On Thu, 6 Oct 2011, Andrew Morton wrote:
> On Wed, 14 Sep 2011 14:35:21 -0400 (EDT)
> Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote:
>
> >
> > The existing vm_area_register_early() allows for early vmalloc space
> > allocation. However upcoming cleanups in the ARM architecture require
> > that some fixed locations in the vmalloc area be reserved also very early.
> >
> > The name "vm_area_register_early" would have been a good name for the
> > reservation part without the allocation. Since it is already in use with
> > different semantics, let's create vm_area_add_early() instead.
> >
> > Both vm_area_register_early() and vm_area_add_early() can be used together
> > meaning that the former is now implemented using the later where it is
> > ensured that no conflicting areas are added, but no attempt is made to
> > make the allocation scheme in vm_area_register_early() more sophisticated.
> > After all, you must know what you're doing when using those functions.
> >
> > Signed-off-by: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
> > ---
> >
> > Comments / ACKs appreciated.
>
> Deafening silence?
I interpreted it as "no objections".
> > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> > index 9332e52ea8..e7d2cba995 100644
> > --- a/include/linux/vmalloc.h
> > +++ b/include/linux/vmalloc.h
> > @@ -130,6 +130,7 @@ extern long vwrite(char *buf, char *addr, unsigned long count);
> > */
> > extern rwlock_t vmlist_lock;
> > extern struct vm_struct *vmlist;
> > +extern __init void vm_area_add_early(struct vm_struct *vm);
> > extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
> >
> > #ifdef CONFIG_SMP
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index 7ef0903058..bf20a0ff95 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -1118,6 +1118,31 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro
> > EXPORT_SYMBOL(vm_map_ram);
> >
> > /**
> > + * vm_area_add_early - add vmap area early during boot
> > + * @vm: vm_struct to add
> > + *
> > + * This function is used to add fixed kernel vm area to vmlist before
> > + * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
> > + * should contain proper values and the other fields should be zero.
> > + *
> > + * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
> > + */
> > +void __init vm_area_add_early(struct vm_struct *vm)
> > +{
> > + struct vm_struct *tmp, **p;
> > +
> > + for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
> > + if (tmp->addr >= vm->addr) {
> > + BUG_ON(tmp->addr < vm->addr + vm->size);
> > + break;
> > + } else
> > + BUG_ON(tmp->addr + tmp->size > vm->addr);
> > + }
> > + vm->next = *p;
> > + *p = vm;
> > +}
> > +
> > +/**
> > * vm_area_register_early - register vmap area early during boot
> > * @vm: vm_struct to register
> > * @align: requested alignment
> > @@ -1139,8 +1164,7 @@ void __init vm_area_register_early(struct vm_struct *vm, size_t align)
> >
> > vm->addr = (void *)addr;
> >
> > - vm->next = vmlist;
> > - vmlist = vm;
> > + vm_area_add_early(vm);
> > }
> >
> > void __init vmalloc_init(void)
>
> I tossed this into my tree for a bit of testing, assuming it's
> up-to-date and still desired?
Yes it is, on both counts.
> Feel free to add it to some ARM tree. I'll drop my copy when that
> turns up in linux-next.
So I did, however I'm postponing the whole series that depend on this to
the next cycle because of other prerequisite cleanups that are going in
this cycle from different paths.
> Yes, the naming scheme in there is gruseome.
I didn't want to go as far as renaming it across the tree, in case other
people are relying on the current name in their own tree.
Nicolas
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