[PATCH 383/437] intel_th: convert to read/write iterators

Jens Axboe
2024-04-11T15:42:26Z

drivers/hwtracing/intel_th/msu.c | 46 +++++++++++++++-----------------
1 file changed, 22 insertions(+), 24 deletions(-)

diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index 9621efe0e95c..a48d7ca8209a 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -1429,8 +1429,8 @@ static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
* @offset: running offset
*/
struct msc_win_to_user_struct {
- char __user *buf;
- unsigned long offset;
+ struct iov_iter *to;
+ struct kiocb *iocb;
};

/**
@@ -1442,11 +1442,11 @@ struct msc_win_to_user_struct {
static unsigned long msc_win_to_user(void *data, void *src, size_t len)
{
struct msc_win_to_user_struct *u = data;
- unsigned long ret;
-
- ret = copy_to_user(u->buf + u->offset, src, len);
- u->offset += len - ret;
+ size_t ret;

+ ret = copy_to_iter(src, len, u->to);
+ if (ret > 0)
+ u->iocb->ki_pos += ret;
return ret;
}

@@ -1483,20 +1483,20 @@ static int intel_th_msc_release(struct inode *inode, struct file *file)
return 0;
}

-static ssize_t
-msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
+static ssize_t msc_single_to_user(struct msc *msc, struct kiocb *iocb,
+ struct iov_iter *to)
{
+ size_t len = iov_iter_count(to);
unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len;
- unsigned long start = off, tocopy = 0;
+ unsigned long start = iocb->ki_pos, tocopy = 0;

if (msc->single_wrap) {
start += msc->single_sz;
if (start < size) {
tocopy = min(rem, size - start);
- if (copy_to_user(buf, msc->base + start, tocopy))
+ if (!copy_to_iter_full(msc->base + start, tocopy, to))
return -EFAULT;

- buf += tocopy;
rem -= tocopy;
start += tocopy;
}
@@ -1504,7 +1504,7 @@ msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
start &= size - 1;
if (rem) {
tocopy = min(rem, msc->single_sz - start);
- if (copy_to_user(buf, msc->base + start, tocopy))
+ if (!copy_to_iter_full(msc->base + start, tocopy, to))
return -EFAULT;

rem -= tocopy;
@@ -1513,19 +1513,19 @@ msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
return len - rem;
}

- if (copy_to_user(buf, msc->base + start, rem))
+ if (!copy_to_iter_full(msc->base + start, rem, to))
return -EFAULT;

return len;
}

-static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
- size_t len, loff_t *ppos)
+static ssize_t intel_th_msc_read(struct kiocb *iocb, struct iov_iter *to)
{
- struct msc_iter *iter = file->private_data;
+ struct msc_iter *iter = iocb->ki_filp->private_data;
struct msc *msc = iter->msc;
+ size_t len = iov_iter_count(to);
size_t size;
- loff_t off = *ppos;
+ loff_t off = iocb->ki_pos;
ssize_t ret = 0;

if (!atomic_inc_unless_negative(&msc->user_count))
@@ -1546,18 +1546,16 @@ static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
len = size - off;

if (msc->mode == MSC_MODE_SINGLE) {
- ret = msc_single_to_user(msc, buf, off, len);
+ ret = msc_single_to_user(msc, iocb, to);
if (ret >= 0)
- *ppos += ret;
+ iocb->ki_pos += ret;
} else if (msc->mode == MSC_MODE_MULTI) {
struct msc_win_to_user_struct u = {
- .buf = buf,
- .offset = 0,
+ .to = to,
+ .iocb = iocb,
};

ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user);
- if (ret >= 0)
- *ppos = iter->offset;
} else {
ret = -EINVAL;
}
@@ -1667,7 +1665,7 @@ static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma)
static const struct file_operations intel_th_msc_fops = {
.open = intel_th_msc_open,
.release = intel_th_msc_release,
- .read = intel_th_msc_read,
+ .read_iter = intel_th_msc_read,
.mmap = intel_th_msc_mmap,
.llseek = no_llseek,