[GIT PULL] x86/asm changes for v4.18
From: Ingo Molnar
Date: Mon Jun 04 2018 - 08:21:41 EST
Linus,
Please pull the latest x86-asm-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-asm-for-linus
# HEAD: 6469a0ee0a06b2ea1f5afbb1d5a3feed017d4c7a x86/io: Define readq()/writeq() to use 64-bit type
Two smaller changes:
- better support (non-atomic) 64-bit readq()/writeq() variants (Andy Shevchenko)
- __clear_user() micro-optimization (Alexey Dobriyan)
Thanks,
Ingo
------------------>
Alexey Dobriyan (1):
x86/asm/64: Micro-optimize __clear_user() - Use immediate constants
Andy Shevchenko (1):
x86/io: Define readq()/writeq() to use 64-bit type
arch/x86/include/asm/io.h | 8 ++++----
arch/x86/lib/usercopy_64.c | 9 ++++-----
2 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index f6e5b9375d8c..6de64840dd22 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -94,10 +94,10 @@ build_mmio_write(__writel, "l", unsigned int, "r", )
#ifdef CONFIG_X86_64
-build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
-build_mmio_read(__readq, "q", unsigned long, "=r", )
-build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
-build_mmio_write(__writeq, "q", unsigned long, "r", )
+build_mmio_read(readq, "q", u64, "=r", :"memory")
+build_mmio_read(__readq, "q", u64, "=r", )
+build_mmio_write(writeq, "q", u64, "r", :"memory")
+build_mmio_write(__writeq, "q", u64, "r", )
#define readq_relaxed(a) __readq(a)
#define writeq_relaxed(v, a) __writeq(v, a)
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 75d3776123cc..a624dcc4de10 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -23,13 +23,13 @@ unsigned long __clear_user(void __user *addr, unsigned long size)
asm volatile(
" testq %[size8],%[size8]\n"
" jz 4f\n"
- "0: movq %[zero],(%[dst])\n"
- " addq %[eight],%[dst]\n"
+ "0: movq $0,(%[dst])\n"
+ " addq $8,%[dst]\n"
" decl %%ecx ; jnz 0b\n"
"4: movq %[size1],%%rcx\n"
" testl %%ecx,%%ecx\n"
" jz 2f\n"
- "1: movb %b[zero],(%[dst])\n"
+ "1: movb $0,(%[dst])\n"
" incq %[dst]\n"
" decl %%ecx ; jnz 1b\n"
"2:\n"
@@ -40,8 +40,7 @@ unsigned long __clear_user(void __user *addr, unsigned long size)
_ASM_EXTABLE(0b,3b)
_ASM_EXTABLE(1b,2b)
: [size8] "=&c"(size), [dst] "=&D" (__d0)
- : [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr),
- [zero] "r" (0UL), [eight] "r" (8UL));
+ : [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr));
clac();
return size;
}