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From: Jens Axboe <axboe@kernel.dk>
To: linux-kernel@vger.kernel.org
Cc: Bui Quang Minh <minhquangbui99@gmail.com>,
	Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 329/437] drivers/net/ethernet/mellanox/mlx5/core: convert to read/write iterators
Date: Thu, 11 Apr 2024 09:17:49 -0600
Message-ID: <20240411153126.16201-330-axboe@kernel.dk>
In-Reply-To: <20240411153126.16201-1-axboe@kernel.dk>
References: <20240411153126.16201-1-axboe@kernel.dk>
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MIME-Version: 1.0
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From: Bui Quang Minh <minhquangbui99@gmail.com>

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 78 ++++++++++---------
 .../net/ethernet/mellanox/mlx5/core/debugfs.c | 49 ++++++------
 .../net/ethernet/mellanox/mlx5/core/lib/sd.c  | 13 ++--
 3 files changed, 69 insertions(+), 71 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
index 4957412ff1f6..fecd1553fac5 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -1246,13 +1246,13 @@ static int mlx5_cmd_invoke(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *in,
 	return err ? : status;
 }
 
-static ssize_t dbg_write(struct file *filp, const char __user *buf,
-			 size_t count, loff_t *pos)
+static ssize_t dbg_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
-	struct mlx5_core_dev *dev = filp->private_data;
+	struct mlx5_core_dev *dev = iocb->ki_filp->private_data;
 	struct mlx5_cmd_debug *dbg = &dev->cmd.dbg;
 	char lbuf[3];
 	int err;
+	size_t count = iov_iter_count(from);
 
 	if (!dbg->in_msg || !dbg->out_msg)
 		return -ENOMEM;
@@ -1260,7 +1260,7 @@ static ssize_t dbg_write(struct file *filp, const char __user *buf,
 	if (count < sizeof(lbuf) - 1)
 		return -EINVAL;
 
-	if (copy_from_user(lbuf, buf, sizeof(lbuf) - 1))
+	if (!copy_from_iter_full(lbuf, sizeof(lbuf) - 1, from))
 		return -EFAULT;
 
 	lbuf[sizeof(lbuf) - 1] = 0;
@@ -1274,9 +1274,9 @@ static ssize_t dbg_write(struct file *filp, const char __user *buf,
 }
 
 static const struct file_operations fops = {
-	.owner	= THIS_MODULE,
-	.open	= simple_open,
-	.write	= dbg_write,
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.write_iter	= dbg_write_iter,
 };
 
 static int mlx5_copy_to_msg(struct mlx5_cmd_msg *to, void *from, int size,
@@ -1435,54 +1435,56 @@ static void mlx5_free_cmd_msg(struct mlx5_core_dev *dev,
 	kfree(msg);
 }
 
-static ssize_t data_write(struct file *filp, const char __user *buf,
-			  size_t count, loff_t *pos)
+static ssize_t data_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
-	struct mlx5_core_dev *dev = filp->private_data;
+	struct mlx5_core_dev *dev = iocb->ki_filp->private_data;
 	struct mlx5_cmd_debug *dbg = &dev->cmd.dbg;
 	void *ptr;
+	size_t count = iov_iter_count(from);
 
-	if (*pos != 0)
+	if (iocb->ki_pos != 0)
 		return -EINVAL;
 
 	kfree(dbg->in_msg);
 	dbg->in_msg = NULL;
 	dbg->inlen = 0;
-	ptr = memdup_user(buf, count);
-	if (IS_ERR(ptr))
-		return PTR_ERR(ptr);
+	ptr = kmalloc(count, GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	if (!copy_from_iter_full(ptr, count, from))
+		return -EFAULT;
+
 	dbg->in_msg = ptr;
 	dbg->inlen = count;
 
-	*pos = count;
+	iocb->ki_pos = count;
 
 	return count;
 }
 
-static ssize_t data_read(struct file *filp, char __user *buf, size_t count,
-			 loff_t *pos)
+static ssize_t data_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	struct mlx5_core_dev *dev = filp->private_data;
+	struct mlx5_core_dev *dev = iocb->ki_filp->private_data;
 	struct mlx5_cmd_debug *dbg = &dev->cmd.dbg;
 
 	if (!dbg->out_msg)
 		return -ENOMEM;
 
-	return simple_read_from_buffer(buf, count, pos, dbg->out_msg,
-				       dbg->outlen);
+	return simple_copy_to_iter(dbg->out_msg, &iocb->ki_pos,
+				   dbg->outlen, to);
 }
 
 static const struct file_operations dfops = {
-	.owner	= THIS_MODULE,
-	.open	= simple_open,
-	.write	= data_write,
-	.read	= data_read,
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.write_iter	= data_write_iter,
+	.read_iter	= data_read_iter,
 };
 
-static ssize_t outlen_read(struct file *filp, char __user *buf, size_t count,
-			   loff_t *pos)
+static ssize_t outlen_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	struct mlx5_core_dev *dev = filp->private_data;
+	struct mlx5_core_dev *dev = iocb->ki_filp->private_data;
 	struct mlx5_cmd_debug *dbg = &dev->cmd.dbg;
 	char outlen[8];
 	int err;
@@ -1491,27 +1493,27 @@ static ssize_t outlen_read(struct file *filp, char __user *buf, size_t count,
 	if (err < 0)
 		return err;
 
-	return simple_read_from_buffer(buf, count, pos, outlen, err);
+	return simple_copy_to_iter(outlen, &iocb->ki_pos, err, to);
 }
 
-static ssize_t outlen_write(struct file *filp, const char __user *buf,
-			    size_t count, loff_t *pos)
+static ssize_t outlen_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
-	struct mlx5_core_dev *dev = filp->private_data;
+	struct mlx5_core_dev *dev = iocb->ki_filp->private_data;
 	struct mlx5_cmd_debug *dbg = &dev->cmd.dbg;
 	char outlen_str[8] = {0};
 	int outlen;
 	void *ptr;
 	int err;
+	size_t count = iov_iter_count(from);
 
-	if (*pos != 0 || count > 6)
+	if (iocb->ki_pos != 0 || count > 6)
 		return -EINVAL;
 
 	kfree(dbg->out_msg);
 	dbg->out_msg = NULL;
 	dbg->outlen = 0;
 
-	if (copy_from_user(outlen_str, buf, count))
+	if (!copy_from_iter_full(outlen_str, count, from))
 		return -EFAULT;
 
 	err = sscanf(outlen_str, "%d", &outlen);
@@ -1525,16 +1527,16 @@ static ssize_t outlen_write(struct file *filp, const char __user *buf,
 	dbg->out_msg = ptr;
 	dbg->outlen = outlen;
 
-	*pos = count;
+	iocb->ki_pos = count;
 
 	return count;
 }
 
 static const struct file_operations olfops = {
-	.owner	= THIS_MODULE,
-	.open	= simple_open,
-	.write	= outlen_write,
-	.read	= outlen_read,
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.write_iter	= outlen_write_iter,
+	.read_iter	= outlen_read_iter,
 };
 
 static void set_wqname(struct mlx5_core_dev *dev)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/debugfs.c b/drivers/net/ethernet/mellanox/mlx5/core/debugfs.c
index 09652dc89115..090b5b5d0acd 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/debugfs.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/debugfs.c
@@ -126,48 +126,46 @@ void mlx5_eq_debugfs_cleanup(struct mlx5_core_dev *dev)
 	debugfs_remove_recursive(dev->priv.dbg.eq_debugfs);
 }
 
-static ssize_t average_read(struct file *filp, char __user *buf, size_t count,
-			    loff_t *pos)
+static ssize_t average_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct mlx5_cmd_stats *stats;
 	u64 field = 0;
 	int ret;
 	char tbuf[22];
 
-	stats = filp->private_data;
+	stats = iocb->ki_filp->private_data;
 	spin_lock_irq(&stats->lock);
 	if (stats->n)
 		field = div64_u64(stats->sum, stats->n);
 	spin_unlock_irq(&stats->lock);
 	ret = snprintf(tbuf, sizeof(tbuf), "%llu\n", field);
-	return simple_read_from_buffer(buf, count, pos, tbuf, ret);
+	return simple_copy_to_iter(tbuf, &iocb->ki_pos, ret, to);
 }
 
-static ssize_t average_write(struct file *filp, const char __user *buf,
-			     size_t count, loff_t *pos)
+static ssize_t average_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	struct mlx5_cmd_stats *stats;
+	size_t count = iov_iter_count(from);
 
-	stats = filp->private_data;
+	stats = iocb->ki_filp->private_data;
 	spin_lock_irq(&stats->lock);
 	stats->sum = 0;
 	stats->n = 0;
 	spin_unlock_irq(&stats->lock);
 
-	*pos += count;
+	iocb->ki_pos += count;
 
 	return count;
 }
 
 static const struct file_operations stats_fops = {
-	.owner	= THIS_MODULE,
-	.open	= simple_open,
-	.read	= average_read,
-	.write	= average_write,
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.read_iter	= average_read_iter,
+	.write_iter	= average_write_iter,
 };
 
-static ssize_t slots_read(struct file *filp, char __user *buf, size_t count,
-			  loff_t *pos)
+static ssize_t slots_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct mlx5_cmd *cmd;
 	char tbuf[6];
@@ -175,17 +173,17 @@ static ssize_t slots_read(struct file *filp, char __user *buf, size_t count,
 	int field;
 	int ret;
 
-	cmd = filp->private_data;
+	cmd = iocb->ki_filp->private_data;
 	weight = bitmap_weight(&cmd->vars.bitmask, cmd->vars.max_reg_cmds);
 	field = cmd->vars.max_reg_cmds - weight;
 	ret = snprintf(tbuf, sizeof(tbuf), "%d\n", field);
-	return simple_read_from_buffer(buf, count, pos, tbuf, ret);
+	return simple_copy_to_iter(tbuf, &iocb->ki_pos, ret, to);
 }
 
 static const struct file_operations slots_fops = {
-	.owner	= THIS_MODULE,
-	.open	= simple_open,
-	.read	= slots_read,
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.read_iter	= slots_read_iter,
 };
 
 static struct mlx5_cmd_stats *
@@ -445,8 +443,7 @@ static u64 cq_read_field(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
 	return param;
 }
 
-static ssize_t dbg_read(struct file *filp, char __user *buf, size_t count,
-			loff_t *pos)
+static ssize_t dbg_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct mlx5_field_desc *desc;
 	struct mlx5_rsc_debug *d;
@@ -455,7 +452,7 @@ static ssize_t dbg_read(struct file *filp, char __user *buf, size_t count,
 	u64 field;
 	int ret;
 
-	desc = filp->private_data;
+	desc = iocb->ki_filp->private_data;
 	d = (void *)(desc - desc->i) - sizeof(*d);
 	switch (d->type) {
 	case MLX5_DBG_RSC_QP:
@@ -480,13 +477,13 @@ static ssize_t dbg_read(struct file *filp, char __user *buf, size_t count,
 	else
 		ret = snprintf(tbuf, sizeof(tbuf), "0x%llx\n", field);
 
-	return simple_read_from_buffer(buf, count, pos, tbuf, ret);
+	return simple_copy_to_iter(tbuf, &iocb->ki_pos, ret, to);
 }
 
 static const struct file_operations fops = {
-	.owner	= THIS_MODULE,
-	.open	= simple_open,
-	.read	= dbg_read,
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.read_iter	= dbg_read_iter,
 };
 
 static int add_res_tree(struct mlx5_core_dev *dev, enum dbg_rsc_type type,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c
index 5b28084e8a03..09429b069c20 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c
@@ -393,24 +393,23 @@ static void sd_print_group(struct mlx5_core_dev *primary)
 			MLX5_CAP_GEN(pos, vhca_id));
 }
 
-static ssize_t dev_read(struct file *filp, char __user *buf, size_t count,
-			loff_t *pos)
+static ssize_t dev_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct mlx5_core_dev *dev;
 	char tbuf[32];
 	int ret;
 
-	dev = filp->private_data;
+	dev = iocb->ki_filp->private_data;
 	ret = snprintf(tbuf, sizeof(tbuf), "%s vhca %#x\n", pci_name(dev->pdev),
 		       MLX5_CAP_GEN(dev, vhca_id));
 
-	return simple_read_from_buffer(buf, count, pos, tbuf, ret);
+	return simple_copy_to_iter(tbuf, &iocb->ki_pos, ret, to);
 }
 
 static const struct file_operations dev_fops = {
-	.owner	= THIS_MODULE,
-	.open	= simple_open,
-	.read	= dev_read,
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.read_iter	= dev_read_iter,
 };
 
 int mlx5_sd_init(struct mlx5_core_dev *dev)
-- 
2.43.0