On 2015/1/31 3:18, Marc Zyngier wrote:

On 30/01/15 07:46, Yun Wu wrote:

quoted

The field of page size in register GITS_BASERn might be read-only
if an implementation only supports a single, fixed page size. But
currently the ITS driver will throw out an error when PAGE_SIZE
is less than the minimum size supported by an ITS. So addressing
this problem by using 64KB pages as default granule for all the
ITS base tables.

Do you actually know of an implementation with such a behaviour?

Yes, Hisilicon implemented a fixed page size of 16KB.

quoted

Signed-off-by: Yun Wu <redacted>
---
 drivers/irqchip/irq-gic-v3-its.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 2a08d85..430bc92 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c

@@ -801,7 +801,7 @@ static int its_alloc_tables(struct its_node *its)
 	int err;
 	int i;
 	int size;
-	int psz = PAGE_SIZE;
+	int psz = SZ_64K;
 	u64 shr = GITS_BASER_InnerShareable;

 	for (i = 0; i < GITS_BASER_NR_REGS; i++) {

Assuming such an implementation exists, you'll have to rebase this on
top of the patch I mentioned in my reply to patch #1.

OK, I will.

Thanks,
	Abel