On Sun, Apr 30 2017 at 3:36:15 pm BST, Shanker Donthineni
<shank...@codeaurora.org> wrote:
> We are always allocating extra 255Bytes of memory to handle ITE
> physical address alignment requirement. The kmalloc() satisfies
> the ITE alignment since the ITS driver is requesting a minimum
> size of ITS_ITT_ALIGN bytes.
>
> Let's try to allocate the exact amount of memory that is required
> for ITEs to avoid wastage.
>
> Signed-off-by: Shanker Donthineni <shank...@codeaurora.org>
> ---
> Changes:
> v2: removed 'Change-Id: Ia8084189833f2081ff13c392deb5070c46a64038' from
> commit.
> v3: changed from IITE to ITE.
> v3: removed fallback since kmalloc() guarantees the right alignment.
>
> drivers/irqchip/irq-gic-v3-its.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c
> b/drivers/irqchip/irq-gic-v3-its.c
> index 45ea1933..72e56f03 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -261,7 +261,6 @@ static struct its_collection *its_build_mapd_cmd(struct
> its_cmd_block *cmd,
> u8 size = ilog2(desc->its_mapd_cmd.dev->nr_ites);
>
> itt_addr = virt_to_phys(desc->its_mapd_cmd.dev->itt);
> - itt_addr = ALIGN(itt_addr, ITS_ITT_ALIGN);
>
> its_encode_cmd(cmd, GITS_CMD_MAPD);
> its_encode_devid(cmd, desc->its_mapd_cmd.dev->device_id);
> @@ -1329,13 +1328,14 @@ static struct its_device *its_create_device(struct
> its_node *its, u32 dev_id,
> */
> nr_ites = max(2UL, roundup_pow_of_two(nvecs));
> sz = nr_ites * its->ite_size;
> - sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
> + sz = max(sz, ITS_ITT_ALIGN);
> itt = kzalloc(sz, GFP_KERNEL);
> lpi_map = its_lpi_alloc_chunks(nvecs, &lpi_base, &nr_lpis);
> if (lpi_map)
> col_map = kzalloc(sizeof(*col_map) * nr_lpis, GFP_KERNEL);
>
> - if (!dev || !itt || !lpi_map || !col_map) {
> + if (!dev || !itt || !lpi_map || !col_map ||
> + !IS_ALIGNED(virt_to_phys(itt), ITS_ITT_ALIGN)) {
> kfree(dev);
> kfree(itt);
> kfree(lpi_map);
I'm confused. Either the alignment is guaranteed (and you should
document why it is so), or it is not, and we need to handle the
non-alignment (instead of failing).
Thanks,
M.
--
Jazz is not dead, it just smell funny.
