linux-nvgpu/drivers/gpu/nvgpu/common/init/nvgpu_init.c

/*
 * GK20A Graphics
 *
 * Copyright (c) 2011-2019, NVIDIA CORPORATION.  All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, 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 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 <nvgpu/nvgpu_common.h>
#include <nvgpu/kmem.h>
#include <nvgpu/allocator.h>
#include <nvgpu/timers.h>
#include <nvgpu/soc.h>
#include <nvgpu/enabled.h>
#include <nvgpu/gmmu.h>
#include <nvgpu/vidmem.h>
#include <nvgpu/soc.h>
#include <nvgpu/mc.h>
#include <nvgpu/gk20a.h>
#include <nvgpu/channel_sync.h>
#include <nvgpu/nvgpu_init.h>
#include <nvgpu/gops_mc.h>

#ifdef CONFIG_NVGPU_TRACE
#include <trace/events/gk20a.h>
#endif
#ifdef CONFIG_NVGPU_LS_PMU
#include <nvgpu/pmu/pmu_pstate.h>
#endif

bool is_nvgpu_gpu_state_valid(struct gk20a *g)
{
	u32 boot_0 = g->ops.mc.get_chip_details(g, NULL, NULL, NULL);

	if (boot_0 == 0xffffffffU) {
		nvgpu_err(g, "GPU has disappeared from bus!!");
		return false;
	}
	return true;
}

void nvgpu_check_gpu_state(struct gk20a *g)
{
	if (!is_nvgpu_gpu_state_valid(g)) {
		nvgpu_err(g, "Rebooting system!!");
		nvgpu_kernel_restart(NULL);
	}
}

static void gk20a_mask_interrupts(struct gk20a *g)
{
	nvgpu_mc_intr_mask(g);
#ifdef CONFIG_NVGPU_NON_FUSA
	nvgpu_mc_log_pending_intrs(g);
#endif
}

#ifndef CONFIG_NVGPU_RECOVERY
static int nvgpu_sw_quiesce_thread(void *data)
{
	struct gk20a *g = data;
	int err = 0;

	g->sw_quiesce_init_done = true;
	nvgpu_cond_signal(&g->sw_quiesce_cond);

	/* wait until all SW quiesce is requested */
	NVGPU_COND_WAIT(&g->sw_quiesce_cond,
		g->sw_quiesce_pending ||
		nvgpu_thread_should_stop(&g->sw_quiesce_thread), 0U);

	if (nvgpu_thread_should_stop(&g->sw_quiesce_thread)) {
		goto done;
	}
	nvgpu_wait_for_deferred_interrupts(g);

	nvgpu_err(g, "sw quiesce in progress");

	nvgpu_mutex_acquire(&g->power_lock);

	if (nvgpu_is_powered_off(g) || g->is_virtual) {
		err = -EINVAL;
		goto idle;
	}

	nvgpu_start_gpu_idle(g);
	nvgpu_disable_irqs(g);
	gk20a_mask_interrupts(g);
	nvgpu_fifo_sw_quiesce(g);

idle:
	nvgpu_mutex_release(&g->power_lock);
	nvgpu_err(g, "sw quiesce done, err=%d", err);

done:
	nvgpu_log_info(g, "done");
	return err;
}
#endif

static int nvgpu_sw_quiesce_init_support(struct gk20a *g)
{
#ifdef CONFIG_NVGPU_RECOVERY
	nvgpu_set_enabled(g, NVGPU_SUPPORT_FAULT_RECOVERY, true);
#else
	int err;

	if (g->sw_quiesce_init_done) {
		return 0;
	}

	nvgpu_set_enabled(g, NVGPU_SUPPORT_FAULT_RECOVERY, false);

	nvgpu_cond_init(&g->sw_quiesce_cond);
	g->sw_quiesce_pending = false;

	err = nvgpu_thread_create(&g->sw_quiesce_thread, g,
			nvgpu_sw_quiesce_thread, "sw-quiesce");
	if (err != 0) {
		nvgpu_cond_destroy(&g->sw_quiesce_cond);
		return err;
	}

	/* wait until thread actually starts */
	NVGPU_COND_WAIT(&g->sw_quiesce_cond, g->sw_quiesce_init_done, 0U);
#endif

	return 0;
}

void nvgpu_sw_quiesce_remove_support(struct gk20a *g)
{
#ifndef CONFIG_NVGPU_RECOVERY
	if (g->sw_quiesce_init_done) {
		nvgpu_thread_stop(&g->sw_quiesce_thread);
		nvgpu_cond_destroy(&g->sw_quiesce_cond);
		g->sw_quiesce_init_done = false;
	}
#endif
}

void nvgpu_sw_quiesce(struct gk20a *g)
{
#ifndef CONFIG_NVGPU_RECOVERY
	if (g->is_virtual || g->enabled_flags == NULL ||
		nvgpu_is_enabled(g, NVGPU_DISABLE_SW_QUIESCE)) {
		goto fail;
	}

	nvgpu_err(g, "SW quiesce requested");

	/*
	 * When this flag is set, interrupt handlers should
	 * exit after masking interrupts. This should mitigate
	 * interrupt storm cases.
	 */
	g->sw_quiesce_pending = true;

	nvgpu_cond_signal(&g->sw_quiesce_cond);

	return;

fail:
#endif
	nvgpu_err(g, "sw quiesce not supported");
}

/* init interface layer support for all falcons */
static int nvgpu_falcons_sw_init(struct gk20a *g)
{
	int err;

	err = g->ops.falcon.falcon_sw_init(g, FALCON_ID_PMU);
	if (err != 0) {
		nvgpu_err(g, "failed to sw init FALCON_ID_PMU");
		return err;
	}

	err = g->ops.falcon.falcon_sw_init(g, FALCON_ID_FECS);
	if (err != 0) {
		nvgpu_err(g, "failed to sw init FALCON_ID_FECS");
		goto done_pmu;
	}

#ifdef CONFIG_NVGPU_DGPU
	err = g->ops.falcon.falcon_sw_init(g, FALCON_ID_SEC2);
	if (err != 0) {
		nvgpu_err(g, "failed to sw init FALCON_ID_SEC2");
		goto done_fecs;
	}

	err = g->ops.falcon.falcon_sw_init(g, FALCON_ID_NVDEC);
	if (err != 0) {
		nvgpu_err(g, "failed to sw init FALCON_ID_NVDEC");
		goto done_sec2;
	}

	err = g->ops.falcon.falcon_sw_init(g, FALCON_ID_GSPLITE);
	if (err != 0) {
		nvgpu_err(g, "failed to sw init FALCON_ID_GSPLITE");
		goto done_nvdec;
	}
#endif

	return 0;

#ifdef CONFIG_NVGPU_DGPU
done_nvdec:
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_NVDEC);
done_sec2:
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_SEC2);
done_fecs:
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_FECS);
#endif
done_pmu:
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_PMU);

	return err;
}

/* handle poweroff and error case for all falcons interface layer support */
static void nvgpu_falcons_sw_free(struct gk20a *g)
{
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_PMU);
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_FECS);

#ifdef CONFIG_NVGPU_DGPU
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_GSPLITE);
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_NVDEC);
	g->ops.falcon.falcon_sw_free(g, FALCON_ID_SEC2);
#endif
}

int nvgpu_prepare_poweroff(struct gk20a *g)
{
	int tmp_ret, ret = 0;

	nvgpu_log_fn(g, " ");

	if (g->ops.channel.suspend_all_serviceable_ch != NULL) {
		ret = g->ops.channel.suspend_all_serviceable_ch(g);
		if (ret != 0) {
			return ret;
		}
	}

#ifdef CONFIG_NVGPU_LS_PMU
	/* disable elpg before gr or fifo suspend */
	if (g->support_ls_pmu) {
		ret = g->ops.pmu.pmu_destroy(g, g->pmu);
	}
#endif

#ifdef CONFIG_NVGPU_DGPU
	if (nvgpu_is_enabled(g, NVGPU_SUPPORT_SEC2_RTOS)) {
		tmp_ret = g->ops.sec2.sec2_destroy(g);
		if ((tmp_ret != 0) && (ret == 0)) {
			ret = tmp_ret;
		}
	}
#endif
	tmp_ret = g->ops.gr.gr_suspend(g);
	if (tmp_ret != 0) {
		ret = tmp_ret;
	}
	tmp_ret = g->ops.mm.mm_suspend(g);
	if (tmp_ret != 0) {
		ret = tmp_ret;
	}
	tmp_ret = g->ops.fifo.fifo_suspend(g);
	if (tmp_ret != 0) {
		ret = tmp_ret;
	}

	nvgpu_falcons_sw_free(g);

#ifdef CONFIG_NVGPU_DGPU
	g->ops.ce.ce_app_suspend(g);
#endif

#ifdef CONFIG_NVGPU_DGPU
	if (g->ops.bios.bios_sw_deinit != NULL) {
		/* deinit the bios */
		g->ops.bios.bios_sw_deinit(g, g->bios);
	}
#endif

	/* Disable GPCPLL */
	if (g->ops.clk.suspend_clk_support != NULL) {
		g->ops.clk.suspend_clk_support(g);
	}
#ifdef CONFIG_NVGPU_CLK_ARB
	if (g->ops.clk_arb.stop_clk_arb_threads != NULL) {
		g->ops.clk_arb.stop_clk_arb_threads(g);
	}
#endif
	gk20a_mask_interrupts(g);

	return ret;
}

#ifdef CONFIG_NVGPU_TPC_POWERGATE
static bool have_tpc_pg_lock = false;

static int nvgpu_init_acquire_tpc_pg_lock(struct gk20a *g)
{
	nvgpu_mutex_acquire(&g->tpc_pg_lock);
	have_tpc_pg_lock = true;
	return 0;
}

static int nvgpu_init_release_tpc_pg_lock(struct gk20a *g)
{
	nvgpu_mutex_release(&g->tpc_pg_lock);
	have_tpc_pg_lock = false;
	return 0;
}
#endif

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

	if ((g->ops.fb.mem_unlock != NULL) && (!g->is_fusa_sku)) {
		err = g->ops.fb.mem_unlock(g);
		if (err != 0) {
			return err;
		}
	} else {
		nvgpu_log_info(g, "skipping fb mem_unlock");
	}

	return 0;
}

#ifdef CONFIG_NVGPU_TPC_POWERGATE
static int nvgpu_init_power_gate(struct gk20a *g)
{
	int err;
	u32 fuse_status;

	/*
	 *  Power gate the chip as per the TPC PG mask
	 *  and the fuse_status register.
	 *  If TPC PG mask is invalid halt the GPU poweron.
	 */
	g->can_tpc_powergate = false;
	fuse_status = g->ops.fuse.fuse_status_opt_tpc_gpc(g, 0);

	if (g->ops.tpc.init_tpc_powergate != NULL) {
		err = g->ops.tpc.init_tpc_powergate(g, fuse_status);
		if (err != 0) {
			return err;
		}
	}

	return 0;
}

static int nvgpu_init_power_gate_gr(struct gk20a *g)
{
	if (g->can_tpc_powergate && (g->ops.tpc.tpc_gr_pg != NULL)) {
		g->ops.tpc.tpc_gr_pg(g);
	}
	return 0;
}
#endif

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

#ifdef CONFIG_NVGPU_LS_PMU
	if (nvgpu_is_enabled(g, NVGPU_PMU_PSTATE) &&
		(g->pmu->fw->ops.clk.clk_set_boot_clk != NULL)) {
		err = g->pmu->fw->ops.clk.clk_set_boot_clk(g);
		if (err != 0) {
			nvgpu_err(g, "failed to set boot clk");
			return err;
		}
	} else
#endif
	{
#ifdef CONFIG_NVGPU_CLK_ARB
		err = g->ops.clk_arb.clk_arb_init_arbiter(g);
		if (err != 0) {
			nvgpu_err(g, "failed to init clk arb");
			return err;
		}
#endif
	}

	return err;
}

static int nvgpu_init_set_debugger_mode(struct gk20a *g)
{
#ifdef CONFIG_NVGPU_DEBUGGER
	/* Restore the debug setting */
	g->ops.fb.set_debug_mode(g, g->mmu_debug_ctrl);
#endif
	return 0;
}

static int nvgpu_init_xve_set_speed(struct gk20a *g)
{
#ifdef CONFIG_NVGPU_DGPU
	int err;

	if (g->ops.xve.available_speeds != NULL) {
		u32 speed;

		if (!nvgpu_is_enabled(g, NVGPU_SUPPORT_ASPM) &&
				(g->ops.xve.disable_aspm != NULL)) {
			g->ops.xve.disable_aspm(g);
		}

		g->ops.xve.available_speeds(g, &speed);

		/* Set to max speed */
		speed = (u32)nvgpu_fls(speed);

		if (speed > 0U) {
			speed = BIT32((speed - 1U));
		} else {
			speed = BIT32(speed);
		}

		err = g->ops.xve.set_speed(g, speed);
		if (err != 0) {
			nvgpu_err(g, "Failed to set PCIe bus speed!");
			return err;
		}
	}
#endif
	return 0;
}

static int nvgpu_init_syncpt_mem(struct gk20a *g)
{
#if defined(CONFIG_TEGRA_GK20A_NVHOST)
	int err;
	u64 nr_pages;

	if (nvgpu_has_syncpoints(g) && (g->syncpt_unit_size != 0UL)) {
		if (!nvgpu_mem_is_valid(&g->syncpt_mem)) {
			nr_pages = U64(DIV_ROUND_UP(g->syncpt_unit_size,
						    PAGE_SIZE));
			err = nvgpu_mem_create_from_phys(g, &g->syncpt_mem,
					g->syncpt_unit_base, nr_pages);
			if (err != 0) {
				nvgpu_err(g, "Failed to create syncpt mem");
				return err;
			}
		}
	}
#endif
	return 0;
}

static int nvgpu_init_interrupt_setup(struct gk20a *g)
{
	/**
	 * Disable all interrupts at the start.
	 */
	nvgpu_mc_intr_mask(g);

#ifdef CONFIG_NVGPU_NON_FUSA
	/**
	 * For certain chips like gm20b, there is global interrupt control in
	 * registers mc_intr_en_*_r. Program them here upfront.
	 */
	nvgpu_mc_intr_enable(g);
#endif

	return 0;
}

typedef int (*nvgpu_init_func_t)(struct gk20a *g);
struct nvgpu_init_table_t {
	nvgpu_init_func_t func;
	const char *name;
	u32 enable_flag;
};
#define NVGPU_INIT_TABLE_ENTRY(ops_ptr, enable_flag) \
	{ (ops_ptr), #ops_ptr,  (enable_flag) }
#define NO_FLAG 0U

static bool needs_init(struct gk20a *g, nvgpu_init_func_t func, u32 enable_flag)
{
	return ((enable_flag == NO_FLAG) ||
		nvgpu_is_enabled(g, enable_flag)) && (func != NULL);
}

int nvgpu_finalize_poweron(struct gk20a *g)
{
	int err = 0;
	/*
	 * This cannot be static because we use the func ptrs as initializers
	 * and static variables require constant literals for initializers.
	 */
	const struct nvgpu_init_table_t nvgpu_init_table[] = {
		/*
		 * Do this early so any early VMs that get made are capable of
		 * mapping buffers.
		 */
		/**
		 * ECC support initialization is split into generic init
		 * followed by per unit initialization and ends with sysfs
		 * support init. This is done to setup ECC data structures
		 * prior to enabling interrupts for corresponding units.
		 */
		NVGPU_INIT_TABLE_ENTRY(g->ops.ecc.ecc_init_support, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.mm.pd_cache_init, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_falcons_sw_init, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.pmu.pmu_early_init, NO_FLAG),
#ifdef CONFIG_NVGPU_DGPU
		NVGPU_INIT_TABLE_ENTRY(g->ops.sec2.init_sec2_setup_sw,
				       NVGPU_SUPPORT_SEC2_RTOS),
#endif
		NVGPU_INIT_TABLE_ENTRY(g->ops.acr.acr_init,
				       NVGPU_SEC_PRIVSECURITY),
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_sw_quiesce_init_support, NO_FLAG),
#ifdef CONFIG_NVGPU_DGPU
		NVGPU_INIT_TABLE_ENTRY(g->ops.bios.bios_sw_init, NO_FLAG),
#endif
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_interrupt_setup, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.bus.init_hw, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.priv_ring.enable_priv_ring,
				       NO_FLAG),
		/* 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.
		 */
		NVGPU_INIT_TABLE_ENTRY(g->ops.clk.init_clk_support, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.nvlink.init,
				       NVGPU_SUPPORT_NVLINK),
		NVGPU_INIT_TABLE_ENTRY(g->ops.fb.init_fbpa, NO_FLAG),
#ifdef CONFIG_NVGPU_DEBUGGER
		NVGPU_INIT_TABLE_ENTRY(g->ops.ptimer.config_gr_tick_freq,
				       NO_FLAG),
#endif
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_fb_mem_unlock, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.fifo.reset_enable_hw, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.ltc.init_ltc_support, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.mm.init_mm_support, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.fifo.fifo_init_support, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.therm.elcg_init_idle_filters,
				       NO_FLAG),
#ifdef CONFIG_NVGPU_TPC_POWERGATE
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_power_gate, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_acquire_tpc_pg_lock, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_power_gate_gr, NO_FLAG),
#endif
		/* prepare portion of sw required for enable hw */
		NVGPU_INIT_TABLE_ENTRY(g->ops.gr.gr_prepare_sw, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.gr.gr_enable_hw, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.acr.acr_construct_execute,
				       NVGPU_SEC_PRIVSECURITY),
#ifdef CONFIG_NVGPU_DGPU
		NVGPU_INIT_TABLE_ENTRY(g->ops.sec2.init_sec2_support,
				       NVGPU_SUPPORT_SEC2_RTOS),
#endif
#ifdef CONFIG_NVGPU_LS_PMU
		NVGPU_INIT_TABLE_ENTRY(g->ops.pmu.pmu_rtos_init, NO_FLAG),
#endif
		NVGPU_INIT_TABLE_ENTRY(g->ops.fbp.fbp_init_support, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.gr.gr_init_support, NO_FLAG),
		/**
		 * All units requiring ECC stats must initialize ECC counters
		 * before this call to finalize ECC support.
		 */
		NVGPU_INIT_TABLE_ENTRY(g->ops.ecc.ecc_finalize_support,
				       NO_FLAG),
#ifdef CONFIG_NVGPU_TPC_POWERGATE
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_release_tpc_pg_lock,
				       NO_FLAG),
#endif

#ifdef CONFIG_NVGPU_LS_PMU
		NVGPU_INIT_TABLE_ENTRY(g->ops.pmu.pmu_pstate_sw_setup,
				       NVGPU_PMU_PSTATE),
		NVGPU_INIT_TABLE_ENTRY(g->ops.pmu.pmu_pstate_pmu_setup,
				       NVGPU_PMU_PSTATE),
#endif
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_boot_clk_or_clk_arb, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.therm.init_therm_support, NO_FLAG),
#ifdef CONFIG_NVGPU_COMPRESSION
		NVGPU_INIT_TABLE_ENTRY(g->ops.cbc.cbc_init_support, NO_FLAG),
#endif
		NVGPU_INIT_TABLE_ENTRY(g->ops.chip_init_gpu_characteristics,
				       NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_set_debugger_mode, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.ce.ce_init_support, NO_FLAG),
#ifdef CONFIG_NVGPU_DGPU
		NVGPU_INIT_TABLE_ENTRY(g->ops.ce.ce_app_init_support, NO_FLAG),
#endif
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_xve_set_speed, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(&nvgpu_init_syncpt_mem, NO_FLAG),
		NVGPU_INIT_TABLE_ENTRY(g->ops.channel.resume_all_serviceable_ch,
				       NO_FLAG),
	};
	size_t i;

	nvgpu_log_fn(g, " ");

#ifdef CONFIG_NVGPU_DGPU
	/*
	 * Before probing the GPU make sure the GPU's state is cleared. This is
	 * relevant for rebind operations.
	 */
	if ((g->ops.xve.reset_gpu != NULL) && !g->gpu_reset_done) {
		g->ops.xve.reset_gpu(g);
		g->gpu_reset_done = true;
	}
#endif

	for (i = 0; i < ARRAY_SIZE(nvgpu_init_table); i++) {
		if (!needs_init(g, nvgpu_init_table[i].func,
				nvgpu_init_table[i].enable_flag)) {
			nvgpu_log_info(g, "Skipping initializing %s (enable_flag=%u func=%p)",
				       nvgpu_init_table[i].name,
				       nvgpu_init_table[i].enable_flag,
				       nvgpu_init_table[i].func);
		} else {
			nvgpu_log_info(g, "Initializing %s",
				       nvgpu_init_table[i].name);
			err = nvgpu_init_table[i].func(g);
			if (err != 0) {
				nvgpu_err(g, "Failed initialization for: %s",
					  nvgpu_init_table[i].name);
				goto done;
			}
		}
	}

	return err;

done:
#ifdef CONFIG_NVGPU_TPC_POWERGATE
	if (have_tpc_pg_lock) {
		int release_err = nvgpu_init_release_tpc_pg_lock(g);

		if (release_err != 0) {
			nvgpu_err(g, "failed to release tpc_gp_lock");
		}
	}
#endif
	nvgpu_falcons_sw_free(g);

	return err;
}

/*
 * Check if the device can go busy. Basically if the driver is currently
 * in the process of dying then do not let new places make the driver busy.
 */
int nvgpu_can_busy(struct gk20a *g)
{
	/* Can't do anything if the system is rebooting/shutting down
	 * or the driver is restarting
	 */
	if (nvgpu_is_enabled(g, NVGPU_KERNEL_IS_DYING) ||
		nvgpu_is_enabled(g, NVGPU_DRIVER_IS_DYING)) {
		return 0;
	} else {
		return 1;
	}
}

int nvgpu_init_gpu_characteristics(struct gk20a *g)
{
#ifdef CONFIG_NVGPU_BUILD_CONFIGURATION_IS_SAFETY
	nvgpu_set_enabled(g, NVGPU_DRIVER_REDUCED_PROFILE, true);
#endif
	nvgpu_set_enabled(g, NVGPU_SUPPORT_MAP_DIRECT_KIND_CTRL, true);
	nvgpu_set_enabled(g, NVGPU_SUPPORT_MAP_BUFFER_BATCH, true);
	nvgpu_set_enabled(g, NVGPU_SUPPORT_SPARSE_ALLOCS, true);

	/*
	 * Fast submits are supported as long as the user doesn't request
	 * anything that depends on job tracking. (Here, fast means strictly no
	 * metadata, just the gpfifo contents are copied and gp_put updated).
	 */
	nvgpu_set_enabled(g,
			NVGPU_SUPPORT_DETERMINISTIC_SUBMIT_NO_JOBTRACKING,
			true);

	/*
	 * Sync framework requires deferred job cleanup, wrapping syncs in FDs,
	 * and other heavy stuff, which prevents deterministic submits. This is
	 * supported otherwise, provided that the user doesn't request anything
	 * that depends on deferred cleanup.
	 */
	if (!nvgpu_channel_sync_needs_os_fence_framework(g)) {
		nvgpu_set_enabled(g,
				NVGPU_SUPPORT_DETERMINISTIC_SUBMIT_FULL,
				true);
	}

	nvgpu_set_enabled(g, NVGPU_SUPPORT_TSG, true);

#ifdef CONFIG_NVGPU_CLK_ARB
	if (g->ops.clk_arb.check_clk_arb_support != NULL) {
		if (g->ops.clk_arb.check_clk_arb_support(g)) {
			nvgpu_set_enabled(g, NVGPU_SUPPORT_CLOCK_CONTROLS,
					true);
		}
	}
#endif

	g->ops.gr.init.detect_sm_arch(g);

#ifdef CONFIG_NVGPU_CYCLESTATS
	if (g->ops.gr.init_cyclestats != NULL) {
		g->ops.gr.init_cyclestats(g);
	}
#endif

	return 0;
}

static struct gk20a *gk20a_from_refcount(struct nvgpu_ref *refcount)
{
	return (struct gk20a *)((uintptr_t)refcount -
				offsetof(struct gk20a, refcount));
}

/*
 * Free the gk20a struct.
 */
static void gk20a_free_cb(struct nvgpu_ref *refcount)
{
	struct gk20a *g = gk20a_from_refcount(refcount);

	nvgpu_log(g, gpu_dbg_shutdown, "Freeing GK20A struct!");

#ifdef CONFIG_NVGPU_DGPU
	if (g->ops.ce.ce_app_destroy != NULL) {
		g->ops.ce.ce_app_destroy(g);
	}
#endif

#ifdef CONFIG_NVGPU_COMPRESSION
	if (g->ops.cbc.cbc_remove_support != NULL) {
		g->ops.cbc.cbc_remove_support(g);
	}
#endif

	if (g->ops.ecc.ecc_remove_support != NULL) {
		g->ops.ecc.ecc_remove_support(g);
	}

	if (g->remove_support != NULL) {
		g->remove_support(g);
	}

	if (g->ops.ltc.ltc_remove_support != NULL) {
		g->ops.ltc.ltc_remove_support(g);
	}

	nvgpu_sw_quiesce_remove_support(g);

	if (g->gfree != NULL) {
		g->gfree(g);
	}
}

struct gk20a * __must_check nvgpu_get(struct gk20a *g)
{
	int success;

	/*
	 * Handle the possibility we are still freeing the gk20a struct while
	 * nvgpu_get() is called. Unlikely but plausible race condition. Ideally
	 * the code will never be in such a situation that this race is
	 * possible.
	 */
	success = nvgpu_ref_get_unless_zero(&g->refcount);

	nvgpu_log(g, gpu_dbg_shutdown, "GET: refs currently %d %s",
		nvgpu_atomic_read(&g->refcount.refcount),
			(success != 0) ? "" : "(FAILED)");

	return (success != 0) ? g : NULL;
}

void nvgpu_put(struct gk20a *g)
{
	/*
	 * Note - this is racy, two instances of this could run before the
	 * actual kref_put(0 runs, you could see something like:
	 *
	 *  ... PUT: refs currently 2
	 *  ... PUT: refs currently 2
	 *  ... Freeing GK20A struct!
	 */
	nvgpu_log(g, gpu_dbg_shutdown, "PUT: refs currently %d",
		nvgpu_atomic_read(&g->refcount.refcount));

	nvgpu_ref_put(&g->refcount, gk20a_free_cb);
}