Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3829ee6b authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
Browse files

[PATCH] x86_64: Small assembly improvements 



Save a byte here and there.  Ultimatively useless, but these things always
catch my eyes when reading the code so just fix them for now.

Also I got at least one patch fixing of them already, which gives a good
excuse.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 3ba80e75

arch/x86_64/kernel/entry.S

+5 −5
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ 


	.macro FAKE_STACK_FRAME child_rip

	/* push in order ss, rsp, eflags, cs, rip */

	xorq %rax, %rax

	xorl %eax, %eax

	pushq %rax /* ss */

	CFI_ADJUST_CFA_OFFSET	8

	pushq %rax /* rsp */
@@ -423,7 +423,7 @@ ENTRY(stub_rt_sigreturn) 
	testl $3,CS(%rdi)

	je 1f

	swapgs	

1:	addl $1,%gs:pda_irqcount	# RED-PEN should check preempt count

1:	incl	%gs:pda_irqcount	# RED-PEN should check preempt count

	movq %gs:pda_irqstackptr,%rax

	cmoveq %rax,%rsp							

	pushq %rdi			# save old stack
@@ -436,7 +436,7 @@ ENTRY(common_interrupt) 
ret_from_intr:		

	popq  %rdi

	cli	

	subl $1,%gs:pda_irqcount

	decl %gs:pda_irqcount

#ifdef CONFIG_DEBUG_INFO

	movq RBP(%rdi),%rbp

#endif
@@ -494,7 +494,7 @@ retint_signal: 
	sti

	SAVE_REST

	movq $-1,ORIG_RAX(%rsp) 			

	xorq %rsi,%rsi		# oldset

	xorl %esi,%esi		# oldset

	movq %rsp,%rdi		# &pt_regs

	call do_notify_resume

	RESTORE_REST
@@ -752,7 +752,7 @@ child_rip: 
	movq %rsi, %rdi

	call *%rax

	# exit

	xorq %rdi, %rdi

	xorl %edi, %edi

	call do_exit



/*

arch/x86_64/kernel/head.S

+8 −8
Original line number Diff line number Diff line
@@ -137,14 +137,14 @@ startup_64: 
	wrmsr



	/* Setup cr0 */

	xorq	%rax, %rax

	btsq	$31, %rax			/* Enable paging */

	btsq	$0, %rax			/* Enable protected mode */

	btsq	$1, %rax			/* Enable MP */

	btsq	$4, %rax			/* Enable ET */

	btsq	$5, %rax			/* Enable NE */

	btsq	$16, %rax			/* Enable WP */

	btsq	$18, %rax			/* Enable AM */

#define CR0_PM				1		/* protected mode */

#define CR0_MP				(1<<1)

#define CR0_ET				(1<<4)

#define CR0_NE				(1<<5)

#define CR0_WP				(1<<16)

#define CR0_AM				(1<<18)

#define CR0_PAGING 			(1<<31)

	movl $CR0_PM|CR0_MP|CR0_ET|CR0_NE|CR0_WP|CR0_AM|CR0_PAGING,%eax

	/* Make changes effective */

	movq	%rax, %cr0