drm_dp_aux_dev: switch to read_iter/write_iter (3941dae1) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/gpu/drm/drm_dp_aux_dev.c

+46 −63

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/uaccess.h>
		#include <linux/uio.h>
		#include <drm/drm_dp_helper.h>
		#include <drm/drm_crtc.h>
		#include <drm/drmP.h>
		@@ -140,101 +141,83 @@ static loff_t auxdev_llseek(struct file *file, loff_t offset, int whence)
		return fixed_size_llseek(file, offset, whence, AUX_MAX_OFFSET);
		}

		static ssize_t auxdev_read(struct file file, char __user buf, size_t count,
		loff_t *offset)
		static ssize_t auxdev_read_iter(struct kiocb iocb, struct iov_iter to)
		{
		size_t bytes_pending, num_bytes_processed = 0;
		struct drm_dp_aux_dev *aux_dev = file->private_data;
		struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data;
		loff_t pos = iocb->ki_pos;
		ssize_t res = 0;

		if (!atomic_inc_not_zero(&aux_dev->usecount))
		return -ENODEV;

		bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - (*offset));

		if (!access_ok(VERIFY_WRITE, buf, bytes_pending)) {
		res = -EFAULT;
		goto out;
		}
		iov_iter_truncate(to, AUX_MAX_OFFSET - pos);

		while (bytes_pending > 0) {
		uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES];
		ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf));
		while (iov_iter_count(to)) {
		uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES];
		ssize_t todo = min(iov_iter_count(to), sizeof(buf));

		if (signal_pending(current)) {
		res = num_bytes_processed ?
		num_bytes_processed : -ERESTARTSYS;
		goto out;
		res = -ERESTARTSYS;
		break;
		}

		res = drm_dp_dpcd_read(aux_dev->aux, *offset, localbuf, todo);
		if (res <= 0) {
		res = num_bytes_processed ? num_bytes_processed : res;
		goto out;
		}
		if (__copy_to_user(buf + num_bytes_processed, localbuf, res)) {
		res = num_bytes_processed ?
		num_bytes_processed : -EFAULT;
		goto out;
		res = drm_dp_dpcd_read(aux_dev->aux, pos, buf, todo);
		if (res <= 0)
		break;

		if (copy_to_iter(buf, res, to) != res) {
		res = -EFAULT;
		break;
		}
		bytes_pending -= res;
		*offset += res;
		num_bytes_processed += res;
		res = num_bytes_processed;

		pos += res;
		}

		out:
		if (pos != iocb->ki_pos)
		res = pos - iocb->ki_pos;
		iocb->ki_pos = pos;

		atomic_dec(&aux_dev->usecount);
		wake_up_atomic_t(&aux_dev->usecount);
		return res;
		}

		static ssize_t auxdev_write(struct file file, const char __user buf,
		size_t count, loff_t *offset)
		static ssize_t auxdev_write_iter(struct kiocb iocb, struct iov_iter from)
		{
		size_t bytes_pending, num_bytes_processed = 0;
		struct drm_dp_aux_dev *aux_dev = file->private_data;
		struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data;
		loff_t pos = iocb->ki_pos;
		ssize_t res = 0;

		if (!atomic_inc_not_zero(&aux_dev->usecount))
		return -ENODEV;

		bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - *offset);

		if (!access_ok(VERIFY_READ, buf, bytes_pending)) {
		res = -EFAULT;
		goto out;
		}
		iov_iter_truncate(from, AUX_MAX_OFFSET - pos);

		while (bytes_pending > 0) {
		uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES];
		ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf));
		while (iov_iter_count(from)) {
		uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES];
		ssize_t todo = min(iov_iter_count(from), sizeof(buf));

		if (signal_pending(current)) {
		res = num_bytes_processed ?
		num_bytes_processed : -ERESTARTSYS;
		goto out;
		res = -ERESTARTSYS;
		break;
		}

		if (__copy_from_user(localbuf,
		buf + num_bytes_processed, todo)) {
		res = num_bytes_processed ?
		num_bytes_processed : -EFAULT;
		goto out;
		if (!copy_from_iter_full(buf, todo, from)) {
		res = -EFAULT;
		break;
		}

		res = drm_dp_dpcd_write(aux_dev->aux, *offset, localbuf, todo);
		if (res <= 0) {
		res = num_bytes_processed ? num_bytes_processed : res;
		goto out;
		}
		bytes_pending -= res;
		*offset += res;
		num_bytes_processed += res;
		res = num_bytes_processed;
		res = drm_dp_dpcd_write(aux_dev->aux, pos, buf, todo);
		if (res <= 0)
		break;

		pos += res;
		}

		out:
		if (pos != iocb->ki_pos)
		res = pos - iocb->ki_pos;
		iocb->ki_pos = pos;

		atomic_dec(&aux_dev->usecount);
		wake_up_atomic_t(&aux_dev->usecount);
		return res;
		@@ -251,8 +234,8 @@ static int auxdev_release(struct inode inode, struct file file)
		static const struct file_operations auxdev_fops = {
		.owner = THIS_MODULE,
		.llseek = auxdev_llseek,
		.read = auxdev_read,
		.write = auxdev_write,
		.read_iter = auxdev_read_iter,
		.write_iter = auxdev_write_iter,
		.open = auxdev_open,
		.release = auxdev_release,
		};