore_fw_release_timer, (unsigned long)d);

        dev_priv->uncore.fw_domains |= (1 << domain_id);

        fw_domain_reset(d);
}

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

        if (INTEL_INFO(dev_priv->dev)->gen <= 5)
                return;

        if (IS_GEN9(dev)) {
                dev_priv->uncore.funcs.force_wake_get = fw_domains_get;
                dev_priv->uncore.funcs.force_wake_put = fw_domains_put;
                fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
                               FORCEWAKE_RENDER_GEN9,
                               FORCEWAKE_ACK_RENDER_GEN9);
                fw_domain_init(dev_priv, FW_DOMAIN_ID_BLITTER,
                               FORCEWAKE_BLITTER_GEN9,
                               FORCEWAKE_ACK_BLITTER_GEN9);
                fw_domain_init(dev_priv, FW_DOMAIN_ID_MEDIA,
                               FORCEWAKE_MEDIA_GEN9, FORCEWAKE_ACK_MEDIA_GEN9);
        } else if (IS_VALLEYVIEW(dev)) {
                dev_priv->uncore.funcs.force_wake_get = fw_domains_get;
                if (!IS_CHERRYVIEW(dev))
                        dev_priv->uncore.funcs.force_wake_put =
                                fw_domains_put_with_fifo;
                else
                        dev_priv->uncore.funcs.force_wake_put = fw_domains_put;
                fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
                               FORCEWAKE_VLV, FORCEWAKE_ACK_VLV);
                fw_domain_init(dev_priv, FW_DOMAIN_ID_MEDIA,
                               FORCEWAKE_MEDIA_VLV, FORCEWAKE_ACK_MEDIA_VLV);
        } else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
                dev_priv->uncore.funcs.force_wake_get =
                        fw_domains_get_with_thread_status;
                dev_priv->uncore.funcs.force_wake_put = fw_domains_put;
                fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
                               FORCEWAKE_MT, FORCEWAKE_ACK_HSW);
        } else if (IS_IVYBRIDGE(dev)) {
                u32 ecobus;

                /* IVB configs may use multi-threaded forcewake */

                /* A small trick here - if the bios hasn't configured
                 * MT forcewake, and if the device is in RC6, then
                 * force_wake_mt_get will not wake the device and the
                 * ECOBUS read will return zero. Which will be
                 * (correctly) interpreted by the test below as MT
                 * forcewake being disabled.
                 */
                dev_priv->uncore.funcs.force_wake_get =
                        fw_domains_get_with_thread_status;
                dev_priv->uncore.funcs.force_wake_put =
                        fw_domains_put_with_fifo;

                /* We need to init first for ECOBUS access and then
                 * determine later if we want to reinit, in case of MT access is
                 * not working. In this stage we don't know which flavour this
                 * ivb is, so it is better to reset also the gen6 fw registers
                 * before the ecobus check.
                 */

                __raw_i915_write32(dev_priv, FORCEWAKE, 0);
                __raw_posting_read(dev_priv, ECOBUS);

                fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
                               FORCEWAKE_MT, FORCEWAKE_MT_ACK);

                mutex_lock(&dev->struct_mutex);
                fw_domains_get_with_thread_status(dev_priv, FORCEWAKE_ALL);
                ecobus = __raw_i915_read32(dev_priv, ECOBUS);
                fw_domains_put_with_fifo(dev_priv, FORCEWAKE_ALL);
                mutex_unlock(&dev->struct_mutex);

                if (!(ecobus & FORCEWAKE_MT_ENABLE)) {
                        DRM_INFO("No MT forcewake available on Ivybridge, this can result in issues\n");
                        DRM_INFO("when using vblank-synced partial screen updates.\n");
                        fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
                                       FORCEWAKE, FORCEWAKE_ACK);
                }
        } else if (IS_GEN6(dev)) {
                dev_priv->uncore.funcs.force_wake_get =
                        fw_domains_get_with_thread_status;
                dev_priv->uncore.funcs.force_wake_put =
                        fw_domains_put_with_fifo;
                fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
                               FORCEWAKE, FORCEWAKE_ACK);
        }

        /* All future platforms are expected to require complex power gating */
        WARN_ON(dev_priv->uncore.fw_domains == 0);
}

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

        i915_check_vgpu(dev);

        intel_uncore_ellc_detect(dev);
        intel_uncore_fw_domains_init(dev);
        __intel_uncore_early_sanitize(dev, false);

        switch (INTEL_INFO(dev)->gen) {
        default:
                MISSING_CASE(INTEL_INFO(dev)->gen);
                return;
        case 9:
                ASSIGN_WRITE_MMIO_VFUNCS(gen9);
                ASSIGN_READ_MMIO_VFUNCS(gen9);
                break;
        case 8:
                if (IS_CHERRYVIEW(dev)) {
                        ASSIGN_WRITE_MMIO_VFUNCS(chv);
                        ASSIGN_READ_MMIO_VFUNCS(chv);

                } else {
                        ASSIGN_WRITE_MMIO_VFUNCS(gen8);
                        ASSIGN_READ_MMIO_VFUNCS(gen6);
                }
                break;
        case 7:
        case 6:
                if (IS_HASWELL(dev)) {
                        ASSIGN_WRITE_MMIO_VFUNCS(hsw);
                } else {
                        ASSIGN_WRITE_MMIO_VFUNCS(gen6);
                }

                if (IS_VALLEYVIEW(dev)) {
                        ASSIGN_READ_MMIO_VFUNCS(vlv);
                } else {
                        ASSIGN_READ_MMIO_VFUNCS(gen6);
                }
                break;
        case 5:
                ASSIGN_WRITE_MMIO_VFUNCS(gen5);
                ASSIGN_READ_MMIO_VFUNCS(gen5);
                break;
        case 4:
        case 3:
        case 2:
                ASSIGN_WRITE_MMIO_VFUNCS(gen2);
                ASSIGN_READ_MMIO_VFUNCS(gen2);
                break;
        }

        if (intel_vgpu_active(dev)) {
                ASSIGN_WRITE_MMIO_VFUNCS(vgpu);
                ASSIGN_READ_MMIO_VFUNCS(vgpu);
        }

        i915_check_and_clear_faults(dev);
}
#undef ASSIGN_WRITE_MMIO_VFUNCS
#undef ASSIGN_READ_MMIO_VFUNCS

void intel_uncore_fini(struct drm_device *dev)
{
        /* Paranoia: make sure we have disabled everything before we exit. */
        intel_uncore_sanitize(dev);
        intel_uncore_forcewake_reset(dev, false);
}

#define GEN_RANGE(l, h) GENMASK(h, l)

static const struct register_whitelist {
        uint64_t offset;
        uint32_t size;
        /* supported gens, 0x10 for 4, 0x30 for 4 and 5, etc. */
        uint32_t gen_bitmask;
} whitelist[] = {
        { RING_TIMESTAMP(RENDER_RING_BASE), 8, GEN_RANGE(4, 9) },
};

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, ret = 0;

        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;

        intel_runtime_pm_get(dev_priv);

        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:
                MISSING_CASE(entry->size);
                ret = -EINVAL;
                goto out;
        }

out:
        intel_runtime_pm_put(dev_priv);
        return ret;
}

int i915_get_reset_stats_ioctl(struct drm_device *dev,
                               void *data, struct drm_file *file)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_i915_reset_stats *args = data;
        struct i915_ctx_hang_stats *hs;
        struct intel_context *ctx;
        int ret;

        if (args->flags || args->pad)
                return -EINVAL;

        if (args->ctx_id == DEFAULT_CONTEXT_HANDLE && !capable(CAP_SYS_ADMIN))
                return -EPERM;

        ret = mutex_lock_interruptible(&dev->struct_mutex);
        if (ret)
                return ret;

        ctx = i915_gem_context_get(file->driver_priv, args->ctx_id);
        if (IS_ERR(ctx)) {
                mutex_unlock(&dev->struct_mutex);
                return PTR_ERR(ctx);
        }
        hs = &ctx->hang_stats;

        if (capable(CAP_SYS_ADMIN))
                args->reset_count = i915_reset_count(&dev_priv->gpu_error);
        else
                args->reset_count = 0;

        args->batch_active = hs->batch_active;
        args->batch_pending = hs->batch_pending;

        mutex_unlock(&dev->struct_mutex);

        return 0;
}

static int i915_reset_complete(struct drm_device *dev)
{
        u8 gdrst;
        pci_read_config_byte(dev->pdev, I915_GDRST, &gdrst);
        return (gdrst & GRDOM_RESET_STATUS) == 0;
}

static int i915_do_reset(struct drm_device *dev)
{
        /* assert reset for at least 20 usec */
        pci_write_config_byte(dev->pdev, I915_GDRST, GRDOM_RESET_ENABLE);
        udelay(20);
        pci_write_config_byte(dev->pdev, I915_GDRST, 0);

        return wait_for(i915_reset_complete(dev), 500);
}

static int g4x_reset_complete(struct drm_device *dev)
{
        u8 gdrst;
        pci_read_config_byte(dev->pdev, I915_GDRST, &gdrst);
        return (gdrst & GRDOM_RESET_ENABLE) == 0;
}

static int g33_do_reset(struct drm_device *dev)
{
        pci_write_config_byte(dev->pdev, I915_GDRST, GRDOM_RESET_ENABLE);
        return wait_for(g4x_reset_complete(dev), 500);
}

static int g4x_do_reset(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int ret;

        pci_write_config_byte(dev->pdev, I915_GDRST,
                              GRDOM_RENDER | GRDOM_RESET_ENABLE);
        ret =  wait_for(g4x_reset_complete(dev), 500);
        if (ret)
                return ret;

        /* WaVcpClkGateDisableForMediaReset:ctg,elk */
        I915_WRITE(VDECCLK_GATE_D, I915_READ(VDECCLK_GATE_D) | VCP_UNIT_CLOCK_GATE_DISABLE);
        POSTING_READ(VDECCLK_GATE_D);

        pci_write_config_byte(dev->pdev, I915_GDRST,
                              GRDOM_MEDIA | GRDOM_RESET_ENABLE);
        ret =  wait_for(g4x_reset_complete(dev), 500);
        if (ret)
                return ret;

        /* WaVcpClkGateDisableForMediaReset:ctg,elk */
        I915_WRITE(VDECCLK_GATE_D, I915_READ(VDECCLK_GATE_D) & ~VCP_UNIT_CLOCK_GATE_DISABLE);
        POSTING_READ(VDECCLK_GATE_D);

        pci_write_config_byte(dev->pdev, I915_GDRST, 0);

        return 0;
}

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

        I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
                   ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
        ret = wait_for((I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) &
                        ILK_GRDOM_RESET_ENABLE) == 0, 500);
        if (ret)
                return ret;

        I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
                   ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
        ret = wait_for((I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) &
                        ILK_GRDOM_RESET_ENABLE) == 0, 500);
        if (ret)
                return ret;

        I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR, 0);

        return 0;
}

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

        /* 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
         */
        __raw_i915_write32(dev_priv, GEN6_GDRST, GEN6_GRDOM_FULL);

        /* Spin waiting for the device to ack the reset request */
        ret = wait_for((__raw_i915_read32(dev_priv, GEN6_GDRST) & GEN6_GRDOM_FULL) == 0, 500);

        intel_uncore_forcewake_reset(dev, true);

        return ret;
}

int intel_gpu_reset(struct drm_device *dev)
{
        if (INTEL_INFO(dev)->gen >= 6)
                return gen6_do_reset(dev);
        else if (IS_GEN5(dev))
                return ironlake_do_reset(dev);
        else if (IS_G4X(dev))
                return g4x_do_reset(dev);
        else if (IS_G33(dev))
                return g33_do_reset(dev);
        else if (INTEL_INFO(dev)->gen >= 3)
                return i915_do_reset(dev);
        else
                return -ENODEV;
}

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

        if (HAS_FPGA_DBG_UNCLAIMED(dev) &&
            (__raw_i915_read32(dev_priv, FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) {
                DRM_ERROR("Unclaimed register before interrupt\n");
                __raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
        }
}