[PATCH 2/2] irqchip/gic-v3-its: Rely on genpool alignment

From: Steven Price
Date: Thu Sep 05 2024 - 05:18:16 EST


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().

Tested-by: Will Deacon <will@xxxxxxxxxx>
Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
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 557214c774c3..49aacf96ade2 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -700,7 +700,6 @@ 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);
@@ -3495,7 +3494,7 @@ 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);

--
2.34.1