Merge tag 'icc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/djakov/icc into char-misc-next

Georgi writes:

interconnect changes for 6.6

This pull request contains the interconnect changes for the 6.6-rc1 merge
window which is a mix of core and driver changes with the following highlights:

Core changes:
- New generic test client driver that allows issuing bandwidth requests
  between endpoints via debugfs.
- Annotate all structs with flexible array members with the __counted_by
  attribute.
- Introduce new icc_bw_lock for cases where we need to serialize bandwidth
  aggregation and update to decouple that from paths that require memory
  allocation.

Driver changes:
- Move the Qualcomm SMD RPM bus-clocks from CCF to interconnect framework
  where they actually belong. This brings power management improvements
  and reduces the overhead and layering. These changes are in immutable
  branch that is being pulled also into the qcom tree.
- Fixes for QUP nodes on SM8250.
- Enable sync_state and keepalive for QCM2290.
- Enable sync_state for SM8450.
- Improve enable_mask-based BCMs handling and fix some bugs.
- Add compatible string for the OSM-L3 on SDM670.
- Add compatible strings for SC7180, SM8250 and SM6350 bandwidth monitors.
- Expand and retire the DEFINE_QNODE and DEFINE_QBCM macros, which have
  become ugly beasts with many different arguments.

Signed-off-by: Georgi Djakov <djakov@kernel.org>

* tag 'icc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/djakov/icc: (64 commits)
  interconnect: Add debugfs test client
  interconnect: Reintroduce icc_get()
  debugfs: Add write support to debugfs_create_str()
  interconnect: qcom: icc-rpmh: Retire DEFINE_QBCM
  interconnect: qcom: sm8350: Retire DEFINE_QBCM
  interconnect: qcom: sm8250: Retire DEFINE_QBCM
  interconnect: qcom: sm8150: Retire DEFINE_QBCM
  interconnect: qcom: sm6350: Retire DEFINE_QBCM
  interconnect: qcom: sdx65: Retire DEFINE_QBCM
  interconnect: qcom: sdx55: Retire DEFINE_QBCM
  interconnect: qcom: sdm845: Retire DEFINE_QBCM
  interconnect: qcom: sdm670: Retire DEFINE_QBCM
  interconnect: qcom: sc7180: Retire DEFINE_QBCM
  interconnect: qcom: icc-rpmh: Retire DEFINE_QNODE
  interconnect: qcom: sm8350: Retire DEFINE_QNODE
  interconnect: qcom: sm8250: Retire DEFINE_QNODE
  interconnect: qcom: sm8150: Retire DEFINE_QNODE
  interconnect: qcom: sm6350: Retire DEFINE_QNODE
  interconnect: qcom: sdx65: Retire DEFINE_QNODE
  interconnect: qcom: sdx55: Retire DEFINE_QNODE
  ...

1 files changed, 46 insertions, 2 deletions

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index b7711888dd17..87b3753aa4b1 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -904,8 +904,52 @@ EXPORT_SYMBOL_GPL(debugfs_create_str);
 static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf,
 				      size_t count, loff_t *ppos)
 {
-	/* This is really only for read-only strings */
-	return -EINVAL;
+	struct dentry *dentry = F_DENTRY(file);
+	char *old, *new = NULL;
+	int pos = *ppos;
+	int r;
+
+	r = debugfs_file_get(dentry);
+	if (unlikely(r))
+		return r;
+
+	old = *(char **)file->private_data;
+
+	/* only allow strict concatenation */
+	r = -EINVAL;
+	if (pos && pos != strlen(old))
+		goto error;
+
+	r = -E2BIG;
+	if (pos + count + 1 > PAGE_SIZE)
+		goto error;
+
+	r = -ENOMEM;
+	new = kmalloc(pos + count + 1, GFP_KERNEL);
+	if (!new)
+		goto error;
+
+	if (pos)
+		memcpy(new, old, pos);
+
+	r = -EFAULT;
+	if (copy_from_user(new + pos, user_buf, count))
+		goto error;
+
+	new[pos + count] = '\0';
+	strim(new);
+
+	rcu_assign_pointer(*(char **)file->private_data, new);
+	synchronize_rcu();
+	kfree(old);
+
+	debugfs_file_put(dentry);
+	return count;
+
+error:
+	kfree(new);
+	debugfs_file_put(dentry);
+	return r;
 }
 
 static const struct file_operations fops_str = {