From: Dan Williams on
On Tue, Jun 1, 2010 at 5:22 AM, Linus Walleij
<linus.walleij(a)stericsson.com> wrote:
> Switch to allocating LCLA in memory instead of having a fixed
> address.
>
> Signed-off-by: Jonas Aaberg <jonas.aberg(a)stericsson.com>
> Signed-off-by: Linus Walleij <linus.walleij(a)stericsson.com>
> ---
> �drivers/dma/ste_dma40.c � �| �246 +++++++++++++++++++++++++++-----------------
> �drivers/dma/ste_dma40_ll.c | � �5 +-
> �drivers/dma/ste_dma40_ll.h | � 12 +-
> �3 files changed, 161 insertions(+), 102 deletions(-)
>
> diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
> index 5579401..ec092fa 100644
> --- a/drivers/dma/ste_dma40.c
> +++ b/drivers/dma/ste_dma40.c
[..]
> @@ -2482,6 +2501,71 @@ static void __init d40_hw_init(struct d40_base *base)
>
> �}
>
> +static int __init d40_lcla_allocate(struct d40_base *base)
> +{
> + � � � unsigned long *page_list;
> + � � � int i, j;
> + � � � int ret = 0;
> +
> + � � � /*
> + � � � �* This is somewhat ugly. We need 8192 bytes that are 18 bit aligned,
> + � � � �* To full fill this hardware requirement without wasting 256 kb
> + � � � �* we allocate pages until we get an aligned one.
> + � � � �*/
> + � � � page_list = kmalloc(sizeof(unsigned long) * MAX_LCLA_ALLOC_ATTEMPTS,
> + � � � � � � � � � � � � � GFP_KERNEL);
> +
> + � � � if (!page_list) {
> + � � � � � � � ret = -ENOMEM;
> + � � � � � � � goto failure;
> + � � � }
> +
> + � � � /* Calculating how many pages that are required */
> + � � � base->lcla_pool.pages = SZ_1K * (base->num_phy_chans + PAGE_SIZE /
> + � � � � � � � � � � � � � � � � � � � �SZ_1K - 1) / PAGE_SIZE + 3;
> +

What?

> + � � � for (i = 0; i < MAX_LCLA_ALLOC_ATTEMPTS; i++) {
> + � � � � � � � page_list[i] = __get_free_pages(GFP_KERNEL,
> + � � � � � � � � � � � � � � � � � � � � � � � base->lcla_pool.pages);
> +
> + � � � � � � � if ((virt_to_phys((void *)page_list[i]) &
> + � � � � � � � � � �(LCLA_ALIGNMENT - 1)) == 0 && page_list[i] != 0)
> + � � � � � � � � � � � break;

It looks odd to test for page_list[i] being null after determining if
this is the desired alignment.

--
Dan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/