drm/amdkfd: Do copy_to/from_user in general kfd_ioctl()

This patch moves the copy_to_user() and copy_from_user() calls from the
different ioctl functions in amdkfd to the general kfd_ioctl() function, as
this is a common code for all ioctls.

This was done according to example taken from drm_ioctl.c
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

@@ -126,17 +126,14 @@ static int kfd_open(struct inode *inode, struct file *filep)
 	return 0;
 }
 
-static long kfd_ioctl_get_version(struct file *filep, struct kfd_process *p,
-					void __user *arg)
+static int kfd_ioctl_get_version(struct file *filep, struct kfd_process *p,
+					void *data)
 {
-	struct kfd_ioctl_get_version_args args;
+	struct kfd_ioctl_get_version_args *args = data;
 	int err = 0;
 
-	args.major_version = KFD_IOCTL_MAJOR_VERSION;
-	args.minor_version = KFD_IOCTL_MINOR_VERSION;
-
-	if (copy_to_user(arg, &args, sizeof(args)))
-		err = -EFAULT;
+	args->major_version = KFD_IOCTL_MAJOR_VERSION;
+	args->minor_version = KFD_IOCTL_MINOR_VERSION;
 
 	return err;
 }
@@ -220,10 +217,10 @@ static int set_queue_properties_from_user(struct queue_properties *q_properties,
 	return 0;
 }
 
-static long kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
-					void __user *arg)
+static int kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
+					void *data)
 {
-	struct kfd_ioctl_create_queue_args args;
+	struct kfd_ioctl_create_queue_args *args = data;
 	struct kfd_dev *dev;
 	int err = 0;
 	unsigned int queue_id;
@@ -232,16 +229,13 @@ static long kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
 
 	memset(&q_properties, 0, sizeof(struct queue_properties));
 
-	if (copy_from_user(&args, arg, sizeof(args)))
-		return -EFAULT;
-
 	pr_debug("kfd: creating queue ioctl\n");
 
-	err = set_queue_properties_from_user(&q_properties, &args);
+	err = set_queue_properties_from_user(&q_properties, args);
 	if (err)
 		return err;
 
-	dev = kfd_device_by_id(args.gpu_id);
+	dev = kfd_device_by_id(args->gpu_id);
 	if (dev == NULL)
 		return -EINVAL;
 
@@ -249,7 +243,7 @@ static long kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
 
 	pdd = kfd_bind_process_to_device(dev, p);
 	if (IS_ERR(pdd)) {
-		err = PTR_ERR(pdd);
+		err = -ESRCH;
 		goto err_bind_process;
 	}
 
@@ -262,33 +256,26 @@ static long kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
 	if (err != 0)
 		goto err_create_queue;
 
-	args.queue_id = queue_id;
+	args->queue_id = queue_id;
 
 	/* Return gpu_id as doorbell offset for mmap usage */
-	args.doorbell_offset = args.gpu_id << PAGE_SHIFT;
-
-	if (copy_to_user(arg, &args, sizeof(args))) {
-		err = -EFAULT;
-		goto err_copy_args_out;
-	}
+	args->doorbell_offset = args->gpu_id << PAGE_SHIFT;
 
 	mutex_unlock(&p->mutex);
 
-	pr_debug("kfd: queue id %d was created successfully\n", args.queue_id);
+	pr_debug("kfd: queue id %d was created successfully\n", args->queue_id);
 
 	pr_debug("ring buffer address == 0x%016llX\n",
-			args.ring_base_address);
+			args->ring_base_address);
 
 	pr_debug("read ptr address    == 0x%016llX\n",
-			args.read_pointer_address);
+			args->read_pointer_address);
 
 	pr_debug("write ptr address   == 0x%016llX\n",
-			args.write_pointer_address);
+			args->write_pointer_address);
 
 	return 0;
 
-err_copy_args_out:
-	pqm_destroy_queue(&p->pqm, queue_id);
 err_create_queue:
 err_bind_process:
 	mutex_unlock(&p->mutex);
@@ -296,99 +283,90 @@ static long kfd_ioctl_create_queue(struct file *filep, struct kfd_process *p,
 }
 
 static int kfd_ioctl_destroy_queue(struct file *filp, struct kfd_process *p,
-					void __user *arg)
+					void *data)
 {
 	int retval;
-	struct kfd_ioctl_destroy_queue_args args;
-
-	if (copy_from_user(&args, arg, sizeof(args)))
-		return -EFAULT;
+	struct kfd_ioctl_destroy_queue_args *args = data;
 
 	pr_debug("kfd: destroying queue id %d for PASID %d\n",
-				args.queue_id,
+				args->queue_id,
 				p->pasid);
 
 	mutex_lock(&p->mutex);
 
-	retval = pqm_destroy_queue(&p->pqm, args.queue_id);
+	retval = pqm_destroy_queue(&p->pqm, args->queue_id);
 
 	mutex_unlock(&p->mutex);
 	return retval;
 }
 
 static int kfd_ioctl_update_queue(struct file *filp, struct kfd_process *p,
-					void __user *arg)
+					void *data)
 {
 	int retval;
-	struct kfd_ioctl_update_queue_args args;
+	struct kfd_ioctl_update_queue_args *args = data;
 	struct queue_properties properties;
 
-	if (copy_from_user(&args, arg, sizeof(args)))
-		return -EFAULT;
-
-	if (args.queue_percentage > KFD_MAX_QUEUE_PERCENTAGE) {
+	if (args->queue_percentage > KFD_MAX_QUEUE_PERCENTAGE) {
 		pr_err("kfd: queue percentage must be between 0 to KFD_MAX_QUEUE_PERCENTAGE\n");
 		return -EINVAL;
 	}
 
-	if (args.queue_priority > KFD_MAX_QUEUE_PRIORITY) {
+	if (args->queue_priority > KFD_MAX_QUEUE_PRIORITY) {
 		pr_err("kfd: queue priority must be between 0 to KFD_MAX_QUEUE_PRIORITY\n");
 		return -EINVAL;
 	}
 
-	if ((args.ring_base_address) &&
+	if ((args->ring_base_address) &&
 		(!access_ok(VERIFY_WRITE,
-			(const void __user *) args.ring_base_address,
+			(const void __user *) args->ring_base_address,
 			sizeof(uint64_t)))) {
 		pr_err("kfd: can't access ring base address\n");
 		return -EFAULT;
 	}
 
-	if (!is_power_of_2(args.ring_size) && (args.ring_size != 0)) {
+	if (!is_power_of_2(args->ring_size) && (args->ring_size != 0)) {
 		pr_err("kfd: ring size must be a power of 2 or 0\n");
 		return -EINVAL;
 	}
 
-	properties.queue_address = args.ring_base_address;
-	properties.queue_size = args.ring_size;
-	properties.queue_percent = args.queue_percentage;
-	properties.priority = args.queue_priority;
+	properties.queue_address = args->ring_base_address;
+	properties.queue_size = args->ring_size;
+	properties.queue_percent = args->queue_percentage;
+	properties.priority = args->queue_priority;
 
 	pr_debug("kfd: updating queue id %d for PASID %d\n",
-			args.queue_id, p->pasid);
+			args->queue_id, p->pasid);
 
 	mutex_lock(&p->mutex);
 
-	retval = pqm_update_queue(&p->pqm, args.queue_id, &properties);
+	retval = pqm_update_queue(&p->pqm, args->queue_id, &properties);
 
 	mutex_unlock(&p->mutex);
 
 	return retval;
 }
 
-static long kfd_ioctl_set_memory_policy(struct file *filep,
-				struct kfd_process *p, void __user *arg)
+static int kfd_ioctl_set_memory_policy(struct file *filep,
+					struct kfd_process *p, void *data)
 {
-	struct kfd_ioctl_set_memory_policy_args args;
+	struct kfd_ioctl_set_memory_policy_args *args = data;
 	struct kfd_dev *dev;
 	int err = 0;
 	struct kfd_process_device *pdd;
 	enum cache_policy default_policy, alternate_policy;
 
-	if (copy_from_user(&args, arg, sizeof(args)))
-		return -EFAULT;
-
-	if (args.default_policy != KFD_IOC_CACHE_POLICY_COHERENT
-	    && args.default_policy != KFD_IOC_CACHE_POLICY_NONCOHERENT) {
+	if (args->default_policy != KFD_IOC_CACHE_POLICY_COHERENT
+	    && args->default_policy != KFD_IOC_CACHE_POLICY_NONCOHERENT) {
 		return -EINVAL;
 	}
 
-	if (args.alternate_policy != KFD_IOC_CACHE_POLICY_COHERENT
-	    && args.alternate_policy != KFD_IOC_CACHE_POLICY_NONCOHERENT) {
+	if (args->alternate_policy != KFD_IOC_CACHE_POLICY_COHERENT
+	    && args->alternate_policy != KFD_IOC_CACHE_POLICY_NONCOHERENT) {
 		return -EINVAL;
 	}
 
-	dev = kfd_device_by_id(args.gpu_id);
+	dev = kfd_device_by_id(args->gpu_id);
 	if (dev == NULL)
 		return -EINVAL;
 
@@ -396,23 +374,23 @@ static long kfd_ioctl_set_memory_policy(struct file *filep,
 
 	pdd = kfd_bind_process_to_device(dev, p);
 	if (IS_ERR(pdd)) {
-		err = PTR_ERR(pdd);
+		err = -ESRCH;
 		goto out;
 	}
 
-	default_policy = (args.default_policy == KFD_IOC_CACHE_POLICY_COHERENT)
+	default_policy = (args->default_policy == KFD_IOC_CACHE_POLICY_COHERENT)
 			 ? cache_policy_coherent : cache_policy_noncoherent;
 
 	alternate_policy =
-		(args.alternate_policy == KFD_IOC_CACHE_POLICY_COHERENT)
+		(args->alternate_policy == KFD_IOC_CACHE_POLICY_COHERENT)
 		   ? cache_policy_coherent : cache_policy_noncoherent;
 
 	if (!dev->dqm->set_cache_memory_policy(dev->dqm,
 				&pdd->qpd,
 				default_policy,
 				alternate_policy,
-				(void __user *)args.alternate_aperture_base,
-				args.alternate_aperture_size))
+				(void __user *)args->alternate_aperture_base,
+				args->alternate_aperture_size))
 		err = -EINVAL;
 
 out:
@@ -421,53 +399,44 @@ static long kfd_ioctl_set_memory_policy(struct file *filep,
 	return err;
 }
 
-static long kfd_ioctl_get_clock_counters(struct file *filep,
-				struct kfd_process *p, void __user *arg)
+static int kfd_ioctl_get_clock_counters(struct file *filep,
+				struct kfd_process *p, void *data)
 {
-	struct kfd_ioctl_get_clock_counters_args args;
+	struct kfd_ioctl_get_clock_counters_args *args = data;
 	struct kfd_dev *dev;
 	struct timespec time;
 
-	if (copy_from_user(&args, arg, sizeof(args)))
-		return -EFAULT;
-
-	dev = kfd_device_by_id(args.gpu_id);
+	dev = kfd_device_by_id(args->gpu_id);
 	if (dev == NULL)
 		return -EINVAL;
 
 	/* Reading GPU clock counter from KGD */
-	args.gpu_clock_counter = kfd2kgd->get_gpu_clock_counter(dev->kgd);
+	args->gpu_clock_counter = kfd2kgd->get_gpu_clock_counter(dev->kgd);
 
 	/* No access to rdtsc. Using raw monotonic time */
 	getrawmonotonic(&time);
-	args.cpu_clock_counter = (uint64_t)timespec_to_ns(&time);
+	args->cpu_clock_counter = (uint64_t)timespec_to_ns(&time);
 
 	get_monotonic_boottime(&time);
-	args.system_clock_counter = (uint64_t)timespec_to_ns(&time);
+	args->system_clock_counter = (uint64_t)timespec_to_ns(&time);
 
 	/* Since the counter is in nano-seconds we use 1GHz frequency */
-	args.system_clock_freq = 1000000000;
-
-	if (copy_to_user(arg, &args, sizeof(args)))
-		return -EFAULT;
+	args->system_clock_freq = 1000000000;
 
 	return 0;
 }
 
 
 static int kfd_ioctl_get_process_apertures(struct file *filp,
-				struct kfd_process *p, void __user *arg)
+				struct kfd_process *p, void *data)
 {
-	struct kfd_ioctl_get_process_apertures_args args;
+	struct kfd_ioctl_get_process_apertures_args *args = data;
 	struct kfd_process_device_apertures *pAperture;
 	struct kfd_process_device *pdd;
 
 	dev_dbg(kfd_device, "get apertures for PASID %d", p->pasid);
 
-	if (copy_from_user(&args, arg, sizeof(args)))
-		return -EFAULT;
-
-	args.num_of_nodes = 0;
+	args->num_of_nodes = 0;
 
 	mutex_lock(&p->mutex);
 
@@ -476,7 +445,8 @@ static int kfd_ioctl_get_process_apertures(struct file *filp,
 		/* Run over all pdd of the process */
 		pdd = kfd_get_first_process_device_data(p);
 		do {
-			pAperture = &args.process_apertures[args.num_of_nodes];
+			pAperture =
+				&args->process_apertures[args->num_of_nodes];
 			pAperture->gpu_id = pdd->dev->id;
 			pAperture->lds_base = pdd->lds_base;
 			pAperture->lds_limit = pdd->lds_limit;
@@ -486,7 +456,7 @@ static int kfd_ioctl_get_process_apertures(struct file *filp,
 			pAperture->scratch_limit = pdd->scratch_limit;
 
 			dev_dbg(kfd_device,
-				"node id %u\n", args.num_of_nodes);
+				"node id %u\n", args->num_of_nodes);
 			dev_dbg(kfd_device,
 				"gpu id %u\n", pdd->dev->id);
 			dev_dbg(kfd_device,
@@ -502,23 +472,23 @@ static int kfd_ioctl_get_process_apertures(struct file *filp,
 			dev_dbg(kfd_device,
 				"scratch_limit %llX\n", pdd->scratch_limit);
 
-			args.num_of_nodes++;
+			args->num_of_nodes++;
 		} while ((pdd = kfd_get_next_process_device_data(p, pdd)) != NULL &&
-				(args.num_of_nodes < NUM_OF_SUPPORTED_GPUS));
+				(args->num_of_nodes < NUM_OF_SUPPORTED_GPUS));
 	}
 
 	mutex_unlock(&p->mutex);
 
-	if (copy_to_user(arg, &args, sizeof(args)))
-		return -EFAULT;
-
 	return 0;
 }
 
 static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 {
 	struct kfd_process *process;
-	long err = -EINVAL;
+	char stack_kdata[128];
+	char *kdata = NULL;
+	unsigned int usize, asize;
+	int retcode = -EINVAL;
 
 	dev_dbg(kfd_device,
 		"ioctl cmd 0x%x (#%d), arg 0x%lx\n",
@@ -528,54 +498,84 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 	if (IS_ERR(process))
 		return PTR_ERR(process);
 
+	if (cmd & (IOC_IN | IOC_OUT)) {
+		if (asize <= sizeof(stack_kdata)) {
+			kdata = stack_kdata;
+		} else {
+			kdata = kmalloc(asize, GFP_KERNEL);
+			if (!kdata) {
+				retcode = -ENOMEM;
+				goto err_i1;
+			}
+		}
+		if (asize > usize)
+			memset(kdata + usize, 0, asize - usize);
+	}
+
+	if (cmd & IOC_IN) {
+		if (copy_from_user(kdata, (void __user *)arg, usize) != 0) {
+			retcode = -EFAULT;
+			goto err_i1;
+		}
+	} else if (cmd & IOC_OUT) {
+		memset(kdata, 0, usize);
+	}
+
+
 	switch (cmd) {
 	case KFD_IOC_GET_VERSION:
-		err = kfd_ioctl_get_version(filep, process, (void __user *)arg);
+		retcode = kfd_ioctl_get_version(filep, process, kdata);
 		break;
 	case KFD_IOC_CREATE_QUEUE:
-		err = kfd_ioctl_create_queue(filep, process,
-						(void __user *)arg);
+		retcode = kfd_ioctl_create_queue(filep, process,
+						kdata);
 		break;
 
 	case KFD_IOC_DESTROY_QUEUE:
-		err = kfd_ioctl_destroy_queue(filep, process,
-						(void __user *)arg);
+		retcode = kfd_ioctl_destroy_queue(filep, process,
+						kdata);
 		break;
 
 	case KFD_IOC_SET_MEMORY_POLICY:
-		err = kfd_ioctl_set_memory_policy(filep, process,
-						(void __user *)arg);
+		retcode = kfd_ioctl_set_memory_policy(filep, process,
+						kdata);
 		break;
 
 	case KFD_IOC_GET_CLOCK_COUNTERS:
-		err = kfd_ioctl_get_clock_counters(filep, process,
-						(void __user *)arg);
+		retcode = kfd_ioctl_get_clock_counters(filep, process,
+						kdata);
 		break;
 
 	case KFD_IOC_GET_PROCESS_APERTURES:
-		err = kfd_ioctl_get_process_apertures(filep, process,
-						(void __user *)arg);
+		retcode = kfd_ioctl_get_process_apertures(filep, process,
+						kdata);
 		break;
 
 	case KFD_IOC_UPDATE_QUEUE:
-		err = kfd_ioctl_update_queue(filep, process,
-						(void __user *)arg);
+		retcode = kfd_ioctl_update_queue(filep, process,
+						kdata);
 		break;
 
 	default:
-		dev_err(kfd_device,
+		dev_dbg(kfd_device,
 			"unknown ioctl cmd 0x%x, arg 0x%lx)\n",
 			cmd, arg);
-		err = -EINVAL;
+		retcode = -EINVAL;
 		break;
 	}
 
-	if (err < 0)
-		dev_err(kfd_device,
-			"ioctl error %ld for ioctl cmd 0x%x (#%d)\n",
-			err, cmd, _IOC_NR(cmd));
+	if (cmd & IOC_OUT)
+		if (copy_to_user((void __user *)arg, kdata, usize) != 0)
+			retcode = -EFAULT;
 
-	return err;
+err_i1:
+	if (kdata != stack_kdata)
+		kfree(kdata);
+
+	if (retcode)
+		dev_dbg(kfd_device, "ret = %d\n", retcode);
+
+	return retcode;
 }
 
 static int kfd_mmap(struct file *filp, struct vm_area_struct *vma)