Re: [PATCH v4 13/15] irqchip/gic-v3-its: Rely on genpool alignment

Will Deacon
2024-07-10T13:17:59Z

On Mon, Jul 01, 2024 at 10:55:03AM +0100, Steven Price wrote:
> its_create_device() over-allocated by ITS_ITT_ALIGN - 1 bytes to ensure
> that an aligned area was available within the allocation. The new
> genpool allocator has its min_alloc_order set to
> get_order(ITS_ITT_ALIGN) so all allocations from it should be
> appropriately aligned.
>
> Remove the over-allocation from its_create_device() and alignment from
> its_build_mapd_cmd().
>
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 7d12556bc498..ab697e4004b9 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -699,7 +699,6 @@ static struct its_collection *its_build_mapd_cmd(struct its_node *its,
> 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);
> @@ -3520,7 +3519,7 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
> */
> nr_ites = max(2, nvecs);
> sz = nr_ites * (FIELD_GET(GITS_TYPER_ITT_ENTRY_SIZE, its->typer) + 1);
> - sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
> + sz = max(sz, ITS_ITT_ALIGN);
>
> itt = itt_alloc_pool(its->numa_node, sz);

Tested-by: Will Deacon <will@kernel.org>

Will