From: Matthew Wilcox <willy@infradead.org>
To: linux-kernel@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org, linux-arch@vger.kernel.org,
linux-alpha@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, x86@kernel.org,
linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org,
sparclinux@vger.kernel.org, Minchan Kim <minchan@kernel.org>,
Matthew Wilcox <mawilcox@microsoft.com>
Subject: [PATCH v3 1/7] Add multibyte memset functions
Date: Fri, 24 Mar 2017 09:13:12 -0700 [thread overview]
Message-ID: <20170324161318.18718-2-willy@infradead.org> (raw)
In-Reply-To: <20170324161318.18718-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
memset16(), memset32() and memset64() are like memset(), but allow the
caller to fill the destination with a multibyte pattern. memset_l()
and memset_p() allow the caller to use unsigned long and pointer
values respectively. memset64() is currently only available on 64-bit
architectures.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
include/linux/string.h | 30 ++++++++++++++++++++++
lib/string.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 98 insertions(+)
diff --git a/include/linux/string.h b/include/linux/string.h
index 26b6f6a66f83..b376875b650c 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -99,6 +99,36 @@ extern __kernel_size_t strcspn(const char *,const char *);
#ifndef __HAVE_ARCH_MEMSET
extern void * memset(void *,int,__kernel_size_t);
#endif
+
+#ifndef __HAVE_ARCH_MEMSET16
+extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
+#endif
+
+#ifndef __HAVE_ARCH_MEMSET32
+extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
+#endif
+
+#ifndef __HAVE_ARCH_MEMSET64
+extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
+#endif
+
+static inline void *memset_l(unsigned long *p, unsigned long v,
+ __kernel_size_t n)
+{
+ if (BITS_PER_LONG == 32)
+ return memset32((uint32_t *)p, v, n);
+ else
+ return memset64((uint64_t *)p, v, n);
+}
+
+static inline void *memset_p(void **p, void *v, __kernel_size_t n)
+{
+ if (BITS_PER_LONG == 32)
+ return memset32((uint32_t *)p, (uintptr_t)v, n);
+ else
+ return memset64((uint64_t *)p, (uintptr_t)v, n);
+}
+
#ifndef __HAVE_ARCH_MEMCPY
extern void * memcpy(void *,const void *,__kernel_size_t);
#endif
diff --git a/lib/string.c b/lib/string.c
index ed83562a53ae..f18ba402e503 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -697,6 +697,74 @@ void memzero_explicit(void *s, size_t count)
}
EXPORT_SYMBOL(memzero_explicit);
+#ifndef __HAVE_ARCH_MEMSET16
+/**
+ * memset16() - Fill a memory area with a uint16_t
+ * @s: Pointer to the start of the area.
+ * @v: The value to fill the area with
+ * @count: The number of values to store
+ *
+ * Differs from memset() in that it fills with a uint16_t instead
+ * of a byte. Remember that @count is the number of uint16_ts to
+ * store, not the number of bytes.
+ */
+void *memset16(uint16_t *s, uint16_t v, size_t count)
+{
+ uint16_t *xs = s;
+
+ while (count--)
+ *xs++ = v;
+ return s;
+}
+EXPORT_SYMBOL(memset16);
+#endif
+
+#ifndef __HAVE_ARCH_MEMSET32
+/**
+ * memset32() - Fill a memory area with a uint32_t
+ * @s: Pointer to the start of the area.
+ * @v: The value to fill the area with
+ * @count: The number of values to store
+ *
+ * Differs from memset() in that it fills with a uint32_t instead
+ * of a byte. Remember that @count is the number of uint32_ts to
+ * store, not the number of bytes.
+ */
+void *memset32(uint32_t *s, uint32_t v, size_t count)
+{
+ uint32_t *xs = s;
+
+ while (count--)
+ *xs++ = v;
+ return s;
+}
+EXPORT_SYMBOL(memset32);
+#endif
+
+#ifndef __HAVE_ARCH_MEMSET64
+#if BITS_PER_LONG > 32
+/**
+ * memset64() - Fill a memory area with a uint64_t
+ * @s: Pointer to the start of the area.
+ * @v: The value to fill the area with
+ * @count: The number of values to store
+ *
+ * Differs from memset() in that it fills with a uint64_t instead
+ * of a byte. Remember that @count is the number of uint64_ts to
+ * store, not the number of bytes.
+ */
+void *memset64(uint64_t *s, uint64_t v, size_t count)
+{
+ uint64_t *xs = s;
+
+ while (count--)
+ *xs++ = v;
+ return s;
+}
+EXPORT_SYMBOL(memset64);
+#endif
+#endif
+
#ifndef __HAVE_ARCH_MEMCPY
/**
* memcpy - Copy one area of memory to another
--
2.11.0
next prev parent reply other threads:[~2017-03-24 16:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-24 16:13 [PATCH v3 0/7] Add memsetN functions Matthew Wilcox
2017-03-24 16:13 ` Matthew Wilcox [this message]
2017-03-24 16:13 ` [PATCH v3 2/7] ARM: Implement memset16, memset32 & memset64 Matthew Wilcox
2017-03-24 16:13 ` [PATCH v3 3/7] x86: " Matthew Wilcox
2017-03-26 7:44 ` kbuild test robot
2017-03-24 16:13 ` [PATCH v3 4/7] alpha: Add support for memset16 Matthew Wilcox
2017-03-26 7:28 ` kbuild test robot
2017-03-24 16:13 ` [PATCH v3 5/7] zram: Convert to using memset_l Matthew Wilcox
2017-03-27 5:01 ` Minchan Kim
2017-03-27 5:01 ` Minchan Kim
2017-03-24 16:13 ` [PATCH v3 6/7] sym53c8xx_2: Convert to use memset32 Matthew Wilcox
2017-03-24 16:13 ` [PATCH v3 7/7] vga: Optimise console scrolling Matthew Wilcox
2017-03-26 8:45 ` kbuild test robot
2017-03-26 9:53 ` kbuild test robot
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