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Commit 45876233 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Andi Kleen
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[PATCH] i386: PARAVIRT: use paravirt_nop to consistently mark no-op operations 



Add a _paravirt_nop function for use as a stub for no-op operations,
and paravirt_nop #defined void * version to make using it easier
(since all its uses are as a void *).

This is useful to allow the patcher to automatically identify noop
operations so it can simply nop out the callsite.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
[mingo] but only as a cleanup of the current open-coded (void *) casts.
My problem with this is that it loses the types. Not that there is much
to check for, but still, this adds some assumptions about how function
calls look like
parent 7f63c41c

arch/i386/kernel/paravirt.c

+12 −12
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ 
#include <asm/timer.h>



/* nop stub */

static void native_nop(void)

void _paravirt_nop(void)

{

}
@@ -207,7 +207,7 @@ struct paravirt_ops paravirt_ops = { 


 	.patch = native_patch,

	.banner = default_banner,

	.arch_setup = native_nop,

	.arch_setup = paravirt_nop,

	.memory_setup = machine_specific_memory_setup,

	.get_wallclock = native_get_wallclock,

	.set_wallclock = native_set_wallclock,
@@ -263,25 +263,25 @@ struct paravirt_ops paravirt_ops = { 
	.setup_boot_clock = setup_boot_APIC_clock,

	.setup_secondary_clock = setup_secondary_APIC_clock,

#endif

	.set_lazy_mode = (void *)native_nop,

	.set_lazy_mode = paravirt_nop,



	.flush_tlb_user = native_flush_tlb,

	.flush_tlb_kernel = native_flush_tlb_global,

	.flush_tlb_single = native_flush_tlb_single,



	.map_pt_hook = (void *)native_nop,

	.map_pt_hook = paravirt_nop,



	.alloc_pt = (void *)native_nop,

	.alloc_pd = (void *)native_nop,

	.alloc_pd_clone = (void *)native_nop,

	.release_pt = (void *)native_nop,

	.release_pd = (void *)native_nop,

	.alloc_pt = paravirt_nop,

	.alloc_pd = paravirt_nop,

	.alloc_pd_clone = paravirt_nop,

	.release_pt = paravirt_nop,

	.release_pd = paravirt_nop,



	.set_pte = native_set_pte,

	.set_pte_at = native_set_pte_at,

	.set_pmd = native_set_pmd,

	.pte_update = (void *)native_nop,

	.pte_update_defer = (void *)native_nop,

	.pte_update = paravirt_nop,

	.pte_update_defer = paravirt_nop,

#ifdef CONFIG_X86_PAE

	.set_pte_atomic = native_set_pte_atomic,

	.set_pte_present = native_set_pte_present,
@@ -293,7 +293,7 @@ struct paravirt_ops paravirt_ops = { 
	.irq_enable_sysexit = native_irq_enable_sysexit,

	.iret = native_iret,



	.startup_ipi_hook = (void *)native_nop,

	.startup_ipi_hook = paravirt_nop,

};



/*

include/asm-i386/paravirt.h

+3 −0
Original line number Diff line number Diff line
@@ -434,6 +434,9 @@ static inline void pmd_clear(pmd_t *pmdp) 
#define arch_leave_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_NONE)

#define arch_flush_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_FLUSH)



void _paravirt_nop(void);

#define paravirt_nop	((void *)_paravirt_nop)



/* These all sit in the .parainstructions section to tell us what to patch. */

struct paravirt_patch {

	u8 *instr; 		/* original instructions */