Commit 4cdd9c89 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Andi Kleen
Browse files

[PATCH] i386: PARAVIRT: drop unused ptep_get_and_clear 



In shadow mode hypervisors, ptep_get_and_clear achieves the desired
purpose of keeping the shadows in sync by issuing a native_get_and_clear,
followed by a call to pte_update, which indicates the PTE has been
modified.

Direct mode hypervisors (Xen) have no need for this anyway, and will trap
the update using writable pagetables.

This means no hypervisor makes use of ptep_get_and_clear; there is no
reason to have it in the paravirt-ops structure.  Change confusing
terminology about raw vs. native functions into consistent use of
native_pte_xxx for operations which do not invoke paravirt-ops.

Signed-off-by: default avatarZachary Amsden <zach@vmware.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 1a45b7aa

arch/i386/kernel/paravirt.c

+0 −2
Original line number Diff line number Diff line
@@ -315,8 +315,6 @@ struct paravirt_ops paravirt_ops = { 
	.pte_update = paravirt_nop,

	.pte_update_defer = paravirt_nop,



	.ptep_get_and_clear = native_ptep_get_and_clear,



#ifdef CONFIG_HIGHPTE

	.kmap_atomic_pte = kmap_atomic,

#endif

include/asm-i386/paravirt.h

+1 −12
Original line number Diff line number Diff line
@@ -188,8 +188,6 @@ struct paravirt_ops 
	void (*pte_update_defer)(struct mm_struct *mm,

				 unsigned long addr, pte_t *ptep);



 	pte_t (*ptep_get_and_clear)(pte_t *ptep);



#ifdef CONFIG_HIGHPTE

	void *(*kmap_atomic_pte)(struct page *page, enum km_type type);

#endif
@@ -859,12 +857,8 @@ static inline void pmd_clear(pmd_t *pmdp) 
	PVOP_VCALL1(pmd_clear, pmdp);

}



static inline pte_t raw_ptep_get_and_clear(pte_t *p)

{

	unsigned long long val = PVOP_CALL1(unsigned long long, ptep_get_and_clear, p);

	return (pte_t) { val, val >> 32 };

}

#else  /* !CONFIG_X86_PAE */



static inline pte_t __pte(unsigned long val)

{

	return (pte_t) { PVOP_CALL1(unsigned long, make_pte, val) };
@@ -900,11 +894,6 @@ static inline void set_pmd(pmd_t *pmdp, pmd_t pmdval) 
{

	PVOP_VCALL2(set_pmd, pmdp, pmdval.pud.pgd.pgd);

}



static inline pte_t raw_ptep_get_and_clear(pte_t *p)

{

	return (pte_t) { PVOP_CALL1(unsigned long, ptep_get_and_clear, p) };

}

#endif	/* CONFIG_X86_PAE */



#define  __HAVE_ARCH_ENTER_LAZY_CPU_MODE

include/asm-i386/pgtable.h

+1 −3
Original line number Diff line number Diff line
@@ -267,8 +267,6 @@ extern void vmalloc_sync_all(void); 
 */

#define pte_update(mm, addr, ptep)		do { } while (0)

#define pte_update_defer(mm, addr, ptep)	do { } while (0)



#define raw_ptep_get_and_clear(xp)     native_ptep_get_and_clear(xp)

#endif



/*
@@ -335,7 +333,7 @@ do { \ 
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR

static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)

{

	pte_t pte = raw_ptep_get_and_clear(ptep);

	pte_t pte = native_ptep_get_and_clear(ptep);

	pte_update(mm, addr, ptep);

	return pte;

}

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