On Tue, 2018-02-27 at 17:31 +0000, Ard Biesheuvel wrote:
> On 27 February 2018 at 17:27, Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> > The memory we are accessing through virtual address has no IO side
> > effects. Moreover, for IO memory we have to use special accessors,
> > which we don't use.
> >
>
> Not 100% relevant in this context, but perhaps interesting
> nonetheless: using device mappings to access things like firmware
> tables or other structured data will break ARM and other non-x86
> architectures that do not tolerate unaligned accessed to device
> memory.
>
> > Due to above, convert the driver to use memremap() instead of
> > ioremap().
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
> Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Thanks!
It's supposed to go through EFI tree.
>
> > ---
> > drivers/firmware/efi/apple-properties.c | 11 ++++++-----
> > 1 file changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/firmware/efi/apple-properties.c
> > b/drivers/firmware/efi/apple-properties.c
> > index b9602e0d7b50..adaa9a3714b9 100644
> > --- a/drivers/firmware/efi/apple-properties.c
> > +++ b/drivers/firmware/efi/apple-properties.c
> > @@ -19,6 +19,7 @@
> >
> > #include <linux/bootmem.h>
> > #include <linux/efi.h>
> > +#include <linux/io.h>
> > #include <linux/platform_data/x86/apple.h>
> > #include <linux/property.h>
> > #include <linux/slab.h>
> > @@ -189,7 +190,7 @@ static int __init map_properties(void)
> >
> > pa_data = boot_params.hdr.setup_data;
> > while (pa_data) {
> > - data = ioremap(pa_data, sizeof(*data));
> > + data = memremap(pa_data, sizeof(*data),
> > MEMREMAP_WB);
> > if (!data) {
> > pr_err("cannot map setup_data header\n");
> > return -ENOMEM;
> > @@ -197,14 +198,14 @@ static int __init map_properties(void)
> >
> > if (data->type != SETUP_APPLE_PROPERTIES) {
> > pa_data = data->next;
> > - iounmap(data);
> > + memunmap(data);
> > continue;
> > }
> >
> > data_len = data->len;
> > - iounmap(data);
> > + memunmap(data);
> >
> > - data = ioremap(pa_data, sizeof(*data) + data_len);
> > + data = memremap(pa_data, sizeof(*data) + data_len,
> > MEMREMAP_WB);
> > if (!data) {
> > pr_err("cannot map setup_data payload\n");
> > return -ENOMEM;
> > @@ -229,7 +230,7 @@ static int __init map_properties(void)
> > * to avoid breaking the chain of ->next pointers.
> > */
> > data->len = 0;
> > - iounmap(data);
> > + memunmap(data);
> > free_bootmem_late(pa_data + sizeof(*data),
> > data_len);
> >
> > return ret;
> > --
> > 2.16.1
> >
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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