I'm trying to use the bigphysarea patch to help me allocate big
physical chunks of memory for use by some custom embedded devices.
I've applied the bigphysarea-2.4.20 patch and built, no trouble,
and I've got it to config for my PPC. I can see at boot time that
the bigphysarea is getting its pages.
I'm trying to use a mmap call to the driver to map a chunk of this
memory into the process. The mmap for the driver has this:
pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
vma->vm_flags |= VM_RESERVED;
npages = (vma->vm_end - vma->vm_start) / PAGE_SIZE;
heap_map_base = bigphysarea_alloc_pages(npages, 1, GFP_KERNEL);
printk("XXXX Map base=%p, %ld pages\n", heap_map_base, npages);
rc = remap_page_range(vma->vm_start,
(unsigned long)heap_map_base,
npages*PAGE_SIZE,
vma->vm_page_prot);
The mmap returns without an error, but any access to the mapped
region gets me an immediate "Oops: machine check, sig: 7". I don't
see it. Where is the stupid mistake that I'm invariably making?
--
Steve Williams "The woods are lovely, dark and deep.
steve at icarus.com But I have promises to keep,
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