| Message ID | 20181008183352.16291-7-julien.grall@arm.com |
|---|---|
| State | Accepted |
| Commit | e03885248cb965ed23b51df0c044a762c7d339ad |
| Headers | show |
| Series | xen/arm: Implement Set/Way operations | expand |
On Mon, 8 Oct 2018, Julien Grall wrote: > Generate P2M table entry requires to set some default values which are > worth to explain in a comment. At the moment, there are 2 places where > such entry are created but only one as proper comment. > > Some move the code to generate P2M table entry in a separate helper. > This will be helpful in a follow-up patch to make modification on the > defaults. > > At the same time, switch the default access from p2m->default_access to > p2m_access_rwx. This should not matter as permission are ignored for > table by the hardware. > > Signed-off-by: Julien Grall <julien.grall@arm.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > xen/arch/arm/p2m.c | 25 ++++++++++++------------- > 1 file changed, 12 insertions(+), 13 deletions(-) > > diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c > index 8fffb42889..6c76298ebc 100644 > --- a/xen/arch/arm/p2m.c > +++ b/xen/arch/arm/p2m.c > @@ -538,6 +538,16 @@ static lpae_t mfn_to_p2m_entry(mfn_t mfn, p2m_type_t t, p2m_access_t a) > return e; > } > > +/* Generate table entry with correct attributes. */ > +static lpae_t page_to_p2m_table(struct page_info *page) > +{ > + /* > + * The access value does not matter because the hardware will ignore > + * the permission fields for table entry. > + */ > + return mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid, p2m_access_rwx); > +} > + > static inline void p2m_write_pte(lpae_t *p, lpae_t pte, bool clean_pte) > { > write_pte(p, pte); > @@ -558,7 +568,6 @@ static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry) > { > struct page_info *page; > lpae_t *p; > - lpae_t pte; > > ASSERT(!lpae_is_valid(*entry)); > > @@ -576,14 +585,7 @@ static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry) > > unmap_domain_page(p); > > - /* > - * The access value does not matter because the hardware will ignore > - * the permission fields for table entry. > - */ > - pte = mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid, > - p2m->default_access); > - > - p2m_write_pte(entry, pte, p2m->clean_pte); > + p2m_write_pte(entry, page_to_p2m_table(page), p2m->clean_pte); > > return 0; > } > @@ -764,14 +766,11 @@ static bool p2m_split_superpage(struct p2m_domain *p2m, lpae_t *entry, > > unmap_domain_page(table); > > - pte = mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid, > - p2m->default_access); > - > /* > * Even if we failed, we should install the newly allocated LPAE > * entry. The caller will be in charge to free the sub-tree. > */ > - p2m_write_pte(entry, pte, p2m->clean_pte); > + p2m_write_pte(entry, page_to_p2m_table(page), p2m->clean_pte); > > return rv; > } > -- > 2.11.0 >
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 8fffb42889..6c76298ebc 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -538,6 +538,16 @@ static lpae_t mfn_to_p2m_entry(mfn_t mfn, p2m_type_t t, p2m_access_t a) return e; } +/* Generate table entry with correct attributes. */ +static lpae_t page_to_p2m_table(struct page_info *page) +{ + /* + * The access value does not matter because the hardware will ignore + * the permission fields for table entry. + */ + return mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid, p2m_access_rwx); +} + static inline void p2m_write_pte(lpae_t *p, lpae_t pte, bool clean_pte) { write_pte(p, pte); @@ -558,7 +568,6 @@ static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry) { struct page_info *page; lpae_t *p; - lpae_t pte; ASSERT(!lpae_is_valid(*entry)); @@ -576,14 +585,7 @@ static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry) unmap_domain_page(p); - /* - * The access value does not matter because the hardware will ignore - * the permission fields for table entry. - */ - pte = mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid, - p2m->default_access); - - p2m_write_pte(entry, pte, p2m->clean_pte); + p2m_write_pte(entry, page_to_p2m_table(page), p2m->clean_pte); return 0; } @@ -764,14 +766,11 @@ static bool p2m_split_superpage(struct p2m_domain *p2m, lpae_t *entry, unmap_domain_page(table); - pte = mfn_to_p2m_entry(page_to_mfn(page), p2m_invalid, - p2m->default_access); - /* * Even if we failed, we should install the newly allocated LPAE * entry. The caller will be in charge to free the sub-tree. */ - p2m_write_pte(entry, pte, p2m->clean_pte); + p2m_write_pte(entry, page_to_p2m_table(page), p2m->clean_pte); return rv; }
Generate P2M table entry requires to set some default values which are worth to explain in a comment. At the moment, there are 2 places where such entry are created but only one as proper comment. Some move the code to generate P2M table entry in a separate helper. This will be helpful in a follow-up patch to make modification on the defaults. At the same time, switch the default access from p2m->default_access to p2m_access_rwx. This should not matter as permission are ignored for table by the hardware. Signed-off-by: Julien Grall <julien.grall@arm.com> --- xen/arch/arm/p2m.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)