gpu: nvgpu: Move Linux kernel driver code to module.c

Move Linux driver specific code to common/linux/module.c. This includes
module initialization, power management, and interrupt functions.

Move pci.c, pci.h and nvgpu_common.c under common/linux as they're
Linux only files.

JIRA NVGPU-16

Change-Id: If92b4dd78ebc0c2bbfa9fbca258e9552e4979b4b
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/1456162
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 1052 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/module.c b/drivers/gpu/nvgpu/common/linux/module.c
new file mode 100644
index 00000000..2cbf996b
--- /dev/null
+++ b/drivers/gpu/nvgpu/common/linux/module.c
@@ -0,0 +1,1052 @@
+/*
+ * GK20A Graphics
+ *
+ * Copyright (c) 2011-2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/platform/tegra/common.h>
+
+#include <nvgpu/kmem.h>
+#include <nvgpu/nvgpu_common.h>
+#include <nvgpu/soc.h>
+
+#include "gk20a/gk20a.h"
+#include "vgpu/vgpu.h"
+#include "gk20a/gk20a_scale.h"
+#include "gk20a/ctxsw_trace_gk20a.h"
+#include "pci.h"
+#include "module.h"
+#ifdef CONFIG_TEGRA_19x_GPU
+#include "nvgpu_gpuid_t19x.h"
+#endif
+
+#define CLASS_NAME "nvidia-gpu"
+/* TODO: Change to e.g. "nvidia-gpu%s" once we have symlinks in place. */
+
+#define GK20A_WAIT_FOR_IDLE_MS  2000
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/gk20a.h>
+
+void gk20a_busy_noresume(struct device *dev)
+{
+        pm_runtime_get_noresume(dev);
+}
+
+int gk20a_busy(struct gk20a *g)
+{
+        int ret = 0;
+        struct device *dev;
+
+        if (!g)
+                return -ENODEV;
+
+        atomic_inc(&g->usage_count);
+
+        down_read(&g->busy_lock);
+
+        if (!gk20a_can_busy(g)) {
+                ret = -ENODEV;
+                atomic_dec(&g->usage_count);
+                goto fail;
+        }
+
+        dev = g->dev;
+
+        if (pm_runtime_enabled(dev)) {
+                ret = pm_runtime_get_sync(dev);
+                if (ret < 0) {
+                        pm_runtime_put_noidle(dev);
+                        atomic_dec(&g->usage_count);
+                        goto fail;
+                }
+        } else {
+                if (!g->power_on) {
+                        ret = gk20a_gpu_is_virtual(dev) ?
+                                vgpu_pm_finalize_poweron(dev)
+                                : gk20a_pm_finalize_poweron(dev);
+                        if (ret) {
+                                atomic_dec(&g->usage_count);
+                                goto fail;
+                        }
+                }
+        }
+
+        gk20a_scale_notify_busy(dev);
+
+fail:
+        up_read(&g->busy_lock);
+
+        return ret < 0 ? ret : 0;
+}
+
+void gk20a_idle_nosuspend(struct device *dev)
+{
+        pm_runtime_put_noidle(dev);
+}
+
+void gk20a_idle(struct gk20a *g)
+{
+        struct device *dev;
+
+        atomic_dec(&g->usage_count);
+        down_read(&g->busy_lock);
+
+        dev = g->dev;
+
+        if (!(dev && gk20a_can_busy(g)))
+                goto fail;
+
+        if (pm_runtime_enabled(dev)) {
+#ifdef CONFIG_PM
+                if (atomic_read(&g->dev->power.usage_count) == 1)
+                        gk20a_scale_notify_idle(dev);
+#endif
+
+                pm_runtime_mark_last_busy(dev);
+                pm_runtime_put_sync_autosuspend(dev);
+
+        } else {
+                gk20a_scale_notify_idle(dev);
+        }
+fail:
+        up_read(&g->busy_lock);
+}
+
+int gk20a_pm_finalize_poweron(struct device *dev)
+{
+        struct gk20a *g = get_gk20a(dev);
+        struct gk20a_platform *platform = gk20a_get_platform(dev);
+        int err, nice_value;
+
+        gk20a_dbg_fn("");
+
+        if (g->power_on)
+                return 0;
+
+        trace_gk20a_finalize_poweron(dev_name(dev));
+
+        /* Increment platform power refcount */
+        if (platform->busy) {
+                err = platform->busy(dev);
+                if (err < 0) {
+                        nvgpu_err(g, "failed to poweron platform dependency");
+                        return err;
+                }
+        }
+
+        err = gk20a_restore_registers(g);
+        if (err)
+                return err;
+
+        nice_value = task_nice(current);
+        set_user_nice(current, -20);
+
+        err = gk20a_finalize_poweron(g);
+        set_user_nice(current, nice_value);
+        if (err)
+                goto done;
+
+        trace_gk20a_finalize_poweron_done(dev_name(dev));
+
+        enable_irq(g->irq_stall);
+        if (g->irq_stall != g->irq_nonstall)
+                enable_irq(g->irq_nonstall);
+        g->irqs_enabled = 1;
+
+        gk20a_scale_resume(g->dev);
+
+        if (platform->has_cde)
+                gk20a_init_cde_support(g);
+
+done:
+        if (err)
+                g->power_on = false;
+
+        return err;
+}
+
+static int gk20a_pm_prepare_poweroff(struct device *dev)
+{
+        struct gk20a *g = get_gk20a(dev);
+        int ret = 0;
+        struct gk20a_platform *platform = gk20a_get_platform(dev);
+
+        gk20a_dbg_fn("");
+
+        nvgpu_mutex_acquire(&g->poweroff_lock);
+
+        if (!g->power_on)
+                goto done;
+
+        gk20a_scale_suspend(dev);
+
+        ret = gk20a_prepare_poweroff(g);
+        if (ret)
+                goto error;
+
+        /*
+         * After this point, gk20a interrupts should not get
+         * serviced.
+         */
+        disable_irq(g->irq_stall);
+        if (g->irq_stall != g->irq_nonstall)
+                disable_irq(g->irq_nonstall);
+
+        /*
+         * is_fmodel needs to be in gk20a struct for deferred teardown
+        */
+        g->is_fmodel = platform->is_fmodel;
+
+        /* Decrement platform power refcount */
+        if (platform->idle)
+                platform->idle(dev);
+
+        /* Stop CPU from accessing the GPU registers. */
+        gk20a_lockout_registers(g);
+
+        nvgpu_mutex_release(&g->poweroff_lock);
+        return 0;
+
+error:
+        gk20a_scale_resume(dev);
+done:
+        nvgpu_mutex_release(&g->poweroff_lock);
+
+        return ret;
+}
+
+static struct of_device_id tegra_gk20a_of_match[] = {
+#ifdef CONFIG_TEGRA_GK20A
+        { .compatible = "nvidia,tegra124-gk20a",
+                .data = &gk20a_tegra_platform },
+        { .compatible = "nvidia,tegra210-gm20b",
+                .data = &gm20b_tegra_platform },
+#ifdef CONFIG_ARCH_TEGRA_18x_SOC
+        { .compatible = "nvidia,tegra186-gp10b",
+                .data = &gp10b_tegra_platform },
+#endif
+#ifdef CONFIG_TEGRA_19x_GPU
+        { .compatible = TEGRA_19x_GPU_COMPAT_TEGRA,
+                .data = &t19x_gpu_tegra_platform },
+#endif
+#ifdef CONFIG_TEGRA_GR_VIRTUALIZATION
+        { .compatible = "nvidia,tegra124-gk20a-vgpu",
+                .data = &vgpu_tegra_platform },
+#endif
+#else
+        { .compatible = "nvidia,tegra124-gk20a",
+                .data = &gk20a_generic_platform },
+        { .compatible = "nvidia,tegra210-gm20b",
+                .data = &gk20a_generic_platform },
+#ifdef CONFIG_ARCH_TEGRA_18x_SOC
+        { .compatible = TEGRA_18x_GPU_COMPAT_TEGRA,
+                .data = &gk20a_generic_platform },
+#endif
+
+#endif
+        { .compatible = "nvidia,generic-gk20a",
+                .data = &gk20a_generic_platform },
+        { .compatible = "nvidia,generic-gm20b",
+                .data = &gk20a_generic_platform },
+#ifdef CONFIG_ARCH_TEGRA_18x_SOC
+        { .compatible = "nvidia,generic-gp10b",
+                .data = &gk20a_generic_platform },
+#endif
+        { },
+};
+
+#ifdef CONFIG_PM
+/**
+ * __gk20a_do_idle() - force the GPU to idle and railgate
+ *
+ * In success, this call MUST be balanced by caller with __gk20a_do_unidle()
+ *
+ * Acquires two locks : &g->busy_lock and &platform->railgate_lock
+ * In success, we hold these locks and return
+ * In failure, we release these locks and return
+ */
+int __gk20a_do_idle(struct device *dev, bool force_reset)
+{
+        struct gk20a *g = get_gk20a(dev);
+        struct gk20a_platform *platform = dev_get_drvdata(dev);
+        struct nvgpu_timeout timeout;
+        int ref_cnt;
+        int target_ref_cnt = 0;
+        bool is_railgated;
+        int err = 0;
+
+        /* acquire busy lock to block other busy() calls */
+        down_write(&g->busy_lock);
+
+        /* acquire railgate lock to prevent unrailgate in midst of do_idle() */
+        nvgpu_mutex_acquire(&platform->railgate_lock);
+
+        /* check if it is already railgated ? */
+        if (platform->is_railgated(dev))
+                return 0;
+
+        /*
+         * release railgate_lock, prevent suspend by incrementing usage counter,
+         * re-acquire railgate_lock
+         */
+        nvgpu_mutex_release(&platform->railgate_lock);
+        pm_runtime_get_sync(dev);
+
+        /*
+         * One refcount taken in this API
+         * If User disables rail gating, we take one more
+         * extra refcount
+         */
+        if (platform->user_railgate_disabled)
+                target_ref_cnt = 2;
+        else
+                target_ref_cnt = 1;
+        nvgpu_mutex_acquire(&platform->railgate_lock);
+
+        nvgpu_timeout_init(g, &timeout, GK20A_WAIT_FOR_IDLE_MS,
+                           NVGPU_TIMER_CPU_TIMER);
+
+        /* check and wait until GPU is idle (with a timeout) */
+        do {
+                nvgpu_msleep(1);
+                ref_cnt = atomic_read(&dev->power.usage_count);
+        } while (ref_cnt != target_ref_cnt && !nvgpu_timeout_expired(&timeout));
+
+        if (ref_cnt != target_ref_cnt) {
+                nvgpu_err(g, "failed to idle - refcount %d != 1",
+                        ref_cnt);
+                goto fail_drop_usage_count;
+        }
+
+        /* check if global force_reset flag is set */
+        force_reset |= platform->force_reset_in_do_idle;
+
+        nvgpu_timeout_init(g, &timeout, GK20A_WAIT_FOR_IDLE_MS,
+                           NVGPU_TIMER_CPU_TIMER);
+
+        if (platform->can_railgate && !force_reset) {
+                /*
+                 * Case 1 : GPU railgate is supported
+                 *
+                 * if GPU is now idle, we will have only one ref count,
+                 * drop this ref which will rail gate the GPU
+                 */
+                pm_runtime_put_sync(dev);
+
+                /* add sufficient delay to allow GPU to rail gate */
+                nvgpu_msleep(platform->railgate_delay);
+
+                /* check in loop if GPU is railgated or not */
+                do {
+                        nvgpu_msleep(1);
+                        is_railgated = platform->is_railgated(dev);
+                } while (!is_railgated && !nvgpu_timeout_expired(&timeout));
+
+                if (is_railgated) {
+                        return 0;
+                } else {
+                        nvgpu_err(g, "failed to idle in timeout");
+                        goto fail_timeout;
+                }
+        } else {
+                /*
+                 * Case 2 : GPU railgate is not supported or we explicitly
+                 * do not want to depend on runtime PM
+                 *
+                 * if GPU is now idle, call prepare_poweroff() to save the
+                 * state and then do explicit railgate
+                 *
+                 * __gk20a_do_unidle() needs to unrailgate, call
+                 * finalize_poweron(), and then call pm_runtime_put_sync()
+                 * to balance the GPU usage counter
+                 */
+
+                /* Save the GPU state */
+                err = gk20a_pm_prepare_poweroff(dev);
+                if (err)
+                        goto fail_drop_usage_count;
+
+                /* railgate GPU */
+                platform->railgate(dev);
+
+                nvgpu_udelay(10);
+
+                g->forced_reset = true;
+                return 0;
+        }
+
+fail_drop_usage_count:
+        pm_runtime_put_noidle(dev);
+fail_timeout:
+        nvgpu_mutex_release(&platform->railgate_lock);
+        up_write(&g->busy_lock);
+        return -EBUSY;
+}
+
+/**
+ * gk20a_do_idle() - wrap up for __gk20a_do_idle() to be called
+ * from outside of GPU driver
+ *
+ * In success, this call MUST be balanced by caller with gk20a_do_unidle()
+ */
+int gk20a_do_idle(void)
+{
+        struct device_node *node =
+                        of_find_matching_node(NULL, tegra_gk20a_of_match);
+        struct platform_device *pdev = of_find_device_by_node(node);
+
+        int ret =  __gk20a_do_idle(&pdev->dev, true);
+
+        of_node_put(node);
+
+        return ret;
+}
+
+/**
+ * __gk20a_do_unidle() - unblock all the tasks blocked by __gk20a_do_idle()
+ */
+int __gk20a_do_unidle(struct device *dev)
+{
+        struct gk20a *g = get_gk20a(dev);
+        struct gk20a_platform *platform = dev_get_drvdata(dev);
+        int err;
+
+        if (g->forced_reset) {
+                /*
+                 * If we did a forced-reset/railgate
+                 * then unrailgate the GPU here first
+                 */
+                platform->unrailgate(dev);
+
+                /* restore the GPU state */
+                err = gk20a_pm_finalize_poweron(dev);
+                if (err)
+                        return err;
+
+                /* balance GPU usage counter */
+                pm_runtime_put_sync(dev);
+
+                g->forced_reset = false;
+        }
+
+        /* release the lock and open up all other busy() calls */
+        nvgpu_mutex_release(&platform->railgate_lock);
+        up_write(&g->busy_lock);
+
+        return 0;
+}
+
+/**
+ * gk20a_do_unidle() - wrap up for __gk20a_do_unidle()
+ */
+int gk20a_do_unidle(void)
+{
+        struct device_node *node =
+                        of_find_matching_node(NULL, tegra_gk20a_of_match);
+        struct platform_device *pdev = of_find_device_by_node(node);
+
+        int ret = __gk20a_do_unidle(&pdev->dev);
+
+        of_node_put(node);
+
+        return ret;
+}
+#endif
+
+static void __iomem *gk20a_ioremap_resource(struct platform_device *dev, int i,
+                                            struct resource **out)
+{
+        struct resource *r = platform_get_resource(dev, IORESOURCE_MEM, i);
+
+        if (!r)
+                return NULL;
+        if (out)
+                *out = r;
+        return devm_ioremap_resource(&dev->dev, r);
+}
+
+static irqreturn_t gk20a_intr_isr_stall(int irq, void *dev_id)
+{
+        struct gk20a *g = dev_id;
+
+        return g->ops.mc.isr_stall(g);
+}
+
+static irqreturn_t gk20a_intr_isr_nonstall(int irq, void *dev_id)
+{
+        struct gk20a *g = dev_id;
+
+        return g->ops.mc.isr_nonstall(g);
+}
+
+static irqreturn_t gk20a_intr_thread_stall(int irq, void *dev_id)
+{
+        struct gk20a *g = dev_id;
+
+        return g->ops.mc.isr_thread_stall(g);
+}
+
+void gk20a_remove_support(struct gk20a *g)
+{
+#ifdef CONFIG_TEGRA_COMMON
+        tegra_unregister_idle_unidle();
+#endif
+        nvgpu_kfree(g, g->dbg_regops_tmp_buf);
+
+        if (g->pmu.remove_support)
+                g->pmu.remove_support(&g->pmu);
+
+        if (g->gr.remove_support)
+                g->gr.remove_support(&g->gr);
+
+        if (g->mm.remove_ce_support)
+                g->mm.remove_ce_support(&g->mm);
+
+        if (g->fifo.remove_support)
+                g->fifo.remove_support(&g->fifo);
+
+        if (g->mm.remove_support)
+                g->mm.remove_support(&g->mm);
+
+        if (g->sim.remove_support)
+                g->sim.remove_support(&g->sim);
+
+        /* free mappings to registers, etc */
+
+        if (g->regs) {
+                iounmap(g->regs);
+                g->regs = NULL;
+        }
+        if (g->bar1) {
+                iounmap(g->bar1);
+                g->bar1 = NULL;
+        }
+}
+
+static int gk20a_init_support(struct platform_device *dev)
+{
+        int err = 0;
+        struct gk20a *g = get_gk20a(&dev->dev);
+
+#ifdef CONFIG_TEGRA_COMMON
+        tegra_register_idle_unidle(gk20a_do_idle, gk20a_do_unidle);
+#endif
+
+        g->regs = gk20a_ioremap_resource(dev, GK20A_BAR0_IORESOURCE_MEM,
+                                         &g->reg_mem);
+        if (IS_ERR(g->regs)) {
+                nvgpu_err(g, "failed to remap gk20a registers");
+                err = PTR_ERR(g->regs);
+                goto fail;
+        }
+
+        g->bar1 = gk20a_ioremap_resource(dev, GK20A_BAR1_IORESOURCE_MEM,
+                                         &g->bar1_mem);
+        if (IS_ERR(g->bar1)) {
+                nvgpu_err(g, "failed to remap gk20a bar1");
+                err = PTR_ERR(g->bar1);
+                goto fail;
+        }
+
+        if (nvgpu_platform_is_simulation(g)) {
+                g->sim.g = g;
+                g->sim.regs = gk20a_ioremap_resource(dev,
+                                                     GK20A_SIM_IORESOURCE_MEM,
+                                                     &g->sim.reg_mem);
+                if (IS_ERR(g->sim.regs)) {
+                        nvgpu_err(g, "failed to remap gk20a sim regs");
+                        err = PTR_ERR(g->sim.regs);
+                        goto fail;
+                }
+
+                err = gk20a_init_sim_support(dev);
+                if (err)
+                        goto fail;
+        }
+
+        return 0;
+
+fail:
+        return err;
+}
+
+static int gk20a_pm_railgate(struct device *dev)
+{
+        struct gk20a_platform *platform = dev_get_drvdata(dev);
+        int ret = 0;
+#ifdef CONFIG_DEBUG_FS
+        struct gk20a *g = get_gk20a(dev);
+
+        g->pstats.last_rail_gate_start = jiffies;
+
+        if (g->pstats.railgating_cycle_count >= 1)
+                g->pstats.total_rail_ungate_time_ms =
+                        g->pstats.total_rail_ungate_time_ms +
+                        jiffies_to_msecs(g->pstats.last_rail_gate_start -
+                                        g->pstats.last_rail_ungate_complete);
+#endif
+
+        if (platform->railgate)
+                ret = platform->railgate(dev);
+
+#ifdef CONFIG_DEBUG_FS
+        g->pstats.last_rail_gate_complete = jiffies;
+#endif
+
+        return ret;
+}
+
+static int gk20a_pm_unrailgate(struct device *dev)
+{
+        struct gk20a_platform *platform = dev_get_drvdata(dev);
+        int ret = 0;
+        struct gk20a *g = get_gk20a(dev);
+
+#ifdef CONFIG_DEBUG_FS
+        g->pstats.last_rail_ungate_start = jiffies;
+        if (g->pstats.railgating_cycle_count >= 1)
+                g->pstats.total_rail_gate_time_ms =
+                        g->pstats.total_rail_gate_time_ms +
+                        jiffies_to_msecs(g->pstats.last_rail_ungate_start -
+                                g->pstats.last_rail_gate_complete);
+
+        g->pstats.railgating_cycle_count++;
+#endif
+
+        trace_gk20a_pm_unrailgate(dev_name(dev));
+
+        if (platform->unrailgate) {
+                nvgpu_mutex_acquire(&platform->railgate_lock);
+                ret = platform->unrailgate(dev);
+                nvgpu_mutex_release(&platform->railgate_lock);
+        }
+
+#ifdef CONFIG_DEBUG_FS
+        g->pstats.last_rail_ungate_complete = jiffies;
+#endif
+
+        return ret;
+}
+
+static void gk20a_pm_shutdown(struct platform_device *pdev)
+{
+        struct gk20a_platform *platform = platform_get_drvdata(pdev);
+        struct gk20a *g = platform->g;
+        int err;
+
+        nvgpu_info(g, "shutting down");
+
+        /* vgpu has nothing to clean up currently */
+        if (gk20a_gpu_is_virtual(&pdev->dev))
+                return;
+
+        gk20a_driver_start_unload(g);
+
+        /* If GPU is already railgated,
+         * just prevent more requests, and return */
+        if (platform->is_railgated && platform->is_railgated(&pdev->dev)) {
+                __pm_runtime_disable(&pdev->dev, false);
+                nvgpu_info(g, "already railgated, shut down complete");
+                return;
+        }
+
+        /* Prevent more requests by disabling Runtime PM */
+        __pm_runtime_disable(&pdev->dev, false);
+
+        err = gk20a_wait_for_idle(&pdev->dev);
+        if (err) {
+                nvgpu_err(g, "failed to idle GPU, err=%d", err);
+                goto finish;
+        }
+
+        err = gk20a_fifo_disable_all_engine_activity(g, true);
+        if (err) {
+                nvgpu_err(g, "failed to disable engine activity, err=%d",
+                        err);
+                goto finish;
+        }
+
+        err = gk20a_fifo_wait_engine_idle(g);
+        if (err) {
+                nvgpu_err(g, "failed to idle engines, err=%d",
+                        err);
+                goto finish;
+        }
+
+        if (gk20a_gpu_is_virtual(&pdev->dev))
+                err = vgpu_pm_prepare_poweroff(&pdev->dev);
+        else
+                err = gk20a_pm_prepare_poweroff(&pdev->dev);
+        if (err) {
+                nvgpu_err(g, "failed to prepare for poweroff, err=%d",
+                        err);
+                goto finish;
+        }
+
+        err = gk20a_pm_railgate(&pdev->dev);
+        if (err)
+                nvgpu_err(g, "failed to railgate, err=%d", err);
+
+finish:
+        nvgpu_info(g, "shut down complete");
+}
+
+#ifdef CONFIG_PM
+static int gk20a_pm_runtime_resume(struct device *dev)
+{
+        int err = 0;
+
+        err = gk20a_pm_unrailgate(dev);
+        if (err)
+                goto fail;
+
+        err = gk20a_pm_finalize_poweron(dev);
+        if (err)
+                goto fail_poweron;
+
+        return 0;
+
+fail_poweron:
+        gk20a_pm_railgate(dev);
+fail:
+        return err;
+}
+
+static int gk20a_pm_runtime_suspend(struct device *dev)
+{
+        int err = 0;
+
+        err = gk20a_pm_prepare_poweroff(dev);
+        if (err)
+                goto fail;
+
+        err = gk20a_pm_railgate(dev);
+        if (err)
+                goto fail_railgate;
+
+        return 0;
+
+fail_railgate:
+        gk20a_pm_finalize_poweron(dev);
+fail:
+        pm_runtime_mark_last_busy(dev);
+        return err;
+}
+
+static int gk20a_pm_suspend(struct device *dev)
+{
+        struct gk20a_platform *platform = dev_get_drvdata(dev);
+        struct gk20a *g = get_gk20a(dev);
+        int ret = 0;
+
+        if (platform->user_railgate_disabled)
+                gk20a_idle_nosuspend(dev);
+
+        if (atomic_read(&dev->power.usage_count) > 1) {
+                ret = -EBUSY;
+                goto fail;
+        }
+
+        if (!g->power_on)
+                return 0;
+
+        ret = gk20a_pm_runtime_suspend(dev);
+        if (ret)
+                goto fail;
+
+        if (platform->suspend)
+                platform->suspend(dev);
+
+        g->suspended = true;
+
+        return 0;
+
+fail:
+        if (platform->user_railgate_disabled)
+                gk20a_busy_noresume(dev);
+
+        return ret;
+}
+
+static int gk20a_pm_resume(struct device *dev)
+{
+        struct gk20a *g = get_gk20a(dev);
+        struct gk20a_platform *platform = dev_get_drvdata(dev);
+        int ret = 0;
+
+        if (platform->user_railgate_disabled)
+                gk20a_busy_noresume(dev);
+
+        if (!g->suspended)
+                return 0;
+
+        ret = gk20a_pm_runtime_resume(dev);
+
+        g->suspended = false;
+
+        return ret;
+}
+
+static const struct dev_pm_ops gk20a_pm_ops = {
+        .runtime_resume = gk20a_pm_runtime_resume,
+        .runtime_suspend = gk20a_pm_runtime_suspend,
+        .resume = gk20a_pm_resume,
+        .suspend = gk20a_pm_suspend,
+};
+#endif
+
+int gk20a_pm_init(struct device *dev)
+{
+        struct gk20a_platform *platform = dev_get_drvdata(dev);
+        int err = 0;
+
+        gk20a_dbg_fn("");
+
+        /* Initialise pm runtime */
+        if (platform->railgate_delay) {
+                pm_runtime_set_autosuspend_delay(dev,
+                                 platform->railgate_delay);
+                pm_runtime_use_autosuspend(dev);
+        }
+
+        if (platform->can_railgate) {
+                pm_runtime_enable(dev);
+                if (!pm_runtime_enabled(dev))
+                        gk20a_pm_unrailgate(dev);
+                else
+                        gk20a_pm_railgate(dev);
+        } else {
+                __pm_runtime_disable(dev, false);
+                gk20a_pm_unrailgate(dev);
+        }
+
+        return err;
+}
+
+static inline void set_gk20a(struct platform_device *pdev, struct gk20a *gk20a)
+{
+        gk20a_get_platform(&pdev->dev)->g = gk20a;
+}
+
+static int gk20a_probe(struct platform_device *dev)
+{
+        struct gk20a *gk20a;
+        int err;
+        struct gk20a_platform *platform = NULL;
+
+        if (dev->dev.of_node) {
+                const struct of_device_id *match;
+
+                match = of_match_device(tegra_gk20a_of_match, &dev->dev);
+                if (match)
+                        platform = (struct gk20a_platform *)match->data;
+        } else
+                platform = (struct gk20a_platform *)dev->dev.platform_data;
+
+        if (!platform) {
+                dev_err(&dev->dev, "no platform data\n");
+                return -ENODATA;
+        }
+
+        gk20a_dbg_fn("");
+
+        platform_set_drvdata(dev, platform);
+
+        if (gk20a_gpu_is_virtual(&dev->dev))
+                return vgpu_probe(dev);
+
+        gk20a = kzalloc(sizeof(struct gk20a), GFP_KERNEL);
+        if (!gk20a) {
+                dev_err(&dev->dev, "couldn't allocate gk20a support");
+                return -ENOMEM;
+        }
+
+        set_gk20a(dev, gk20a);
+        gk20a->dev = &dev->dev;
+
+        if (nvgpu_platform_is_simulation(gk20a))
+                platform->is_fmodel = true;
+
+        nvgpu_kmem_init(gk20a);
+
+        gk20a->irq_stall = platform_get_irq(dev, 0);
+        gk20a->irq_nonstall = platform_get_irq(dev, 1);
+        if (gk20a->irq_stall < 0 || gk20a->irq_nonstall < 0)
+                return -ENXIO;
+
+        err = devm_request_threaded_irq(&dev->dev,
+                        gk20a->irq_stall,
+                        gk20a_intr_isr_stall,
+                        gk20a_intr_thread_stall,
+                        0, "gk20a_stall", gk20a);
+        if (err) {
+                dev_err(&dev->dev,
+                        "failed to request stall intr irq @ %d\n",
+                                gk20a->irq_stall);
+                return err;
+        }
+        err = devm_request_irq(&dev->dev,
+                        gk20a->irq_nonstall,
+                        gk20a_intr_isr_nonstall,
+                        0, "gk20a_nonstall", gk20a);
+        if (err) {
+                dev_err(&dev->dev,
+                        "failed to request non-stall intr irq @ %d\n",
+                                gk20a->irq_nonstall);
+                return err;
+        }
+        disable_irq(gk20a->irq_stall);
+        if (gk20a->irq_stall != gk20a->irq_nonstall)
+                disable_irq(gk20a->irq_nonstall);
+
+        err = gk20a_init_support(dev);
+        if (err)
+                return err;
+
+#ifdef CONFIG_RESET_CONTROLLER
+        platform->reset_control = devm_reset_control_get(&dev->dev, NULL);
+        if (IS_ERR(platform->reset_control))
+                platform->reset_control = NULL;
+#endif
+
+        err = nvgpu_probe(gk20a, "gpu.0", INTERFACE_NAME, &nvgpu_class);
+        if (err)
+                return err;
+
+        err = gk20a_pm_init(&dev->dev);
+        if (err) {
+                dev_err(&dev->dev, "pm init failed");
+                return err;
+        }
+
+        gk20a->mm.has_physical_mode = !nvgpu_is_hypervisor_mode(gk20a);
+
+        return 0;
+}
+
+static int __exit gk20a_remove(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct gk20a *g = get_gk20a(dev);
+        struct gk20a_platform *platform = gk20a_get_platform(dev);
+
+        gk20a_dbg_fn("");
+
+        if (gk20a_gpu_is_virtual(dev))
+                return vgpu_remove(pdev);
+
+        if (platform->has_cde)
+                gk20a_cde_destroy(g);
+
+        gk20a_ctxsw_trace_cleanup(g);
+
+        gk20a_sched_ctrl_cleanup(g);
+
+        if (IS_ENABLED(CONFIG_GK20A_DEVFREQ))
+                gk20a_scale_exit(dev);
+
+        if (g->remove_support)
+                g->remove_support(g);
+
+        gk20a_ce_destroy(g);
+
+#ifdef CONFIG_ARCH_TEGRA_18x_SOC
+        nvgpu_clk_arb_cleanup_arbiter(g);
+#endif
+
+        gk20a_user_deinit(dev, &nvgpu_class);
+
+        debugfs_remove_recursive(platform->debugfs);
+        debugfs_remove_recursive(platform->debugfs_alias);
+
+        gk20a_remove_sysfs(dev);
+
+        if (platform->secure_buffer.destroy)
+                platform->secure_buffer.destroy(dev,
+                                &platform->secure_buffer);
+
+        if (pm_runtime_enabled(dev))
+                pm_runtime_disable(dev);
+
+        if (platform->remove)
+                platform->remove(dev);
+
+        set_gk20a(pdev, NULL);
+        gk20a_put(g);
+
+        gk20a_dbg_fn("removed");
+
+        return 0;
+}
+
+static struct platform_driver gk20a_driver = {
+        .probe = gk20a_probe,
+        .remove = __exit_p(gk20a_remove),
+        .shutdown = gk20a_pm_shutdown,
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = "gk20a",
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,18,0)
+                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+#endif
+#ifdef CONFIG_OF
+                .of_match_table = tegra_gk20a_of_match,
+#endif
+#ifdef CONFIG_PM
+                .pm = &gk20a_pm_ops,
+#endif
+                .suppress_bind_attrs = true,
+        }
+};
+
+struct class nvgpu_class = {
+        .owner = THIS_MODULE,
+        .name = CLASS_NAME,
+};
+
+static int __init gk20a_init(void)
+{
+
+        int ret;
+
+        ret = class_register(&nvgpu_class);
+        if (ret)
+                return ret;
+
+        ret = nvgpu_pci_init();
+        if (ret)
+                return ret;
+
+        return platform_driver_register(&gk20a_driver);
+}
+
+static void __exit gk20a_exit(void)
+{
+        nvgpu_pci_exit();
+        platform_driver_unregister(&gk20a_driver);
+        class_unregister(&nvgpu_class);
+}
+
+MODULE_LICENSE("GPL v2");
+module_init(gk20a_init);
+module_exit(gk20a_exit);