[v3,3/7] x86: Implement memset16, memset32 & memset64
diff mbox

Message ID 20170324161318.18718-4-willy@infradead.org
State New, archived
Headers show

Commit Message

Matthew Wilcox March 24, 2017, 4:13 p.m. UTC
From: Matthew Wilcox <mawilcox@microsoft.com>

These are single instructions on x86.  There's no 64-bit instruction
for x86-32, but we don't yet have any user for memset64() on 32-bit
architectures, so don't bother to implement it.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
 arch/x86/include/asm/string_32.h | 24 ++++++++++++++++++++++++
 arch/x86/include/asm/string_64.h | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

Comments

kernel test robot March 26, 2017, 7:44 a.m. UTC | #1
Hi Matthew,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.11-rc3 next-20170324]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Matthew-Wilcox/Add-memsetN-functions/20170326-140108
config: i386-randconfig-x077-201713 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

>> lib/string.c:733:7: error: redefinition of 'memset32'
    void *memset32(uint32_t *s, uint32_t v, size_t count)
          ^~~~~~~~
   In file included from arch/x86/include/asm/string.h:2:0,
                    from include/linux/string.h:18,
                    from lib/string.c:23:
   arch/x86/include/asm/string_32.h:347:21: note: previous definition of 'memset32' was here
    static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
                        ^~~~~~~~

vim +/memset32 +733 lib/string.c

9114f9de Matthew Wilcox 2017-03-24  717  	return s;
9114f9de Matthew Wilcox 2017-03-24  718  }
9114f9de Matthew Wilcox 2017-03-24  719  EXPORT_SYMBOL(memset16);
9114f9de Matthew Wilcox 2017-03-24  720  #endif
9114f9de Matthew Wilcox 2017-03-24  721  
9114f9de Matthew Wilcox 2017-03-24  722  #ifndef __HAVE_ARCH_MEMSET32
9114f9de Matthew Wilcox 2017-03-24  723  /**
9114f9de Matthew Wilcox 2017-03-24  724   * memset32() - Fill a memory area with a uint32_t
9114f9de Matthew Wilcox 2017-03-24  725   * @s: Pointer to the start of the area.
9114f9de Matthew Wilcox 2017-03-24  726   * @v: The value to fill the area with
9114f9de Matthew Wilcox 2017-03-24  727   * @count: The number of values to store
9114f9de Matthew Wilcox 2017-03-24  728   *
9114f9de Matthew Wilcox 2017-03-24  729   * Differs from memset() in that it fills with a uint32_t instead
9114f9de Matthew Wilcox 2017-03-24  730   * of a byte.  Remember that @count is the number of uint32_ts to
9114f9de Matthew Wilcox 2017-03-24  731   * store, not the number of bytes.
9114f9de Matthew Wilcox 2017-03-24  732   */
9114f9de Matthew Wilcox 2017-03-24 @733  void *memset32(uint32_t *s, uint32_t v, size_t count)
9114f9de Matthew Wilcox 2017-03-24  734  {
9114f9de Matthew Wilcox 2017-03-24  735  	uint32_t *xs = s;
9114f9de Matthew Wilcox 2017-03-24  736  
9114f9de Matthew Wilcox 2017-03-24  737  	while (count--)
9114f9de Matthew Wilcox 2017-03-24  738  		*xs++ = v;
9114f9de Matthew Wilcox 2017-03-24  739  	return s;
9114f9de Matthew Wilcox 2017-03-24  740  }
9114f9de Matthew Wilcox 2017-03-24  741  EXPORT_SYMBOL(memset32);

:::::: The code at line 733 was first introduced by commit
:::::: 9114f9de5005f9468370ed1cb1b5b841b10d3bad Add multibyte memset functions

:::::: TO: Matthew Wilcox <mawilcox@microsoft.com>
:::::: CC: 0day robot <fengguang.wu@intel.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Patch
diff mbox

diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h
index 3d3e8353ee5c..84da91fe13ac 100644
--- a/arch/x86/include/asm/string_32.h
+++ b/arch/x86/include/asm/string_32.h
@@ -331,6 +331,30 @@  void *__constant_c_and_count_memset(void *s, unsigned long pattern,
 	 : __memset((s), (c), (count)))
 #endif
 
+#define __HAVE_ARCH_MEMSET16
+static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
+{
+	int d0, d1;
+	asm volatile("rep\n\t"
+		     "stosw"
+		     : "=&c" (d0), "=&D" (d1)
+		     : "a" (v), "1" (s), "0" (n)
+		     : "memory");
+	return s;
+}
+
+#define __HAVE_ARCH_MEMSET_32
+static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
+{
+	int d0, d1;
+	asm volatile("rep\n\t"
+		     "stosl"
+		     : "=&c" (d0), "=&D" (d1)
+		     : "a" (v), "1" (s), "0" (n)
+		     : "memory");
+	return s;
+}
+
 /*
  * find the first occurrence of byte 'c', or 1 past the area if none
  */
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index a164862d77e3..71c5e860c7da 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -56,6 +56,42 @@  extern void *__memcpy(void *to, const void *from, size_t len);
 void *memset(void *s, int c, size_t n);
 void *__memset(void *s, int c, size_t n);
 
+#define __HAVE_ARCH_MEMSET16
+static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
+{
+	long d0, d1;
+	asm volatile("rep\n\t"
+		     "stosw"
+		     : "=&c" (d0), "=&D" (d1)
+		     : "a" (v), "1" (s), "0" (n)
+		     : "memory");
+	return s;
+}
+
+#define __HAVE_ARCH_MEMSET32
+static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
+{
+	long d0, d1;
+	asm volatile("rep\n\t"
+		     "stosl"
+		     : "=&c" (d0), "=&D" (d1)
+		     : "a" (v), "1" (s), "0" (n)
+		     : "memory");
+	return s;
+}
+
+#define __HAVE_ARCH_MEMSET64
+static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
+{
+	long d0, d1;
+	asm volatile("rep\n\t"
+		     "stosq"
+		     : "=&c" (d0), "=&D" (d1)
+		     : "a" (v), "1" (s), "0" (n)
+		     : "memory");
+	return s;
+}
+
 #define __HAVE_ARCH_MEMMOVE
 void *memmove(void *dest, const void *src, size_t count);
 void *__memmove(void *dest, const void *src, size_t count);