On Thu, 28 Jul 2016, Julien Grall wrote:
> The helper p2m_create_table is only called to create a brand new table.
>
> Signed-off-by: Julien Grall
Reviewed-by: Stefano Stabellini
> xen/arch/arm/p2m.c | 51 ++-
> 1 file changed, 6 insertions(+), 45 deletions(-)
>
> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
> index 16ed393..4aaa96f 100644
> --- a/xen/arch/arm/p2m.c
> +++ b/xen/arch/arm/p2m.c
> @@ -264,8 +264,7 @@ static p2m_access_t p2m_mem_access_radix_get(struct
> p2m_domain *p2m, gfn_t gfn)
> #define GUEST_TABLE_SUPER_PAGE 1
> #define GUEST_TABLE_NORMAL_PAGE 2
>
> -static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry,
> -int level_shift);
> +static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry);
>
> /*
> * Take the currently mapped table, find the corresponding GFN entry,
> @@ -291,7 +290,7 @@ static int p2m_next_level(struct p2m_domain *p2m, bool
> read_only,
> if ( read_only )
> return GUEST_TABLE_MAP_FAILED;
>
> -ret = p2m_create_table(p2m, entry, /* not used */ ~0);
> +ret = p2m_create_table(p2m, entry);
> if ( ret )
> return GUEST_TABLE_MAP_FAILED;
> }
> @@ -557,25 +556,14 @@ static inline void p2m_remove_pte(lpae_t *p, bool
> clean_pte)
> p2m_write_pte(p, pte, clean_pte);
> }
>
> -/*
> - * Allocate a new page table page and hook it in via the given entry.
> - * apply_one_level relies on this returning 0 on success
> - * and -ve on failure.
> - *
> - * If the existing entry is present then it must be a mapping and not
> - * a table and it will be shattered into the next level down.
> - *
> - * level_shift is the number of bits at the level we want to create.
> - */
> -static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry,
> -int level_shift)
> +/* Allocate a new page table page and hook it in via the given entry. */
> +static int p2m_create_table(struct p2m_domain *p2m, lpae_t *entry)
> {
> struct page_info *page;
> lpae_t *p;
> lpae_t pte;
> -int splitting = p2m_valid(*entry);
>
> -BUG_ON(p2m_table(*entry));
> +ASSERT(!p2m_valid(*entry));
>
> page = alloc_domheap_page(NULL, 0);
> if ( page == NULL )
> @@ -584,35 +572,8 @@ static int p2m_create_table(struct p2m_domain *p2m,
> lpae_t *entry,
> page_list_add(page, &p2m->pages);
>
> p = __map_domain_page(page);
> -if ( splitting )
> -{
> -p2m_type_t t = entry->p2m.type;
> -mfn_t mfn = _mfn(entry->p2m.base);
> -int i;
>
> -/*
> - * We are either splitting a first level 1G page into 512 second
> level
> - * 2M pages, or a second level 2M page into 512 third level 4K pages.
> - */
> - for ( i=0 ; i < LPAE_ENTRIES; i++ )
> - {
> - pte = mfn_to_p2m_entry(mfn_add(mfn, i << (level_shift -
> LPAE_SHIFT)),
> -t, p2m->default_access);
> -
> - /*
> - * First and second level super pages set p2m.table = 0, but
> - * third level entries set table = 1.
> - */
> - if ( level_shift - LPAE_SHIFT )
> - pte.p2m.table = 0;
> -
> - write_pte(&p[i], pte);
> - }
> -
> - page->u.inuse.p2m_refcount = LPAE_ENTRIES;
> -}
> -else
> -clear_page(p);
> +clear_page(p);
>
> if ( p2m->clean_pte )
> clean_dcache_va_range(p, PAGE_SIZE);
> --
> 1.9.1
>
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