Commit 9535239f authored by Greg Ungerer's avatar Greg Ungerer Committed by Linus Torvalds
Browse files

changing include/asm-generic/pgtable.h for non-mmu 



There are some parts of include/asm-generic/pgtable.h that are relevant to
the non-mmu architectures.  To make it easier to include this from them I
would like to ifdef the relevant parts.

Without this there is a handful of functions that are referenced in here
that are not defined on many non-mmu architectures.  They could be defined
out of course, as an alternative approach.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 73c59afc

include/asm-generic/pgtable.h

+38 −35
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#define _ASM_GENERIC_PGTABLE_H



#ifndef __ASSEMBLY__

#ifdef CONFIG_MMU



#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS

/*
@@ -132,41 +133,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres 
#define move_pte(pte, prot, old_addr, new_addr)	(pte)

#endif



/*

 * A facility to provide lazy MMU batching.  This allows PTE updates and

 * page invalidations to be delayed until a call to leave lazy MMU mode

 * is issued.  Some architectures may benefit from doing this, and it is

 * beneficial for both shadow and direct mode hypervisors, which may batch

 * the PTE updates which happen during this window.  Note that using this

 * interface requires that read hazards be removed from the code.  A read

 * hazard could result in the direct mode hypervisor case, since the actual

 * write to the page tables may not yet have taken place, so reads though

 * a raw PTE pointer after it has been modified are not guaranteed to be

 * up to date.  This mode can only be entered and left under the protection of

 * the page table locks for all page tables which may be modified.  In the UP

 * case, this is required so that preemption is disabled, and in the SMP case,

 * it must synchronize the delayed page table writes properly on other CPUs.

 */

#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE

#define arch_enter_lazy_mmu_mode()	do {} while (0)

#define arch_leave_lazy_mmu_mode()	do {} while (0)

#define arch_flush_lazy_mmu_mode()	do {} while (0)

#endif



/*

 * A facility to provide batching of the reload of page tables with the

 * actual context switch code for paravirtualized guests.  By convention,

 * only one of the lazy modes (CPU, MMU) should be active at any given

 * time, entry should never be nested, and entry and exits should always

 * be paired.  This is for sanity of maintaining and reasoning about the

 * kernel code.

 */

#ifndef __HAVE_ARCH_ENTER_LAZY_CPU_MODE

#define arch_enter_lazy_cpu_mode()	do {} while (0)

#define arch_leave_lazy_cpu_mode()	do {} while (0)

#define arch_flush_lazy_cpu_mode()	do {} while (0)

#endif



/*

 * When walking page tables, get the address of the next boundary,

 * or the end address of the range if that comes earlier.  Although no
@@ -233,6 +199,43 @@ static inline int pmd_none_or_clear_bad(pmd_t *pmd) 
	}

	return 0;

}

#endif /* CONFIG_MMU */



/*

 * A facility to provide lazy MMU batching.  This allows PTE updates and

 * page invalidations to be delayed until a call to leave lazy MMU mode

 * is issued.  Some architectures may benefit from doing this, and it is

 * beneficial for both shadow and direct mode hypervisors, which may batch

 * the PTE updates which happen during this window.  Note that using this

 * interface requires that read hazards be removed from the code.  A read

 * hazard could result in the direct mode hypervisor case, since the actual

 * write to the page tables may not yet have taken place, so reads though

 * a raw PTE pointer after it has been modified are not guaranteed to be

 * up to date.  This mode can only be entered and left under the protection of

 * the page table locks for all page tables which may be modified.  In the UP

 * case, this is required so that preemption is disabled, and in the SMP case,

 * it must synchronize the delayed page table writes properly on other CPUs.

 */

#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE

#define arch_enter_lazy_mmu_mode()	do {} while (0)

#define arch_leave_lazy_mmu_mode()	do {} while (0)

#define arch_flush_lazy_mmu_mode()	do {} while (0)

#endif



/*

 * A facility to provide batching of the reload of page tables with the

 * actual context switch code for paravirtualized guests.  By convention,

 * only one of the lazy modes (CPU, MMU) should be active at any given

 * time, entry should never be nested, and entry and exits should always

 * be paired.  This is for sanity of maintaining and reasoning about the

 * kernel code.

 */

#ifndef __HAVE_ARCH_ENTER_LAZY_CPU_MODE

#define arch_enter_lazy_cpu_mode()	do {} while (0)

#define arch_leave_lazy_cpu_mode()	do {} while (0)

#define arch_flush_lazy_cpu_mode()	do {} while (0)

#endif



#endif /* !__ASSEMBLY__ */



#endif /* _ASM_GENERIC_PGTABLE_H */

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