From: Nick Hu <nickhu@andestech.com>
To: <alankao@andestech.com>, <paul.walmsley@sifive.com>,
<palmer@sifive.com>, <aou@eecs.berkeley.edu>,
<green.hu@gmail.com>, <deanbo422@gmail.com>, <tglx@linutronix.de>,
<linux-riscv@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
<aryabinin@virtuozzo.com>, <glider@google.com>,
<dvyukov@google.com>, <Anup.Patel@wdc.com>,
<gregkh@linuxfoundation.org>, <alexios.zavras@intel.com>,
<atish.patra@wdc.com>, <zong@andestech.com>,
<kasan-dev@googlegroups.com>
Cc: Nick Hu <nickhu@andestech.com>
Subject: [PATCH 1/2] riscv: Add memmove string operation.
Date: Wed, 7 Aug 2019 15:19:14 +0800 [thread overview]
Message-ID: <a6c24ce01dc40da10d58fdd30bc3e1316035c832.1565161957.git.nickhu@andestech.com> (raw)
In-Reply-To: <cover.1565161957.git.nickhu@andestech.com>
There are some features which need this string operation for compilation,
like KASAN. So the purpose of this porting is for the features like KASAN
which cannot be compiled without it.
KASAN's string operations would replace the original string operations and
call for the architecture defined string operations. Since we don't have
this in current kernel, this patch provides the implementation.
This porting refers to the 'arch/nds32/lib/memmove.S'.
Signed-off-by: Nick Hu <nickhu@andestech.com>
---
arch/riscv/include/asm/string.h | 3 ++
arch/riscv/kernel/riscv_ksyms.c | 1 +
arch/riscv/lib/Makefile | 1 +
arch/riscv/lib/memmove.S | 63 +++++++++++++++++++++++++++++++++++++++
4 files changed, 68 insertions(+), 0 deletions(-)
create mode 100644 arch/riscv/lib/memmove.S
diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
index 1b5d445..11210f1 100644
--- a/arch/riscv/include/asm/string.h
+++ b/arch/riscv/include/asm/string.h
@@ -15,4 +15,7 @@
#define __HAVE_ARCH_MEMCPY
extern asmlinkage void *memcpy(void *, const void *, size_t);
+#define __HAVE_ARCH_MEMMOVE
+extern asmlinkage void *memmove(void *, const void *, size_t);
+
#endif /* _ASM_RISCV_STRING_H */
diff --git a/arch/riscv/kernel/riscv_ksyms.c b/arch/riscv/kernel/riscv_ksyms.c
index 4800cf7..ffabaf1 100644
--- a/arch/riscv/kernel/riscv_ksyms.c
+++ b/arch/riscv/kernel/riscv_ksyms.c
@@ -14,3 +14,4 @@
EXPORT_SYMBOL(__asm_copy_from_user);
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memcpy);
+EXPORT_SYMBOL(memmove);
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 8e364eb..9a4d5b3 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -2,6 +2,7 @@
lib-y += delay.o
lib-y += memcpy.o
lib-y += memset.o
+lib-y += memmove.o
lib-y += uaccess.o
lib-$(CONFIG_64BIT) += tishift.o
diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S
new file mode 100644
index 0000000..3657a06
--- /dev/null
+++ b/arch/riscv/lib/memmove.S
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+
+ENTRY(memmove)
+ move t0, a0
+ move t1, a1
+
+ beq a0, a1, exit_memcpy
+ beqz a2, exit_memcpy
+ srli t2, a2, 0x2
+
+ slt t3, a0, a1
+ beqz t3, do_reverse
+
+ andi a2, a2, 0x3
+ li t4, 1
+ beqz t2, byte_copy
+
+word_copy:
+ lw t3, 0(a1)
+ addi t2, t2, -1
+ addi a1, a1, 4
+ sw t3, 0(a0)
+ addi a0, a0, 4
+ bnez t2, word_copy
+ beqz a2, exit_memcpy
+ j byte_copy
+
+do_reverse:
+ add a0, a0, a2
+ add a1, a1, a2
+ andi a2, a2, 0x3
+ li t4, -1
+ beqz t2, reverse_byte_copy
+
+reverse_word_copy:
+ addi a1, a1, -4
+ addi t2, t2, -1
+ lw t3, 0(a1)
+ addi a0, a0, -4
+ sw t3, 0(a0)
+ bnez t2, reverse_word_copy
+ beqz a2, exit_memcpy
+
+reverse_byte_copy:
+ addi a0, a0, -1
+ addi a1, a1, -1
+byte_copy:
+ lb t3, 0(a1)
+ addi a2, a2, -1
+ sb t3, 0(a0)
+ add a1, a1, t4
+ add a0, a0, t4
+ bnez a2, byte_copy
+
+exit_memcpy:
+ move a0, t0
+ move a1, t1
+ ret
+
+END(memmove)
--
1.7.1
next prev parent reply other threads:[~2019-08-07 7:49 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-07 7:19 [PATCH 0/2] KASAN support for RISC-V Nick Hu
2019-08-07 7:19 ` Nick Hu [this message]
2019-08-12 15:04 ` [PATCH 1/2] riscv: Add memmove string operation Christoph Hellwig
2019-08-13 23:50 ` Palmer Dabbelt
2019-08-14 2:22 ` Paul Walmsley
2019-08-14 3:27 ` Nick Hu
[not found] ` <alpine.DEB.2.21.9999.1908141002500.18249@viisi.sifive.com>
2019-08-15 3:12 ` Nick Hu
[not found] ` <alpine.DEB.2.21.9999.1908151124450.18249@viisi.sifive.com>
2019-08-19 6:29 ` Nick Hu
2019-08-14 18:33 ` Palmer Dabbelt
2019-08-22 15:59 ` Andrey Ryabinin
2019-08-27 9:07 ` Nick Hu
2019-08-27 9:33 ` Andrey Ryabinin
2019-08-28 3:06 ` Nick Hu
2019-08-07 7:19 ` [PATCH 2/2] riscv: Add KASAN support Nick Hu
2019-08-12 15:10 ` Christoph Hellwig
2019-08-14 7:44 ` Nick Hu
2019-08-22 17:08 ` Andrey Ryabinin
2019-09-03 15:08 ` Daniel Axtens
2019-09-04 2:24 ` Nick Hu
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