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    SubjectRe: [PATCH 16/28] nios2: System calls handling
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    On Fri, Apr 18, 2014 at 2:26 PM, Ley Foon Tan <lftan@altera.com> wrote:
    > +/* sys_cacheflush -- flush the processor cache. */
    > +asmlinkage int sys_cacheflush(unsigned long addr, unsigned long len,
    > + unsigned int op)
    > +{
    > + struct vm_area_struct *vma;
    > +
    > + if (len == 0)
    > + return 0;
    > +
    > + /* Check for overflow */
    > + if (addr + len < addr)
    > + return -EFAULT;
    > +
    > + /*
    > + * Verify that the specified address region actually belongs
    > + * to this process.
    > + */
    > + vma = find_vma(current->mm, addr);
    > + if (vma == NULL || addr < vma->vm_start || addr + len > vma->vm_end)
    > + return -EFAULT;
    > +
    > + /* Ignore the scope and cache arguments. */

    This function doesn't have scope and cache arguments
    (sys_cacheflush() on m68k does have them ;-)

    On Sat, Apr 19, 2014 at 6:09 PM, Pavel Machek <pavel@denx.de> wrote:
    > Also... explanation why you need this syscall while other
    > architectures live happily without it would be nice.

    12 our of 28 architectures provide such a syscall...

    Is flushing the cache a privileged operation on nios2?

    Gr{oetje,eeting}s,

    Geert

    --
    Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

    In personal conversations with technical people, I call myself a hacker. But
    when I'm talking to journalists I just say "programmer" or something like that.
    -- Linus Torvalds


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