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: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
[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
---
arch/i386/kernel/paravirt.c | 26 +++++++++++++-------------
include/asm-i386/paravirt.h | 3 +++
2 files changed, 16 insertions(+), 13 deletions(-)
===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -35,7 +35,7 @@
#include <asm/timer.h>
/* nop stub */
-static void native_nop(void)
+void _paravirt_nop(void)
{
}
@@ -490,7 +490,7 @@ 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,
@@ -546,25 +546,25 @@ 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,
-
- .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,
+ .map_pt_hook = paravirt_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,
@@ -576,7 +576,7 @@ 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,
};
/*
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -430,6 +430,9 @@ static inline void pmd_clear(pmd_t *pmdp
#define arch_enter_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_MMU)
#define arch_leave_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_NONE)
+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 */
--
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