From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <40473464.8010203@imc-berlin.de> Date: Thu, 04 Mar 2004 14:51:32 +0100 From: Steven Scholz MIME-Version: 1.0 To: LinuxPPC Subject: uncached user space mapping with mmap() ??? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Hi there, I am trying to access a hardware timer implemented in an FPGA from user space. I implemented a simple mmap() functionality (taken from Runbini's Linux Device Driver) int simple_remap_mmap(struct file *filp, struct vm_area_struct *vma) { unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; if (offset >= __pa(high_memory) || (filp->f_flags & O_SYNC)) { vma->vm_flags |= VM_IO; } vma->vm_flags |= VM_RESERVED; if (remap_page_range(vma->vm_start, offset, vma->vm_end-vma->vm_start, vma->vm_page_prot)) return -EAGAIN; return 0; } I just learned that > getting an uncached user space mapping is architecture dependent. > On ARM, however, passing pgprot_noncached(vma->vm_page_prot) to > remap_page_range() will alter the page protections such that the > mapping will be uncached. How could I do this on an MPC8xx? Thanks a million! -- Steven Scholz imc Measurement & Control imc Meßsysteme GmbH Voltastr. 5 Voltastr. 5 13355 Berlin 13355 Berlin Germany Deutschland ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/