Hi Simon,
On Mon, Nov 13, 2017 at 8:00 AM, Simon Horman <horms@xxxxxxxxxxxx> wrote:
> On Fri, Nov 10, 2017 at 10:53:07PM +0100, Marek Vasut wrote:
>> On 11/10/2017 10:09 AM, Simon Horman wrote:
>> > On Wed, Nov 08, 2017 at 10:28:06AM +0100, Marek Vasut wrote:
>> >> @@ -872,11 +902,25 @@ static const struct irq_domain_ops msi_domain_ops = {
>> >> .map = rcar_msi_map,
>> >> };
>> >>
>> >> +static void rcar_pcie_hw_enable_msi(struct rcar_pcie *pcie)
>> >> +{
>> >> + struct rcar_msi *msi = &pcie->msi;
>> >> + unsigned long base;
>> >> +
>> >> + /* setup MSI data target */
>> >> + base = virt_to_phys((void *)msi->pages);
>> >
>> > Why do you need to cast to void *?
>> > I expect such casting can be done implicitly.
>>
>> Because __get_free_pages() returns unsigned long and that's what's used
>> to assign msi->pages . And virt_to_phys() expects void * instead, thus
>> the cast.
>
> Right, but I don't think one should ever need to explicitly cast
> to or from void *. What mean is, can you just remove "(void *)" without
In general, I agree ("casts are evil").
> changing any behaviour?
In this particular case, there's no way around the cast, as __get_free_pages()
returns unsigned long because of historical reasons (if written today, it
would return a pointer for sure).
Other exceptions are storing integral types in of_device_id.data (which is
void *), and storing private data pointers in Scsi_Host.hostdata (which is
unsigned long).
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
