Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

[Franck Bui-Huu <vagabon.xyz@gmail.com>]

Andrew,

Andrew Morton wrote:
> On Thu, 26 Oct 2006 17:48:58 +0000
> Miguel Ojeda Sandonis <maxextreme@gmail.com> wrote:
> 
[snip]
> 
>> +struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
>> +	unsigned long address, int *type)
> 
> This function can have static scope.
> 
>> +{
>> +	struct page *page;
>> +	down(&cfag12864bfb_sem);
>> +
>> +	page = virt_to_page(cfag12864b_buffer);
>> +	get_page(page);
>> +
>> +	if(type)
>> +		*type = VM_FAULT_MINOR;
>> +
>> +	up(&cfag12864bfb_sem);
>> +	return page;
>> +}
> 

Any idea why LDD3 states:

	An interesting limitation of remap_pfn_range is that it gives
	access only to reserved pages and physical addresses above the
	top of physical memory.

Is that true we can't do:

	buf = (char *)__get_free_page(...);
	pfn = PFN_DOWN(virt_to_phys(buf));
	remap_pfn_range(vma, vma->vm_start, pfn, PAGE_SIZE, vma->vm_page_prot);

Thanks
		Franck