path: root/drivers/gpu/nvgpu/gk20a/gk20a.c

/*
 * drivers/video/tegra/host/gk20a/gk20a.c
 *
 * GK20A Graphics
 *
 * Copyright (c) 2011-2014, 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/>.
 */

#define CREATE_TRACE_POINTS
#include <trace/events/gk20a.h>

#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <linux/string.h>
#include <linux/cdev.h>
#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/export.h>
#include <linux/file.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
#include <linux/thermal.h>
#include <asm/cacheflush.h>
#include <linux/debugfs.h>
#include <linux/spinlock.h>
#include <linux/tegra-powergate.h>

#include <linux/sched.h>
#include <linux/input-cfboost.h>

#include <mach/pm_domains.h>

#include "gk20a.h"
#include "debug_gk20a.h"
#include "ctrl_gk20a.h"
#include "hw_mc_gk20a.h"
#include "hw_timer_gk20a.h"
#include "hw_bus_gk20a.h"
#include "hw_sim_gk20a.h"
#include "hw_top_gk20a.h"
#include "hw_ltc_gk20a.h"
#include "gk20a_scale.h"
#include "dbg_gpu_gk20a.h"
#include "hal.h"

#ifdef CONFIG_ARM64
#define __cpuc_flush_dcache_area __flush_dcache_area
#endif

#define CLASS_NAME "nvidia-gpu"
/* TODO: Change to e.g. "nvidia-gpu%s" once we have symlinks in place. */
#define INTERFACE_NAME "nvhost%s-gpu"

#define GK20A_NUM_CDEVS 5

#if defined(GK20A_DEBUG)
u32 gk20a_dbg_mask = GK20A_DEFAULT_DBG_MASK;
u32 gk20a_dbg_ftrace;
#endif

static int gk20a_pm_finalize_poweron(struct device *dev);
static int gk20a_pm_prepare_poweroff(struct device *dev);

static inline void set_gk20a(struct platform_device *dev, struct gk20a *gk20a)
{
	gk20a_get_platform(dev)->g = gk20a;
}

static const struct file_operations gk20a_channel_ops = {
	.owner = THIS_MODULE,
	.release = gk20a_channel_release,
	.open = gk20a_channel_open,
#ifdef CONFIG_COMPAT
	.compat_ioctl = gk20a_channel_ioctl,
#endif
	.unlocked_ioctl = gk20a_channel_ioctl,
};

static const struct file_operations gk20a_ctrl_ops = {
	.owner = THIS_MODULE,
	.release = gk20a_ctrl_dev_release,
	.open = gk20a_ctrl_dev_open,
	.unlocked_ioctl = gk20a_ctrl_dev_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = gk20a_ctrl_dev_ioctl,
#endif
};

static const struct file_operations gk20a_dbg_ops = {
	.owner = THIS_MODULE,
	.release        = gk20a_dbg_gpu_dev_release,
	.open           = gk20a_dbg_gpu_dev_open,
	.unlocked_ioctl = gk20a_dbg_gpu_dev_ioctl,
	.poll		= gk20a_dbg_gpu_dev_poll,
#ifdef CONFIG_COMPAT
	.compat_ioctl = gk20a_dbg_gpu_dev_ioctl,
#endif
};

static const struct file_operations gk20a_as_ops = {
	.owner = THIS_MODULE,
	.release = gk20a_as_dev_release,
	.open = gk20a_as_dev_open,
#ifdef CONFIG_COMPAT
	.compat_ioctl = gk20a_as_dev_ioctl,
#endif
	.unlocked_ioctl = gk20a_as_dev_ioctl,
};

/*
 * Note: We use a different 'open' to trigger handling of the profiler session.
 * Most of the code is shared between them...  Though, at some point if the
 * code does get too tangled trying to handle each in the same path we can
 * separate them cleanly.
 */
static const struct file_operations gk20a_prof_ops = {
	.owner = THIS_MODULE,
	.release        = gk20a_dbg_gpu_dev_release,
	.open           = gk20a_prof_gpu_dev_open,
	.unlocked_ioctl = gk20a_dbg_gpu_dev_ioctl,
	/* .mmap           = gk20a_prof_gpu_dev_mmap,*/
	/*int (*mmap) (struct file *, struct vm_area_struct *);*/
	.compat_ioctl = gk20a_dbg_gpu_dev_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = gk20a_dbg_gpu_dev_ioctl,
#endif
};

static inline void sim_writel(struct gk20a *g, u32 r, u32 v)
{
	writel(v, g->sim.regs+r);
}

static inline u32 sim_readl(struct gk20a *g, u32 r)
{
	return readl(g->sim.regs+r);
}

static void kunmap_and_free_iopage(void **kvaddr, struct page **page)
{
	if (*kvaddr) {
		kunmap(*kvaddr);
		*kvaddr = 0;
	}
	if (*page) {
		__free_page(*page);
		*page = 0;
	}
}

static void gk20a_free_sim_support(struct gk20a *g)
{
	/* free sim mappings, bfrs */
	kunmap_and_free_iopage(&g->sim.send_bfr.kvaddr,
			       &g->sim.send_bfr.page);

	kunmap_and_free_iopage(&g->sim.recv_bfr.kvaddr,
			       &g->sim.recv_bfr.page);

	kunmap_and_free_iopage(&g->sim.msg_bfr.kvaddr,
			       &g->sim.msg_bfr.page);
}

static void gk20a_remove_sim_support(struct sim_gk20a *s)
{
	struct gk20a *g = s->g;
	if (g->sim.regs)
		sim_writel(g, sim_config_r(), sim_config_mode_disabled_v());
	gk20a_free_sim_support(g);
}

static int alloc_and_kmap_iopage(struct device *d,
				 void **kvaddr,
				 phys_addr_t *phys,
				 struct page **page)
{
	int err = 0;
	*page = alloc_page(GFP_KERNEL);

	if (!*page) {
		err = -ENOMEM;
		dev_err(d, "couldn't allocate io page\n");
		goto fail;
	}

	*kvaddr = kmap(*page);
	if (!*kvaddr) {
		err = -ENOMEM;
		dev_err(d, "couldn't kmap io page\n");
		goto fail;
	}
	*phys = page_to_phys(*page);
	return 0;

 fail:
	kunmap_and_free_iopage(kvaddr, page);
	return err;

}

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_request_and_ioremap(&dev->dev, r);
}

/* TBD: strip from released */
static int gk20a_init_sim_support(struct platform_device *dev)
{
	int err = 0;
	struct gk20a *g = get_gk20a(dev);
	struct device *d = &dev->dev;
	phys_addr_t phys;

	g->sim.g = g;
	g->sim.regs = gk20a_ioremap_resource(dev, GK20A_SIM_IORESOURCE_MEM,
					     &g->sim.reg_mem);
	if (!g->sim.regs) {
		dev_err(d, "failed to remap gk20a sim regs\n");
		err = -ENXIO;
		goto fail;
	}

	/* allocate sim event/msg buffers */
	err = alloc_and_kmap_iopage(d, &g->sim.send_bfr.kvaddr,
				    &g->sim.send_bfr.phys,
				    &g->sim.send_bfr.page);

	err = err || alloc_and_kmap_iopage(d, &g->sim.recv_bfr.kvaddr,
					   &g->sim.recv_bfr.phys,
					   &g->sim.recv_bfr.page);

	err = err || alloc_and_kmap_iopage(d, &g->sim.msg_bfr.kvaddr,
					   &g->sim.msg_bfr.phys,
					   &g->sim.msg_bfr.page);

	if (!(g->sim.send_bfr.kvaddr && g->sim.recv_bfr.kvaddr &&
	      g->sim.msg_bfr.kvaddr)) {
		dev_err(d, "couldn't allocate all sim buffers\n");
		goto fail;
	}

	/*mark send ring invalid*/
	sim_writel(g, sim_send_ring_r(), sim_send_ring_status_invalid_f());

	/*read get pointer and make equal to put*/
	g->sim.send_ring_put = sim_readl(g, sim_send_get_r());
	sim_writel(g, sim_send_put_r(), g->sim.send_ring_put);

	/*write send ring address and make it valid*/
	/*TBD: work for >32b physmem*/
	phys = g->sim.send_bfr.phys;
	sim_writel(g, sim_send_ring_hi_r(), 0);
	sim_writel(g, sim_send_ring_r(),
		   sim_send_ring_status_valid_f() |
		   sim_send_ring_target_phys_pci_coherent_f() |
		   sim_send_ring_size_4kb_f() |
		   sim_send_ring_addr_lo_f(phys >> PAGE_SHIFT));

	/*repeat for recv ring (but swap put,get as roles are opposite) */
	sim_writel(g, sim_recv_ring_r(), sim_recv_ring_status_invalid_f());

	/*read put pointer and make equal to get*/
	g->sim.recv_ring_get = sim_readl(g, sim_recv_put_r());
	sim_writel(g, sim_recv_get_r(), g->sim.recv_ring_get);

	/*write send ring address and make it valid*/
	/*TBD: work for >32b physmem*/
	phys = g->sim.recv_bfr.phys;
	sim_writel(g, sim_recv_ring_hi_r(), 0);
	sim_writel(g, sim_recv_ring_r(),
		   sim_recv_ring_status_valid_f() |
		   sim_recv_ring_target_phys_pci_coherent_f() |
		   sim_recv_ring_size_4kb_f() |
		   sim_recv_ring_addr_lo_f(phys >> PAGE_SHIFT));

	g->sim.remove_support = gk20a_remove_sim_support;
	return 0;

 fail:
	gk20a_free_sim_support(g);
	return err;
}

static inline u32 sim_msg_header_size(void)
{
	return 24;/*TBD: fix the header to gt this from NV_VGPU_MSG_HEADER*/
}

static inline u32 *sim_msg_bfr(struct gk20a *g, u32 byte_offset)
{
	return (u32 *)(g->sim.msg_bfr.kvaddr + byte_offset);
}

static inline u32 *sim_msg_hdr(struct gk20a *g, u32 byte_offset)
{
	return sim_msg_bfr(g, byte_offset); /*starts at 0*/
}

static inline u32 *sim_msg_param(struct gk20a *g, u32 byte_offset)
{
	/*starts after msg header/cmn*/
	return sim_msg_bfr(g, byte_offset + sim_msg_header_size());
}

static inline void sim_write_hdr(struct gk20a *g, u32 func, u32 size)
{
	/*memset(g->sim.msg_bfr.kvaddr,0,min(PAGE_SIZE,size));*/
	*sim_msg_hdr(g, sim_msg_signature_r()) = sim_msg_signature_valid_v();
	*sim_msg_hdr(g, sim_msg_result_r())    = sim_msg_result_rpc_pending_v();
	*sim_msg_hdr(g, sim_msg_spare_r())     = sim_msg_spare__init_v();
	*sim_msg_hdr(g, sim_msg_function_r())  = func;
	*sim_msg_hdr(g, sim_msg_length_r())    = size + sim_msg_header_size();
}

static inline u32 sim_escape_read_hdr_size(void)
{
	return 12; /*TBD: fix NV_VGPU_SIM_ESCAPE_READ_HEADER*/
}

static u32 *sim_send_ring_bfr(struct gk20a *g, u32 byte_offset)
{
	return (u32 *)(g->sim.send_bfr.kvaddr + byte_offset);
}

static int rpc_send_message(struct gk20a *g)
{
	/* calculations done in units of u32s */
	u32 send_base = sim_send_put_pointer_v(g->sim.send_ring_put) * 2;
	u32 dma_offset = send_base + sim_dma_r()/sizeof(u32);
	u32 dma_hi_offset = send_base + sim_dma_hi_r()/sizeof(u32);

	*sim_send_ring_bfr(g, dma_offset*sizeof(u32)) =
		sim_dma_target_phys_pci_coherent_f() |
		sim_dma_status_valid_f() |
		sim_dma_size_4kb_f() |
		sim_dma_addr_lo_f(g->sim.msg_bfr.phys >> PAGE_SHIFT);

	*sim_send_ring_bfr(g, dma_hi_offset*sizeof(u32)) = 0; /*TBD >32b phys*/

	*sim_msg_hdr(g, sim_msg_sequence_r()) = g->sim.sequence_base++;

	g->sim.send_ring_put = (g->sim.send_ring_put + 2 * sizeof(u32)) %
		PAGE_SIZE;

	__cpuc_flush_dcache_area(g->sim.msg_bfr.kvaddr, PAGE_SIZE);
	__cpuc_flush_dcache_area(g->sim.send_bfr.kvaddr, PAGE_SIZE);
	__cpuc_flush_dcache_area(g->sim.recv_bfr.kvaddr, PAGE_SIZE);

	/* Update the put pointer. This will trap into the host. */
	sim_writel(g, sim_send_put_r(), g->sim.send_ring_put);

	return 0;
}

static inline u32 *sim_recv_ring_bfr(struct gk20a *g, u32 byte_offset)
{
	return (u32 *)(g->sim.recv_bfr.kvaddr + byte_offset);
}

static int rpc_recv_poll(struct gk20a *g)
{
	phys_addr_t recv_phys_addr;

	/* XXX This read is not required (?) */
	/*pVGpu->recv_ring_get = VGPU_REG_RD32(pGpu, NV_VGPU_RECV_GET);*/

	/* Poll the recv ring get pointer in an infinite loop*/
	do {
		g->sim.recv_ring_put = sim_readl(g, sim_recv_put_r());
	} while (g->sim.recv_ring_put == g->sim.recv_ring_get);

	/* process all replies */
	while (g->sim.recv_ring_put != g->sim.recv_ring_get) {
		/* these are in u32 offsets*/
		u32 dma_lo_offset =
			sim_recv_put_pointer_v(g->sim.recv_ring_get)*2 + 0;
		/*u32 dma_hi_offset = dma_lo_offset + 1;*/
		u32 recv_phys_addr_lo =	sim_dma_addr_lo_v(*sim_recv_ring_bfr(g, dma_lo_offset*4));

		/*u32 recv_phys_addr_hi = sim_dma_hi_addr_v(
		      (phys_addr_t)sim_recv_ring_bfr(g,dma_hi_offset*4));*/

		/*TBD >32b phys addr */
		recv_phys_addr = recv_phys_addr_lo << PAGE_SHIFT;

		if (recv_phys_addr != g->sim.msg_bfr.phys) {
			dev_err(dev_from_gk20a(g), "%s Error in RPC reply\n",
				__func__);
			return -1;
		}

		/* Update GET pointer */
		g->sim.recv_ring_get = (g->sim.recv_ring_get + 2*sizeof(u32)) %
			PAGE_SIZE;

		__cpuc_flush_dcache_area(g->sim.msg_bfr.kvaddr, PAGE_SIZE);
		__cpuc_flush_dcache_area(g->sim.send_bfr.kvaddr, PAGE_SIZE);
		__cpuc_flush_dcache_area(g->sim.recv_bfr.kvaddr, PAGE_SIZE);

		sim_writel(g, sim_recv_get_r(), g->sim.recv_ring_get);

		g->sim.recv_ring_put = sim_readl(g, sim_recv_put_r());
	}

	return 0;
}

static int issue_rpc_and_wait(struct gk20a *g)
{
	int err;

	err = rpc_send_message(g);
	if (err) {
		dev_err(dev_from_gk20a(g), "%s failed rpc_send_message\n",
			__func__);
		return err;
	}

	err = rpc_recv_poll(g);
	if (err) {
		dev_err(dev_from_gk20a(g), "%s failed rpc_recv_poll\n",
			__func__);
		return err;
	}

	/* Now check if RPC really succeeded */
	if (*sim_msg_hdr(g, sim_msg_result_r()) != sim_msg_result_success_v()) {
		dev_err(dev_from_gk20a(g), "%s received failed status!\n",
			__func__);
		return -(*sim_msg_hdr(g, sim_msg_result_r()));
	}
	return 0;
}

int gk20a_sim_esc_read(struct gk20a *g, char *path, u32 index, u32 count, u32 *data)
{
	int err;
	size_t pathlen = strlen(path);
	u32 data_offset;

	sim_write_hdr(g, sim_msg_function_sim_escape_read_v(),
		      sim_escape_read_hdr_size());
	*sim_msg_param(g, 0) = index;
	*sim_msg_param(g, 4) = count;
	data_offset = roundup(0xc +  pathlen + 1, sizeof(u32));
	*sim_msg_param(g, 8) = data_offset;
	strcpy((char *)sim_msg_param(g, 0xc), path);

	err = issue_rpc_and_wait(g);

	if (!err)
		memcpy(data, sim_msg_param(g, data_offset), count);
	return err;
}

static irqreturn_t gk20a_intr_isr_stall(int irq, void *dev_id)
{
	struct gk20a *g = dev_id;
	u32 mc_intr_0;

	if (!g->power_on)
		return IRQ_NONE;

	/* not from gpu when sharing irq with others */
	mc_intr_0 = gk20a_readl(g, mc_intr_0_r());
	if (unlikely(!mc_intr_0))
		return IRQ_NONE;

	gk20a_writel(g, mc_intr_en_0_r(),
		mc_intr_en_0_inta_disabled_f());

	/* flush previous write */
	gk20a_readl(g, mc_intr_en_0_r());

	return IRQ_WAKE_THREAD;
}

static irqreturn_t gk20a_intr_isr_nonstall(int irq, void *dev_id)
{
	struct gk20a *g = dev_id;
	u32 mc_intr_1;

	if (!g->power_on)
		return IRQ_NONE;

	/* not from gpu when sharing irq with others */
	mc_intr_1 = gk20a_readl(g, mc_intr_1_r());
	if (unlikely(!mc_intr_1))
		return IRQ_NONE;

	gk20a_writel(g, mc_intr_en_1_r(),
		mc_intr_en_1_inta_disabled_f());

	/* flush previous write */
	gk20a_readl(g, mc_intr_en_1_r());

	return IRQ_WAKE_THREAD;
}

static void gk20a_pbus_isr(struct gk20a *g)
{
	u32 val;
	val = gk20a_readl(g, bus_intr_0_r());
	if (val & (bus_intr_0_pri_squash_m() |
			bus_intr_0_pri_fecserr_m() |
			bus_intr_0_pri_timeout_m())) {
		gk20a_err(dev_from_gk20a(g), "top_fs_status_r : 0x%x",
			gk20a_readl(g, top_fs_status_r()));
		gk20a_err(dev_from_gk20a(g), "pmc_enable : 0x%x",
			gk20a_readl(g, mc_enable_r()));
		gk20a_err(&g->dev->dev,
			"NV_PTIMER_PRI_TIMEOUT_SAVE_0: 0x%x\n",
			gk20a_readl(g, timer_pri_timeout_save_0_r()));
		gk20a_err(&g->dev->dev,
			"NV_PTIMER_PRI_TIMEOUT_SAVE_1: 0x%x\n",
			gk20a_readl(g, timer_pri_timeout_save_1_r()));
		gk20a_err(&g->dev->dev,
			"NV_PTIMER_PRI_TIMEOUT_FECS_ERRCODE: 0x%x\n",
			gk20a_readl(g, timer_pri_timeout_fecs_errcode_r()));
	}

	if (val)
		gk20a_err(&g->dev->dev,
			"Unhandled pending pbus interrupt\n");

	gk20a_writel(g, bus_intr_0_r(), val);
}

static irqreturn_t gk20a_intr_thread_stall(int irq, void *dev_id)
{
	struct gk20a *g = dev_id;
	u32 mc_intr_0;

	gk20a_dbg(gpu_dbg_intr, "interrupt thread launched");

	mc_intr_0 = gk20a_readl(g, mc_intr_0_r());

	gk20a_dbg(gpu_dbg_intr, "stall intr %08x\n", mc_intr_0);

	if (mc_intr_0 & mc_intr_0_pgraph_pending_f())
		gr_gk20a_elpg_protected_call(g, gk20a_gr_isr(g));
	if (mc_intr_0 & mc_intr_0_pfifo_pending_f())
		gk20a_fifo_isr(g);
	if (mc_intr_0 & mc_intr_0_pmu_pending_f())
		gk20a_pmu_isr(g);
	if (mc_intr_0 & mc_intr_0_priv_ring_pending_f())
		gk20a_priv_ring_isr(g);
	if (mc_intr_0 & mc_intr_0_ltc_pending_f())
		gk20a_mm_ltc_isr(g);
	if (mc_intr_0 & mc_intr_0_pbus_pending_f())
		gk20a_pbus_isr(g);

	gk20a_writel(g, mc_intr_en_0_r(),
		mc_intr_en_0_inta_hardware_f());

	/* flush previous write */
	gk20a_readl(g, mc_intr_en_0_r());

	return IRQ_HANDLED;
}

static irqreturn_t gk20a_intr_thread_nonstall(int irq, void *dev_id)
{
	struct gk20a *g = dev_id;
	u32 mc_intr_1;

	gk20a_dbg(gpu_dbg_intr, "interrupt thread launched");

	mc_intr_1 = gk20a_readl(g, mc_intr_1_r());

	gk20a_dbg(gpu_dbg_intr, "non-stall intr %08x\n", mc_intr_1);

	if (mc_intr_1 & mc_intr_0_pfifo_pending_f())
		gk20a_fifo_nonstall_isr(g);
	if (mc_intr_1 & mc_intr_0_pgraph_pending_f())
		gk20a_gr_nonstall_isr(g);

	gk20a_writel(g, mc_intr_en_1_r(),
		mc_intr_en_1_inta_hardware_f());

	/* flush previous write */
	gk20a_readl(g, mc_intr_en_1_r());

	return IRQ_HANDLED;
}

static void gk20a_remove_support(struct platform_device *dev)
{
	struct gk20a *g = get_gk20a(dev);

	/* pmu support should already be removed when driver turns off
	   gpu power rail in prepapre_poweroff */
	if (g->gk20a_cdev.gk20a_cooling_dev)
		thermal_cooling_device_unregister(g->gk20a_cdev.gk20a_cooling_dev);

	if (g->gr.remove_support)
		g->gr.remove_support(&g->gr);

	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);

	release_firmware(g->pmu_fw);

	if (g->irq_requested) {
		free_irq(g->irq_stall, g);
		free_irq(g->irq_nonstall, g);
		g->irq_requested = false;
	}

	/* free mappings to registers, etc*/

	if (g->regs) {
		iounmap(g->regs);
		g->regs = 0;
	}
	if (g->bar1) {
		iounmap(g->bar1);
		g->bar1 = 0;
	}
}

static int gk20a_init_support(struct platform_device *dev)
{
	int err = 0;
	struct gk20a *g = get_gk20a(dev);

	g->regs = gk20a_ioremap_resource(dev, GK20A_BAR0_IORESOURCE_MEM,
					 &g->reg_mem);
	if (!g->regs) {
		dev_err(dev_from_gk20a(g), "failed to remap gk20a registers\n");
		err = -ENXIO;
		goto fail;
	}

	g->bar1 = gk20a_ioremap_resource(dev, GK20A_BAR1_IORESOURCE_MEM,
					 &g->bar1_mem);
	if (!g->bar1) {
		dev_err(dev_from_gk20a(g), "failed to remap gk20a bar1\n");
		err = -ENXIO;
		goto fail;
	}

	/* Get interrupt numbers */
	g->irq_stall = platform_get_irq(dev, 0);
	g->irq_nonstall = platform_get_irq(dev, 1);
	if (g->irq_stall < 0 || g->irq_nonstall < 0) {
		err = -ENXIO;
		goto fail;
	}

	if (tegra_cpu_is_asim()) {
		err = gk20a_init_sim_support(dev);
		if (err)
			goto fail;
	}

	mutex_init(&g->dbg_sessions_lock);
	mutex_init(&g->client_lock);

	g->remove_support = gk20a_remove_support;
	return 0;

 fail:
	gk20a_remove_support(dev);
	return err;
}

static int gk20a_init_client(struct platform_device *dev)
{
	struct gk20a *g = get_gk20a(dev);
	int err;

	gk20a_dbg_fn("");

#ifndef CONFIG_PM_RUNTIME
	gk20a_pm_finalize_poweron(&dev->dev);
#endif

	err = gk20a_init_mm_setup_sw(g);
	if (err)
		return err;

	if (IS_ENABLED(CONFIG_GK20A_DEVFREQ))
		gk20a_scale_hw_init(dev);
	return 0;
}

static void gk20a_deinit_client(struct platform_device *dev)
{
	gk20a_dbg_fn("");
#ifndef CONFIG_PM_RUNTIME
	gk20a_pm_prepare_poweroff(&dev->dev);
#endif
}

int gk20a_get_client(struct gk20a *g)
{
	int err = 0;

	mutex_lock(&g->client_lock);
	if (g->client_refcount == 0)
		err = gk20a_init_client(g->dev);
	if (!err)
		g->client_refcount++;
	mutex_unlock(&g->client_lock);
	return err;
}

void gk20a_put_client(struct gk20a *g)
{
	mutex_lock(&g->client_lock);
	if (g->client_refcount == 1)
		gk20a_deinit_client(g->dev);
	g->client_refcount--;
	mutex_unlock(&g->client_lock);
	WARN_ON(g->client_refcount < 0);
}

static int gk20a_pm_prepare_poweroff(struct device *_dev)
{
	struct platform_device *dev = to_platform_device(_dev);
	struct gk20a *g = get_gk20a(dev);
	int ret = 0;

	gk20a_dbg_fn("");

	if (!g->power_on)
		return 0;

	/*
	 * After this point, gk20a interrupts should not get
	 * serviced.
	 */
	if (g->irq_requested) {
		free_irq(g->irq_stall, g);
		free_irq(g->irq_nonstall, g);
		g->irq_requested = false;
	}

	ret |= gk20a_channel_suspend(g);

	/* disable elpg before gr or fifo suspend */
	ret |= gk20a_pmu_destroy(g);
	ret |= gk20a_gr_suspend(g);
	ret |= gk20a_mm_suspend(g);
	ret |= gk20a_fifo_suspend(g);

	/* Disable GPCPLL */
	ret |= gk20a_suspend_clk_support(g);
	g->power_on = false;

	return ret;
}

static void gk20a_detect_chip(struct gk20a *g)
{
	struct nvhost_gpu_characteristics *gpu = &g->gpu_characteristics;

	u32 mc_boot_0_value = gk20a_readl(g, mc_boot_0_r());
	gpu->arch = mc_boot_0_architecture_v(mc_boot_0_value) <<
		NVHOST_GPU_ARCHITECTURE_SHIFT;
	gpu->impl = mc_boot_0_implementation_v(mc_boot_0_value);
	gpu->rev =
		(mc_boot_0_major_revision_v(mc_boot_0_value) << 4) |
		mc_boot_0_minor_revision_v(mc_boot_0_value);

	gk20a_dbg_info("arch: %x, impl: %x, rev: %x\n",
			g->gpu_characteristics.arch,
			g->gpu_characteristics.impl,
			g->gpu_characteristics.rev);
}

static int gk20a_pm_finalize_poweron(struct device *_dev)
{
	struct platform_device *dev = to_platform_device(_dev);
	struct gk20a *g = get_gk20a(dev);
	int err, nice_value;

	gk20a_dbg_fn("");

	if (g->power_on)
		return 0;

	nice_value = task_nice(current);
	set_user_nice(current, -20);

	if (!g->irq_requested) {
		err = request_threaded_irq(g->irq_stall,
				gk20a_intr_isr_stall,
				gk20a_intr_thread_stall,
				0, "gk20a_stall", g);
		if (err) {
			dev_err(dev_from_gk20a(g),
				"failed to request stall intr irq @ %lld\n",
					(u64)g->irq_stall);
			goto done;
		}
		err = request_threaded_irq(g->irq_nonstall,
				gk20a_intr_isr_nonstall,
				gk20a_intr_thread_nonstall,
				0, "gk20a_nonstall", g);
		if (err) {
			dev_err(dev_from_gk20a(g),
				"failed to request non-stall intr irq @ %lld\n",
					(u64)g->irq_nonstall);
			goto done;
		}
		g->irq_requested = true;
	}

	g->power_on = true;

	gk20a_writel(g, mc_intr_mask_1_r(),
			mc_intr_0_pfifo_pending_f()
			| mc_intr_0_pgraph_pending_f());
	gk20a_writel(g, mc_intr_en_1_r(),
		mc_intr_en_1_inta_hardware_f());

	gk20a_writel(g, mc_intr_mask_0_r(),
			mc_intr_0_pgraph_pending_f()
			| mc_intr_0_pfifo_pending_f()
			| mc_intr_0_priv_ring_pending_f()
			| mc_intr_0_ltc_pending_f()
			| mc_intr_0_pbus_pending_f());
	gk20a_writel(g, mc_intr_en_0_r(),
		mc_intr_en_0_inta_hardware_f());

	if (!tegra_platform_is_silicon())
		gk20a_writel(g, bus_intr_en_0_r(), 0x0);
	else
		gk20a_writel(g, bus_intr_en_0_r(),
			        bus_intr_en_0_pri_squash_m() |
			        bus_intr_en_0_pri_fecserr_m() |
			        bus_intr_en_0_pri_timeout_m());
	gk20a_reset_priv_ring(g);

	gk20a_detect_chip(g);
	err = gpu_init_hal(g);
	if (err)
		goto done;

	/* TBD: move this after graphics init in which blcg/slcg is enabled.
	   This function removes SlowdownOnBoot which applies 32x divider
	   on gpcpll bypass path. The purpose of slowdown is to save power
	   during boot but it also significantly slows down gk20a init on
	   simulation and emulation. We should remove SOB after graphics power
	   saving features (blcg/slcg) are enabled. For now, do it here. */
	err = gk20a_init_clk_support(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a clk");
		goto done;
	}

	/* enable pri timeout only on silicon */
	if (tegra_platform_is_silicon()) {
		gk20a_writel(g,
			timer_pri_timeout_r(),
			timer_pri_timeout_period_f(0x186A0) |
			timer_pri_timeout_en_en_enabled_f());
	} else {
		gk20a_writel(g,
			timer_pri_timeout_r(),
			timer_pri_timeout_period_f(0x186A0) |
			timer_pri_timeout_en_en_disabled_f());
	}

	err = gk20a_init_fifo_reset_enable_hw(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to reset gk20a fifo");
		goto done;
	}

	err = gk20a_init_mm_support(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a mm");
		goto done;
	}

	err = gk20a_init_pmu_support(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a pmu");
		goto done;
	}

	err = gk20a_init_fifo_support(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a fifo");
		goto done;
	}

	err = gk20a_init_gr_support(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a gr");
		goto done;
	}

	err = gk20a_init_pmu_setup_hw2(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a pmu_hw2");
		goto done;
	}

	err = gk20a_init_therm_support(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a therm");
		goto done;
	}

	err = gk20a_init_gpu_characteristics(g);
	if (err) {
		gk20a_err(&dev->dev, "failed to init gk20a gpu characteristics");
		goto done;
	}

	gk20a_channel_resume(g);
	set_user_nice(current, nice_value);

done:
	return err;
}

static struct of_device_id tegra_gk20a_of_match[] = {
#ifdef CONFIG_TEGRA_GK20A
	{ .compatible = "nvidia,tegra124-gk20a",
		.data = &gk20a_tegra_platform },
#endif
	{ .compatible = "nvidia,generic-gk20a",
		.data = &gk20a_generic_platform },
	{ },
};

int tegra_gpu_get_max_state(struct thermal_cooling_device *cdev,
		unsigned long *max_state)
{
	struct cooling_device_gk20a *gk20a_gpufreq_device = cdev->devdata;

	*max_state = gk20a_gpufreq_device->gk20a_freq_table_size - 1;
	return 0;
}

int tegra_gpu_get_cur_state(struct thermal_cooling_device *cdev,
		unsigned long *cur_state)
{
	struct cooling_device_gk20a  *gk20a_gpufreq_device = cdev->devdata;

	*cur_state = gk20a_gpufreq_device->gk20a_freq_state;
	return 0;
}

int tegra_gpu_set_cur_state(struct thermal_cooling_device *c_dev,
		unsigned long cur_state)
{
	u32 target_freq;
	struct gk20a *g;
	struct gpufreq_table_data *gpu_cooling_table;
	struct cooling_device_gk20a *gk20a_gpufreq_device = c_dev->devdata;

	BUG_ON(cur_state >= gk20a_gpufreq_device->gk20a_freq_table_size);

	g = container_of(gk20a_gpufreq_device, struct gk20a, gk20a_cdev);

	gpu_cooling_table = tegra_gpufreq_table_get();
	target_freq = gpu_cooling_table[cur_state].frequency;

	/* ensure a query for state will get the proper value */
	gk20a_gpufreq_device->gk20a_freq_state = cur_state;

	gk20a_clk_set_rate(g, target_freq);

	return 0;
}

static struct thermal_cooling_device_ops tegra_gpu_cooling_ops = {
	.get_max_state = tegra_gpu_get_max_state,
	.get_cur_state = tegra_gpu_get_cur_state,
	.set_cur_state = tegra_gpu_set_cur_state,
};

static int gk20a_create_device(
	struct platform_device *pdev, int devno, const char *cdev_name,
	struct cdev *cdev, struct device **out,
	const struct file_operations *ops)
{
	struct device *dev;
	int err;
	struct gk20a *g = get_gk20a(pdev);

	gk20a_dbg_fn("");

	cdev_init(cdev, ops);
	cdev->owner = THIS_MODULE;

	err = cdev_add(cdev, devno, 1);
	if (err) {
		dev_err(&pdev->dev,
			"failed to add %s cdev\n", cdev_name);
		return err;
	}

	dev = device_create(g->class, NULL, devno, NULL,
		(pdev->id <= 0) ? INTERFACE_NAME : INTERFACE_NAME ".%d",
		cdev_name, pdev->id);

	if (IS_ERR(dev)) {
		err = PTR_ERR(dev);
		cdev_del(cdev);
		dev_err(&pdev->dev,
			"failed to create %s device for %s\n",
			cdev_name, pdev->name);
		return err;
	}

	*out = dev;
	return 0;
}

static void gk20a_user_deinit(struct platform_device *dev)
{
	struct gk20a *g = get_gk20a(dev);

	if (g->channel.node) {
		device_destroy(g->class, g->channel.cdev.dev);
		cdev_del(&g->channel.cdev);
	}

	if (g->as.node) {
		device_destroy(g->class, g->as.cdev.dev);
		cdev_del(&g->as.cdev);
	}

	if (g->ctrl.node) {
		device_destroy(g->class, g->ctrl.cdev.dev);
		cdev_del(&g->ctrl.cdev);
	}

	if (g->dbg.node) {
		device_destroy(g->class, g->dbg.cdev.dev);
		cdev_del(&g->dbg.cdev);
	}

	if (g->prof.node) {
		device_destroy(g->class, g->prof.cdev.dev);
		cdev_del(&g->prof.cdev);
	}

	if (g->cdev_region)
		unregister_chrdev_region(g->cdev_region, GK20A_NUM_CDEVS);

	if (g->class)
		class_destroy(g->class);
}

static int gk20a_user_init(struct platform_device *dev)
{
	int err;
	dev_t devno;
	struct gk20a *g = get_gk20a(dev);

	g->class = class_create(THIS_MODULE, CLASS_NAME);
	if (IS_ERR(g->class)) {
		err = PTR_ERR(g->class);
		g->class = NULL;
		dev_err(&dev->dev,
			"failed to create " CLASS_NAME " class\n");
		goto fail;
	}

	err = alloc_chrdev_region(&devno, 0, GK20A_NUM_CDEVS, CLASS_NAME);
	if (err) {
		dev_err(&dev->dev, "failed to allocate devno\n");
		goto fail;
	}
	g->cdev_region = devno;

	err = gk20a_create_device(dev, devno++, "",
				  &g->channel.cdev, &g->channel.node,
				  &gk20a_channel_ops);
	if (err)
		goto fail;

	err = gk20a_create_device(dev, devno++, "-as",
				  &g->as.cdev, &g->as.node,
				  &gk20a_as_ops);
	if (err)
		goto fail;

	err = gk20a_create_device(dev, devno++, "-ctrl",
				  &g->ctrl.cdev, &g->ctrl.node,
				  &gk20a_ctrl_ops);
	if (err)
		goto fail;

	err = gk20a_create_device(dev, devno++, "-dbg",
				  &g->dbg.cdev, &g->dbg.node,
				  &gk20a_dbg_ops);
	if (err)
		goto fail;

	err = gk20a_create_device(dev, devno++, "-prof",
				  &g->prof.cdev, &g->prof.node,
				  &gk20a_prof_ops);
	if (err)
		goto fail;

	return 0;
fail:
	gk20a_user_deinit(dev);
	return err;
}

struct channel_gk20a *gk20a_get_channel_from_file(int fd)
{
	struct channel_gk20a *ch;
	struct file *f = fget(fd);
	if (!f)
		return 0;

	if (f->f_op != &gk20a_channel_ops) {
		fput(f);
		return 0;
	}

	ch = (struct channel_gk20a *)f->private_data;
	fput(f);
	return ch;
}

static int gk20a_pm_enable_clk(struct device *dev)
{
	int index = 0;
	struct gk20a_platform *platform;

	platform = dev_get_drvdata(dev);
	if (!platform)
		return -EINVAL;

	for (index = 0; index < platform->num_clks; index++) {
		int err = clk_prepare_enable(platform->clk[index]);
		if (err)
			return -EINVAL;
	}

	return 0;
}

static int gk20a_pm_disable_clk(struct device *dev)
{
	int index = 0;
	struct gk20a_platform *platform;

	platform = dev_get_drvdata(dev);
	if (!platform)
		return -EINVAL;

	for (index = 0; index < platform->num_clks; index++)
		clk_disable_unprepare(platform->clk[index]);

	return 0;
}

#ifdef CONFIG_PM
const struct dev_pm_ops gk20a_pm_ops = {
#if defined(CONFIG_PM_RUNTIME) && !defined(CONFIG_PM_GENERIC_DOMAINS)
	.runtime_resume = gk20a_pm_enable_clk,
	.runtime_suspend = gk20a_pm_disable_clk,
#endif
};
#endif

static int gk20a_pm_railgate(struct generic_pm_domain *domain)
{
	struct gk20a *g = container_of(domain, struct gk20a, pd);
	struct gk20a_platform *platform = platform_get_drvdata(g->dev);
	int ret = 0;

	if (platform->railgate)
		ret = platform->railgate(platform->g->dev);

	return ret;
}

static int gk20a_pm_unrailgate(struct generic_pm_domain *domain)
{
	struct gk20a *g = container_of(domain, struct gk20a, pd);
	struct gk20a_platform *platform = platform_get_drvdata(g->dev);
	int ret = 0;

	if (platform->unrailgate)
		ret = platform->unrailgate(platform->g->dev);

	return ret;
}

static int gk20a_pm_suspend(struct device *dev)
{
	struct gk20a_platform *platform = dev_get_drvdata(dev);
	int ret = 0;

	if (atomic_read(&dev->power.usage_count) > 1)
		return -EBUSY;

	ret = gk20a_pm_prepare_poweroff(dev);
	if (ret)
		return ret;

	gk20a_scale_suspend(to_platform_device(dev));

	if (platform->suspend)
		platform->suspend(dev);

	return 0;
}

static int gk20a_pm_resume(struct device *dev)
{
	int ret = 0;

	ret = gk20a_pm_finalize_poweron(dev);
	if (ret)
		return ret;

	gk20a_scale_resume(to_platform_device(dev));

	return 0;
}

static int gk20a_pm_initialise_domain(struct platform_device *pdev)
{
	struct gk20a_platform *platform = platform_get_drvdata(pdev);
	struct dev_power_governor *pm_domain_gov = NULL;
	struct generic_pm_domain *domain = &platform->g->pd;
	int ret = 0;

	domain->name = "gpu";

	if (!platform->can_railgate)
		pm_domain_gov = &pm_domain_always_on_gov;

	pm_genpd_init(domain, pm_domain_gov, true);

	domain->power_off = gk20a_pm_railgate;
	domain->power_on = gk20a_pm_unrailgate;
	domain->dev_ops.start = gk20a_pm_enable_clk;
	domain->dev_ops.stop = gk20a_pm_disable_clk;
	domain->dev_ops.save_state = gk20a_pm_prepare_poweroff;
	domain->dev_ops.restore_state = gk20a_pm_finalize_poweron;
	domain->dev_ops.suspend = gk20a_pm_suspend;
	domain->dev_ops.resume = gk20a_pm_resume;

	device_set_wakeup_capable(&pdev->dev, 0);
	ret = pm_genpd_add_device(domain, &pdev->dev);

	if (platform->railgate_delay)
		pm_genpd_set_poweroff_delay(domain, platform->railgate_delay);

	return ret;
}

static int gk20a_pm_init(struct platform_device *dev)
{
	struct gk20a_platform *platform = platform_get_drvdata(dev);
	int err = 0;

	/* Initialise pm runtime */
	if (platform->clockgate_delay) {
		pm_runtime_set_autosuspend_delay(&dev->dev,
						 platform->clockgate_delay);
		pm_runtime_use_autosuspend(&dev->dev);
	}

	pm_runtime_enable(&dev->dev);
	if (!pm_runtime_enabled(&dev->dev))
		gk20a_pm_enable_clk(&dev->dev);

	/* Enable runtime railgating if possible. If not,
	 * turn on the rail now. */
	if (platform->can_railgate && IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS))
		platform->railgate(dev);
	else
		platform->unrailgate(dev);

	/* genpd will take care of runtime power management if it is enabled */
	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS))
		err = gk20a_pm_initialise_domain(dev);

	return err;
}

static int gk20a_probe(struct platform_device *dev)
{
	struct gk20a *gk20a;
	int err;
	struct gk20a_platform *platform = NULL;
	struct cooling_device_gk20a *gpu_cdev = 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);

	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;

	err = gk20a_user_init(dev);
	if (err)
		return err;

	gk20a_init_support(dev);

	spin_lock_init(&gk20a->mc_enable_lock);

	/* Initialize the platform interface. */
	err = platform->probe(dev);
	if (err) {
		dev_err(&dev->dev, "platform probe failed");
		return err;
	}

	err = gk20a_pm_init(dev);
	if (err) {
		dev_err(&dev->dev, "pm init failed");
		return err;
	}

	/* Initialise scaling */
	if (IS_ENABLED(CONFIG_GK20A_DEVFREQ))
		gk20a_scale_init(dev);

	if (platform->late_probe) {
		err = platform->late_probe(dev);
		if (err) {
			dev_err(&dev->dev, "late probe failed");
			return err;
		}
	}

	gk20a_debug_init(dev);

	/* Set DMA parameters to allow larger sgt lists */
	dev->dev.dma_parms = &gk20a->dma_parms;
	dma_set_max_seg_size(&dev->dev, UINT_MAX);

	gpu_cdev = &gk20a->gk20a_cdev;
	gpu_cdev->gk20a_freq_table_size = tegra_gpufreq_table_size_get();
	gpu_cdev->gk20a_freq_state = 0;
	gpu_cdev->g = gk20a;
	gpu_cdev->gk20a_cooling_dev = thermal_cooling_device_register("gk20a_cdev", gpu_cdev,
					&tegra_gpu_cooling_ops);

	gk20a->gr_idle_timeout_default =
			CONFIG_GK20A_DEFAULT_TIMEOUT;
	gk20a->timeouts_enabled = true;

	/* Set up initial clock gating settings */
	if (tegra_platform_is_silicon()) {
		gk20a->slcg_enabled = true;
		gk20a->blcg_enabled = true;
		gk20a->elcg_enabled = true;
		gk20a->elpg_enabled = true;
		gk20a->aelpg_enabled = true;
	}

	gk20a_create_sysfs(dev);

#ifdef CONFIG_DEBUG_FS
	clk_gk20a_debugfs_init(dev);

	spin_lock_init(&gk20a->debugfs_lock);
	gk20a->mm.ltc_enabled = true;
	gk20a->mm.ltc_enabled_debug = true;
	gk20a->debugfs_ltc_enabled =
			debugfs_create_bool("ltc_enabled", S_IRUGO|S_IWUSR,
				 platform->debugfs,
				 &gk20a->mm.ltc_enabled_debug);
	gk20a->mm.ltc_enabled_debug = true;
	gk20a->debugfs_gr_idle_timeout_default =
			debugfs_create_u32("gr_idle_timeout_default_us",
					S_IRUGO|S_IWUSR, platform->debugfs,
					 &gk20a->gr_idle_timeout_default);
	gk20a->debugfs_timeouts_enabled =
			debugfs_create_bool("timeouts_enabled",
					S_IRUGO|S_IWUSR,
					platform->debugfs,
					&gk20a->timeouts_enabled);
	gk20a_pmu_debugfs_init(dev);
#endif

#ifdef CONFIG_INPUT_CFBOOST
	cfb_add_device(&dev->dev);
#endif

	return 0;
}

static int __exit gk20a_remove(struct platform_device *dev)
{
	struct gk20a *g = get_gk20a(dev);
	gk20a_dbg_fn("");

#ifdef CONFIG_INPUT_CFBOOST
	cfb_remove_device(&dev->dev);
#endif

	if (g->remove_support)
		g->remove_support(dev);

	gk20a_user_deinit(dev);

	set_gk20a(dev, 0);
#ifdef CONFIG_DEBUG_FS
	debugfs_remove(g->debugfs_ltc_enabled);
	debugfs_remove(g->debugfs_gr_idle_timeout_default);
	debugfs_remove(g->debugfs_timeouts_enabled);
#endif

	kfree(g);

#ifdef CONFIG_PM_RUNTIME
	pm_runtime_put(&dev->dev);
	pm_runtime_disable(&dev->dev);
#else
	nvhost_module_disable_clk(&dev->dev);
#endif

	return 0;
}

static struct platform_driver gk20a_driver = {
	.probe = gk20a_probe,
	.remove = __exit_p(gk20a_remove),
	.driver = {
		.owner = THIS_MODULE,
		.name = "gk20a",
#ifdef CONFIG_OF
		.of_match_table = tegra_gk20a_of_match,
#endif
#ifdef CONFIG_PM
		.pm = &gk20a_pm_ops,
#endif
	}
};

static int __init gk20a_init(void)
{
	return platform_driver_register(&gk20a_driver);
}

static void __exit gk20a_exit(void)
{
	platform_driver_unregister(&gk20a_driver);
}

bool is_gk20a_module(struct platform_device *dev)
{
	return &gk20a_driver.driver == dev->dev.driver;
}

void gk20a_busy_noresume(struct platform_device *pdev)
{
	pm_runtime_get_noresume(&pdev->dev);
}

int gk20a_channel_busy(struct platform_device *pdev)
{
	int ret = 0;

	ret = gk20a_platform_channel_busy(pdev);
	if (ret)
		return ret;

	ret = gk20a_busy(pdev);
	if (ret)
		gk20a_platform_channel_idle(pdev);

	return ret;
}

void gk20a_channel_idle(struct platform_device *pdev)
{
	gk20a_idle(pdev);
	gk20a_platform_channel_idle(pdev);
}

int gk20a_busy(struct platform_device *pdev)
{
	int ret = 0;

#ifdef CONFIG_PM_RUNTIME
	ret = pm_runtime_get_sync(&pdev->dev);
#endif
	gk20a_scale_notify_busy(pdev);

	return ret < 0 ? ret : 0;
}

void gk20a_idle(struct platform_device *pdev)
{
#ifdef CONFIG_PM_RUNTIME
	if (atomic_read(&pdev->dev.power.usage_count) == 1)
		gk20a_scale_notify_idle(pdev);
	pm_runtime_mark_last_busy(&pdev->dev);
	pm_runtime_put_sync_autosuspend(&pdev->dev);
#else
	gk20a_scale_notify_idle(pdev);
#endif
}

void gk20a_disable(struct gk20a *g, u32 units)
{
	u32 pmc;

	gk20a_dbg(gpu_dbg_info, "pmc disable: %08x\n", units);

	spin_lock(&g->mc_enable_lock);
	pmc = gk20a_readl(g, mc_enable_r());
	pmc &= ~units;
	gk20a_writel(g, mc_enable_r(), pmc);
	spin_unlock(&g->mc_enable_lock);
}

void gk20a_enable(struct gk20a *g, u32 units)
{
	u32 pmc;

	gk20a_dbg(gpu_dbg_info, "pmc enable: %08x\n", units);

	spin_lock(&g->mc_enable_lock);
	pmc = gk20a_readl(g, mc_enable_r());
	pmc |= units;
	gk20a_writel(g, mc_enable_r(), pmc);
	spin_unlock(&g->mc_enable_lock);
	gk20a_readl(g, mc_enable_r());

	udelay(20);
}

void gk20a_reset(struct gk20a *g, u32 units)
{
	gk20a_disable(g, units);
	udelay(20);
	gk20a_enable(g, units);
}

int gk20a_init_gpu_characteristics(struct gk20a *g)
{
	struct nvhost_gpu_characteristics *gpu = &g->gpu_characteristics;

	gpu->L2_cache_size = g->ops.ltc.determine_L2_size_bytes(g);
	gpu->on_board_video_memory_size = 0; /* integrated GPU */

	gpu->num_gpc = g->gr.gpc_count;
	gpu->num_tpc_per_gpc = g->gr.max_tpc_per_gpc_count;

	gpu->bus_type = NVHOST_GPU_BUS_TYPE_AXI; /* always AXI for now */

	gpu->big_page_size = g->mm.big_page_size;
	gpu->compression_page_size = g->mm.compression_page_size;
	gpu->pde_coverage_bit_count = g->mm.pde_stride_shift;
	gpu->reserved = 0;

	return 0;
}

int nvhost_vpr_info_fetch(void)
{
	struct gk20a *g = get_gk20a(to_platform_device(
			bus_find_device_by_name(&platform_bus_type,
			NULL, "gk20a.0")));

	if (!g) {
		pr_info("gk20a ins't ready yet\n");
		return 0;
	}

	return gk20a_mm_mmu_vpr_info_fetch(g);
}

static const struct firmware *
do_request_firmware(struct device *dev, const char *prefix, const char *fw_name)
{
	const struct firmware *fw;
	char *fw_path = NULL;
	int path_len, err;

	if (prefix) {
		path_len = strlen(prefix) + strlen(fw_name);
		path_len += 2; /* for the path separator and zero terminator*/

		fw_path = kzalloc(sizeof(*fw_path) * path_len, GFP_KERNEL);
		if (!fw_path)
			return NULL;

		sprintf(fw_path, "%s/%s", prefix, fw_name);
		fw_name = fw_path;
	}

	err = request_firmware(&fw, fw_name, dev);
	kfree(fw_path);
	if (err)
		return NULL;
	return fw;
}

/* This is a simple wrapper around request_firmware that takes 'fw_name' and
 * applies an IP specific relative path prefix to it. The caller is
 * responsible for calling release_firmware later. */
const struct firmware *
gk20a_request_firmware(struct gk20a *g, const char *fw_name)
{
	struct device *dev = &g->dev->dev;
	const struct firmware *fw;

	/* current->fs is NULL when calling from SYS_EXIT.
	   Add a check here to prevent crash in request_firmware */
	if (!current->fs || !fw_name)
		return NULL;

	BUG_ON(!g->ops.name);
	fw = do_request_firmware(dev, g->ops.name, fw_name);

#ifdef CONFIG_TEGRA_GK20A
	/* TO BE REMOVED - Support loading from legacy SOC specific path. */
	if (!fw)
		fw = nvhost_client_request_firmware(g->dev, fw_name);
#endif

	if (!fw) {
		dev_err(dev, "failed to get firmware\n");
		return NULL;
	}

	return fw;
}

module_init(gk20a_init);
module_exit(gk20a_exit);