Re: [Linux-fbdev-devel] How to mmap a shadow framebuffer in virtualmemory

From: Bernardo Innocenti
Date: Tue Feb 06 2007 - 09:57:53 EST


Bernardo Innocenti wrote:

I still couldn't solve my problem, but thanks for helping.

The way you map memory in ps3fb_mmap() is basically the same.
In my case, memory is allocated with __get_free_pages() instead
of being at an absolute physical address, but I can't see how
it could make any difference.

A few weeks ago I found the solution, which I report here to help
people who are googling for the same problem.

consistent_alloc() performed all the required magic to allocate
a contiguous buffer in phisical memory:

- if (!(fb_info.shadow = (void *)__get_free_pages(GFP_KERNEL, OLED_MEMORDER))
+ if (!(fb_info.shadow = consistent_alloc(GFP_KERNEL, PAGE_ALIGN(OLED_MEMSIZE),
+ &fb_info.shadow_phys, PTE_BUFFERABLE))


The complete patch set is here, just in case:

http://www.develer.com/patches/linux/pending/

--
// Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/ http://www.develer.com/

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