[Xen-devel] [PATCH 13/15] xen/arm: p2m: Introduce a new variable removing_mapping in __p2m_set_entry
This is making the code slightly easier to understand. Signed-off-by: Julien Grall --- xen/arch/arm/p2m.c | 10 ++ 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 66d58fabd7..e826f57842 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -792,6 +792,8 @@ static int __p2m_set_entry(struct p2m_domain *p2m, unsigned int target = 3 - (page_order / LPAE_SHIFT); lpae_t *entry, *table, orig_pte; int rc; +/* A mapping is removed if the MFN is invalid. */ +bool removing_mapping = mfn_eq(smfn, INVALID_MFN); /* Convenience aliases */ const unsigned int offsets[4] = { @@ -817,9 +819,9 @@ static int __p2m_set_entry(struct p2m_domain *p2m, { /* * Don't try to allocate intermediate page table if the mapping - * is about to be removed (i.e mfn == INVALID_MFN). + * is about to be removed. */ -rc = p2m_next_level(p2m, mfn_eq(smfn, INVALID_MFN), +rc = p2m_next_level(p2m, removing_mapping, level, &table, offsets[level]); if ( rc == GUEST_TABLE_MAP_FAILED ) { @@ -830,7 +832,7 @@ static int __p2m_set_entry(struct p2m_domain *p2m, * when removing a mapping as it may not exist in the * page table. In this case, just ignore it. */ -rc = mfn_eq(smfn, INVALID_MFN) ? 0 : -ENOENT; +rc = removing_mapping ? 0 : -ENOENT; goto out; } else if ( rc != GUEST_TABLE_NORMAL_PAGE ) @@ -925,7 +927,7 @@ static int __p2m_set_entry(struct p2m_domain *p2m, if ( lpae_is_valid(orig_pte) ) p2m_remove_pte(entry, p2m->clean_pte); -if ( mfn_eq(smfn, INVALID_MFN) ) +if ( removing_mapping ) /* Flush can be deferred if the entry is removed */ p2m->need_flush |= !!lpae_is_valid(orig_pte); else -- 2.11.0 ___ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
Re: [Xen-devel] [PATCH 13/15] xen/arm: p2m: Introduce a new variable removing_mapping in __p2m_set_entry
On Mon, 16 Jul 2018, Julien Grall wrote: > This is making the code slightly easier to understand. > > Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini > --- > xen/arch/arm/p2m.c | 10 ++ > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c > index 66d58fabd7..e826f57842 100644 > --- a/xen/arch/arm/p2m.c > +++ b/xen/arch/arm/p2m.c > @@ -792,6 +792,8 @@ static int __p2m_set_entry(struct p2m_domain *p2m, > unsigned int target = 3 - (page_order / LPAE_SHIFT); > lpae_t *entry, *table, orig_pte; > int rc; > +/* A mapping is removed if the MFN is invalid. */ > +bool removing_mapping = mfn_eq(smfn, INVALID_MFN); > > /* Convenience aliases */ > const unsigned int offsets[4] = { > @@ -817,9 +819,9 @@ static int __p2m_set_entry(struct p2m_domain *p2m, > { > /* > * Don't try to allocate intermediate page table if the mapping > - * is about to be removed (i.e mfn == INVALID_MFN). > + * is about to be removed. > */ > -rc = p2m_next_level(p2m, mfn_eq(smfn, INVALID_MFN), > +rc = p2m_next_level(p2m, removing_mapping, > level, &table, offsets[level]); > if ( rc == GUEST_TABLE_MAP_FAILED ) > { > @@ -830,7 +832,7 @@ static int __p2m_set_entry(struct p2m_domain *p2m, > * when removing a mapping as it may not exist in the > * page table. In this case, just ignore it. > */ > -rc = mfn_eq(smfn, INVALID_MFN) ? 0 : -ENOENT; > +rc = removing_mapping ? 0 : -ENOENT; > goto out; > } > else if ( rc != GUEST_TABLE_NORMAL_PAGE ) > @@ -925,7 +927,7 @@ static int __p2m_set_entry(struct p2m_domain *p2m, > if ( lpae_is_valid(orig_pte) ) > p2m_remove_pte(entry, p2m->clean_pte); > > -if ( mfn_eq(smfn, INVALID_MFN) ) > +if ( removing_mapping ) > /* Flush can be deferred if the entry is removed */ > p2m->need_flush |= !!lpae_is_valid(orig_pte); > else > -- > 2.11.0 > ___ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel