Merge tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm/unaligned.h unification from Arnd Bergmann:
 "Unify asm/unaligned.h around struct helper

  The get_unaligned()/put_unaligned() helpers are traditionally
  architecture specific, with the two main variants being the
  "access-ok.h" version that assumes unaligned pointer accesses always
  work on a particular architecture, and the "le-struct.h" version that
  casts the data to a byte aligned type before dereferencing, for
  architectures that cannot always do unaligned accesses in hardware.

  Based on the discussion linked below, it appears that the access-ok
  version is not realiable on any architecture, but the struct version
  probably has no downsides. This series changes the code to use the
  same implementation on all architectures, addressing the few
  exceptions separately"

Link: https://lore.kernel.org/lkml/75d07691-1e4f-741f-9852-38c0b4f520bc@synopsys.com/
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363
Link: https://lore.kernel.org/lkml/20210507220813.365382-14-arnd@kernel.org/
Link: git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git unaligned-rework-v2
Link: https://lore.kernel.org/lkml/CAHk-=whGObOKruA_bU3aPGZfoDqZM1_9wBkwREp0H0FgR-90uQ@mail.gmail.com/

* tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: simplify asm/unaligned.h
  asm-generic: uaccess: 1-byte access is always aligned
  netpoll: avoid put_unaligned() on single character
  mwifiex: re-fix for unaligned accesses
  apparmor: use get_unaligned() only for multi-byte words
  partitions: msdos: fix one-byte get_unaligned()
  asm-generic: unaligned always use struct helpers
  asm-generic: unaligned: remove byteshift helpers
  powerpc: use linux/unaligned/le_struct.h on LE power7
  m68k: select CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  sh: remove unaligned access for sh4a
  openrisc: always use unaligned-struct header
  asm-generic: use asm-generic/unaligned.h for most architectures

2 files changed, 119 insertions, 26 deletions

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 4973328f3c6e..a0b2f270dddc 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -19,7 +19,7 @@ __get_user_fn(size_t size, const void __user *from, void *to)
 
 	switch (size) {
 	case 1:
-		*(u8 *)to = get_unaligned((u8 __force *)from);
+		*(u8 *)to = *((u8 __force *)from);
 		return 0;
 	case 2:
 		*(u16 *)to = get_unaligned((u16 __force *)from);
@@ -45,7 +45,7 @@ __put_user_fn(size_t size, void __user *to, void *from)
 
 	switch (size) {
 	case 1:
-		put_unaligned(*(u8 *)from, (u8 __force *)to);
+		*(u8 __force *)to = *(u8 *)from;
 		return 0;
 	case 2:
 		put_unaligned(*(u16 *)from, (u16 __force *)to);
diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h
index 374c940e9be1..1c4242416c9f 100644
--- a/include/asm-generic/unaligned.h
+++ b/include/asm-generic/unaligned.h
@@ -6,31 +6,124 @@
  * This is the most generic implementation of unaligned accesses
  * and should work almost anywhere.
  */
+#include <linux/unaligned/packed_struct.h>
 #include <asm/byteorder.h>
 
-/* Set by the arch if it can handle unaligned accesses in hardware. */
-#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
-# include <linux/unaligned/access_ok.h>
-#endif
-
-#if defined(__LITTLE_ENDIAN)
-# ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
-#  include <linux/unaligned/le_struct.h>
-#  include <linux/unaligned/be_byteshift.h>
-# endif
-# include <linux/unaligned/generic.h>
-# define get_unaligned	__get_unaligned_le
-# define put_unaligned	__put_unaligned_le
-#elif defined(__BIG_ENDIAN)
-# ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
-#  include <linux/unaligned/be_struct.h>
-#  include <linux/unaligned/le_byteshift.h>
-# endif
-# include <linux/unaligned/generic.h>
-# define get_unaligned	__get_unaligned_be
-# define put_unaligned	__put_unaligned_be
-#else
-# error need to define endianess
-#endif
+#define __get_unaligned_t(type, ptr) ({						\
+	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\
+	__pptr->x;								\
+})
+
+#define __put_unaligned_t(type, val, ptr) do {					\
+	struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);		\
+	__pptr->x = (val);							\
+} while (0)
+
+#define get_unaligned(ptr)	__get_unaligned_t(typeof(*(ptr)), (ptr))
+#define put_unaligned(val, ptr) __put_unaligned_t(typeof(*(ptr)), (val), (ptr))
+
+static inline u16 get_unaligned_le16(const void *p)
+{
+	return le16_to_cpu(__get_unaligned_t(__le16, p));
+}
+
+static inline u32 get_unaligned_le32(const void *p)
+{
+	return le32_to_cpu(__get_unaligned_t(__le32, p));
+}
+
+static inline u64 get_unaligned_le64(const void *p)
+{
+	return le64_to_cpu(__get_unaligned_t(__le64, p));
+}
+
+static inline void put_unaligned_le16(u16 val, void *p)
+{
+	__put_unaligned_t(__le16, cpu_to_le16(val), p);
+}
+
+static inline void put_unaligned_le32(u32 val, void *p)
+{
+	__put_unaligned_t(__le32, cpu_to_le32(val), p);
+}
+
+static inline void put_unaligned_le64(u64 val, void *p)
+{
+	__put_unaligned_t(__le64, cpu_to_le64(val), p);
+}
+
+static inline u16 get_unaligned_be16(const void *p)
+{
+	return be16_to_cpu(__get_unaligned_t(__be16, p));
+}
+
+static inline u32 get_unaligned_be32(const void *p)
+{
+	return be32_to_cpu(__get_unaligned_t(__be32, p));
+}
+
+static inline u64 get_unaligned_be64(const void *p)
+{
+	return be64_to_cpu(__get_unaligned_t(__be64, p));
+}
+
+static inline void put_unaligned_be16(u16 val, void *p)
+{
+	__put_unaligned_t(__be16, cpu_to_be16(val), p);
+}
+
+static inline void put_unaligned_be32(u32 val, void *p)
+{
+	__put_unaligned_t(__be32, cpu_to_be32(val), p);
+}
+
+static inline void put_unaligned_be64(u64 val, void *p)
+{
+	__put_unaligned_t(__be64, cpu_to_be64(val), p);
+}
+
+static inline u32 __get_unaligned_be24(const u8 *p)
+{
+	return p[0] << 16 | p[1] << 8 | p[2];
+}
+
+static inline u32 get_unaligned_be24(const void *p)
+{
+	return __get_unaligned_be24(p);
+}
+
+static inline u32 __get_unaligned_le24(const u8 *p)
+{
+	return p[0] | p[1] << 8 | p[2] << 16;
+}
+
+static inline u32 get_unaligned_le24(const void *p)
+{
+	return __get_unaligned_le24(p);
+}
+
+static inline void __put_unaligned_be24(const u32 val, u8 *p)
+{
+	*p++ = val >> 16;
+	*p++ = val >> 8;
+	*p++ = val;
+}
+
+static inline void put_unaligned_be24(const u32 val, void *p)
+{
+	__put_unaligned_be24(val, p);
+}
+
+static inline void __put_unaligned_le24(const u32 val, u8 *p)
+{
+	*p++ = val;
+	*p++ = val >> 8;
+	*p++ = val >> 16;
+}
+
+static inline void put_unaligned_le24(const u32 val, void *p)
+{
+	__put_unaligned_le24(val, p);
+}
 
 #endif /* __ASM_GENERIC_UNALIGNED_H */