diff mbox series

[05/17] prmem: shorthands for write rare on common types

Message ID 20181023213504.28905-6-igor.stoppa@huawei.com (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Igor Stoppa Oct. 23, 2018, 9:34 p.m. UTC 
Wrappers around the basic write rare functionality, addressing several
common data types found in the kernel, allowing to specify the new
values through immediates, like constants and defines.

Note:
The list is not complete and could be expanded.

Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
CC: Michal Hocko <mhocko@kernel.org>
CC: Vlastimil Babka <vbabka@suse.cz>
CC: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Pavel Tatashin <pasha.tatashin@oracle.com>
CC: linux-mm@kvack.org
CC: linux-kernel@vger.kernel.org
---
 MAINTAINERS                |   1 +
 include/linux/prmemextra.h | 133 +++++++++++++++++++++++++++++++++++++
 2 files changed, 134 insertions(+)
 create mode 100644 include/linux/prmemextra.h

Comments

Dave Hansen Oct. 25, 2018, 12:28 a.m. UTC | #1 
On 10/23/18 2:34 PM, Igor Stoppa wrote:
> Wrappers around the basic write rare functionality, addressing several
> common data types found in the kernel, allowing to specify the new
> values through immediates, like constants and defines.

I have to wonder whether this is the right way, or whether a
size-agnostic function like put_user() is the right way.  put_user() is
certainly easier to use.
Igor Stoppa Oct. 29, 2018, 6:12 p.m. UTC | #2 
On 25/10/2018 01:28, Dave Hansen wrote:
> On 10/23/18 2:34 PM, Igor Stoppa wrote:
>> Wrappers around the basic write rare functionality, addressing several
>> common data types found in the kernel, allowing to specify the new
>> values through immediates, like constants and defines.
> 
> I have to wonder whether this is the right way, or whether a
> size-agnostic function like put_user() is the right way.  put_user() is
> certainly easier to use.

I definitely did not like it either.
But it was the best that came to my mind ...
The main purpose of this code was to show what I wanted to do.
Once more, thanks for pointing out a better way to do it.

--
igor
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e566c5d09faf..df7221eca160 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9459,6 +9459,7 @@  M:	Igor Stoppa <igor.stoppa@gmail.com>
 L:	kernel-hardening@lists.openwall.com
 S:	Maintained
 F:	include/linux/prmem.h
+F:	include/linux/prmemextra.h
 F:	mm/prmem.c
 
 MEMORY MANAGEMENT
diff --git a/include/linux/prmemextra.h b/include/linux/prmemextra.h
new file mode 100644
index 000000000000..36995717720e
--- /dev/null
+++ b/include/linux/prmemextra.h
@@ -0,0 +1,133 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * prmemextra.h: Shorthands for write rare of basic data types
+ *
+ * (C) Copyright 2018 Huawei Technologies Co. Ltd.
+ * Author: Igor Stoppa <igor.stoppa@huawei.com>
+ *
+ */
+
+#ifndef _LINUX_PRMEMEXTRA_H
+#define _LINUX_PRMEMEXTRA_H
+
+#include <linux/prmem.h>
+
+/**
+ * wr_char - alters a char in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_char(const char *dst, const char val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_short - alters a short in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_short(const short *dst, const short val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_ushort - alters an unsigned short in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_ushort(const unsigned short *dst, const unsigned short val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_int - alters an int in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_int(const int *dst, const int val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_uint - alters an unsigned int in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_uint(const unsigned int *dst, const unsigned int val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_long - alters a long in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_long(const long *dst, const long val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_ulong - alters an unsigned long in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_ulong(const unsigned long *dst, const unsigned long val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_longlong - alters a long long in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_longlong(const long long *dst, const long long val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+/**
+ * wr_ulonglong - alters an unsigned long long in write rare memory
+ * @dst: target for write
+ * @val: new value
+ *
+ * Returns true on success, false otherwise.
+ */
+static __always_inline
+bool wr_ulonglong(const unsigned long long *dst,
+			  const unsigned long long val)
+{
+	return wr_memcpy(dst, &val, sizeof(val));
+}
+
+#endif