Re: [PATCH 02/16] acpi: vmap pages in acpi_os_alloc_memory

[Hongyan Xia <hx242@xxxxxxx>]

On Fri, 2020-05-01 at 12:02 +0000, Wei Liu wrote:
> On Thu, Apr 30, 2020 at 09:44:11PM +0100, Hongyan Xia wrote:
> > From: Hongyan Xia <hongyxia@xxxxxxxxxx>
> > 
> > Also, introduce a wrapper around vmap that maps a contiguous range
> > for
> > boot allocations.
> > 
> > Signed-off-by: Hongyan Xia <hongyxia@xxxxxxxxxx>
> > ---
> >  xen/drivers/acpi/osl.c | 9 ++++++++-
> >  xen/include/xen/vmap.h | 5 +++++
> >  2 files changed, 13 insertions(+), 1 deletion(-)
> > 
> > diff --git a/xen/drivers/acpi/osl.c b/xen/drivers/acpi/osl.c
> > index 4c8bb7839e..d0762dad4e 100644
> > --- a/xen/drivers/acpi/osl.c
> > +++ b/xen/drivers/acpi/osl.c
> > @@ -219,7 +219,11 @@ void *__init acpi_os_alloc_memory(size_t sz)
> >     void *ptr;
> >  
> >     if (system_state == SYS_STATE_early_boot)
> > -           return mfn_to_virt(mfn_x(alloc_boot_pages(PFN_UP(sz),
> > 1)));
> > +   {
> > +           mfn_t mfn = alloc_boot_pages(PFN_UP(sz), 1);
> > +
> > +           return vmap_boot_pages(mfn, PFN_UP(sz));
> > +   }
> >  
> >     ptr = xmalloc_bytes(sz);
> >     ASSERT(!ptr || is_xmalloc_memory(ptr));
> > @@ -244,5 +248,8 @@ void __init acpi_os_free_memory(void *ptr)
> >     if (is_xmalloc_memory(ptr))
> >             xfree(ptr);
> >     else if (ptr && system_state == SYS_STATE_early_boot)
> > +   {
> > +           vunmap(ptr);
> >             init_boot_pages(__pa(ptr), __pa(ptr) + PAGE_SIZE);
> > +   }
> >  }
> > diff --git a/xen/include/xen/vmap.h b/xen/include/xen/vmap.h
> > index 369560e620..c70801e195 100644
> > --- a/xen/include/xen/vmap.h
> > +++ b/xen/include/xen/vmap.h
> > @@ -23,6 +23,11 @@ void *vmalloc_xen(size_t size);
> >  void *vzalloc(size_t size);
> >  void vfree(void *va);
> >  
> > +static inline void *vmap_boot_pages(mfn_t mfn, unsigned int
> > nr_pages)
> 
> Nothing seems to tie this to boot pages only. Maybe it is better to
> name
> it after what it does, like vmap_mfns?

Hmm, indeed nothing so special about *boot* pages. Will change.

Hongyan