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Commit 1b246d22 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 asm updates from Ingo Molnar:

 - better support (non-atomic) 64-bit readq()/writeq() variants (Andy
   Shevchenko)

 - __clear_user() micro-optimization (Alexey Dobriyan)

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/io: Define readq()/writeq() to use 64-bit type
  x86/asm/64: Micro-optimize __clear_user() - Use immediate constants
parents 5cef8c2a 6469a0ee

arch/x86/include/asm/io.h

+4 −4
Original line number Diff line number Diff line
@@ -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)

arch/x86/lib/usercopy_64.c

+4 −5
Original line number Diff line number Diff line
@@ -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;

}