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    SubjectRe: [PATCH v2 24/29] nios2: Module support
    Date
    On Tuesday 15 July 2014 13:12:37 Tobias Klauser wrote:
    > On 2014-07-15 at 12:24:46 +0200, Arnd Bergmann <arnd@arndb.de> wrote:
    > > On Tuesday 15 July 2014 16:45:51 Ley Foon Tan wrote:
    > > > +void *module_alloc(unsigned long size)
    > > > +{
    > > > + if (size == 0)
    > > > + return NULL;
    > > > + return kmalloc(size, GFP_KERNEL);
    > > > +}
    > > > +
    > > > +/* Free memory returned from module_alloc */
    > > > +void module_free(struct module *mod, void *module_region)
    > > > +{
    > > > + kfree(module_region);
    > > > +}
    > >
    > > Any particular reason for defining these to use kmalloc rather than
    > > the default vmalloc based functions?
    >
    > AFAIR this is due to relocation issues, as the FIXME comment in the
    > "original" code [1] states. I don't know whether this still applies,
    > though (or what would be the proper fix for this to overcome the
    > relocation issues).
    >
    > [1] https://github.com/tklauser/linux-nios2/blob/nios2/arch/nios2/kernel/module.c#L45
    >

    Ah, I see. Please at least copy over that comment then.

    A long-term solution would be to copy what ARM does, since that
    has the same problem. The modules are allocated with
    __vmalloc_node_range, passing a virtual address range that
    is just before the kernel virtual address, taken out of the
    top 16MB of the user space addresses.

    Arnd


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