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* [PATCH v10 1/5] overlayfs: check CAP_DAC_READ_SEARCH before issuing exportfs_decode_fh
From: Mark Salyzyn @ 2019-07-24 19:57 UTC (permalink / raw)
  To: linux-kernel
  Cc: kernel-team, Mark Salyzyn, Miklos Szeredi, Jonathan Corbet,
	Vivek Goyal, Eric W . Biederman, Amir Goldstein, Randy Dunlap,
	Stephen Smalley, linux-unionfs, linux-doc
In-Reply-To: <20190724195719.218307-1-salyzyn@android.com>

Assumption never checked, should fail if the mounter creds are not
sufficient.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: linux-unionfs@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com
---
v10:
- return NULL rather than ERR_PTR(-EPERM)
- did _not_ add it ovl_can_decode_fh() because of changes since last
  review, suspect needs to be added to ovl_lower_uuid_ok()?

v8 + v9:
- rebase

v7:
- This time for realz

v6:
- rebase

v5:
- dependency of "overlayfs: override_creds=off option bypass creator_cred"
---
 fs/overlayfs/namei.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index e9717c2f7d45..9702f0d5309d 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -161,6 +161,9 @@ struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
 	if (!uuid_equal(&fh->uuid, &mnt->mnt_sb->s_uuid))
 		return NULL;
 
+	if (!capable(CAP_DAC_READ_SEARCH))
+		return NULL;
+
 	bytes = (fh->len - offsetof(struct ovl_fh, fid));
 	real = exportfs_decode_fh(mnt, (struct fid *)fh->fid,
 				  bytes >> 2, (int)fh->type,
-- 
2.22.0.657.g960e92d24f-goog


^ permalink raw reply related

* [PATCH v10 3/5] overlayfs: add __get xattr method
From: Mark Salyzyn @ 2019-07-24 19:57 UTC (permalink / raw)
  To: linux-kernel
  Cc: kernel-team, Mark Salyzyn, Miklos Szeredi, Jonathan Corbet,
	Vivek Goyal, Eric W . Biederman, Amir Goldstein, Randy Dunlap,
	Stephen Smalley, linux-unionfs, linux-doc
In-Reply-To: <20190724195719.218307-1-salyzyn@android.com>

Because of the overlayfs getxattr recursion, the incoming inode fails
to update the selinux sid resulting in avc denials being reported
against a target context of u:object_r:unlabeled:s0.

Solution is to add a _get xattr method that calls the __vfs_getxattr
handler so that the context can be read in, rather than being denied
with an -EACCES when vfs_getxattr handler is called.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: linux-unionfs@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com
---
v10 - added to patch series
---
 fs/overlayfs/inode.c     | 15 +++++++++++++++
 fs/overlayfs/overlayfs.h |  2 ++
 fs/overlayfs/super.c     | 18 ++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 7663aeb85fa3..d3b53849615c 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -362,6 +362,21 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
 	return err;
 }
 
+int __ovl_xattr_get(struct dentry *dentry, struct inode *inode,
+		    const char *name, void *value, size_t size)
+{
+	ssize_t res;
+	const struct cred *old_cred;
+	struct dentry *realdentry =
+		ovl_i_dentry_upper(inode) ?: ovl_dentry_lower(dentry);
+
+	old_cred = ovl_override_creds(dentry->d_sb);
+	res = __vfs_getxattr(realdentry, d_inode(realdentry), name, value,
+			     size);
+	ovl_revert_creds(old_cred);
+	return res;
+}
+
 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
 		  void *value, size_t size)
 {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 6934bcf030f0..73a02a263fbc 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -357,6 +357,8 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
 		  const void *value, size_t size, int flags);
 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
 		  void *value, size_t size);
+int __ovl_xattr_get(struct dentry *dentry, struct inode *inode,
+		    const char *name, void *value, size_t size);
 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
 struct posix_acl *ovl_get_acl(struct inode *inode, int type);
 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index b368e2e102fa..82e1130de206 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -859,6 +859,14 @@ ovl_posix_acl_xattr_get(const struct xattr_handler *handler,
 	return ovl_xattr_get(dentry, inode, handler->name, buffer, size);
 }
 
+static int __maybe_unused
+__ovl_posix_acl_xattr_get(const struct xattr_handler *handler,
+			  struct dentry *dentry, struct inode *inode,
+			  const char *name, void *buffer, size_t size)
+{
+	return __ovl_xattr_get(dentry, inode, handler->name, buffer, size);
+}
+
 static int __maybe_unused
 ovl_posix_acl_xattr_set(const struct xattr_handler *handler,
 			struct dentry *dentry, struct inode *inode,
@@ -939,6 +947,13 @@ static int ovl_other_xattr_get(const struct xattr_handler *handler,
 	return ovl_xattr_get(dentry, inode, name, buffer, size);
 }
 
+static int __ovl_other_xattr_get(const struct xattr_handler *handler,
+				 struct dentry *dentry, struct inode *inode,
+				 const char *name, void *buffer, size_t size)
+{
+	return __ovl_xattr_get(dentry, inode, name, buffer, size);
+}
+
 static int ovl_other_xattr_set(const struct xattr_handler *handler,
 			       struct dentry *dentry, struct inode *inode,
 			       const char *name, const void *value,
@@ -952,6 +967,7 @@ ovl_posix_acl_access_xattr_handler = {
 	.name = XATTR_NAME_POSIX_ACL_ACCESS,
 	.flags = ACL_TYPE_ACCESS,
 	.get = ovl_posix_acl_xattr_get,
+	.__get = __ovl_posix_acl_xattr_get,
 	.set = ovl_posix_acl_xattr_set,
 };
 
@@ -960,6 +976,7 @@ ovl_posix_acl_default_xattr_handler = {
 	.name = XATTR_NAME_POSIX_ACL_DEFAULT,
 	.flags = ACL_TYPE_DEFAULT,
 	.get = ovl_posix_acl_xattr_get,
+	.__get = __ovl_posix_acl_xattr_get,
 	.set = ovl_posix_acl_xattr_set,
 };
 
@@ -972,6 +989,7 @@ static const struct xattr_handler ovl_own_xattr_handler = {
 static const struct xattr_handler ovl_other_xattr_handler = {
 	.prefix	= "", /* catch all */
 	.get = ovl_other_xattr_get,
+	.__get = __ovl_other_xattr_get,
 	.set = ovl_other_xattr_set,
 };
 
-- 
2.22.0.657.g960e92d24f-goog


^ permalink raw reply related

* [PATCH v10 4/5] overlayfs: internal getxattr operations without sepolicy checking
From: Mark Salyzyn @ 2019-07-24 19:57 UTC (permalink / raw)
  To: linux-kernel
  Cc: kernel-team, Mark Salyzyn, Miklos Szeredi, Jonathan Corbet,
	Vivek Goyal, Eric W . Biederman, Amir Goldstein, Randy Dunlap,
	Stephen Smalley, linux-unionfs, linux-doc
In-Reply-To: <20190724195719.218307-1-salyzyn@android.com>

Check impure, opaque, origin & meta xattr with no sepolicy audit
(using __vfs_getxattr) since these operations are internal to
overlayfs operations and do not disclose any data.  This became
an issue for credential override off since sys_admin would have
been required by the caller; whereas would have been inherently
present for the creator since it performed the mount.

This is a change in operations since we do not check in the new
ovl_vfs_getxattr function if the credential override is off or
not.  Reasoning is that the sepolicy check is unnecessary overhead,
especially since the check can be expensive.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: linux-unionfs@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com
---
v10 - added to patch series
---
 fs/overlayfs/namei.c     | 12 +++++++-----
 fs/overlayfs/overlayfs.h |  2 ++
 fs/overlayfs/util.c      | 24 +++++++++++++++---------
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 9702f0d5309d..fb6c0cd7b65f 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -106,10 +106,11 @@ int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
 
 static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
 {
-	int res, err;
+	ssize_t res;
+	int err;
 	struct ovl_fh *fh = NULL;
 
-	res = vfs_getxattr(dentry, name, NULL, 0);
+	res = ovl_vfs_getxattr(dentry, name, NULL, 0);
 	if (res < 0) {
 		if (res == -ENODATA || res == -EOPNOTSUPP)
 			return NULL;
@@ -123,7 +124,7 @@ static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
 	if (!fh)
 		return ERR_PTR(-ENOMEM);
 
-	res = vfs_getxattr(dentry, name, fh, res);
+	res = ovl_vfs_getxattr(dentry, name, fh, res);
 	if (res < 0)
 		goto fail;
 
@@ -141,10 +142,11 @@ static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
 	return NULL;
 
 fail:
-	pr_warn_ratelimited("overlayfs: failed to get origin (%i)\n", res);
+	pr_warn_ratelimited("overlayfs: failed to get origin (%zi)\n", res);
 	goto out;
 invalid:
-	pr_warn_ratelimited("overlayfs: invalid origin (%*phN)\n", res, fh);
+	pr_warn_ratelimited("overlayfs: invalid origin (%*phN)\n",
+			    (int)res, fh);
 	goto out;
 }
 
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 73a02a263fbc..82574684a9b6 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -205,6 +205,8 @@ int ovl_want_write(struct dentry *dentry);
 void ovl_drop_write(struct dentry *dentry);
 struct dentry *ovl_workdir(struct dentry *dentry);
 const struct cred *ovl_override_creds(struct super_block *sb);
+ssize_t ovl_vfs_getxattr(struct dentry *dentry, const char *name, void *buf,
+			 size_t size);
 struct super_block *ovl_same_sb(struct super_block *sb);
 int ovl_can_decode_fh(struct super_block *sb);
 struct dentry *ovl_indexdir(struct super_block *sb);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index f5678a3f8350..672459c3cff7 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -40,6 +40,12 @@ const struct cred *ovl_override_creds(struct super_block *sb)
 	return override_creds(ofs->creator_cred);
 }
 
+ssize_t ovl_vfs_getxattr(struct dentry *dentry, const char *name, void *buf,
+			 size_t size)
+{
+	return __vfs_getxattr(dentry, d_inode(dentry), name, buf, size);
+}
+
 struct super_block *ovl_same_sb(struct super_block *sb)
 {
 	struct ovl_fs *ofs = sb->s_fs_info;
@@ -537,9 +543,9 @@ void ovl_copy_up_end(struct dentry *dentry)
 
 bool ovl_check_origin_xattr(struct dentry *dentry)
 {
-	int res;
+	ssize_t res;
 
-	res = vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0);
+	res = ovl_vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0);
 
 	/* Zero size value means "copied up but origin unknown" */
 	if (res >= 0)
@@ -550,13 +556,13 @@ bool ovl_check_origin_xattr(struct dentry *dentry)
 
 bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)
 {
-	int res;
+	ssize_t res;
 	char val;
 
 	if (!d_is_dir(dentry))
 		return false;
 
-	res = vfs_getxattr(dentry, name, &val, 1);
+	res = ovl_vfs_getxattr(dentry, name, &val, 1);
 	if (res == 1 && val == 'y')
 		return true;
 
@@ -837,13 +843,13 @@ int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir)
 /* err < 0, 0 if no metacopy xattr, 1 if metacopy xattr found */
 int ovl_check_metacopy_xattr(struct dentry *dentry)
 {
-	int res;
+	ssize_t res;
 
 	/* Only regular files can have metacopy xattr */
 	if (!S_ISREG(d_inode(dentry)->i_mode))
 		return 0;
 
-	res = vfs_getxattr(dentry, OVL_XATTR_METACOPY, NULL, 0);
+	res = ovl_vfs_getxattr(dentry, OVL_XATTR_METACOPY, NULL, 0);
 	if (res < 0) {
 		if (res == -ENODATA || res == -EOPNOTSUPP)
 			return 0;
@@ -852,7 +858,7 @@ int ovl_check_metacopy_xattr(struct dentry *dentry)
 
 	return 1;
 out:
-	pr_warn_ratelimited("overlayfs: failed to get metacopy (%i)\n", res);
+	pr_warn_ratelimited("overlayfs: failed to get metacopy (%zi)\n", res);
 	return res;
 }
 
@@ -878,7 +884,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
 	ssize_t res;
 	char *buf = NULL;
 
-	res = vfs_getxattr(dentry, name, NULL, 0);
+	res = ovl_vfs_getxattr(dentry, name, NULL, 0);
 	if (res < 0) {
 		if (res == -ENODATA || res == -EOPNOTSUPP)
 			return -ENODATA;
@@ -890,7 +896,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
 		if (!buf)
 			return -ENOMEM;
 
-		res = vfs_getxattr(dentry, name, buf, res);
+		res = ovl_vfs_getxattr(dentry, name, buf, res);
 		if (res < 0)
 			goto fail;
 	}
-- 
2.22.0.657.g960e92d24f-goog


^ permalink raw reply related

* [PATCH v10 5/5] overlayfs: override_creds=off option bypass creator_cred
From: Mark Salyzyn @ 2019-07-24 19:57 UTC (permalink / raw)
  To: linux-kernel
  Cc: kernel-team, Mark Salyzyn, Miklos Szeredi, Jonathan Corbet,
	Vivek Goyal, Eric W . Biederman, Amir Goldstein, Randy Dunlap,
	Stephen Smalley, linux-unionfs, linux-doc
In-Reply-To: <20190724195719.218307-1-salyzyn@android.com>

By default, all access to the upper, lower and work directories is the
recorded mounter's MAC and DAC credentials.  The incoming accesses are
checked against the caller's credentials.

If the principles of least privilege are applied, the mounter's
credentials might not overlap the credentials of the caller's when
accessing the overlayfs filesystem.  For example, a file that a lower
DAC privileged caller can execute, is MAC denied to the generally
higher DAC privileged mounter, to prevent an attack vector.

We add the option to turn off override_creds in the mount options; all
subsequent operations after mount on the filesystem will be only the
caller's credentials.  The module boolean parameter and mount option
override_creds is also added as a presence check for this "feature",
existence of /sys/module/overlay/parameters/override_creds.

It was not always this way.  Circa 4.6 there was no recorded mounter's
credentials, instead privileged access to upper or work directories
were temporarily increased to perform the operations.  The MAC
(selinux) policies were caller's in all cases.  override_creds=off
partially returns us to this older access model minus the insecure
temporary credential increases.  This is to permit use in a system
with non-overlapping security models for each executable including
the agent that mounts the overlayfs filesystem.  In Android
this is the case since init, which performs the mount operations,
has a minimal MAC set of privileges to reduce any attack surface,
and services that use the content have a different set of MAC
privileges (eg: read, for vendor labelled configuration, execute for
vendor libraries and modules).  The caveats are not a problem in
the Android usage model, however they should be fixed for
completeness and for general use in time.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: linux-unionfs@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com
---
v10:
- Rebase (and expand because of increased revert_cred usage)

v9:
- Add to the caveats

v8:
- drop pr_warn message after straw poll to remove it.
- added a use case in the commit message

v7:
- change name of internal parameter to ovl_override_creds_def
- report override_creds only if different than default

v6:
- Drop CONFIG_OVERLAY_FS_OVERRIDE_CREDS.
- Do better with the documentation.
- pr_warn message adjusted to report consequences.

v5:
- beefed up the caveats in the Documentation
- Is dependent on
  "overlayfs: check CAP_DAC_READ_SEARCH before issuing exportfs_decode_fh"
  "overlayfs: check CAP_MKNOD before issuing vfs_whiteout"
- Added prwarn when override_creds=off

v4:
- spelling and grammar errors in text

v3:
- Change name from caller_credentials / creator_credentials to the
  boolean override_creds.
- Changed from creator to mounter credentials.
- Updated and fortified the documentation.
- Added CONFIG_OVERLAY_FS_OVERRIDE_CREDS

v2:
- Forward port changed attr to stat, resulting in a build error.
- altered commit message.

a
---
 Documentation/filesystems/overlayfs.txt | 23 +++++++++++++++++++++++
 fs/overlayfs/copy_up.c                  |  2 +-
 fs/overlayfs/dir.c                      | 11 ++++++-----
 fs/overlayfs/file.c                     | 20 ++++++++++----------
 fs/overlayfs/inode.c                    | 18 +++++++++---------
 fs/overlayfs/namei.c                    |  6 +++---
 fs/overlayfs/overlayfs.h                |  1 +
 fs/overlayfs/ovl_entry.h                |  1 +
 fs/overlayfs/readdir.c                  |  4 ++--
 fs/overlayfs/super.c                    | 22 +++++++++++++++++++++-
 fs/overlayfs/util.c                     | 12 ++++++++++--
 11 files changed, 87 insertions(+), 33 deletions(-)

diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt
index 1da2f1668f08..d48125076602 100644
--- a/Documentation/filesystems/overlayfs.txt
+++ b/Documentation/filesystems/overlayfs.txt
@@ -102,6 +102,29 @@ Only the lists of names from directories are merged.  Other content
 such as metadata and extended attributes are reported for the upper
 directory only.  These attributes of the lower directory are hidden.
 
+credentials
+-----------
+
+By default, all access to the upper, lower and work directories is the
+recorded mounter's MAC and DAC credentials.  The incoming accesses are
+checked against the caller's credentials.
+
+In the case where caller MAC or DAC credentials do not overlap, a
+use case available in older versions of the driver, the
+override_creds mount flag can be turned off and help when the use
+pattern has caller with legitimate credentials where the mounter
+does not.  Several unintended side effects will occur though.  The
+caller without certain key capabilities or lower privilege will not
+always be able to delete files or directories, create nodes, or
+search some restricted directories.  The ability to search and read
+a directory entry is spotty as a result of the cache mechanism not
+retesting the credentials because of the assumption, a privileged
+caller can fill cache, then a lower privilege can read the directory
+cache.  The uneven security model where cache, upperdir and workdir
+are opened at privilege, but accessed without creating a form of
+privilege escalation, should only be used with strict understanding
+of the side effects and of the security policies.
+
 whiteouts and opaque directories
 --------------------------------
 
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index b801c6353100..1311ab4aea00 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -886,7 +886,7 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags)
 		dput(parent);
 		dput(next);
 	}
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return err;
 }
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 702aa63f6774..c4b061c3a6ef 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -563,7 +563,8 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
 		override_cred->fsgid = inode->i_gid;
 		if (!attr->hardlink) {
 			err = security_dentry_create_files_as(dentry,
-					attr->mode, &dentry->d_name, old_cred,
+					attr->mode, &dentry->d_name,
+					old_cred ? old_cred : current_cred(),
 					override_cred);
 			if (err) {
 				put_cred(override_cred);
@@ -579,7 +580,7 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
 			err = ovl_create_over_whiteout(dentry, inode, attr);
 	}
 out_revert_creds:
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	return err;
 }
 
@@ -655,7 +656,7 @@ static int ovl_set_link_redirect(struct dentry *dentry)
 
 	old_cred = ovl_override_creds(dentry->d_sb);
 	err = ovl_set_redirect(dentry, false);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return err;
 }
@@ -851,7 +852,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
 		err = ovl_remove_upper(dentry, is_dir, &list);
 	else
 		err = ovl_remove_and_whiteout(dentry, &list);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	if (!err) {
 		if (is_dir)
 			clear_nlink(dentry->d_inode);
@@ -1221,7 +1222,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
 out_unlock:
 	unlock_rename(new_upperdir, old_upperdir);
 out_revert_creds:
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	if (update_nlink)
 		ovl_nlink_end(new);
 out_drop_write:
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index e235a635d9ec..39a50fad9f7f 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -32,7 +32,7 @@ static struct file *ovl_open_realfile(const struct file *file,
 	old_cred = ovl_override_creds(inode->i_sb);
 	realfile = open_with_fake_path(&file->f_path, flags, realinode,
 				       current_cred());
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n",
 		 file, file, ovl_whatisit(inode, realinode), file->f_flags,
@@ -176,7 +176,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
 
 	old_cred = ovl_override_creds(inode->i_sb);
 	ret = vfs_llseek(real.file, offset, whence);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	file->f_pos = real.file->f_pos;
 	inode_unlock(inode);
@@ -242,7 +242,7 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
 	ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
 			    ovl_iocb_to_rwf(iocb));
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	ovl_file_accessed(file);
 
@@ -278,7 +278,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 	ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
 			     ovl_iocb_to_rwf(iocb));
 	file_end_write(real.file);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	/* Update size */
 	ovl_copyattr(ovl_inode_real(inode), inode);
@@ -305,7 +305,7 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 	if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) {
 		old_cred = ovl_override_creds(file_inode(file)->i_sb);
 		ret = vfs_fsync_range(real.file, start, end, datasync);
-		revert_creds(old_cred);
+		ovl_revert_creds(old_cred);
 	}
 
 	fdput(real);
@@ -329,7 +329,7 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
 	ret = call_mmap(vma->vm_file, vma);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	if (ret) {
 		/* Drop reference count from new vm_file value */
@@ -357,7 +357,7 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
 	ret = vfs_fallocate(real.file, mode, offset, len);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	/* Update size */
 	ovl_copyattr(ovl_inode_real(inode), inode);
@@ -379,7 +379,7 @@ static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
 	ret = vfs_fadvise(real.file, offset, len, advice);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	fdput(real);
 
@@ -399,7 +399,7 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd,
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
 	ret = vfs_ioctl(real.file, cmd, arg);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	fdput(real);
 
@@ -589,7 +589,7 @@ static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
 						flags);
 		break;
 	}
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	/* Update size */
 	ovl_copyattr(ovl_inode_real(inode_out), inode_out);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index d3b53849615c..6c11c7af5157 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -61,7 +61,7 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 		inode_lock(upperdentry->d_inode);
 		old_cred = ovl_override_creds(dentry->d_sb);
 		err = notify_change(upperdentry, attr, NULL);
-		revert_creds(old_cred);
+		ovl_revert_creds(old_cred);
 		if (!err)
 			ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
 		inode_unlock(upperdentry->d_inode);
@@ -257,7 +257,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
 		stat->nlink = dentry->d_inode->i_nlink;
 
 out:
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return err;
 }
@@ -291,7 +291,7 @@ int ovl_permission(struct inode *inode, int mask)
 		mask |= MAY_READ;
 	}
 	err = inode_permission(realinode, mask);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return err;
 }
@@ -308,7 +308,7 @@ static const char *ovl_get_link(struct dentry *dentry,
 
 	old_cred = ovl_override_creds(dentry->d_sb);
 	p = vfs_get_link(ovl_dentry_real(dentry), done);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	return p;
 }
 
@@ -351,7 +351,7 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
 		WARN_ON(flags != XATTR_REPLACE);
 		err = vfs_removexattr(realdentry, name);
 	}
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	/* copy c/mtime */
 	ovl_copyattr(d_inode(realdentry), inode);
@@ -387,7 +387,7 @@ int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
 
 	old_cred = ovl_override_creds(dentry->d_sb);
 	res = vfs_getxattr(realdentry, name, value, size);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	return res;
 }
 
@@ -411,7 +411,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
 
 	old_cred = ovl_override_creds(dentry->d_sb);
 	res = vfs_listxattr(realdentry, list, size);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	if (res <= 0 || size == 0)
 		return res;
 
@@ -446,7 +446,7 @@ struct posix_acl *ovl_get_acl(struct inode *inode, int type)
 
 	old_cred = ovl_override_creds(inode->i_sb);
 	acl = get_acl(realinode, type);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return acl;
 }
@@ -484,7 +484,7 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		filemap_write_and_wait(realinode->i_mapping);
 
 	err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return err;
 }
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index fb6c0cd7b65f..12627018b00a 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -1079,7 +1079,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 			goto out_free_oe;
 	}
 
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	if (origin_path) {
 		dput(origin_path->dentry);
 		kfree(origin_path);
@@ -1106,7 +1106,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 	kfree(upperredirect);
 out:
 	kfree(d.redirect);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	return ERR_PTR(err);
 }
 
@@ -1160,7 +1160,7 @@ bool ovl_lower_positive(struct dentry *dentry)
 			dput(this);
 		}
 	}
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return positive;
 }
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 82574684a9b6..cdbdb533d3bd 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -205,6 +205,7 @@ int ovl_want_write(struct dentry *dentry);
 void ovl_drop_write(struct dentry *dentry);
 struct dentry *ovl_workdir(struct dentry *dentry);
 const struct cred *ovl_override_creds(struct super_block *sb);
+void ovl_revert_creds(const struct cred *oldcred);
 ssize_t ovl_vfs_getxattr(struct dentry *dentry, const char *name, void *buf,
 			 size_t size);
 struct super_block *ovl_same_sb(struct super_block *sb);
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 28a2d12a1029..2637c5aadf7f 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -17,6 +17,7 @@ struct ovl_config {
 	bool nfs_export;
 	int xino;
 	bool metacopy;
+	bool override_creds;
 };
 
 struct ovl_sb {
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 47a91c9733a5..f31ef39e5afa 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -286,7 +286,7 @@ static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd)
 		}
 		inode_unlock(dir->d_inode);
 	}
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 	return err;
 }
@@ -918,7 +918,7 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
 
 	old_cred = ovl_override_creds(dentry->d_sb);
 	err = ovl_dir_read_merged(dentry, list, &root);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 	if (err)
 		return err;
 
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 82e1130de206..c2ddce5d488c 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -53,6 +53,11 @@ module_param_named(xino_auto, ovl_xino_auto_def, bool, 0644);
 MODULE_PARM_DESC(xino_auto,
 		 "Auto enable xino feature");
 
+static bool __read_mostly ovl_override_creds_def = true;
+module_param_named(override_creds, ovl_override_creds_def, bool, 0644);
+MODULE_PARM_DESC(ovl_override_creds_def,
+		 "Use mounter's credentials for accesses");
+
 static void ovl_entry_stack_free(struct ovl_entry *oe)
 {
 	unsigned int i;
@@ -362,6 +367,9 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
 	if (ofs->config.metacopy != ovl_metacopy_def)
 		seq_printf(m, ",metacopy=%s",
 			   ofs->config.metacopy ? "on" : "off");
+	if (ofs->config.override_creds != ovl_override_creds_def)
+		seq_show_option(m, "override_creds",
+				ofs->config.override_creds ? "on" : "off");
 	return 0;
 }
 
@@ -402,6 +410,8 @@ enum {
 	OPT_XINO_AUTO,
 	OPT_METACOPY_ON,
 	OPT_METACOPY_OFF,
+	OPT_OVERRIDE_CREDS_ON,
+	OPT_OVERRIDE_CREDS_OFF,
 	OPT_ERR,
 };
 
@@ -420,6 +430,8 @@ static const match_table_t ovl_tokens = {
 	{OPT_XINO_AUTO,			"xino=auto"},
 	{OPT_METACOPY_ON,		"metacopy=on"},
 	{OPT_METACOPY_OFF,		"metacopy=off"},
+	{OPT_OVERRIDE_CREDS_ON,		"override_creds=on"},
+	{OPT_OVERRIDE_CREDS_OFF,	"override_creds=off"},
 	{OPT_ERR,			NULL}
 };
 
@@ -478,6 +490,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
 	config->redirect_mode = kstrdup(ovl_redirect_mode_def(), GFP_KERNEL);
 	if (!config->redirect_mode)
 		return -ENOMEM;
+	config->override_creds = ovl_override_creds_def;
 
 	while ((p = ovl_next_opt(&opt)) != NULL) {
 		int token;
@@ -558,6 +571,14 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
 			config->metacopy = false;
 			break;
 
+		case OPT_OVERRIDE_CREDS_ON:
+			config->override_creds = true;
+			break;
+
+		case OPT_OVERRIDE_CREDS_OFF:
+			config->override_creds = false;
+			break;
+
 		default:
 			pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
 			return -EINVAL;
@@ -1690,7 +1711,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 		       ovl_dentry_lower(root_dentry), NULL);
 
 	sb->s_root = root_dentry;
-
 	return 0;
 
 out_free_oe:
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 672459c3cff7..320aad599bcd 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -37,9 +37,17 @@ const struct cred *ovl_override_creds(struct super_block *sb)
 {
 	struct ovl_fs *ofs = sb->s_fs_info;
 
+	if (!ofs->config.override_creds)
+		return NULL;
 	return override_creds(ofs->creator_cred);
 }
 
+void ovl_revert_creds(const struct cred *old_cred)
+{
+	if (old_cred)
+		revert_creds(old_cred);
+}
+
 ssize_t ovl_vfs_getxattr(struct dentry *dentry, const char *name, void *buf,
 			 size_t size)
 {
@@ -797,7 +805,7 @@ int ovl_nlink_start(struct dentry *dentry)
 	 * value relative to the upper inode nlink in an upper inode xattr.
 	 */
 	err = ovl_set_nlink_upper(dentry);
-	revert_creds(old_cred);
+	ovl_revert_creds(old_cred);
 
 out:
 	if (err)
@@ -815,7 +823,7 @@ void ovl_nlink_end(struct dentry *dentry)
 
 		old_cred = ovl_override_creds(dentry->d_sb);
 		ovl_cleanup_index(dentry);
-		revert_creds(old_cred);
+		ovl_revert_creds(old_cred);
 	}
 
 	ovl_inode_unlock(inode);
-- 
2.22.0.657.g960e92d24f-goog


^ permalink raw reply related

* [PATCH v10 2/5] Add optional __get xattr method paired to __vfs_getxattr
From: Mark Salyzyn @ 2019-07-24 19:57 UTC (permalink / raw)
  To: linux-kernel
  Cc: kernel-team, Mark Salyzyn, Miklos Szeredi, Jonathan Corbet,
	Vivek Goyal, Eric W . Biederman, Amir Goldstein, Randy Dunlap,
	Stephen Smalley, linux-unionfs, linux-doc, Alexander Viro,
	Mark Salyzyn, linux-fsdevel
In-Reply-To: <20190724195719.218307-1-salyzyn@android.com>

Add an optional __get xattr method that would be called, if set, only
in __vfs_getxattr instead of the regular get xattr method.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: linux-unionfs@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com
---
v10 - added to patch series
---
 fs/xattr.c            | 11 ++++++++++-
 include/linux/xattr.h |  7 +++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/fs/xattr.c b/fs/xattr.c
index 90dd78f0eb27..b8f4734e222f 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -306,6 +306,9 @@ __vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name,
 	handler = xattr_resolve_name(inode, &name);
 	if (IS_ERR(handler))
 		return PTR_ERR(handler);
+	if (unlikely(handler->__get))
+		return handler->__get(handler, dentry, inode, name, value,
+				      size);
 	if (!handler->get)
 		return -EOPNOTSUPP;
 	return handler->get(handler, dentry, inode, name, value, size);
@@ -317,6 +320,7 @@ vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
 {
 	struct inode *inode = dentry->d_inode;
 	int error;
+	const struct xattr_handler *handler;
 
 	error = xattr_permission(inode, name, MAY_READ);
 	if (error)
@@ -339,7 +343,12 @@ vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
 		return ret;
 	}
 nolsm:
-	return __vfs_getxattr(dentry, inode, name, value, size);
+	handler = xattr_resolve_name(inode, &name);
+	if (IS_ERR(handler))
+		return PTR_ERR(handler);
+	if (!handler->get)
+		return -EOPNOTSUPP;
+	return handler->get(handler, dentry, inode, name, value, size);
 }
 EXPORT_SYMBOL_GPL(vfs_getxattr);
 
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 6dad031be3c2..30f25e1ac571 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -30,10 +30,13 @@ struct xattr_handler {
 	const char *prefix;
 	int flags;      /* fs private flags */
 	bool (*list)(struct dentry *dentry);
-	int (*get)(const struct xattr_handler *, struct dentry *dentry,
+	int (*get)(const struct xattr_handler *handler, struct dentry *dentry,
 		   struct inode *inode, const char *name, void *buffer,
 		   size_t size);
-	int (*set)(const struct xattr_handler *, struct dentry *dentry,
+	int (*__get)(const struct xattr_handler *handler, struct dentry *dentry,
+		     struct inode *inode, const char *name, void *buffer,
+		     size_t size);
+	int (*set)(const struct xattr_handler *handler, struct dentry *dentry,
 		   struct inode *inode, const char *name, const void *buffer,
 		   size_t size, int flags);
 };
-- 
2.22.0.657.g960e92d24f-goog


^ permalink raw reply related

* [PATCH] Correct documentation for /proc/schedstat
From: Phil Frost @ 2019-07-24 18:50 UTC (permalink / raw)
  Cc: Ingo Molnar, trivial, Phil Frost, Jonathan Corbet, linux-doc,
	linux-kernel

Commit 425e0968a25fa3f111f9919964cac079738140b5 ("sched: move code into
kernel/sched_stats.h") appears to have inadvertently changed the unit of
time from jiffies to nanoseconds as part of the implementation of CFS.

Signed-off-by: Phil Frost <indigo@bitglue.com>
---
 Documentation/scheduler/sched-stats.txt | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Documentation/scheduler/sched-stats.txt b/Documentation/scheduler/sched-stats.txt
index 8259b34a66ae..b6c1807a01b3 100644
--- a/Documentation/scheduler/sched-stats.txt
+++ b/Documentation/scheduler/sched-stats.txt
@@ -19,6 +19,11 @@ are no architectures which need more than three domain levels. The first
 field in the domain stats is a bit map indicating which cpus are affected
 by that domain.
 
+2.6.23 introduced the CFS scheduler, and also an inadvertent
+backwards-incompatible change to the statistics. Although the schedstat version
+is 14 in either case, in 2.6.23 and later, counters accumulate time in
+nanoseconds. Prior to that, jiffies.
+
 These fields are counters, and only increment.  Programs which make use
 of these will need to start with a baseline observation and then calculate
 the change in the counters at each subsequent observation.  A perl script
@@ -48,9 +53,10 @@ Next two are try_to_wake_up() statistics:
      6) # of times try_to_wake_up() was called to wake up the local cpu
 
 Next three are statistics describing scheduling latency:
-     7) sum of all time spent running by tasks on this processor (in jiffies)
+     7) sum of all time spent running by tasks on this processor (in
+        nanoseconds, or jiffies prior to 2.6.23)
      8) sum of all time spent waiting to run by tasks on this processor (in
-        jiffies)
+        nanoseconds, or jiffies prior to 2.6.23)
      9) # of timeslices run on this cpu
 
 
-- 
2.20.1 (Apple Git-117)


^ permalink raw reply related

* Re: [PATCH v5] Documentation/checkpatch: Prefer strscpy/strscpy_pad over strcpy/strlcpy/strncpy
From: Joe Perches @ 2019-07-24 18:29 UTC (permalink / raw)
  To: Gote, Nitin R, Kees Cook
  Cc: corbet@lwn.net, akpm@linux-foundation.org, apw@canonical.com,
	linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com
In-Reply-To: <12356C813DFF6F479B608F81178A561587AE45@BGSMSX101.gar.corp.intel.com>

On Wed, 2019-07-24 at 18:17 +0000, Gote, Nitin R wrote:
> Hi,

Hi again.

[]
> > > > > 3. Deprecate strncpy() in favor of strscpy() or strscpy_pad().

Please remember there does not exist a single actual use
of strscpy_pad in the kernel sources and no apparent real
need for it.  I don't find one anyway.

> Could you please give your opinion on below comment.
>  
> > But, if the destination buffer needs extra NUL-padding for remaining size of
> > destination, then safe replacement is strscpy_pad().  Right?  If yes, then what
> > is your opinion on below change :
> > 
> >         "strncpy" => "strscpy, strcpy_pad - for non-NUL-terminated uses,
> > strncpy() dst should be __nonstring",
> > 
> If you agree on this, then I will include this change in next patch version.

Two things:

The kernel-doc documentation uses dest not dst.
I think stracpy should be preferred over strscpy.



^ permalink raw reply

* RE: [PATCH v5] Documentation/checkpatch: Prefer strscpy/strscpy_pad over strcpy/strlcpy/strncpy
From: Gote, Nitin R @ 2019-07-24 18:17 UTC (permalink / raw)
  To: Joe Perches, Kees Cook
  Cc: corbet@lwn.net, akpm@linux-foundation.org, apw@canonical.com,
	linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com
In-Reply-To: <12356C813DFF6F479B608F81178A561587ABA9@BGSMSX101.gar.corp.intel.com>

Hi,

> -----Original Message-----
> From: Gote, Nitin R [mailto:nitin.r.gote@intel.com]
> Sent: Tuesday, July 23, 2019 2:56 PM
> To: Joe Perches <joe@perches.com>; Kees Cook <keescook@chromium.org>
> Cc: corbet@lwn.net; akpm@linux-foundation.org; apw@canonical.com;
> linux-doc@vger.kernel.org; kernel-hardening@lists.openwall.com
> Subject: RE: [PATCH v5] Documentation/checkpatch: Prefer
> strscpy/strscpy_pad over strcpy/strlcpy/strncpy
> 
> 
> > -----Original Message-----
> > From: Joe Perches [mailto:joe@perches.com]
> > Sent: Monday, July 22, 2019 11:11 PM
> > To: Kees Cook <keescook@chromium.org>; Gote, Nitin R
> > <nitin.r.gote@intel.com>
> > Cc: corbet@lwn.net; akpm@linux-foundation.org; apw@canonical.com;
> > linux-doc@vger.kernel.org; kernel-hardening@lists.openwall.com
> > Subject: Re: [PATCH v5] Documentation/checkpatch: Prefer
> > strscpy/strscpy_pad over strcpy/strlcpy/strncpy
> >
> > On Mon, 2019-07-22 at 10:30 -0700, Kees Cook wrote:
> > > On Wed, Jul 17, 2019 at 10:00:05AM +0530, NitinGote wrote:
> > > > From: Nitin Gote <nitin.r.gote@intel.com>
> > > >
> > > > Added check in checkpatch.pl to
> > > > 1. Deprecate strcpy() in favor of strscpy().
> > > > 2. Deprecate strlcpy() in favor of strscpy().
> > > > 3. Deprecate strncpy() in favor of strscpy() or strscpy_pad().
> > > >
> > > > Updated strncpy() section in Documentation/process/deprecated.rst
> > > > to cover strscpy_pad() case.
> > > >
> > > > Signed-off-by: Nitin Gote <nitin.r.gote@intel.com>
> > >
> > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > >
> > > Joe, does this address your checkpatch concerns?
> >
> > Well, kinda.
> >
> > strscpy_pad isn't used anywhere in the kernel.
> >
> > And
> >
> > +        "strncpy"				=> "strscpy, strscpy_pad or
> for non-
> > NUL-terminated strings, strncpy() can still be used, but destinations
> > should be marked with __nonstring",
> >
> > is a bit verbose.  This could be simply:
> >
> > +        "strncpy" => "strscpy - for non-NUL-terminated uses,
> > + strncpy() dst
> > should be __nonstring",
> >
>

Could you please give your opinion on below comment.
 
> But, if the destination buffer needs extra NUL-padding for remaining size of
> destination, then safe replacement is strscpy_pad().  Right?  If yes, then what
> is your opinion on below change :
> 
>         "strncpy" => "strscpy, strcpy_pad - for non-NUL-terminated uses,
> strncpy() dst should be __nonstring",
> 
> 

If you agree on this, then I will include this change in next patch version.
 
 > -Nitin

^ permalink raw reply

* Re: [PATCH] Documentation: move Documentation/virtual to Documentation/virt
From: Jonathan Corbet @ 2019-07-24 18:00 UTC (permalink / raw)
  To: Paolo Bonzini
  Cc: Christoph Hellwig, rkrcmar, jdike, richard, anton.ivanov,
	linux-doc, kvm, linux-um, linux-kernel
In-Reply-To: <b9baabbb-9e9b-47cf-f5a8-ea42ba1ddc25@redhat.com>

On Wed, 24 Jul 2019 10:51:36 +0200
Paolo Bonzini <pbonzini@redhat.com> wrote:

> On 24/07/19 09:24, Christoph Hellwig wrote:
> > Renaming docs seems to be en vogue at the moment, so fix on of the
> > grossly misnamed directories.  We usually never use "virtual" as
> > a shortcut for virtualization in the kernel, but always virt,
> > as seen in the virt/ top-level directory.  Fix up the documentation
> > to match that.
> > 
> > Fixes: ed16648eb5b8 ("Move kvm, uml, and lguest subdirectories under a common "virtual" directory, I.E:")
> > Signed-off-by: Christoph Hellwig <hch@lst.de>  
> 
> Queued, thanks.  I can't count how many times I said "I really should
> rename that directory".

...and it's up to Linus before I even got a chance to look at it - one has
to be fast around here...:)

There's nothing wrong with this move, but it does miss the point of much
of the reorganization that has been going on in the docs tree.  It's not
just a matter of getting more pleasing names; the real idea is to create a
better, more reader-focused organization on kernel documentation as a
whole.  Documentation/virt still has the sort of confusion of audiences
that we're trying to fix:

 - kvm/api.txt pretty clearly belongs in the userspace-api book, rather
   than tossed in with:

 - kvm/review-checklist.txt, which belongs in the subsystem guide, if only
   we'd gotten around to creating it yet, or

 - kvm/mmu.txt, which is information for kernel developers, or

 - uml/UserModeLinux-HOWTO.txt, which belongs in the admin guide.

I suspect that organization is going to be one of the main issues to talk
about in Lisbon.  Meanwhile, I hope that this rename won't preclude
organizational work in the future.

Thanks,

jon

^ permalink raw reply

* [PATCH v15 11/13] MIPS: CI20: Reduce system timer and clocksource to 3 MHz
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

The default clock (48 MHz) is too fast for the system timer.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v5: New patch
    
    v6: Set also the rate for the clocksource channel's clock
    
    v7: No change
    
    v8: No change
    
    v9: Don't configure clock timer1, as the OS Timer is used as
    	clocksource on this SoC
    
    v10: Revert back to v8 bahaviour. Let the user choose what
    	 clocksource should be used.
    
    v11-v15: No change

 arch/mips/boot/dts/ingenic/ci20.dts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
index 4f7b1fa31cf5..2e9952311ecd 100644
--- a/arch/mips/boot/dts/ingenic/ci20.dts
+++ b/arch/mips/boot/dts/ingenic/ci20.dts
@@ -2,6 +2,7 @@
 /dts-v1/;
 
 #include "jz4780.dtsi"
+#include <dt-bindings/clock/ingenic,tcu.h>
 #include <dt-bindings/gpio/gpio.h>
 
 / {
@@ -238,3 +239,9 @@
 		bias-disable;
 	};
 };
+
+&tcu {
+	/* 3 MHz for the system timer and clocksource */
+	assigned-clocks = <&tcu TCU_CLK_TIMER0>, <&tcu TCU_CLK_TIMER1>;
+	assigned-clock-rates = <3000000>, <3000000>;
+};
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 09/13] MIPS: jz4740: Add DTS nodes for the TCU drivers
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

Add DTS nodes for the JZ4780, JZ4770 and JZ4740 devicetree files.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v5: New patch
    
    v6: Fix register lengths in watchdog/pwm nodes
    
    v7: No change
    
    v8: - Fix wrong start address for PWM node
    	- Add system timer and clocksource sub-nodes
    
    v9: Drop timer and clocksource sub-nodes
    
    v10-v11: No change
    
    v12: Drop PWM/watchdog/OST sub-nodes, for now.
    
    v13-v14: No change
    
    v15: Add "simple-mfd" compatible string

 arch/mips/boot/dts/ingenic/jz4740.dtsi | 22 ++++++++++++++++++++++
 arch/mips/boot/dts/ingenic/jz4770.dtsi | 21 +++++++++++++++++++++
 arch/mips/boot/dts/ingenic/jz4780.dtsi | 23 +++++++++++++++++++++++
 3 files changed, 66 insertions(+)

diff --git a/arch/mips/boot/dts/ingenic/jz4740.dtsi b/arch/mips/boot/dts/ingenic/jz4740.dtsi
index 3ffaf63f22dd..058800bfc875 100644
--- a/arch/mips/boot/dts/ingenic/jz4740.dtsi
+++ b/arch/mips/boot/dts/ingenic/jz4740.dtsi
@@ -53,6 +53,28 @@
 		clock-names = "rtc";
 	};
 
+	tcu: timer@10002000 {
+		compatible = "ingenic,jz4740-tcu", "simple-mfd";
+		reg = <0x10002000 0x1000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x10002000 0x1000>;
+
+		#clock-cells = <1>;
+
+		clocks = <&cgu JZ4740_CLK_RTC
+			  &cgu JZ4740_CLK_EXT
+			  &cgu JZ4740_CLK_PCLK
+			  &cgu JZ4740_CLK_TCU>;
+		clock-names = "rtc", "ext", "pclk", "tcu";
+
+		interrupt-controller;
+		#interrupt-cells = <1>;
+
+		interrupt-parent = <&intc>;
+		interrupts = <23 22 21>;
+	};
+
 	rtc_dev: rtc@10003000 {
 		compatible = "ingenic,jz4740-rtc";
 		reg = <0x10003000 0x40>;
diff --git a/arch/mips/boot/dts/ingenic/jz4770.dtsi b/arch/mips/boot/dts/ingenic/jz4770.dtsi
index 49ede6c14ff3..0bfb9edff3d0 100644
--- a/arch/mips/boot/dts/ingenic/jz4770.dtsi
+++ b/arch/mips/boot/dts/ingenic/jz4770.dtsi
@@ -46,6 +46,27 @@
 		#clock-cells = <1>;
 	};
 
+	tcu: timer@10002000 {
+		compatible = "ingenic,jz4770-tcu", "simple-mfd";
+		reg = <0x10002000 0x1000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x10002000 0x1000>;
+
+		#clock-cells = <1>;
+
+		clocks = <&cgu JZ4770_CLK_RTC
+			  &cgu JZ4770_CLK_EXT
+			  &cgu JZ4770_CLK_PCLK>;
+		clock-names = "rtc", "ext", "pclk";
+
+		interrupt-controller;
+		#interrupt-cells = <1>;
+
+		interrupt-parent = <&intc>;
+		interrupts = <27 26 25>;
+	};
+
 	pinctrl: pin-controller@10010000 {
 		compatible = "ingenic,jz4770-pinctrl";
 		reg = <0x10010000 0x600>;
diff --git a/arch/mips/boot/dts/ingenic/jz4780.dtsi b/arch/mips/boot/dts/ingenic/jz4780.dtsi
index b03cdec56de9..c54bd7cfec55 100644
--- a/arch/mips/boot/dts/ingenic/jz4780.dtsi
+++ b/arch/mips/boot/dts/ingenic/jz4780.dtsi
@@ -46,6 +46,29 @@
 		#clock-cells = <1>;
 	};
 
+	tcu: timer@10002000 {
+		compatible = "ingenic,jz4780-tcu",
+			     "ingenic,jz4770-tcu",
+			     "simple-mfd";
+		reg = <0x10002000 0x1000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x10002000 0x1000>;
+
+		#clock-cells = <1>;
+
+		clocks = <&cgu JZ4780_CLK_RTCLK
+			  &cgu JZ4780_CLK_EXCLK
+			  &cgu JZ4780_CLK_PCLK>;
+		clock-names = "rtc", "ext", "pclk";
+
+		interrupt-controller;
+		#interrupt-cells = <1>;
+
+		interrupt-parent = <&intc>;
+		interrupts = <27 26 25>;
+	};
+
 	rtc_dev: rtc@10003000 {
 		compatible = "ingenic,jz4780-rtc";
 		reg = <0x10003000 0x4c>;
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 13/13] MIPS: jz4740: Drop obsolete code
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

The old clocksource/timer platform code is now obsoleted by the newly
introduced TCU drivers.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v5: New patch
    
    v6-v11: No change
    
    v12: Only remove clocksource code. The rest will eventually be
    	 removed in a future patchset when the PWM/watchdog drivers
    	 are updated.
    
    v13-v15: No change

 arch/mips/jz4740/time.c | 151 +---------------------------------------
 1 file changed, 2 insertions(+), 149 deletions(-)

diff --git a/arch/mips/jz4740/time.c b/arch/mips/jz4740/time.c
index cb768e560d8b..5476899f0882 100644
--- a/arch/mips/jz4740/time.c
+++ b/arch/mips/jz4740/time.c
@@ -4,161 +4,14 @@
  *  JZ4740 platform time support
  */
 
-#include <linux/clk.h>
 #include <linux/clk-provider.h>
-#include <linux/interrupt.h>
-#include <linux/kernel.h>
-#include <linux/time.h>
+#include <linux/clocksource.h>
 
-#include <linux/clockchips.h>
-#include <linux/sched_clock.h>
-
-#include <asm/mach-jz4740/irq.h>
 #include <asm/mach-jz4740/timer.h>
-#include <asm/time.h>
-
-#define TIMER_CLOCKEVENT 0
-#define TIMER_CLOCKSOURCE 1
-
-static uint16_t jz4740_jiffies_per_tick;
-
-static u64 jz4740_clocksource_read(struct clocksource *cs)
-{
-	return jz4740_timer_get_count(TIMER_CLOCKSOURCE);
-}
-
-static struct clocksource jz4740_clocksource = {
-	.name = "jz4740-timer",
-	.rating = 200,
-	.read = jz4740_clocksource_read,
-	.mask = CLOCKSOURCE_MASK(16),
-	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static u64 notrace jz4740_read_sched_clock(void)
-{
-	return jz4740_timer_get_count(TIMER_CLOCKSOURCE);
-}
-
-static irqreturn_t jz4740_clockevent_irq(int irq, void *devid)
-{
-	struct clock_event_device *cd = devid;
-
-	jz4740_timer_ack_full(TIMER_CLOCKEVENT);
-
-	if (!clockevent_state_periodic(cd))
-		jz4740_timer_disable(TIMER_CLOCKEVENT);
-
-	cd->event_handler(cd);
-
-	return IRQ_HANDLED;
-}
-
-static int jz4740_clockevent_set_periodic(struct clock_event_device *evt)
-{
-	jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
-	jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
-	jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
-	jz4740_timer_enable(TIMER_CLOCKEVENT);
-
-	return 0;
-}
-
-static int jz4740_clockevent_resume(struct clock_event_device *evt)
-{
-	jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
-	jz4740_timer_enable(TIMER_CLOCKEVENT);
-
-	return 0;
-}
-
-static int jz4740_clockevent_shutdown(struct clock_event_device *evt)
-{
-	jz4740_timer_disable(TIMER_CLOCKEVENT);
-
-	return 0;
-}
-
-static int jz4740_clockevent_set_next(unsigned long evt,
-	struct clock_event_device *cd)
-{
-	jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
-	jz4740_timer_set_period(TIMER_CLOCKEVENT, evt);
-	jz4740_timer_enable(TIMER_CLOCKEVENT);
-
-	return 0;
-}
-
-static struct clock_event_device jz4740_clockevent = {
-	.name = "jz4740-timer",
-	.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-	.set_next_event = jz4740_clockevent_set_next,
-	.set_state_shutdown = jz4740_clockevent_shutdown,
-	.set_state_periodic = jz4740_clockevent_set_periodic,
-	.set_state_oneshot = jz4740_clockevent_shutdown,
-	.tick_resume = jz4740_clockevent_resume,
-	.rating = 200,
-#ifdef CONFIG_MACH_JZ4740
-	.irq = JZ4740_IRQ_TCU0,
-#endif
-#if defined(CONFIG_MACH_JZ4770) || defined(CONFIG_MACH_JZ4780)
-	.irq = JZ4780_IRQ_TCU2,
-#endif
-};
-
-static struct irqaction timer_irqaction = {
-	.handler	= jz4740_clockevent_irq,
-	.flags		= IRQF_PERCPU | IRQF_TIMER,
-	.name		= "jz4740-timerirq",
-	.dev_id		= &jz4740_clockevent,
-};
 
 void __init plat_time_init(void)
 {
-	int ret;
-	uint32_t clk_rate;
-	uint16_t ctrl;
-	struct clk *ext_clk;
-
 	of_clk_init(NULL);
 	jz4740_timer_init();
-
-	ext_clk = clk_get(NULL, "ext");
-	if (IS_ERR(ext_clk))
-		panic("unable to get ext clock");
-	clk_rate = clk_get_rate(ext_clk) >> 4;
-	clk_put(ext_clk);
-
-	jz4740_jiffies_per_tick = DIV_ROUND_CLOSEST(clk_rate, HZ);
-
-	clockevent_set_clock(&jz4740_clockevent, clk_rate);
-	jz4740_clockevent.min_delta_ns = clockevent_delta2ns(100, &jz4740_clockevent);
-	jz4740_clockevent.min_delta_ticks = 100;
-	jz4740_clockevent.max_delta_ns = clockevent_delta2ns(0xffff, &jz4740_clockevent);
-	jz4740_clockevent.max_delta_ticks = 0xffff;
-	jz4740_clockevent.cpumask = cpumask_of(0);
-
-	clockevents_register_device(&jz4740_clockevent);
-
-	ret = clocksource_register_hz(&jz4740_clocksource, clk_rate);
-
-	if (ret)
-		printk(KERN_ERR "Failed to register clocksource: %d\n", ret);
-
-	sched_clock_register(jz4740_read_sched_clock, 16, clk_rate);
-
-	setup_irq(jz4740_clockevent.irq, &timer_irqaction);
-
-	ctrl = JZ_TIMER_CTRL_PRESCALE_16 | JZ_TIMER_CTRL_SRC_EXT;
-
-	jz4740_timer_set_ctrl(TIMER_CLOCKEVENT, ctrl);
-	jz4740_timer_set_ctrl(TIMER_CLOCKSOURCE, ctrl);
-
-	jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
-	jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
-
-	jz4740_timer_set_period(TIMER_CLOCKSOURCE, 0xffff);
-
-	jz4740_timer_enable(TIMER_CLOCKEVENT);
-	jz4740_timer_enable(TIMER_CLOCKSOURCE);
+	timer_probe();
 }
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 10/13] MIPS: qi_lb60: Reduce system timer and clocksource to 750 kHz
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

The default clock (12 MHz) is too fast for the system timer, which fails
to report time accurately.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v5: New patch
    
    v6: Remove ingenic,clocksource-channel property
    
    v7-v15: No change

 arch/mips/boot/dts/ingenic/qi_lb60.dts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/mips/boot/dts/ingenic/qi_lb60.dts b/arch/mips/boot/dts/ingenic/qi_lb60.dts
index cc26650562c2..933d98ca8d93 100644
--- a/arch/mips/boot/dts/ingenic/qi_lb60.dts
+++ b/arch/mips/boot/dts/ingenic/qi_lb60.dts
@@ -2,6 +2,7 @@
 /dts-v1/;
 
 #include "jz4740.dtsi"
+#include <dt-bindings/clock/ingenic,tcu.h>
 #include <dt-bindings/gpio/gpio.h>
 
 / {
@@ -64,3 +65,9 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&pins_mmc>;
 };
+
+&tcu {
+	/* 750 kHz for the system timer and clocksource */
+	assigned-clocks = <&tcu TCU_CLK_TIMER0>, <&tcu TCU_CLK_TIMER1>;
+	assigned-clock-rates = <750000>, <750000>;
+};
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 12/13] MIPS: GCW0: Reduce system timer and clocksource to 750 kHz
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

The default clock (12 MHz) is too fast for the system timer.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v8: New patch
    
    v9: Don't configure clock timer1, as the OS Timer is used as
    	clocksource on this SoC
    
    v10: Revert back to v8 bahaviour. Let the user choose what
    	 clocksource should be used.
    
    v11: No change
    
    v12: Move clocksource to channel 2, as channel 1 is used as PWM
    	 for the backlight.
    
    v13-v15: No change

 arch/mips/boot/dts/ingenic/gcw0.dts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/mips/boot/dts/ingenic/gcw0.dts b/arch/mips/boot/dts/ingenic/gcw0.dts
index 35f0291e8d38..f58d239c2058 100644
--- a/arch/mips/boot/dts/ingenic/gcw0.dts
+++ b/arch/mips/boot/dts/ingenic/gcw0.dts
@@ -2,6 +2,7 @@
 /dts-v1/;
 
 #include "jz4770.dtsi"
+#include <dt-bindings/clock/ingenic,tcu.h>
 
 / {
 	compatible = "gcw,zero", "ingenic,jz4770";
@@ -60,3 +61,12 @@
 	/* The WiFi module is connected to the UHC. */
 	status = "okay";
 };
+
+&tcu {
+	/* 750 kHz for the system timer and clocksource */
+	assigned-clocks = <&tcu TCU_CLK_TIMER0>, <&tcu TCU_CLK_TIMER2>;
+	assigned-clock-rates = <750000>, <750000>;
+
+	/* PWM1 is in use, so reserve channel #2 for the clocksource */
+	ingenic,pwm-channels-mask = <0xfa>;
+};
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 06/13] irqchip: Add irq-ingenic-tcu driver
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

This driver handles the interrupt controller built in the Timer/Counter
Unit (TCU) of the JZ47xx SoCs from Ingenic.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---

Notes:
    v12: New patch
    
    v13: No change
    
    v14: Remove empty lines in structure definitions
    
    v15: Use device_node_to_regmap()

 drivers/irqchip/Kconfig           |  11 ++
 drivers/irqchip/Makefile          |   1 +
 drivers/irqchip/irq-ingenic-tcu.c | 182 ++++++++++++++++++++++++++++++
 3 files changed, 194 insertions(+)
 create mode 100644 drivers/irqchip/irq-ingenic-tcu.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 80e10f4e213a..3c8308e6b3a7 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -315,6 +315,17 @@ config INGENIC_IRQ
 	depends on MACH_INGENIC
 	default y
 
+config INGENIC_TCU_IRQ
+	bool "Ingenic JZ47xx TCU interrupt controller"
+	default MACH_INGENIC
+	depends on MIPS || COMPILE_TEST
+	select MFD_SYSCON
+	help
+	  Support for interrupts in the Timer/Counter Unit (TCU) of the Ingenic
+	  JZ47xx SoCs.
+
+	  If unsure, say N.
+
 config RENESAS_H8300H_INTC
         bool
 	select IRQ_DOMAIN
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 8d0fcec6ab23..cc7c43932f16 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_RENESAS_H8300H_INTC)	+= irq-renesas-h8300h.o
 obj-$(CONFIG_RENESAS_H8S_INTC)		+= irq-renesas-h8s.o
 obj-$(CONFIG_ARCH_SA1100)		+= irq-sa11x0.o
 obj-$(CONFIG_INGENIC_IRQ)		+= irq-ingenic.o
+obj-$(CONFIG_INGENIC_TCU_IRQ)		+= irq-ingenic-tcu.o
 obj-$(CONFIG_IMX_GPCV2)			+= irq-imx-gpcv2.o
 obj-$(CONFIG_PIC32_EVIC)		+= irq-pic32-evic.o
 obj-$(CONFIG_MSCC_OCELOT_IRQ)		+= irq-mscc-ocelot.o
diff --git a/drivers/irqchip/irq-ingenic-tcu.c b/drivers/irqchip/irq-ingenic-tcu.c
new file mode 100644
index 000000000000..6d05cefe9d79
--- /dev/null
+++ b/drivers/irqchip/irq-ingenic-tcu.c
@@ -0,0 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ47xx SoCs TCU IRQ driver
+ * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_irq.h>
+#include <linux/regmap.h>
+
+struct ingenic_tcu {
+	struct regmap *map;
+	struct clk *clk;
+	struct irq_domain *domain;
+	unsigned int nb_parent_irqs;
+	u32 parent_irqs[3];
+};
+
+static void ingenic_tcu_intc_cascade(struct irq_desc *desc)
+{
+	struct irq_chip *irq_chip = irq_data_get_irq_chip(&desc->irq_data);
+	struct irq_domain *domain = irq_desc_get_handler_data(desc);
+	struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
+	struct regmap *map = gc->private;
+	uint32_t irq_reg, irq_mask;
+	unsigned int i;
+
+	regmap_read(map, TCU_REG_TFR, &irq_reg);
+	regmap_read(map, TCU_REG_TMR, &irq_mask);
+
+	chained_irq_enter(irq_chip, desc);
+
+	irq_reg &= ~irq_mask;
+
+	for_each_set_bit(i, (unsigned long *)&irq_reg, 32)
+		generic_handle_irq(irq_linear_revmap(domain, i));
+
+	chained_irq_exit(irq_chip, desc);
+}
+
+static void ingenic_tcu_gc_unmask_enable_reg(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+	struct regmap *map = gc->private;
+	u32 mask = d->mask;
+
+	irq_gc_lock(gc);
+	regmap_write(map, ct->regs.ack, mask);
+	regmap_write(map, ct->regs.enable, mask);
+	*ct->mask_cache |= mask;
+	irq_gc_unlock(gc);
+}
+
+static void ingenic_tcu_gc_mask_disable_reg(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+	struct regmap *map = gc->private;
+	u32 mask = d->mask;
+
+	irq_gc_lock(gc);
+	regmap_write(map, ct->regs.disable, mask);
+	*ct->mask_cache &= ~mask;
+	irq_gc_unlock(gc);
+}
+
+static void ingenic_tcu_gc_mask_disable_reg_and_ack(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+	struct regmap *map = gc->private;
+	u32 mask = d->mask;
+
+	irq_gc_lock(gc);
+	regmap_write(map, ct->regs.ack, mask);
+	regmap_write(map, ct->regs.disable, mask);
+	irq_gc_unlock(gc);
+}
+
+static int __init ingenic_tcu_irq_init(struct device_node *np,
+				       struct device_node *parent)
+{
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+	struct ingenic_tcu *tcu;
+	struct regmap *map;
+	unsigned int i;
+	int ret, irqs;
+
+	map = device_node_to_regmap(np);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
+	if (!tcu)
+		return -ENOMEM;
+
+	tcu->map = map;
+
+	irqs = of_property_count_elems_of_size(np, "interrupts", sizeof(u32));
+	if (irqs < 0 || irqs > ARRAY_SIZE(tcu->parent_irqs)) {
+		pr_crit("%s: Invalid 'interrupts' property\n", __func__);
+		ret = -EINVAL;
+		goto err_free_tcu;
+	}
+
+	tcu->nb_parent_irqs = irqs;
+
+	tcu->domain = irq_domain_add_linear(np, 32, &irq_generic_chip_ops,
+					    NULL);
+	if (!tcu->domain) {
+		ret = -ENOMEM;
+		goto err_free_tcu;
+	}
+
+	ret = irq_alloc_domain_generic_chips(tcu->domain, 32, 1, "TCU",
+					     handle_level_irq, 0,
+					     IRQ_NOPROBE | IRQ_LEVEL, 0);
+	if (ret) {
+		pr_crit("%s: Invalid 'interrupts' property\n", __func__);
+		goto out_domain_remove;
+	}
+
+	gc = irq_get_domain_generic_chip(tcu->domain, 0);
+	ct = gc->chip_types;
+
+	gc->wake_enabled = IRQ_MSK(32);
+	gc->private = tcu->map;
+
+	ct->regs.disable = TCU_REG_TMSR;
+	ct->regs.enable = TCU_REG_TMCR;
+	ct->regs.ack = TCU_REG_TFCR;
+	ct->chip.irq_unmask = ingenic_tcu_gc_unmask_enable_reg;
+	ct->chip.irq_mask = ingenic_tcu_gc_mask_disable_reg;
+	ct->chip.irq_mask_ack = ingenic_tcu_gc_mask_disable_reg_and_ack;
+	ct->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
+
+	/* Mask all IRQs by default */
+	regmap_write(tcu->map, TCU_REG_TMSR, IRQ_MSK(32));
+
+	/*
+	 * On JZ4740, timer 0 and timer 1 have their own interrupt line;
+	 * timers 2-7 share one interrupt.
+	 * On SoCs >= JZ4770, timer 5 has its own interrupt line;
+	 * timers 0-4 and 6-7 share one single interrupt.
+	 *
+	 * To keep things simple, we just register the same handler to
+	 * all parent interrupts. The handler will properly detect which
+	 * channel fired the interrupt.
+	 */
+	for (i = 0; i < irqs; i++) {
+		tcu->parent_irqs[i] = irq_of_parse_and_map(np, i);
+		if (!tcu->parent_irqs[i]) {
+			ret = -EINVAL;
+			goto out_unmap_irqs;
+		}
+
+		irq_set_chained_handler_and_data(tcu->parent_irqs[i],
+						 ingenic_tcu_intc_cascade,
+						 tcu->domain);
+	}
+
+	return 0;
+
+out_unmap_irqs:
+	for (; i > 0; i--)
+		irq_dispose_mapping(tcu->parent_irqs[i - 1]);
+out_domain_remove:
+	irq_domain_remove(tcu->domain);
+err_free_tcu:
+	kfree(tcu);
+	return ret;
+}
+IRQCHIP_DECLARE(jz4740_tcu_irq, "ingenic,jz4740-tcu", ingenic_tcu_irq_init);
+IRQCHIP_DECLARE(jz4725b_tcu_irq, "ingenic,jz4725b-tcu", ingenic_tcu_irq_init);
+IRQCHIP_DECLARE(jz4770_tcu_irq, "ingenic,jz4770-tcu", ingenic_tcu_irq_init);
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 02/13] doc: Add doc for the Ingenic TCU hardware
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

Add documentation about the Timer/Counter Unit (TCU) present in the
Ingenic JZ47xx SoCs.

The Timer/Counter Unit (TCU) in Ingenic JZ47xx SoCs is a multi-function
hardware block. It features up to to eight channels, that can be used as
counters, timers, or PWM.

- JZ4725B, JZ4750, JZ4755 only have six TCU channels. The other SoCs all
  have eight channels.

- JZ4725B introduced a separate channel, called Operating System Timer
  (OST). It is a 32-bit programmable timer. On JZ4770 and above, it is
  64-bit.

- Each one of the TCU channels has its own clock, which can be reparented
  to three different clocks (pclk, ext, rtc), gated, and reclocked, through
  their TCSR register.
  * The watchdog and OST hardware blocks also feature a TCSR register with
    the same format in their register space.
  * The TCU registers used to gate/ungate can also gate/ungate the watchdog
    and OST clocks.

- Each TCU channel works in one of two modes:
  * mode TCU1: channels cannot work in sleep mode, but are easier to
    operate.
  * mode TCU2: channels can work in sleep mode, but the operation is a bit
    more complicated than with TCU1 channels.

- The mode of each TCU channel depends on the SoC used:
  * On the oldest SoCs (up to JZ4740), all of the eight channels operate in
    TCU1 mode.
  * On JZ4725B, channel 5 operates as TCU2, the others operate as TCU1.
  * On newest SoCs (JZ4750 and above), channels 1-2 operate as TCU2, the
    others operate as TCU1.

- Each channel can generate an interrupt. Some channels share an interrupt
  line, some don't, and this changes between SoC versions:
  * on older SoCs (JZ4740 and below), channel 0 and channel 1 have their
    own interrupt line; channels 2-7 share the last interrupt line.
  * On JZ4725B, channel 0 has its own interrupt; channels 1-5 share one
    interrupt line; the OST uses the last interrupt line.
  * on newer SoCs (JZ4750 and above), channel 5 has its own interrupt;
    channels 0-4 and (if eight channels) 6-7 all share one interrupt line;
    the OST uses the last interrupt line.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v4: New patch in this series
    
    v5: Added information about number of channels, and improved
        documentation about channel modes
    
    v6: Add info about OST (can be 32-bit on older SoCs)
    
    v7-v11: No change
    
    v12: Add details about new implementation
    
    v13: No change
    
    v14: Convert to ReStructured Text
    
    v15: Remove info about MFD driver

 Documentation/index.rst            |  1 +
 Documentation/mips/index.rst       | 11 +++++
 Documentation/mips/ingenic-tcu.rst | 71 ++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 Documentation/mips/index.rst
 create mode 100644 Documentation/mips/ingenic-tcu.rst

diff --git a/Documentation/index.rst b/Documentation/index.rst
index 70ae148ec980..87214feda41f 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -143,6 +143,7 @@ implementation.
    arm64/index
    ia64/index
    m68k/index
+   mips/index
    riscv/index
    s390/index
    sh/index
diff --git a/Documentation/mips/index.rst b/Documentation/mips/index.rst
new file mode 100644
index 000000000000..321b4794f3b8
--- /dev/null
+++ b/Documentation/mips/index.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+MIPS-specific Documentation
+===========================
+
+.. toctree::
+   :maxdepth: 1
+   :numbered:
+
+   ingenic-tcu
diff --git a/Documentation/mips/ingenic-tcu.rst b/Documentation/mips/ingenic-tcu.rst
new file mode 100644
index 000000000000..c4ef4c45aade
--- /dev/null
+++ b/Documentation/mips/ingenic-tcu.rst
@@ -0,0 +1,71 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============================================
+Ingenic JZ47xx SoCs Timer/Counter Unit hardware
+===============================================
+
+The Timer/Counter Unit (TCU) in Ingenic JZ47xx SoCs is a multi-function
+hardware block. It features up to to eight channels, that can be used as
+counters, timers, or PWM.
+
+- JZ4725B, JZ4750, JZ4755 only have six TCU channels. The other SoCs all
+  have eight channels.
+
+- JZ4725B introduced a separate channel, called Operating System Timer
+  (OST). It is a 32-bit programmable timer. On JZ4760B and above, it is
+  64-bit.
+
+- Each one of the TCU channels has its own clock, which can be reparented to three
+  different clocks (pclk, ext, rtc), gated, and reclocked, through their TCSR register.
+
+    - The watchdog and OST hardware blocks also feature a TCSR register with the same
+      format in their register space.
+    - The TCU registers used to gate/ungate can also gate/ungate the watchdog and
+      OST clocks.
+
+- Each TCU channel works in one of two modes:
+
+    - mode TCU1: channels cannot work in sleep mode, but are easier to
+      operate.
+    - mode TCU2: channels can work in sleep mode, but the operation is a bit
+      more complicated than with TCU1 channels.
+
+- The mode of each TCU channel depends on the SoC used:
+
+    - On the oldest SoCs (up to JZ4740), all of the eight channels operate in
+      TCU1 mode.
+    - On JZ4725B, channel 5 operates as TCU2, the others operate as TCU1.
+    - On newest SoCs (JZ4750 and above), channels 1-2 operate as TCU2, the
+      others operate as TCU1.
+
+- Each channel can generate an interrupt. Some channels share an interrupt
+  line, some don't, and this changes between SoC versions:
+
+    - on older SoCs (JZ4740 and below), channel 0 and channel 1 have their
+      own interrupt line; channels 2-7 share the last interrupt line.
+    - On JZ4725B, channel 0 has its own interrupt; channels 1-5 share one
+      interrupt line; the OST uses the last interrupt line.
+    - on newer SoCs (JZ4750 and above), channel 5 has its own interrupt;
+      channels 0-4 and (if eight channels) 6-7 all share one interrupt line;
+      the OST uses the last interrupt line.
+
+Implementation
+==============
+
+The functionalities of the TCU hardware are spread across multiple drivers:
+
+===========  =====
+clocks       drivers/clk/ingenic/tcu.c
+interrupts   drivers/irqchip/irq-ingenic-tcu.c
+timers       drivers/clocksource/ingenic-timer.c
+OST          drivers/clocksource/ingenic-ost.c
+PWM          drivers/pwm/pwm-jz4740.c
+watchdog     drivers/watchdog/jz4740_wdt.c
+===========  =====
+
+Because various functionalities of the TCU that belong to different drivers
+and frameworks can be controlled from the same registers, all of these
+drivers access their registers through the same regmap.
+
+For more information regarding the devicetree bindings of the TCU drivers,
+have a look at Documentation/devicetree/bindings/mfd/ingenic,tcu.txt.
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 07/13] clocksource: Add a new timer-ingenic driver
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

This driver handles the TCU (Timer Counter Unit) present on the Ingenic
JZ47xx SoCs, and provides the kernel with a system timer, a clocksource
and a sched_clock.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---

Notes:
    v2: Use SPDX identifier for the license
    
    v3: - Move documentation to its own patch
    	- Search the devicetree for PWM clients, and use all the TCU
    	  channels that won't be used for PWM
    
    v4: - Add documentation about why we search for PWM clients
    	- Verify that the PWM clients are for the TCU PWM driver
    
    v5: Major overhaul. Too many changes to list. Consider it's a new
    	patch.
    
    v6: - Add two API functions ingenic_tcu_request_channel and
    	  ingenic_tcu_release_channel. To be used by the PWM driver to
    	  request the use of a TCU channel. The driver will now dynamically
    	  move away the system timer or clocksource to a new TCU channel.
    	- The system timer now defaults to channel 0, the clocksource now
    	  defaults to channel 1 and is no more optional. The
    	  ingenic,timer-channel and ingenic,clocksource-channel devicetree
    	  properties are now gone.
    	- Fix round_rate / set_rate not calculating the prescale divider
    	  the same way. This caused problems when (parent_rate / div) would
    	  give a non-integer result. The behaviour is correct now.
    	- The clocksource clock is turned off on suspend now.
    
    v7: Fix section mismatch by using builtin_platform_driver_probe()
    
    v8: - Removed ingenic_tcu_[request,release]_channel, and the mechanism
    	  to dynamically change the TCU channel of the system timer or
    	  the clocksource.
    	- The driver's devicetree node can now have two more children
    	  nodes, that correspond to the system timer and clocksource.
    	  For these two, the driver will use the TCU timer that
    	  correspond to the memory resource supplied in their
    	  respective node.
    
    v9: - Removed support for clocksource / timer children devicetree
    	  nodes. Now, we use a property "ingenic,pwm-channels-mask" to
    	  know which PWM channels are reserved for PWM use and should
    	  not be used as OS timers.
    
    v10: - Use CLK_SET_RATE_UNGATE instead of CLK_SET_RATE_GATE + manually
    	   un-gating the clock before changing rate. Same for re-parenting.
    	 - Unconditionally create the clocksource and sched_clock even if
    	   the SoC possesses a OS Timer. That gives the choice back to the
    	   user which clocksource should be selected.
    	 - Use subsys_initcall() instead of builtin_platform_driver_probe().
    	   The OS Timer driver calls builtin_platform_driver_probe, which
    	   requires the device to be created before that.
    	 - Cosmetic cleanups
    
    v11: - Change prototype of exported function
    	   ingenic_tcu_pwm_can_use_chn(), use a struct device * as first
    	   argument.
    	 - Read clocksource using the regmap instead of bypassing it.
    	   Bypassing the regmap makes sense only for the sched_clock where
    	   the read operation must be as fast as possible.
    	 - Fix incorrect format in pr_crit() macro
    
    v12: - Clock handling and IRQ handling are gone, and are now handled
    	   in their own driver.
    	 - Obtain regmap from the ingenic-tcu MFD driver. As a result, we
    	   cannot bypass the regmap anymore for the sched_clock.
    
    v13: No change
    
    v14: Remove empty lines in structure definitions
    
    v15: Use device_node_to_regmap()

 drivers/clocksource/Kconfig         |  11 +
 drivers/clocksource/Makefile        |   1 +
 drivers/clocksource/ingenic-timer.c | 356 ++++++++++++++++++++++++++++
 3 files changed, 368 insertions(+)
 create mode 100644 drivers/clocksource/ingenic-timer.c

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 5e9317dc3d39..a9cdc2c4f8bd 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -685,4 +685,15 @@ config MILBEAUT_TIMER
 	help
 	  Enables the support for Milbeaut timer driver.
 
+config INGENIC_TIMER
+	bool "Clocksource/timer using the TCU in Ingenic JZ SoCs"
+	default MACH_INGENIC
+	depends on MIPS || COMPILE_TEST
+	depends on COMMON_CLK
+	select MFD_SYSCON
+	select TIMER_OF
+	select IRQ_DOMAIN
+	help
+	  Support for the timer/counter unit of the Ingenic JZ SoCs.
+
 endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 2e7936e7833f..4dfe4225ece7 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_ASM9260_TIMER)		+= asm9260_timer.o
 obj-$(CONFIG_H8300_TMR8)		+= h8300_timer8.o
 obj-$(CONFIG_H8300_TMR16)		+= h8300_timer16.o
 obj-$(CONFIG_H8300_TPU)			+= h8300_tpu.o
+obj-$(CONFIG_INGENIC_TIMER)		+= ingenic-timer.o
 obj-$(CONFIG_CLKSRC_ST_LPC)		+= clksrc_st_lpc.o
 obj-$(CONFIG_X86_NUMACHIP)		+= numachip.o
 obj-$(CONFIG_ATCPIT100_TIMER)		+= timer-atcpit100.o
diff --git a/drivers/clocksource/ingenic-timer.c b/drivers/clocksource/ingenic-timer.c
new file mode 100644
index 000000000000..4bbdb3d3d0c6
--- /dev/null
+++ b/drivers/clocksource/ingenic-timer.c
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ47xx SoCs TCU IRQ driver
+ * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/sched_clock.h>
+
+#include <dt-bindings/clock/ingenic,tcu.h>
+
+struct ingenic_soc_info {
+	unsigned int num_channels;
+};
+
+struct ingenic_tcu {
+	struct regmap *map;
+	struct clk *timer_clk, *cs_clk;
+	unsigned int timer_channel, cs_channel;
+	struct clock_event_device cevt;
+	struct clocksource cs;
+	char name[4];
+	unsigned long pwm_channels_mask;
+};
+
+static struct ingenic_tcu *ingenic_tcu;
+
+static u64 notrace ingenic_tcu_timer_read(void)
+{
+	struct ingenic_tcu *tcu = ingenic_tcu;
+	unsigned int count;
+
+	regmap_read(tcu->map, TCU_REG_TCNTc(tcu->cs_channel), &count);
+
+	return count;
+}
+
+static u64 notrace ingenic_tcu_timer_cs_read(struct clocksource *cs)
+{
+	return ingenic_tcu_timer_read();
+}
+
+static inline struct ingenic_tcu *to_ingenic_tcu(struct clock_event_device *evt)
+{
+	return container_of(evt, struct ingenic_tcu, cevt);
+}
+
+static int ingenic_tcu_cevt_set_state_shutdown(struct clock_event_device *evt)
+{
+	struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
+
+	regmap_write(tcu->map, TCU_REG_TECR, BIT(tcu->timer_channel));
+
+	return 0;
+}
+
+static int ingenic_tcu_cevt_set_next(unsigned long next,
+				     struct clock_event_device *evt)
+{
+	struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
+
+	if (next > 0xffff)
+		return -EINVAL;
+
+	regmap_write(tcu->map, TCU_REG_TDFRc(tcu->timer_channel), next);
+	regmap_write(tcu->map, TCU_REG_TCNTc(tcu->timer_channel), 0);
+	regmap_write(tcu->map, TCU_REG_TESR, BIT(tcu->timer_channel));
+
+	return 0;
+}
+
+static irqreturn_t ingenic_tcu_cevt_cb(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+	struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
+
+	regmap_write(tcu->map, TCU_REG_TECR, BIT(tcu->timer_channel));
+
+	if (evt->event_handler)
+		evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct clk * __init ingenic_tcu_get_clock(struct device_node *np, int id)
+{
+	struct of_phandle_args args;
+
+	args.np = np;
+	args.args_count = 1;
+	args.args[0] = id;
+
+	return of_clk_get_from_provider(&args);
+}
+
+static int __init ingenic_tcu_timer_init(struct device_node *np,
+					 struct ingenic_tcu *tcu)
+{
+	unsigned int timer_virq, channel = tcu->timer_channel;
+	struct irq_domain *domain;
+	unsigned long rate;
+	int err;
+
+	tcu->timer_clk = ingenic_tcu_get_clock(np, channel);
+	if (IS_ERR(tcu->timer_clk))
+		return PTR_ERR(tcu->timer_clk);
+
+	err = clk_prepare_enable(tcu->timer_clk);
+	if (err)
+		goto err_clk_put;
+
+	rate = clk_get_rate(tcu->timer_clk);
+	if (!rate) {
+		err = -EINVAL;
+		goto err_clk_disable;
+	}
+
+	domain = irq_find_host(np);
+	if (!domain) {
+		err = -ENODEV;
+		goto err_clk_disable;
+	}
+
+	timer_virq = irq_create_mapping(domain, channel);
+	if (!timer_virq) {
+		err = -EINVAL;
+		goto err_clk_disable;
+	}
+
+	snprintf(tcu->name, sizeof(tcu->name), "TCU");
+
+	err = request_irq(timer_virq, ingenic_tcu_cevt_cb, IRQF_TIMER,
+			  tcu->name, &tcu->cevt);
+	if (err)
+		goto err_irq_dispose_mapping;
+
+	tcu->cevt.cpumask = cpumask_of(smp_processor_id());
+	tcu->cevt.features = CLOCK_EVT_FEAT_ONESHOT;
+	tcu->cevt.name = tcu->name;
+	tcu->cevt.rating = 200;
+	tcu->cevt.set_state_shutdown = ingenic_tcu_cevt_set_state_shutdown;
+	tcu->cevt.set_next_event = ingenic_tcu_cevt_set_next;
+
+	clockevents_config_and_register(&tcu->cevt, rate, 10, 0xffff);
+
+	return 0;
+
+err_irq_dispose_mapping:
+	irq_dispose_mapping(timer_virq);
+err_clk_disable:
+	clk_disable_unprepare(tcu->timer_clk);
+err_clk_put:
+	clk_put(tcu->timer_clk);
+	return err;
+}
+
+static int __init ingenic_tcu_clocksource_init(struct device_node *np,
+					       struct ingenic_tcu *tcu)
+{
+	unsigned int channel = tcu->cs_channel;
+	struct clocksource *cs = &tcu->cs;
+	unsigned long rate;
+	int err;
+
+	tcu->cs_clk = ingenic_tcu_get_clock(np, channel);
+	if (IS_ERR(tcu->cs_clk))
+		return PTR_ERR(tcu->cs_clk);
+
+	err = clk_prepare_enable(tcu->cs_clk);
+	if (err)
+		goto err_clk_put;
+
+	rate = clk_get_rate(tcu->cs_clk);
+	if (!rate) {
+		err = -EINVAL;
+		goto err_clk_disable;
+	}
+
+	/* Reset channel */
+	regmap_update_bits(tcu->map, TCU_REG_TCSRc(channel),
+			   0xffff & ~TCU_TCSR_RESERVED_BITS, 0);
+
+	/* Reset counter */
+	regmap_write(tcu->map, TCU_REG_TDFRc(channel), 0xffff);
+	regmap_write(tcu->map, TCU_REG_TCNTc(channel), 0);
+
+	/* Enable channel */
+	regmap_write(tcu->map, TCU_REG_TESR, BIT(channel));
+
+	cs->name = "ingenic-timer";
+	cs->rating = 200;
+	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+	cs->mask = CLOCKSOURCE_MASK(16);
+	cs->read = ingenic_tcu_timer_cs_read;
+
+	err = clocksource_register_hz(cs, rate);
+	if (err)
+		goto err_clk_disable;
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(tcu->cs_clk);
+err_clk_put:
+	clk_put(tcu->cs_clk);
+	return err;
+}
+
+static const struct ingenic_soc_info jz4740_soc_info = {
+	.num_channels = 8,
+};
+
+static const struct ingenic_soc_info jz4725b_soc_info = {
+	.num_channels = 6,
+};
+
+static const struct of_device_id ingenic_tcu_of_match[] = {
+	{ .compatible = "ingenic,jz4740-tcu", .data = &jz4740_soc_info, },
+	{ .compatible = "ingenic,jz4725b-tcu", .data = &jz4725b_soc_info, },
+	{ .compatible = "ingenic,jz4770-tcu", .data = &jz4740_soc_info, },
+	{ /* sentinel */ }
+};
+
+static int __init ingenic_tcu_init(struct device_node *np)
+{
+	const struct of_device_id *id = of_match_node(ingenic_tcu_of_match, np);
+	const struct ingenic_soc_info *soc_info = id->data;
+	struct ingenic_tcu *tcu;
+	struct regmap *map;
+	long rate;
+	int ret;
+
+	of_node_clear_flag(np, OF_POPULATED);
+
+	map = device_node_to_regmap(np);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
+	if (!tcu)
+		return -ENOMEM;
+
+	/* Enable all TCU channels for PWM use by default except channels 0/1 */
+	tcu->pwm_channels_mask = GENMASK(soc_info->num_channels - 1, 2);
+	of_property_read_u32(np, "ingenic,pwm-channels-mask",
+			     (u32 *)&tcu->pwm_channels_mask);
+
+	/* Verify that we have at least two free channels */
+	if (hweight8(tcu->pwm_channels_mask) > soc_info->num_channels - 2) {
+		pr_crit("%s: Invalid PWM channel mask: 0x%02lx\n", __func__,
+			tcu->pwm_channels_mask);
+		ret = -EINVAL;
+		goto err_free_ingenic_tcu;
+	}
+
+	tcu->map = map;
+	ingenic_tcu = tcu;
+
+	tcu->timer_channel = find_first_zero_bit(&tcu->pwm_channels_mask,
+						 soc_info->num_channels);
+	tcu->cs_channel = find_next_zero_bit(&tcu->pwm_channels_mask,
+					     soc_info->num_channels,
+					     tcu->timer_channel + 1);
+
+	ret = ingenic_tcu_clocksource_init(np, tcu);
+	if (ret) {
+		pr_crit("%s: Unable to init clocksource: %d\n", __func__, ret);
+		goto err_free_ingenic_tcu;
+	}
+
+	ret = ingenic_tcu_timer_init(np, tcu);
+	if (ret)
+		goto err_tcu_clocksource_cleanup;
+
+	/* Register the sched_clock at the end as there's no way to undo it */
+	rate = clk_get_rate(tcu->cs_clk);
+	sched_clock_register(ingenic_tcu_timer_read, 16, rate);
+
+	return 0;
+
+err_tcu_clocksource_cleanup:
+	clocksource_unregister(&tcu->cs);
+	clk_disable_unprepare(tcu->cs_clk);
+	clk_put(tcu->cs_clk);
+err_free_ingenic_tcu:
+	kfree(tcu);
+	return ret;
+}
+
+TIMER_OF_DECLARE(jz4740_tcu_intc,  "ingenic,jz4740-tcu",  ingenic_tcu_init);
+TIMER_OF_DECLARE(jz4725b_tcu_intc, "ingenic,jz4725b-tcu", ingenic_tcu_init);
+TIMER_OF_DECLARE(jz4770_tcu_intc,  "ingenic,jz4770-tcu",  ingenic_tcu_init);
+
+
+static int __init ingenic_tcu_probe(struct platform_device *pdev)
+{
+	platform_set_drvdata(pdev, ingenic_tcu);
+
+	return 0;
+}
+
+static int __maybe_unused ingenic_tcu_suspend(struct device *dev)
+{
+	struct ingenic_tcu *tcu = dev_get_drvdata(dev);
+
+	clk_disable(tcu->cs_clk);
+	clk_disable(tcu->timer_clk);
+	return 0;
+}
+
+static int __maybe_unused ingenic_tcu_resume(struct device *dev)
+{
+	struct ingenic_tcu *tcu = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(tcu->timer_clk);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(tcu->cs_clk);
+	if (ret) {
+		clk_disable(tcu->timer_clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops __maybe_unused ingenic_tcu_pm_ops = {
+	/* _noirq: We want the TCU clocks to be gated last / ungated first */
+	.suspend_noirq = ingenic_tcu_suspend,
+	.resume_noirq  = ingenic_tcu_resume,
+};
+
+static struct platform_driver ingenic_tcu_driver = {
+	.driver = {
+		.name	= "ingenic-tcu-timer",
+#ifdef CONFIG_PM_SLEEP
+		.pm	= &ingenic_tcu_pm_ops,
+#endif
+		.of_match_table = ingenic_tcu_of_match,
+	},
+};
+builtin_platform_driver_probe(ingenic_tcu_driver, ingenic_tcu_probe);
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 08/13] clk: jz4740: Add TCU clock
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek, Rob Herring
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

Add the missing TCU clock to the list of clocks supplied by the CGU for
the JZ4740 SoC.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
---

Notes:
    v5: New patch
    
    v6-v15: No change

 drivers/clk/ingenic/jz4740-cgu.c       | 6 ++++++
 include/dt-bindings/clock/jz4740-cgu.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/clk/ingenic/jz4740-cgu.c b/drivers/clk/ingenic/jz4740-cgu.c
index 4c0a20949c2c..67f8a0e14284 100644
--- a/drivers/clk/ingenic/jz4740-cgu.c
+++ b/drivers/clk/ingenic/jz4740-cgu.c
@@ -222,6 +222,12 @@ static const struct ingenic_cgu_clk_info jz4740_cgu_clocks[] = {
 		.parents = { JZ4740_CLK_EXT, -1, -1, -1 },
 		.gate = { CGU_REG_CLKGR, 5 },
 	},
+
+	[JZ4740_CLK_TCU] = {
+		"tcu", CGU_CLK_GATE,
+		.parents = { JZ4740_CLK_EXT, -1, -1, -1 },
+		.gate = { CGU_REG_CLKGR, 1 },
+	},
 };
 
 static void __init jz4740_cgu_init(struct device_node *np)
diff --git a/include/dt-bindings/clock/jz4740-cgu.h b/include/dt-bindings/clock/jz4740-cgu.h
index 6ed83f926ae7..e82d77028581 100644
--- a/include/dt-bindings/clock/jz4740-cgu.h
+++ b/include/dt-bindings/clock/jz4740-cgu.h
@@ -34,5 +34,6 @@
 #define JZ4740_CLK_ADC		19
 #define JZ4740_CLK_I2C		20
 #define JZ4740_CLK_AIC		21
+#define JZ4740_CLK_TCU		22
 
 #endif /* __DT_BINDINGS_CLOCK_JZ4740_CGU_H__ */
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 05/13] clk: ingenic: Add driver for the TCU clocks
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

Add driver to support the clocks provided by the Timer/Counter Unit
(TCU) of the JZ47xx SoCs from Ingenic.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v12: New patch
    
    v13:
     - Don't enable/disable the TCU clock on demand. Enable it in the probe
       and call it a day.
     - Register suspend callbacks to gate/ungate the TCU clock on
       suspend/resume.
     - Use pr_fmt and pr_crit instead of custom TCU_ERR() macro
     - Remove useless dependency on COMMON_CLK in Kconfig
     - Remove registration of clkdev
    
    v14: Change %i to %d
    
    v15:
     - Use CLK_OF_DECLARE_DRIVER macro since we use "simple-mfd"
     - Use device_node_to_regmap()

 drivers/clk/ingenic/Kconfig  |  10 +-
 drivers/clk/ingenic/Makefile |   1 +
 drivers/clk/ingenic/tcu.c    | 474 +++++++++++++++++++++++++++++++++++
 3 files changed, 484 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/ingenic/tcu.c

diff --git a/drivers/clk/ingenic/Kconfig b/drivers/clk/ingenic/Kconfig
index fe8db93cf21a..1cb489959a99 100644
--- a/drivers/clk/ingenic/Kconfig
+++ b/drivers/clk/ingenic/Kconfig
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
-menu "Ingenic JZ47xx CGU drivers"
+menu "Ingenic SoCs drivers"
 	depends on MIPS
 
 config INGENIC_CGU_COMMON
@@ -45,4 +45,12 @@ config INGENIC_CGU_JZ4780
 
 	  If building for a JZ4780 SoC, you want to say Y here.
 
+config INGENIC_TCU_CLK
+	bool "Ingenic JZ47xx TCU clocks driver"
+	default MACH_INGENIC
+	select MFD_SYSCON
+	help
+	  Support the clocks of the Timer/Counter Unit (TCU) of the Ingenic
+	  JZ47xx SoCs.
+
 endmenu
diff --git a/drivers/clk/ingenic/Makefile b/drivers/clk/ingenic/Makefile
index 250570a809d3..097220b05131 100644
--- a/drivers/clk/ingenic/Makefile
+++ b/drivers/clk/ingenic/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_INGENIC_CGU_JZ4740)	+= jz4740-cgu.o
 obj-$(CONFIG_INGENIC_CGU_JZ4725B)	+= jz4725b-cgu.o
 obj-$(CONFIG_INGENIC_CGU_JZ4770)	+= jz4770-cgu.o
 obj-$(CONFIG_INGENIC_CGU_JZ4780)	+= jz4780-cgu.o
+obj-$(CONFIG_INGENIC_TCU_CLK)		+= tcu.o
diff --git a/drivers/clk/ingenic/tcu.c b/drivers/clk/ingenic/tcu.c
new file mode 100644
index 000000000000..a1a5f9cb439e
--- /dev/null
+++ b/drivers/clk/ingenic/tcu.c
@@ -0,0 +1,474 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ47xx SoCs TCU clocks driver
+ * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clockchips.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/syscore_ops.h>
+
+#include <dt-bindings/clock/ingenic,tcu.h>
+
+/* 8 channels max + watchdog + OST */
+#define TCU_CLK_COUNT	10
+
+#undef pr_fmt
+#define pr_fmt(fmt) "ingenic-tcu-clk: " fmt
+
+enum tcu_clk_parent {
+	TCU_PARENT_PCLK,
+	TCU_PARENT_RTC,
+	TCU_PARENT_EXT,
+};
+
+struct ingenic_soc_info {
+	unsigned int num_channels;
+	bool has_ost;
+	bool has_tcu_clk;
+};
+
+struct ingenic_tcu_clk_info {
+	struct clk_init_data init_data;
+	u8 gate_bit;
+	u8 tcsr_reg;
+};
+
+struct ingenic_tcu_clk {
+	struct clk_hw hw;
+	unsigned int idx;
+	struct ingenic_tcu *tcu;
+	const struct ingenic_tcu_clk_info *info;
+};
+
+struct ingenic_tcu {
+	const struct ingenic_soc_info *soc_info;
+	struct regmap *map;
+	struct clk *clk;
+
+	struct clk_hw_onecell_data *clocks;
+};
+
+static struct ingenic_tcu *ingenic_tcu;
+
+static inline struct ingenic_tcu_clk *to_tcu_clk(struct clk_hw *hw)
+{
+	return container_of(hw, struct ingenic_tcu_clk, hw);
+}
+
+static int ingenic_tcu_enable(struct clk_hw *hw)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	struct ingenic_tcu *tcu = tcu_clk->tcu;
+
+	regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
+
+	return 0;
+}
+
+static void ingenic_tcu_disable(struct clk_hw *hw)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	struct ingenic_tcu *tcu = tcu_clk->tcu;
+
+	regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
+}
+
+static int ingenic_tcu_is_enabled(struct clk_hw *hw)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	unsigned int value;
+
+	regmap_read(tcu_clk->tcu->map, TCU_REG_TSR, &value);
+
+	return !(value & BIT(info->gate_bit));
+}
+
+static bool ingenic_tcu_enable_regs(struct clk_hw *hw)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	struct ingenic_tcu *tcu = tcu_clk->tcu;
+	bool enabled = false;
+
+	/*
+	 * If the SoC has no global TCU clock, we must ungate the channel's
+	 * clock to be able to access its registers.
+	 * If we have a TCU clock, it will be enabled automatically as it has
+	 * been attached to the regmap.
+	 */
+	if (!tcu->clk) {
+		enabled = !!ingenic_tcu_is_enabled(hw);
+		regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
+	}
+
+	return enabled;
+}
+
+static void ingenic_tcu_disable_regs(struct clk_hw *hw)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	struct ingenic_tcu *tcu = tcu_clk->tcu;
+
+	if (!tcu->clk)
+		regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
+}
+
+static u8 ingenic_tcu_get_parent(struct clk_hw *hw)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	unsigned int val = 0;
+	int ret;
+
+	ret = regmap_read(tcu_clk->tcu->map, info->tcsr_reg, &val);
+	WARN_ONCE(ret < 0, "Unable to read TCSR %d", tcu_clk->idx);
+
+	return ffs(val & TCU_TCSR_PARENT_CLOCK_MASK) - 1;
+}
+
+static int ingenic_tcu_set_parent(struct clk_hw *hw, u8 idx)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	bool was_enabled;
+	int ret;
+
+	was_enabled = ingenic_tcu_enable_regs(hw);
+
+	ret = regmap_update_bits(tcu_clk->tcu->map, info->tcsr_reg,
+				 TCU_TCSR_PARENT_CLOCK_MASK, BIT(idx));
+	WARN_ONCE(ret < 0, "Unable to update TCSR %d", tcu_clk->idx);
+
+	if (!was_enabled)
+		ingenic_tcu_disable_regs(hw);
+
+	return 0;
+}
+
+static unsigned long ingenic_tcu_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	unsigned int prescale;
+	int ret;
+
+	ret = regmap_read(tcu_clk->tcu->map, info->tcsr_reg, &prescale);
+	WARN_ONCE(ret < 0, "Unable to read TCSR %d", tcu_clk->idx);
+
+	prescale = (prescale & TCU_TCSR_PRESCALE_MASK) >> TCU_TCSR_PRESCALE_LSB;
+
+	return parent_rate >> (prescale * 2);
+}
+
+static u8 ingenic_tcu_get_prescale(unsigned long rate, unsigned long req_rate)
+{
+	u8 prescale;
+
+	for (prescale = 0; prescale < 5; prescale++)
+		if ((rate >> (prescale * 2)) <= req_rate)
+			return prescale;
+
+	return 5; /* /1024 divider */
+}
+
+static long ingenic_tcu_round_rate(struct clk_hw *hw, unsigned long req_rate,
+		unsigned long *parent_rate)
+{
+	unsigned long rate = *parent_rate;
+	u8 prescale;
+
+	if (req_rate > rate)
+		return -EINVAL;
+
+	prescale = ingenic_tcu_get_prescale(rate, req_rate);
+
+	return rate >> (prescale * 2);
+}
+
+static int ingenic_tcu_set_rate(struct clk_hw *hw, unsigned long req_rate,
+		unsigned long parent_rate)
+{
+	struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+	u8 prescale = ingenic_tcu_get_prescale(parent_rate, req_rate);
+	bool was_enabled;
+	int ret;
+
+	was_enabled = ingenic_tcu_enable_regs(hw);
+
+	ret = regmap_update_bits(tcu_clk->tcu->map, info->tcsr_reg,
+				 TCU_TCSR_PRESCALE_MASK,
+				 prescale << TCU_TCSR_PRESCALE_LSB);
+	WARN_ONCE(ret < 0, "Unable to update TCSR %d", tcu_clk->idx);
+
+	if (!was_enabled)
+		ingenic_tcu_disable_regs(hw);
+
+	return 0;
+}
+
+static const struct clk_ops ingenic_tcu_clk_ops = {
+	.get_parent	= ingenic_tcu_get_parent,
+	.set_parent	= ingenic_tcu_set_parent,
+
+	.recalc_rate	= ingenic_tcu_recalc_rate,
+	.round_rate	= ingenic_tcu_round_rate,
+	.set_rate	= ingenic_tcu_set_rate,
+
+	.enable		= ingenic_tcu_enable,
+	.disable	= ingenic_tcu_disable,
+	.is_enabled	= ingenic_tcu_is_enabled,
+};
+
+static const char * const ingenic_tcu_timer_parents[] = {
+	[TCU_PARENT_PCLK] = "pclk",
+	[TCU_PARENT_RTC]  = "rtc",
+	[TCU_PARENT_EXT]  = "ext",
+};
+
+#define DEF_TIMER(_name, _gate_bit, _tcsr)				\
+	{								\
+		.init_data = {						\
+			.name = _name,					\
+			.parent_names = ingenic_tcu_timer_parents,	\
+			.num_parents = ARRAY_SIZE(ingenic_tcu_timer_parents),\
+			.ops = &ingenic_tcu_clk_ops,			\
+			.flags = CLK_SET_RATE_UNGATE,			\
+		},							\
+		.gate_bit = _gate_bit,					\
+		.tcsr_reg = _tcsr,					\
+	}
+static const struct ingenic_tcu_clk_info ingenic_tcu_clk_info[] = {
+	[TCU_CLK_TIMER0] = DEF_TIMER("timer0", 0, TCU_REG_TCSRc(0)),
+	[TCU_CLK_TIMER1] = DEF_TIMER("timer1", 1, TCU_REG_TCSRc(1)),
+	[TCU_CLK_TIMER2] = DEF_TIMER("timer2", 2, TCU_REG_TCSRc(2)),
+	[TCU_CLK_TIMER3] = DEF_TIMER("timer3", 3, TCU_REG_TCSRc(3)),
+	[TCU_CLK_TIMER4] = DEF_TIMER("timer4", 4, TCU_REG_TCSRc(4)),
+	[TCU_CLK_TIMER5] = DEF_TIMER("timer5", 5, TCU_REG_TCSRc(5)),
+	[TCU_CLK_TIMER6] = DEF_TIMER("timer6", 6, TCU_REG_TCSRc(6)),
+	[TCU_CLK_TIMER7] = DEF_TIMER("timer7", 7, TCU_REG_TCSRc(7)),
+};
+
+static const struct ingenic_tcu_clk_info ingenic_tcu_watchdog_clk_info =
+					 DEF_TIMER("wdt", 16, TCU_REG_WDT_TCSR);
+static const struct ingenic_tcu_clk_info ingenic_tcu_ost_clk_info =
+					 DEF_TIMER("ost", 15, TCU_REG_OST_TCSR);
+#undef DEF_TIMER
+
+static int __init ingenic_tcu_register_clock(struct ingenic_tcu *tcu,
+			unsigned int idx, enum tcu_clk_parent parent,
+			const struct ingenic_tcu_clk_info *info,
+			struct clk_hw_onecell_data *clocks)
+{
+	struct ingenic_tcu_clk *tcu_clk;
+	int err;
+
+	tcu_clk = kzalloc(sizeof(*tcu_clk), GFP_KERNEL);
+	if (!tcu_clk)
+		return -ENOMEM;
+
+	tcu_clk->hw.init = &info->init_data;
+	tcu_clk->idx = idx;
+	tcu_clk->info = info;
+	tcu_clk->tcu = tcu;
+
+	/* Reset channel and clock divider, set default parent */
+	ingenic_tcu_enable_regs(&tcu_clk->hw);
+	regmap_update_bits(tcu->map, info->tcsr_reg, 0xffff, BIT(parent));
+	ingenic_tcu_disable_regs(&tcu_clk->hw);
+
+	err = clk_hw_register(NULL, &tcu_clk->hw);
+	if (err) {
+		kfree(tcu_clk);
+		return err;
+	}
+
+	clocks->hws[idx] = &tcu_clk->hw;
+
+	return 0;
+}
+
+static const struct ingenic_soc_info jz4740_soc_info = {
+	.num_channels = 8,
+	.has_ost = false,
+	.has_tcu_clk = true,
+};
+
+static const struct ingenic_soc_info jz4725b_soc_info = {
+	.num_channels = 6,
+	.has_ost = true,
+	.has_tcu_clk = true,
+};
+
+static const struct ingenic_soc_info jz4770_soc_info = {
+	.num_channels = 8,
+	.has_ost = true,
+	.has_tcu_clk = false,
+};
+
+static const struct of_device_id ingenic_tcu_of_match[] __initconst = {
+	{ .compatible = "ingenic,jz4740-tcu", .data = &jz4740_soc_info, },
+	{ .compatible = "ingenic,jz4725b-tcu", .data = &jz4725b_soc_info, },
+	{ .compatible = "ingenic,jz4770-tcu", .data = &jz4770_soc_info, },
+	{ /* sentinel */ }
+};
+
+static int __init ingenic_tcu_probe(struct device_node *np)
+{
+	const struct of_device_id *id = of_match_node(ingenic_tcu_of_match, np);
+	struct ingenic_tcu *tcu;
+	struct regmap *map;
+	unsigned int i;
+	int ret;
+
+	map = device_node_to_regmap(np);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
+	if (!tcu)
+		return -ENOMEM;
+
+	tcu->map = map;
+	tcu->soc_info = id->data;
+
+	if (tcu->soc_info->has_tcu_clk) {
+		tcu->clk = of_clk_get_by_name(np, "tcu");
+		if (IS_ERR(tcu->clk)) {
+			ret = PTR_ERR(tcu->clk);
+			pr_crit("Cannot get TCU clock\n");
+			goto err_free_tcu;
+		}
+
+		ret = clk_prepare_enable(tcu->clk);
+		if (ret) {
+			pr_crit("Unable to enable TCU clock\n");
+			goto err_put_clk;
+		}
+	}
+
+	tcu->clocks = kzalloc(sizeof(*tcu->clocks) +
+			      sizeof(*tcu->clocks->hws) * TCU_CLK_COUNT,
+			      GFP_KERNEL);
+	if (!tcu->clocks) {
+		ret = -ENOMEM;
+		goto err_clk_disable;
+	}
+
+	tcu->clocks->num = TCU_CLK_COUNT;
+
+	for (i = 0; i < tcu->soc_info->num_channels; i++) {
+		ret = ingenic_tcu_register_clock(tcu, i, TCU_PARENT_EXT,
+						 &ingenic_tcu_clk_info[i],
+						 tcu->clocks);
+		if (ret) {
+			pr_crit("cannot register clock %d\n", i);
+			goto err_unregister_timer_clocks;
+		}
+	}
+
+	/*
+	 * We set EXT as the default parent clock for all the TCU clocks
+	 * except for the watchdog one, where we set the RTC clock as the
+	 * parent. Since the EXT and PCLK are much faster than the RTC clock,
+	 * the watchdog would kick after a maximum time of 5s, and we might
+	 * want a slower kicking time.
+	 */
+	ret = ingenic_tcu_register_clock(tcu, TCU_CLK_WDT, TCU_PARENT_RTC,
+					 &ingenic_tcu_watchdog_clk_info,
+					 tcu->clocks);
+	if (ret) {
+		pr_crit("cannot register watchdog clock\n");
+		goto err_unregister_timer_clocks;
+	}
+
+	if (tcu->soc_info->has_ost) {
+		ret = ingenic_tcu_register_clock(tcu, TCU_CLK_OST,
+						 TCU_PARENT_EXT,
+						 &ingenic_tcu_ost_clk_info,
+						 tcu->clocks);
+		if (ret) {
+			pr_crit("cannot register ost clock\n");
+			goto err_unregister_watchdog_clock;
+		}
+	}
+
+	ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, tcu->clocks);
+	if (ret) {
+		pr_crit("cannot add OF clock provider\n");
+		goto err_unregister_ost_clock;
+	}
+
+	ingenic_tcu = tcu;
+
+	return 0;
+
+err_unregister_ost_clock:
+	if (tcu->soc_info->has_ost)
+		clk_hw_unregister(tcu->clocks->hws[i + 1]);
+err_unregister_watchdog_clock:
+	clk_hw_unregister(tcu->clocks->hws[i]);
+err_unregister_timer_clocks:
+	for (i = 0; i < tcu->clocks->num; i++)
+		if (tcu->clocks->hws[i])
+			clk_hw_unregister(tcu->clocks->hws[i]);
+	kfree(tcu->clocks);
+err_clk_disable:
+	if (tcu->soc_info->has_tcu_clk)
+		clk_disable_unprepare(tcu->clk);
+err_put_clk:
+	if (tcu->soc_info->has_tcu_clk)
+		clk_put(tcu->clk);
+err_free_tcu:
+	kfree(tcu);
+	return ret;
+}
+
+static int __maybe_unused tcu_pm_suspend(void)
+{
+	struct ingenic_tcu *tcu = ingenic_tcu;
+
+	if (tcu->clk)
+		clk_disable(tcu->clk);
+
+	return 0;
+}
+
+static void __maybe_unused tcu_pm_resume(void)
+{
+	struct ingenic_tcu *tcu = ingenic_tcu;
+
+	if (tcu->clk)
+		clk_enable(tcu->clk);
+}
+
+static struct syscore_ops __maybe_unused tcu_pm_ops = {
+	.suspend = tcu_pm_suspend,
+	.resume = tcu_pm_resume,
+};
+
+static void __init ingenic_tcu_init(struct device_node *np)
+{
+	int ret = ingenic_tcu_probe(np);
+
+	if (ret)
+		pr_crit("Failed to initialize TCU clocks: %d\n", ret);
+
+	if (IS_ENABLED(CONFIG_PM_SLEEP))
+		register_syscore_ops(&tcu_pm_ops);
+}
+
+CLK_OF_DECLARE_DRIVER(jz4740_cgu, "ingenic,jz4740-tcu", ingenic_tcu_init);
+CLK_OF_DECLARE_DRIVER(jz4725b_cgu, "ingenic,jz4725b-tcu", ingenic_tcu_init);
+CLK_OF_DECLARE_DRIVER(jz4770_cgu, "ingenic,jz4770-tcu", ingenic_tcu_init);
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 04/13] mfd/syscon: Add device_node_to_regmap()
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

device_node_to_regmap() is exactly like syscon_node_to_regmap(), but it
does not check that the node is compatible with "syscon", and won't
attach the first clock it finds to the regmap.

The rationale behind this, is that one device node with a standard
compatible string "foo,bar" can be covered by multiple drivers sharing a
regmap, or by a single driver doing all the job without a regmap, but
these are implementation details which shouldn't reflect on the
devicetree.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---

Notes:
    v15: New patch

 drivers/mfd/syscon.c       | 46 +++++++++++++++++++++++++-------------
 include/linux/mfd/syscon.h |  6 +++++
 2 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index b65e585fc8c6..660723276481 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -40,7 +40,7 @@ static const struct regmap_config syscon_regmap_config = {
 	.reg_stride = 4,
 };
 
-static struct syscon *of_syscon_register(struct device_node *np)
+static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
 {
 	struct clk *clk;
 	struct syscon *syscon;
@@ -51,9 +51,6 @@ static struct syscon *of_syscon_register(struct device_node *np)
 	struct regmap_config syscon_config = syscon_regmap_config;
 	struct resource res;
 
-	if (!of_device_is_compatible(np, "syscon"))
-		return ERR_PTR(-EINVAL);
-
 	syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
 	if (!syscon)
 		return ERR_PTR(-ENOMEM);
@@ -117,16 +114,18 @@ static struct syscon *of_syscon_register(struct device_node *np)
 		goto err_regmap;
 	}
 
-	clk = of_clk_get(np, 0);
-	if (IS_ERR(clk)) {
-		ret = PTR_ERR(clk);
-		/* clock is optional */
-		if (ret != -ENOENT)
-			goto err_clk;
-	} else {
-		ret = regmap_mmio_attach_clk(regmap, clk);
-		if (ret)
-			goto err_attach;
+	if (check_clk) {
+		clk = of_clk_get(np, 0);
+		if (IS_ERR(clk)) {
+			ret = PTR_ERR(clk);
+			/* clock is optional */
+			if (ret != -ENOENT)
+				goto err_clk;
+		} else {
+			ret = regmap_mmio_attach_clk(regmap, clk);
+			if (ret)
+				goto err_attach;
+		}
 	}
 
 	syscon->regmap = regmap;
@@ -150,7 +149,8 @@ static struct syscon *of_syscon_register(struct device_node *np)
 	return ERR_PTR(ret);
 }
 
-struct regmap *syscon_node_to_regmap(struct device_node *np)
+static struct regmap *device_node_get_regmap(struct device_node *np,
+					     bool check_clk)
 {
 	struct syscon *entry, *syscon = NULL;
 
@@ -165,13 +165,27 @@ struct regmap *syscon_node_to_regmap(struct device_node *np)
 	spin_unlock(&syscon_list_slock);
 
 	if (!syscon)
-		syscon = of_syscon_register(np);
+		syscon = of_syscon_register(np, check_clk);
 
 	if (IS_ERR(syscon))
 		return ERR_CAST(syscon);
 
 	return syscon->regmap;
 }
+
+struct regmap *device_node_to_regmap(struct device_node *np)
+{
+	return device_node_get_regmap(np, false);
+}
+EXPORT_SYMBOL_GPL(device_node_to_regmap);
+
+struct regmap *syscon_node_to_regmap(struct device_node *np)
+{
+	if (!of_device_is_compatible(np, "syscon"))
+		return ERR_PTR(-EINVAL);
+
+	return device_node_get_regmap(np, true);
+}
 EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
 
 struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h
index 8cfda0554381..112dc66262cc 100644
--- a/include/linux/mfd/syscon.h
+++ b/include/linux/mfd/syscon.h
@@ -17,12 +17,18 @@
 struct device_node;
 
 #ifdef CONFIG_MFD_SYSCON
+extern struct regmap *device_node_to_regmap(struct device_node *np);
 extern struct regmap *syscon_node_to_regmap(struct device_node *np);
 extern struct regmap *syscon_regmap_lookup_by_compatible(const char *s);
 extern struct regmap *syscon_regmap_lookup_by_phandle(
 					struct device_node *np,
 					const char *property);
 #else
+static inline struct regmap *device_node_to_regmap(struct device_node *np)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
+
 static inline struct regmap *syscon_node_to_regmap(struct device_node *np)
 {
 	return ERR_PTR(-ENOTSUPP);
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 03/13] dt-bindings: Add doc for the Ingenic TCU drivers
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Rob Herring, Artur Rojek
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

Add documentation about how to properly use the Ingenic TCU
(Timer/Counter Unit) drivers from devicetree.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
    v4: New patch in this series. Corresponds to V2 patches 3-4-5 with
     added content.
    
    v5:
     - Edited PWM/watchdog DT bindings documentation to point to the new
       document.
     - Moved main document to
       Documentation/devicetree/bindings/timer/ingenic,tcu.txt
     - Updated documentation to reflect the new devicetree bindings.
    
    v6:
     - Removed PWM/watchdog documentation files as asked by upstream
     - Removed doc about properties that should be implicit
     - Removed doc about ingenic,timer-channel /
       ingenic,clocksource-channel as they are gone
     - Fix WDT clock name in the binding doc
     - Fix lengths of register areas in watchdog/pwm nodes
    
    v7: No change
    
    v8:
     - Fix address of the PWM node
     - Added doc about system timer and clocksource children nodes
    
    v9:
     - Remove doc about system timer and clocksource children
       nodes...
     - Add doc about ingenic,pwm-channels-mask property
    
    v10: No change
    
    v11: Fix info about default value of ingenic,pwm-channels-mask
    
    v12: Drop sub-nodes for now; they will be introduced in a follow-up
         patchset.
    
    v13:
     - Revert back to v11. Turns out it was okay.
     - Remove 'interrupt-parent' of the list of required properties.
    
    v14: No change
    
    v15: Add "simple-mfd" compatible string

 .../bindings/pwm/ingenic,jz47xx-pwm.txt       |  22 ---
 .../devicetree/bindings/timer/ingenic,tcu.txt | 137 ++++++++++++++++++
 .../bindings/watchdog/ingenic,jz4740-wdt.txt  |  17 ---
 3 files changed, 137 insertions(+), 39 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt
 create mode 100644 Documentation/devicetree/bindings/timer/ingenic,tcu.txt
 delete mode 100644 Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt

diff --git a/Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt b/Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt
deleted file mode 100644
index 493bec80d59b..000000000000
--- a/Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt
+++ /dev/null
@@ -1,22 +0,0 @@
-Ingenic JZ47xx PWM Controller
-=============================
-
-Required properties:
-- compatible: Should be "ingenic,jz4740-pwm"
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a description
-  of the cells format.
-- clocks : phandle to the external clock.
-- clock-names : Should be "ext".
-
-
-Example:
-
-	pwm: pwm@10002000 {
-		compatible = "ingenic,jz4740-pwm";
-		reg = <0x10002000 0x1000>;
-
-		#pwm-cells = <3>;
-
-		clocks = <&ext>;
-		clock-names = "ext";
-	};
diff --git a/Documentation/devicetree/bindings/timer/ingenic,tcu.txt b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
new file mode 100644
index 000000000000..5a4b9ddd9470
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
@@ -0,0 +1,137 @@
+Ingenic JZ47xx SoCs Timer/Counter Unit devicetree bindings
+==========================================================
+
+For a description of the TCU hardware and drivers, have a look at
+Documentation/mips/ingenic-tcu.txt.
+
+Required properties:
+
+- compatible: Must be one of:
+  * ingenic,jz4740-tcu
+  * ingenic,jz4725b-tcu
+  * ingenic,jz4770-tcu
+  followed by "simple-mfd".
+- reg: Should be the offset/length value corresponding to the TCU registers
+- clocks: List of phandle & clock specifiers for clocks external to the TCU.
+  The "pclk", "rtc" and "ext" clocks should be provided. The "tcu" clock
+  should be provided if the SoC has it.
+- clock-names: List of name strings for the external clocks.
+- #clock-cells: Should be <1>;
+  Clock consumers specify this argument to identify a clock. The valid values
+  may be found in <dt-bindings/clock/ingenic,tcu.h>.
+- interrupt-controller : Identifies the node as an interrupt controller
+- #interrupt-cells : Specifies the number of cells needed to encode an
+  interrupt source. The value should be 1.
+- interrupts : Specifies the interrupt the controller is connected to.
+
+Optional properties:
+
+- ingenic,pwm-channels-mask: Bitmask of TCU channels reserved for PWM use.
+  Default value is 0xfc.
+
+
+Children nodes
+==========================================================
+
+
+PWM node:
+---------
+
+Required properties:
+
+- compatible: Must be one of:
+  * ingenic,jz4740-pwm
+  * ingenic,jz4725b-pwm
+- #pwm-cells: Should be 3. See ../pwm/pwm.txt for a description of the cell
+  format.
+- clocks: List of phandle & clock specifiers for the TCU clocks.
+- clock-names: List of name strings for the TCU clocks.
+
+
+Watchdog node:
+--------------
+
+Required properties:
+
+- compatible: Must be "ingenic,jz4740-watchdog"
+- clocks: phandle to the WDT clock
+- clock-names: should be "wdt"
+
+
+OS Timer node:
+---------
+
+Required properties:
+
+- compatible: Must be one of:
+  * ingenic,jz4725b-ost
+  * ingenic,jz4770-ost
+- clocks: phandle to the OST clock
+- clock-names: should be "ost"
+- interrupts : Specifies the interrupt the OST is connected to.
+
+
+Example
+==========================================================
+
+#include <dt-bindings/clock/jz4770-cgu.h>
+#include <dt-bindings/clock/ingenic,tcu.h>
+
+/ {
+	tcu: timer@10002000 {
+		compatible = "ingenic,jz4770-tcu", "simple-mfd";
+		reg = <0x10002000 0x1000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x10002000 0x1000>;
+
+		#clock-cells = <1>;
+
+		clocks = <&cgu JZ4770_CLK_RTC
+			  &cgu JZ4770_CLK_EXT
+			  &cgu JZ4770_CLK_PCLK>;
+		clock-names = "rtc", "ext", "pclk";
+
+		interrupt-controller;
+		#interrupt-cells = <1>;
+
+		interrupt-parent = <&intc>;
+		interrupts = <27 26 25>;
+
+		watchdog: watchdog@0 {
+			compatible = "ingenic,jz4740-watchdog";
+			reg = <0x0 0xc>;
+
+			clocks = <&tcu TCU_CLK_WDT>;
+			clock-names = "wdt";
+		};
+
+		pwm: pwm@40 {
+			compatible = "ingenic,jz4740-pwm";
+			reg = <0x40 0x80>;
+
+			#pwm-cells = <3>;
+
+			clocks = <&tcu TCU_CLK_TIMER0
+				  &tcu TCU_CLK_TIMER1
+				  &tcu TCU_CLK_TIMER2
+				  &tcu TCU_CLK_TIMER3
+				  &tcu TCU_CLK_TIMER4
+				  &tcu TCU_CLK_TIMER5
+				  &tcu TCU_CLK_TIMER6
+				  &tcu TCU_CLK_TIMER7>;
+			clock-names = "timer0", "timer1", "timer2", "timer3",
+				      "timer4", "timer5", "timer6", "timer7";
+		};
+
+		ost: timer@e0 {
+			compatible = "ingenic,jz4770-ost";
+			reg = <0xe0 0x20>;
+
+			clocks = <&tcu TCU_CLK_OST>;
+			clock-names = "ost";
+
+			interrupts = <15>;
+		};
+	};
+};
diff --git a/Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt b/Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt
deleted file mode 100644
index ce1cb72d5345..000000000000
--- a/Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt
+++ /dev/null
@@ -1,17 +0,0 @@
-Ingenic Watchdog Timer (WDT) Controller for JZ4740 & JZ4780
-
-Required properties:
-compatible: "ingenic,jz4740-watchdog" or "ingenic,jz4780-watchdog"
-reg: Register address and length for watchdog registers
-clocks: phandle to the RTC clock
-clock-names: should be "rtc"
-
-Example:
-
-watchdog: jz4740-watchdog@10002000 {
-	compatible = "ingenic,jz4740-watchdog";
-	reg = <0x10002000 0x10>;
-
-	clocks = <&cgu JZ4740_CLK_RTC>;
-	clock-names = "rtc";
-};
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 01/13] dt-bindings: ingenic: Add DT bindings for TCU clocks
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre, Paul Cercueil, Artur Rojek, Rob Herring
In-Reply-To: <20190724171615.20774-1-paul@crapouillou.net>

This header provides clock numbers for the ingenic,tcu
DT binding.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
---

Notes:
    v2: Use SPDX identifier for the license
    
    v3/v4: No change
    
    v5: s/JZ47*_/TCU_/ and dropped *_CLK_LAST defines
    
    v6-v15: No change

 include/dt-bindings/clock/ingenic,tcu.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 include/dt-bindings/clock/ingenic,tcu.h

diff --git a/include/dt-bindings/clock/ingenic,tcu.h b/include/dt-bindings/clock/ingenic,tcu.h
new file mode 100644
index 000000000000..d569650a7945
--- /dev/null
+++ b/include/dt-bindings/clock/ingenic,tcu.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This header provides clock numbers for the ingenic,tcu DT binding.
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_INGENIC_TCU_H__
+#define __DT_BINDINGS_CLOCK_INGENIC_TCU_H__
+
+#define TCU_CLK_TIMER0	0
+#define TCU_CLK_TIMER1	1
+#define TCU_CLK_TIMER2	2
+#define TCU_CLK_TIMER3	3
+#define TCU_CLK_TIMER4	4
+#define TCU_CLK_TIMER5	5
+#define TCU_CLK_TIMER6	6
+#define TCU_CLK_TIMER7	7
+#define TCU_CLK_WDT	8
+#define TCU_CLK_OST	9
+
+#endif /* __DT_BINDINGS_CLOCK_INGENIC_TCU_H__ */
-- 
2.21.0.593.g511ec345e18


^ permalink raw reply related

* [PATCH v15 00/13] TCU patchset v15
From: Paul Cercueil @ 2019-07-24 17:16 UTC (permalink / raw)
  To: Ralf Baechle, Paul Burton, James Hogan, Jonathan Corbet,
	Lee Jones, Arnd Bergmann, Daniel Lezcano, Thomas Gleixner,
	Michael Turquette, Stephen Boyd, Jason Cooper, Marc Zyngier,
	Rob Herring, Mark Rutland
  Cc: devicetree, linux-kernel, linux-doc, linux-mips, linux-clk, od,
	Mathieu Malaterre

Hi,

This is the V15 of my Ingenic TCU patchet.

The big change since V14 is that the custom MFD driver
(ex patch 04/13) was dropped in favor of a small patch to syscon
and a "simple-mfd" compatible.

The patchset was based on mips/mips-next, but all of them minus
the last one will apply cleanly on v5.3-rc1.

Changelog:

* [02/13]: Remove info about MFD driver
* [03/13]: Add "simple-mfd" compatible string
* [04/13]: New patch
* [05/13]: - Use CLK_OF_DECLARE_DRIVER since we use "simple-mfd"
           - Use device_node_to_regmap()
* [06/13]: Use device_node_to_regmap()
* [07/13]: Use device_node_to_regmap()
* [09/13]: Add "simple-mfd" compatible string

Cheers,
-Paul



^ permalink raw reply

* [PATCH] hung_task: Allow printing warnings every check interval
From: Dmitry Safonov @ 2019-07-24 17:02 UTC (permalink / raw)
  To: linux-kernel
  Cc: Dmitry Safonov, Dmitry Safonov, Andrew Morton, Dmitry Vyukov,
	Ingo Molnar, Jonathan Corbet, Tetsuo Handa, Thomas Gleixner,
	Peter Zijlstra (Intel), Vasiliy Khoruzhick, linux-doc,
	linux-fsdevel

Hung task detector has one timeout and has two associated actions on it:
- issuing warnings with names and stacks of blocked tasks
- panic()

We want switches to panic (and reboot) if there's a task
in uninterruptible sleep for some minutes - at that moment something
ugly has happened and the box needs a reboot.
But we also want to detect conditions that are "out of range"
or approaching the point of failure. Under such conditions we want
to issue an "early warning" of an impending failure, minutes before
the switch is going to panic.

Those "early warnings" serve a purpose while monitoring the network
infrastructure. Those are also valuable on post-mortem analysis, when
the logs from userspace applications aren't enough.
Furthermore, we have a test pool of long-running duts that are
constantly under close to real-world load for weeks. And such early
warnings allowed to figure out some bottle necks without much engineer
work intervention.

There are also not yet upstream patches for other kinds of "early
warnings" as prints whenever a mutex/semaphore is released after being
held for long time, but those patches are much more intricate and have
their runtime cost.

It seems rather easy to add printing tasks and their stacks for
notification and debugging purposes into hung task detector without
complicating the code or major cost (prints are with KERN_INFO loglevel
and so don't go on console, only into dmesg log).

Since commit a2e514453861 ("kernel/hung_task.c: allow to set checking
interval separately from timeout") it's possible to set checking
interval for hung task detector with `hung_task_check_interval_secs`.

Provide `hung_task_interval_warnings` sysctl that allows printing
hung tasks every detection interval. It's not ratelimited, so the root
should be cautious configuring it.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Vasiliy Khoruzhick <vasilykh@arista.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 Documentation/admin-guide/sysctl/kernel.rst | 20 ++++++++-
 include/linux/sched/sysctl.h                |  1 +
 kernel/hung_task.c                          | 50 ++++++++++++++-------
 kernel/sysctl.c                             |  8 ++++
 4 files changed, 62 insertions(+), 17 deletions(-)

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 032c7cd3cede..2e36620ec1e4 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -45,6 +45,7 @@ show up in /proc/sys/kernel:
 - hung_task_timeout_secs
 - hung_task_check_interval_secs
 - hung_task_warnings
+- hung_task_interval_warnings
 - hyperv_record_panic_msg
 - kexec_load_disabled
 - kptr_restrict
@@ -383,14 +384,29 @@ Possible values to set are in range {0..LONG_MAX/HZ}.
 hung_task_warnings:
 ===================
 
-The maximum number of warnings to report. During a check interval
-if a hung task is detected, this value is decreased by 1.
+The maximum number of warnings to report. If after timeout a hung
+task is present, this value is decreased by 1 every check interval,
+producing a warning.
 When this value reaches 0, no more warnings will be reported.
 This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
 
 -1: report an infinite number of warnings.
 
 
+hung_task_interval_warnings:
+===================
+
+The same as hung_task_warnings, but set the number of interval
+warnings to be issued about detected hung tasks during check
+interval. That will produce warnings *before* the timeout happens.
+If a hung task is detected during check interval, this value is
+decreased by 1. When this value reaches 0, only timeout warnings
+will be reported.
+This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
+
+-1: report an infinite number of check interval warnings.
+
+
 hyperv_record_panic_msg:
 ========================
 
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index d4f6215ee03f..89f55e914673 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -12,6 +12,7 @@ extern unsigned int  sysctl_hung_task_panic;
 extern unsigned long sysctl_hung_task_timeout_secs;
 extern unsigned long sysctl_hung_task_check_interval_secs;
 extern int sysctl_hung_task_warnings;
+extern int sysctl_hung_task_interval_warnings;
 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
 					 void __user *buffer,
 					 size_t *lenp, loff_t *ppos);
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 14a625c16cb3..cd971eef8226 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -49,6 +49,7 @@ unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_
 unsigned long __read_mostly sysctl_hung_task_check_interval_secs;
 
 int __read_mostly sysctl_hung_task_warnings = 10;
+int __read_mostly sysctl_hung_task_interval_warnings;
 
 static int __read_mostly did_panic;
 static bool hung_task_show_lock;
@@ -85,6 +86,34 @@ static struct notifier_block panic_block = {
 	.notifier_call = hung_task_panic,
 };
 
+static void hung_task_warning(struct task_struct *t, bool timeout)
+{
+	const char *loglevel = timeout ? KERN_ERR : KERN_INFO;
+	const char *path;
+	int *warnings;
+
+	if (timeout) {
+		warnings = &sysctl_hung_task_warnings;
+		path = "hung_task_timeout_secs";
+	} else {
+		warnings = &sysctl_hung_task_interval_warnings;
+		path = "hung_task_interval_secs";
+	}
+
+	if (*warnings > 0)
+		--*warnings;
+
+	printk("%sINFO: task %s:%d blocked for more than %ld seconds.\n",
+	       loglevel, t->comm, t->pid, (jiffies - t->last_switch_time) / HZ);
+	printk("%s      %s %s %.*s\n",
+		loglevel, print_tainted(), init_utsname()->release,
+		(int)strcspn(init_utsname()->version, " "),
+		init_utsname()->version);
+	printk("%s\"echo 0 > /proc/sys/kernel/%s\" disables this message.\n",
+		loglevel, path);
+	sched_show_task(t);
+}
+
 static void check_hung_task(struct task_struct *t, unsigned long timeout)
 {
 	unsigned long switch_count = t->nvcsw + t->nivcsw;
@@ -109,6 +138,9 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 		t->last_switch_time = jiffies;
 		return;
 	}
+	if (sysctl_hung_task_interval_warnings)
+		hung_task_warning(t, false);
+
 	if (time_is_after_jiffies(t->last_switch_time + timeout * HZ))
 		return;
 
@@ -120,22 +152,10 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 		hung_task_call_panic = true;
 	}
 
-	/*
-	 * Ok, the task did not get scheduled for more than 2 minutes,
-	 * complain:
-	 */
 	if (sysctl_hung_task_warnings) {
-		if (sysctl_hung_task_warnings > 0)
-			sysctl_hung_task_warnings--;
-		pr_err("INFO: task %s:%d blocked for more than %ld seconds.\n",
-		       t->comm, t->pid, (jiffies - t->last_switch_time) / HZ);
-		pr_err("      %s %s %.*s\n",
-			print_tainted(), init_utsname()->release,
-			(int)strcspn(init_utsname()->version, " "),
-			init_utsname()->version);
-		pr_err("\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
-			" disables this message.\n");
-		sched_show_task(t);
+		/* Don't print warings twice */
+		if (!sysctl_hung_task_interval_warnings)
+			hung_task_warning(t, true);
 		hung_task_show_lock = true;
 	}
 
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 078950d9605b..f12888971d66 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1147,6 +1147,14 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= &neg_one,
 	},
+	{
+		.procname	= "hung_task_interval_warnings",
+		.data		= &sysctl_hung_task_interval_warnings,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &neg_one,
+	},
 #endif
 #ifdef CONFIG_RT_MUTEXES
 	{
-- 
2.22.0


^ permalink raw reply related

* Re: [PATCH v3 01/12] fpga: dfl: fme: support 512bit data width PR
From: Wu Hao @ 2019-07-24 14:22 UTC (permalink / raw)
  To: Greg KH
  Cc: mdf, linux-fpga, linux-kernel, linux-api, linux-doc, atull,
	Ananda Ravuri, Xu Yilun
In-Reply-To: <20190724093532.GB29532@kroah.com>

On Wed, Jul 24, 2019 at 11:35:32AM +0200, Greg KH wrote:
> On Tue, Jul 23, 2019 at 12:51:24PM +0800, Wu Hao wrote:
> > In early partial reconfiguration private feature, it only
> > supports 32bit data width when writing data to hardware for
> > PR. 512bit data width PR support is an important optimization
> > for some specific solutions (e.g. XEON with FPGA integrated),
> > it allows driver to use AVX512 instruction to improve the
> > performance of partial reconfiguration. e.g. programming one
> > 100MB bitstream image via this 512bit data width PR hardware
> > only takes ~300ms, but 32bit revision requires ~3s per test
> > result.
> > 
> > Please note now this optimization is only done on revision 2
> > of this PR private feature which is only used in integrated
> > solution that AVX512 is always supported. This revision 2
> > hardware doesn't support 32bit PR.
> > 
> > Signed-off-by: Ananda Ravuri <ananda.ravuri@intel.com>
> > Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> > Signed-off-by: Wu Hao <hao.wu@intel.com>
> > Acked-by: Alan Tull <atull@kernel.org>
> > Signed-off-by: Moritz Fischer <mdf@kernel.org>
> > ---
> > v2: remove DRV/MODULE_VERSION modifications
> > ---
> >  drivers/fpga/dfl-fme-mgr.c | 110 ++++++++++++++++++++++++++++++++++++++-------
> >  drivers/fpga/dfl-fme-pr.c  |  43 +++++++++++-------
> >  drivers/fpga/dfl-fme.h     |   2 +
> >  drivers/fpga/dfl.h         |   5 +++
> >  4 files changed, 129 insertions(+), 31 deletions(-)
> > 
> > diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> > index b3f7eee..46e17f0 100644
> > --- a/drivers/fpga/dfl-fme-mgr.c
> > +++ b/drivers/fpga/dfl-fme-mgr.c
> > @@ -22,6 +22,7 @@
> >  #include <linux/io-64-nonatomic-lo-hi.h>
> >  #include <linux/fpga/fpga-mgr.h>
> >  
> > +#include "dfl.h"
> >  #include "dfl-fme-pr.h"
> >  
> >  /* FME Partial Reconfiguration Sub Feature Register Set */
> > @@ -30,6 +31,7 @@
> >  #define FME_PR_STS		0x10
> >  #define FME_PR_DATA		0x18
> >  #define FME_PR_ERR		0x20
> > +#define FME_PR_512_DATA		0x40 /* Data Register for 512bit datawidth PR */
> >  #define FME_PR_INTFC_ID_L	0xA8
> >  #define FME_PR_INTFC_ID_H	0xB0
> >  
> > @@ -67,8 +69,43 @@
> >  #define PR_WAIT_TIMEOUT   8000000
> >  #define PR_HOST_STATUS_IDLE	0
> >  
> > +#if defined(CONFIG_X86) && defined(CONFIG_AS_AVX512)
> > +
> > +#include <linux/cpufeature.h>
> > +#include <asm/fpu/api.h>
> > +
> > +static inline int is_cpu_avx512_enabled(void)
> > +{
> > +	return cpu_feature_enabled(X86_FEATURE_AVX512F);
> > +}
> 
> That's a very arch specific function, why would a driver ever care about
> this?

Yes, this is only applied to a specific FPGA solution, which FPGA
has been integrated with XEON. Hardware indicates this using register
to software. As it's cpu integrated solution, so CPU always has this
AVX512 capability. The only check we do, is make sure this is not
manually disabled by kernel.

With this hardware, software could use AVX512 to accelerate the FPGA
partial reconfiguration as mentioned in the patch commit message.
It brings performance benifits to people who uses it. This is only one
optimization (512 vs 32bit data write to hw) for a specific hardware.

For other discrete solutions, e.g. FPGA PCIe Card, this is not used
at all as driver does check hardware register to avoid any AVX512 code.

> 
> > +
> > +static inline void copy512(const void *src, void __iomem *dst)
> > +{
> > +	kernel_fpu_begin();
> > +
> > +	asm volatile("vmovdqu64 (%0), %%zmm0;"
> > +		     "vmovntdq %%zmm0, (%1);"
> > +		     :
> > +		     : "r"(src), "r"(dst)
> > +		     : "memory");
> > +
> > +	kernel_fpu_end();
> > +}
> 
> Shouldn't this be an arch-specific function somewhere?  Burying this in
> a random driver is not ok.  Please make this generic for all systems.

If more people need the same avx operation like this in kernel, then maybe
this can be moved to some arch-specific lib code somewhere as some common
functions to everybody, but i am not very sure if this is the case. Let me
think about this more.

> 
> > +#else
> > +static inline int is_cpu_avx512_enabled(void)
> > +{
> > +	return 0;
> > +}
> > +
> > +static inline void copy512(const void *src, void __iomem *dst)
> > +{
> > +	WARN_ON_ONCE(1);
> 
> Are you trying to get reports from syzbot?  :)

Oh.. no.. I will remove it. :)

Thank you very much!

Hao

> 
> Please fix this all up.
> 
> greg k-h

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