Hello everyone,
While developing a method for mapping RAM memory into user space
I stumbled across Suresh Siddha's commit that "broke" my code:
commit be03d9e8022030c16abf534e33e185bfc3d40eef
x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem
I believe there were important reasons for the changes but how do I map
user RAM memory into user space? Up to this point I've used something
along the lines of (error checking removed):
#v+
static int file_mmap(struct file *file, struct vm_area_struct *vma)
{
const size_t start = /* physical address of memory allocated
using alloc_bootmem_low_pages() */;
return remap_pfn_range(vma, vma->vm_start,
(start >> PAGE_SHIFT) + vma->vm_pgoff
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}
#v-
Reverting the be03... commit makes it work again but I guess it's not
a good way to solve this problem.
Could anyone point me to proper function which may be used like
remap_pfn_range() but work on RAM addresses? It is important, that the
function will work in similar fashion, ie. create raw PFN mappings
without associated struct page.
--
Best regards, _ _
.o. | Liege of Serenly Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michal "mina86" Nazarewicz (o o)
ooo +--<mina86*tlen.pl>--<jid:mina86*jabber.org>--ooO--(_)--Ooo--
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