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?
> 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?
Feel free to add it to some ARM tree. I'll drop my copy when that
turns up in linux-next.
Yes, the naming scheme in there is gruseome.
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