drivers/misc/habanalabs/habanalabs_ioctl.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0

 /*
  * Copyright 2016-2019 HabanaLabs, Ltd.
  * All Rights Reserved.
  */

 #include <uapi/misc/habanalabs.h>
 #include "habanalabs.h"

 #include <linux/fs.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>

 static u32 hl_debug_struct_size[HL_DEBUG_OP_TIMESTAMP + 1] = {
 	[HL_DEBUG_OP_ETR] = sizeof(struct hl_debug_params_etr),
 	[HL_DEBUG_OP_ETF] = sizeof(struct hl_debug_params_etf),
 	[HL_DEBUG_OP_STM] = sizeof(struct hl_debug_params_stm),
 	[HL_DEBUG_OP_FUNNEL] = 0,
 	[HL_DEBUG_OP_BMON] = sizeof(struct hl_debug_params_bmon),
 	[HL_DEBUG_OP_SPMU] = sizeof(struct hl_debug_params_spmu),
 	[HL_DEBUG_OP_TIMESTAMP] = 0

 };

 static int device_status_info(struct hl_device *hdev, struct hl_info_args *args)
 {
 	struct hl_info_device_status dev_stat = {0};
 	u32 size = args->return_size;
 	void __user *out = (void __user *) (uintptr_t) args->return_pointer;

 	if ((!size) || (!out))
 		return -EINVAL;

 	dev_stat.status = hl_device_status(hdev);

 	return copy_to_user(out, &dev_stat,
 			min((size_t)size, sizeof(dev_stat))) ? -EFAULT : 0;
 }

 static int hw_ip_info(struct hl_device *hdev, struct hl_info_args *args)
 {
 	struct hl_info_hw_ip_info hw_ip = {0};
 	u32 size = args->return_size;
 	void __user *out = (void __user *) (uintptr_t) args->return_pointer;
 	struct asic_fixed_properties *prop = &hdev->asic_prop;
 	u64 sram_kmd_size, dram_kmd_size;

 	if ((!size) || (!out))
 		return -EINVAL;

 	sram_kmd_size = (prop->sram_user_base_address -
 				prop->sram_base_address);
 	dram_kmd_size = (prop->dram_user_base_address -
 				prop->dram_base_address);

 	hw_ip.device_id = hdev->asic_funcs->get_pci_id(hdev);
 	hw_ip.sram_base_address = prop->sram_user_base_address;
 	hw_ip.dram_base_address = prop->dram_user_base_address;
 	hw_ip.tpc_enabled_mask = prop->tpc_enabled_mask;
 	hw_ip.sram_size = prop->sram_size - sram_kmd_size;
 	hw_ip.dram_size = prop->dram_size - dram_kmd_size;
 	if (hw_ip.dram_size > 0)
 		hw_ip.dram_enabled = 1;
 	hw_ip.num_of_events = prop->num_of_events;
 	memcpy(hw_ip.armcp_version,
 		prop->armcp_info.armcp_version, VERSION_MAX_LEN);
 	hw_ip.armcp_cpld_version = __le32_to_cpu(prop->armcp_info.cpld_version);
 	hw_ip.psoc_pci_pll_nr = prop->psoc_pci_pll_nr;
 	hw_ip.psoc_pci_pll_nf = prop->psoc_pci_pll_nf;
 	hw_ip.psoc_pci_pll_od = prop->psoc_pci_pll_od;
 	hw_ip.psoc_pci_pll_div_factor = prop->psoc_pci_pll_div_factor;

 	return copy_to_user(out, &hw_ip,
 		min((size_t)size, sizeof(hw_ip))) ? -EFAULT : 0;
 }

 static int hw_events_info(struct hl_device *hdev, struct hl_info_args *args)
 {
 	u32 size, max_size = args->return_size;
 	void __user *out = (void __user *) (uintptr_t) args->return_pointer;
 	void *arr;

 	if ((!max_size) || (!out))
 		return -EINVAL;

 	arr = hdev->asic_funcs->get_events_stat(hdev, &size);

 	return copy_to_user(out, arr, min(max_size, size)) ? -EFAULT : 0;
 }

 static int dram_usage_info(struct hl_device *hdev, struct hl_info_args *args)
 {
 	struct hl_info_dram_usage dram_usage = {0};
 	u32 max_size = args->return_size;
 	void __user *out = (void __user *) (uintptr_t) args->return_pointer;
 	struct asic_fixed_properties *prop = &hdev->asic_prop;
 	u64 dram_kmd_size;

 	if ((!max_size) || (!out))
 		return -EINVAL;

 	dram_kmd_size = (prop->dram_user_base_address -
 				prop->dram_base_address);
 	dram_usage.dram_free_mem = (prop->dram_size - dram_kmd_size) -
 					atomic64_read(&hdev->dram_used_mem);
 	dram_usage.ctx_dram_mem = atomic64_read(&hdev->user_ctx->dram_phys_mem);

 	return copy_to_user(out, &dram_usage,
 		min((size_t) max_size, sizeof(dram_usage))) ? -EFAULT : 0;
 }

 static int hw_idle(struct hl_device *hdev, struct hl_info_args *args)
 {
 	struct hl_info_hw_idle hw_idle = {0};
 	u32 max_size = args->return_size;
 	void __user *out = (void __user *) (uintptr_t) args->return_pointer;

 	if ((!max_size) || (!out))
 		return -EINVAL;

 	hw_idle.is_idle = hdev->asic_funcs->is_device_idle(hdev, NULL, 0);

 	return copy_to_user(out, &hw_idle,
 		min((size_t) max_size, sizeof(hw_idle))) ? -EFAULT : 0;
 }

 static int debug_coresight(struct hl_device *hdev, struct hl_debug_args *args)
 {
 	struct hl_debug_params *params;
 	void *input = NULL, *output = NULL;
 	int rc;

 	params = kzalloc(sizeof(*params), GFP_KERNEL);
 	if (!params)
 		return -ENOMEM;

 	params->reg_idx = args->reg_idx;
 	params->enable = args->enable;
 	params->op = args->op;

 	if (args->input_ptr && args->input_size) {
 		input = memdup_user((const void __user *) args->input_ptr,
 					args->input_size);
 		if (IS_ERR(input)) {
 			rc = PTR_ERR(input);
 			input = NULL;
 			dev_err(hdev->dev,
 				"error %d when copying input debug data\n", rc);
 			goto out;
 		}

 		params->input = input;
 	}

 	if (args->output_ptr && args->output_size) {
 		output = kzalloc(args->output_size, GFP_KERNEL);
 		if (!output) {
 			rc = -ENOMEM;
 			goto out;
 		}

 		params->output = output;
 		params->output_size = args->output_size;
 	}

 	rc = hdev->asic_funcs->debug_coresight(hdev, params);
 	if (rc) {
 		dev_err(hdev->dev,
 			"debug coresight operation failed %d\n", rc);
 		goto out;
 	}

 	if (output) {
 		if (copy_to_user((void __user *) (uintptr_t) args->output_ptr,
 					output,
 					args->output_size)) {
 			dev_err(hdev->dev,
 				"copy to user failed in debug ioctl\n");
 			rc = -EFAULT;
 			goto out;
 		}
 	}

 out:
 	kfree(params);
 	kfree(output);
 	kfree(input);

 	return rc;
 }

 static int hl_info_ioctl(struct hl_fpriv *hpriv, void *data)
 {
 	struct hl_info_args *args = data;
 	struct hl_device *hdev = hpriv->hdev;
 	int rc;

 	/* We want to return device status even if it disabled or in reset */
 	if (args->op == HL_INFO_DEVICE_STATUS)
 		return device_status_info(hdev, args);

 	if (hl_device_disabled_or_in_reset(hdev)) {
 		dev_warn_ratelimited(hdev->dev,
 			"Device is %s. Can't execute INFO IOCTL\n",
 			atomic_read(&hdev->in_reset) ? "in_reset" : "disabled");
 		return -EBUSY;
 	}

 	switch (args->op) {
 	case HL_INFO_HW_IP_INFO:
 		rc = hw_ip_info(hdev, args);
 		break;

 	case HL_INFO_HW_EVENTS:
 		rc = hw_events_info(hdev, args);
 		break;

 	case HL_INFO_DRAM_USAGE:
 		rc = dram_usage_info(hdev, args);
 		break;

 	case HL_INFO_HW_IDLE:
 		rc = hw_idle(hdev, args);
 		break;

 	default:
 		dev_err(hdev->dev, "Invalid request %d\n", args->op);
 		rc = -ENOTTY;
 		break;
 	}

 	return rc;
 }

 static int hl_debug_ioctl(struct hl_fpriv *hpriv, void *data)
 {
 	struct hl_debug_args *args = data;
 	struct hl_device *hdev = hpriv->hdev;
 	int rc = 0;

 	if (hl_device_disabled_or_in_reset(hdev)) {
 		dev_warn_ratelimited(hdev->dev,
 			"Device is %s. Can't execute DEBUG IOCTL\n",
 			atomic_read(&hdev->in_reset) ? "in_reset" : "disabled");
 		return -EBUSY;
 	}

 	switch (args->op) {
 	case HL_DEBUG_OP_ETR:
 	case HL_DEBUG_OP_ETF:
 	case HL_DEBUG_OP_STM:
 	case HL_DEBUG_OP_FUNNEL:
 	case HL_DEBUG_OP_BMON:
 	case HL_DEBUG_OP_SPMU:
 	case HL_DEBUG_OP_TIMESTAMP:
 		args->input_size =
 			min(args->input_size, hl_debug_struct_size[args->op]);
 		rc = debug_coresight(hdev, args);
 		break;
 	default:
 		dev_err(hdev->dev, "Invalid request %d\n", args->op);
 		rc = -ENOTTY;
 		break;
 	}

 	return rc;
 }

 #define HL_IOCTL_DEF(ioctl, _func) \
 	[_IOC_NR(ioctl)] = {.cmd = ioctl, .func = _func}

 static const struct hl_ioctl_desc hl_ioctls[] = {
 	HL_IOCTL_DEF(HL_IOCTL_INFO, hl_info_ioctl),
 	HL_IOCTL_DEF(HL_IOCTL_CB, hl_cb_ioctl),
 	HL_IOCTL_DEF(HL_IOCTL_CS, hl_cs_ioctl),
 	HL_IOCTL_DEF(HL_IOCTL_WAIT_CS, hl_cs_wait_ioctl),
 	HL_IOCTL_DEF(HL_IOCTL_MEMORY, hl_mem_ioctl),
 	HL_IOCTL_DEF(HL_IOCTL_DEBUG, hl_debug_ioctl)
 };

 #define HL_CORE_IOCTL_COUNT	ARRAY_SIZE(hl_ioctls)

 long hl_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 {
 	struct hl_fpriv *hpriv = filep->private_data;
 	struct hl_device *hdev = hpriv->hdev;
 	hl_ioctl_t *func;
 	const struct hl_ioctl_desc *ioctl = NULL;
 	unsigned int nr = _IOC_NR(cmd);
 	char stack_kdata[128] = {0};
 	char *kdata = NULL;
 	unsigned int usize, asize;
 	int retcode;

 	if (hdev->hard_reset_pending) {
 		dev_crit_ratelimited(hdev->dev,
 			"Device HARD reset pending! Please close FD\n");
 		return -ENODEV;
 	}

 	if ((nr >= HL_COMMAND_START) && (nr < HL_COMMAND_END)) {
 		u32 hl_size;

 		ioctl = &hl_ioctls[nr];

 		hl_size = _IOC_SIZE(ioctl->cmd);
 		usize = asize = _IOC_SIZE(cmd);
 		if (hl_size > asize)
 			asize = hl_size;

 		cmd = ioctl->cmd;
 	} else {
 		dev_err(hdev->dev, "invalid ioctl: pid=%d, nr=0x%02x\n",
 			  task_pid_nr(current), nr);
 		return -ENOTTY;
 	}

 	/* Do not trust userspace, use our own definition */
 	func = ioctl->func;

 	if (unlikely(!func)) {
 		dev_dbg(hdev->dev, "no function\n");
 		retcode = -ENOTTY;
 		goto out_err;
 	}

 	if (cmd & (IOC_IN | IOC_OUT)) {
 		if (asize <= sizeof(stack_kdata)) {
 			kdata = stack_kdata;
 		} else {
 			kdata = kzalloc(asize, GFP_KERNEL);
 			if (!kdata) {
 				retcode = -ENOMEM;
 				goto out_err;
 			}
 		}
 	}

 	if (cmd & IOC_IN) {
 		if (copy_from_user(kdata, (void __user *)arg, usize)) {
 			retcode = -EFAULT;
 			goto out_err;
 		}
 	} else if (cmd & IOC_OUT) {
 		memset(kdata, 0, usize);
 	}

 	retcode = func(hpriv, kdata);

 	if (cmd & IOC_OUT)
 		if (copy_to_user((void __user *)arg, kdata, usize))
 			retcode = -EFAULT;

 out_err:
 	if (retcode)
 		dev_dbg(hdev->dev,
 			"error in ioctl: pid=%d, cmd=0x%02x, nr=0x%02x\n",
 			  task_pid_nr(current), cmd, nr);

 	if (kdata != stack_kdata)
 		kfree(kdata);

 	return retcode;
 }
	// SPDX-License-Identifier: GPL-2.0

	/*
	* Copyright 2016-2019 HabanaLabs, Ltd.
	* All Rights Reserved.
	*/

	#include <uapi/misc/habanalabs.h>
	#include "habanalabs.h"

	#include <linux/fs.h>
	#include <linux/uaccess.h>
	#include <linux/slab.h>

	static u32 hl_debug_struct_size[HL_DEBUG_OP_TIMESTAMP + 1] = {
	[HL_DEBUG_OP_ETR] = sizeof(struct hl_debug_params_etr),
	[HL_DEBUG_OP_ETF] = sizeof(struct hl_debug_params_etf),
	[HL_DEBUG_OP_STM] = sizeof(struct hl_debug_params_stm),
	[HL_DEBUG_OP_FUNNEL] = 0,
	[HL_DEBUG_OP_BMON] = sizeof(struct hl_debug_params_bmon),
	[HL_DEBUG_OP_SPMU] = sizeof(struct hl_debug_params_spmu),
	[HL_DEBUG_OP_TIMESTAMP] = 0

	};

	static int device_status_info(struct hl_device hdev, struct hl_info_args args)
	{
	struct hl_info_device_status dev_stat = {0};
	u32 size = args->return_size;
	void __user out = (void __user ) (uintptr_t) args->return_pointer;

	if ((!size) \|\| (!out))
	return -EINVAL;

	dev_stat.status = hl_device_status(hdev);

	return copy_to_user(out, &dev_stat,
	min((size_t)size, sizeof(dev_stat))) ? -EFAULT : 0;
	}

	static int hw_ip_info(struct hl_device hdev, struct hl_info_args args)
	{
	struct hl_info_hw_ip_info hw_ip = {0};
	u32 size = args->return_size;
	void __user out = (void __user ) (uintptr_t) args->return_pointer;
	struct asic_fixed_properties *prop = &hdev->asic_prop;
	u64 sram_kmd_size, dram_kmd_size;

	if ((!size) \|\| (!out))
	return -EINVAL;

	sram_kmd_size = (prop->sram_user_base_address -
	prop->sram_base_address);
	dram_kmd_size = (prop->dram_user_base_address -
	prop->dram_base_address);

	hw_ip.device_id = hdev->asic_funcs->get_pci_id(hdev);
	hw_ip.sram_base_address = prop->sram_user_base_address;
	hw_ip.dram_base_address = prop->dram_user_base_address;
	hw_ip.tpc_enabled_mask = prop->tpc_enabled_mask;
	hw_ip.sram_size = prop->sram_size - sram_kmd_size;
	hw_ip.dram_size = prop->dram_size - dram_kmd_size;
	if (hw_ip.dram_size > 0)
	hw_ip.dram_enabled = 1;
	hw_ip.num_of_events = prop->num_of_events;
	memcpy(hw_ip.armcp_version,
	prop->armcp_info.armcp_version, VERSION_MAX_LEN);
	hw_ip.armcp_cpld_version = __le32_to_cpu(prop->armcp_info.cpld_version);
	hw_ip.psoc_pci_pll_nr = prop->psoc_pci_pll_nr;
	hw_ip.psoc_pci_pll_nf = prop->psoc_pci_pll_nf;
	hw_ip.psoc_pci_pll_od = prop->psoc_pci_pll_od;
	hw_ip.psoc_pci_pll_div_factor = prop->psoc_pci_pll_div_factor;

	return copy_to_user(out, &hw_ip,
	min((size_t)size, sizeof(hw_ip))) ? -EFAULT : 0;
	}

	static int hw_events_info(struct hl_device hdev, struct hl_info_args args)
	{
	u32 size, max_size = args->return_size;
	void __user out = (void __user ) (uintptr_t) args->return_pointer;
	void *arr;

	if ((!max_size) \|\| (!out))
	return -EINVAL;

	arr = hdev->asic_funcs->get_events_stat(hdev, &size);

	return copy_to_user(out, arr, min(max_size, size)) ? -EFAULT : 0;
	}

	static int dram_usage_info(struct hl_device hdev, struct hl_info_args args)
	{
	struct hl_info_dram_usage dram_usage = {0};
	u32 max_size = args->return_size;
	void __user out = (void __user ) (uintptr_t) args->return_pointer;
	struct asic_fixed_properties *prop = &hdev->asic_prop;
	u64 dram_kmd_size;

	if ((!max_size) \|\| (!out))
	return -EINVAL;

	dram_kmd_size = (prop->dram_user_base_address -
	prop->dram_base_address);
	dram_usage.dram_free_mem = (prop->dram_size - dram_kmd_size) -
	atomic64_read(&hdev->dram_used_mem);
	dram_usage.ctx_dram_mem = atomic64_read(&hdev->user_ctx->dram_phys_mem);

	return copy_to_user(out, &dram_usage,
	min((size_t) max_size, sizeof(dram_usage))) ? -EFAULT : 0;
	}

	static int hw_idle(struct hl_device hdev, struct hl_info_args args)
	{
	struct hl_info_hw_idle hw_idle = {0};
	u32 max_size = args->return_size;
	void __user out = (void __user ) (uintptr_t) args->return_pointer;

	if ((!max_size) \|\| (!out))
	return -EINVAL;

	hw_idle.is_idle = hdev->asic_funcs->is_device_idle(hdev, NULL, 0);

	return copy_to_user(out, &hw_idle,
	min((size_t) max_size, sizeof(hw_idle))) ? -EFAULT : 0;
	}

	static int debug_coresight(struct hl_device hdev, struct hl_debug_args args)
	{
	struct hl_debug_params *params;
	void input = NULL, output = NULL;
	int rc;

	params = kzalloc(sizeof(*params), GFP_KERNEL);
	if (!params)
	return -ENOMEM;

	params->reg_idx = args->reg_idx;
	params->enable = args->enable;
	params->op = args->op;

	if (args->input_ptr && args->input_size) {
	input = memdup_user((const void __user *) args->input_ptr,
	args->input_size);
	if (IS_ERR(input)) {
	rc = PTR_ERR(input);
	input = NULL;
	dev_err(hdev->dev,
	"error %d when copying input debug data\n", rc);
	goto out;
	}

	params->input = input;
	}

	if (args->output_ptr && args->output_size) {
	output = kzalloc(args->output_size, GFP_KERNEL);
	if (!output) {
	rc = -ENOMEM;
	goto out;
	}

	params->output = output;
	params->output_size = args->output_size;
	}

	rc = hdev->asic_funcs->debug_coresight(hdev, params);
	if (rc) {
	dev_err(hdev->dev,
	"debug coresight operation failed %d\n", rc);
	goto out;
	}

	if (output) {
	if (copy_to_user((void __user *) (uintptr_t) args->output_ptr,
	output,
	args->output_size)) {
	dev_err(hdev->dev,
	"copy to user failed in debug ioctl\n");
	rc = -EFAULT;
	goto out;
	}
	}

	out:
	kfree(params);
	kfree(output);
	kfree(input);

	return rc;
	}

	static int hl_info_ioctl(struct hl_fpriv hpriv, void data)
	{
	struct hl_info_args *args = data;
	struct hl_device *hdev = hpriv->hdev;
	int rc;

	/* We want to return device status even if it disabled or in reset */
	if (args->op == HL_INFO_DEVICE_STATUS)
	return device_status_info(hdev, args);

	if (hl_device_disabled_or_in_reset(hdev)) {
	dev_warn_ratelimited(hdev->dev,
	"Device is %s. Can't execute INFO IOCTL\n",
	atomic_read(&hdev->in_reset) ? "in_reset" : "disabled");
	return -EBUSY;
	}

	switch (args->op) {
	case HL_INFO_HW_IP_INFO:
	rc = hw_ip_info(hdev, args);
	break;

	case HL_INFO_HW_EVENTS:
	rc = hw_events_info(hdev, args);
	break;

	case HL_INFO_DRAM_USAGE:
	rc = dram_usage_info(hdev, args);
	break;

	case HL_INFO_HW_IDLE:
	rc = hw_idle(hdev, args);
	break;

	default:
	dev_err(hdev->dev, "Invalid request %d\n", args->op);
	rc = -ENOTTY;
	break;
	}

	return rc;
	}

	static int hl_debug_ioctl(struct hl_fpriv hpriv, void data)
	{
	struct hl_debug_args *args = data;
	struct hl_device *hdev = hpriv->hdev;
	int rc = 0;

	if (hl_device_disabled_or_in_reset(hdev)) {
	dev_warn_ratelimited(hdev->dev,
	"Device is %s. Can't execute DEBUG IOCTL\n",
	atomic_read(&hdev->in_reset) ? "in_reset" : "disabled");
	return -EBUSY;
	}

	switch (args->op) {
	case HL_DEBUG_OP_ETR:
	case HL_DEBUG_OP_ETF:
	case HL_DEBUG_OP_STM:
	case HL_DEBUG_OP_FUNNEL:
	case HL_DEBUG_OP_BMON:
	case HL_DEBUG_OP_SPMU:
	case HL_DEBUG_OP_TIMESTAMP:
	args->input_size =
	min(args->input_size, hl_debug_struct_size[args->op]);
	rc = debug_coresight(hdev, args);
	break;
	default:
	dev_err(hdev->dev, "Invalid request %d\n", args->op);
	rc = -ENOTTY;
	break;
	}

	return rc;
	}

	#define HL_IOCTL_DEF(ioctl, _func) \
	[_IOC_NR(ioctl)] = {.cmd = ioctl, .func = _func}

	static const struct hl_ioctl_desc hl_ioctls[] = {
	HL_IOCTL_DEF(HL_IOCTL_INFO, hl_info_ioctl),
	HL_IOCTL_DEF(HL_IOCTL_CB, hl_cb_ioctl),
	HL_IOCTL_DEF(HL_IOCTL_CS, hl_cs_ioctl),
	HL_IOCTL_DEF(HL_IOCTL_WAIT_CS, hl_cs_wait_ioctl),
	HL_IOCTL_DEF(HL_IOCTL_MEMORY, hl_mem_ioctl),
	HL_IOCTL_DEF(HL_IOCTL_DEBUG, hl_debug_ioctl)
	};

	#define HL_CORE_IOCTL_COUNT ARRAY_SIZE(hl_ioctls)

	long hl_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
	{
	struct hl_fpriv *hpriv = filep->private_data;
	struct hl_device *hdev = hpriv->hdev;
	hl_ioctl_t *func;
	const struct hl_ioctl_desc *ioctl = NULL;
	unsigned int nr = _IOC_NR(cmd);
	char stack_kdata[128] = {0};
	char *kdata = NULL;
	unsigned int usize, asize;
	int retcode;

	if (hdev->hard_reset_pending) {
	dev_crit_ratelimited(hdev->dev,
	"Device HARD reset pending! Please close FD\n");
	return -ENODEV;
	}

	if ((nr >= HL_COMMAND_START) && (nr < HL_COMMAND_END)) {
	u32 hl_size;

	ioctl = &hl_ioctls[nr];

	hl_size = _IOC_SIZE(ioctl->cmd);
	usize = asize = _IOC_SIZE(cmd);
	if (hl_size > asize)
	asize = hl_size;

	cmd = ioctl->cmd;
	} else {
	dev_err(hdev->dev, "invalid ioctl: pid=%d, nr=0x%02x\n",
	task_pid_nr(current), nr);
	return -ENOTTY;
	}

	/* Do not trust userspace, use our own definition */
	func = ioctl->func;

	if (unlikely(!func)) {
	dev_dbg(hdev->dev, "no function\n");
	retcode = -ENOTTY;
	goto out_err;
	}

	if (cmd & (IOC_IN \| IOC_OUT)) {
	if (asize <= sizeof(stack_kdata)) {
	kdata = stack_kdata;
	} else {
	kdata = kzalloc(asize, GFP_KERNEL);
	if (!kdata) {
	retcode = -ENOMEM;
	goto out_err;
	}
	}
	}

	if (cmd & IOC_IN) {
	if (copy_from_user(kdata, (void __user *)arg, usize)) {
	retcode = -EFAULT;
	goto out_err;
	}
	} else if (cmd & IOC_OUT) {
	memset(kdata, 0, usize);
	}

	retcode = func(hpriv, kdata);

	if (cmd & IOC_OUT)
	if (copy_to_user((void __user *)arg, kdata, usize))
	retcode = -EFAULT;

	out_err:
	if (retcode)
	dev_dbg(hdev->dev,
	"error in ioctl: pid=%d, cmd=0x%02x, nr=0x%02x\n",
	task_pid_nr(current), cmd, nr);

	if (kdata != stack_kdata)
	kfree(kdata);

	return retcode;
	}