2017-03-05 15:29:05

by Shanker Donthineni

[permalink] [raw]
Subject: [PATCH] irqchip/gicv3-its: Avoid memory over allocation for ITTEs

We are always allocating extra 255Bytes of memory to handle ITTE
physical address alignment requirement. The kmalloc() satisfies
the ITTE 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 ITTEs to avoid wastage.

Signed-off-by: Shanker Donthineni <[email protected]>
---
drivers/irqchip/irq-gic-v3-its.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 86bd428..5aeca78 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1329,8 +1329,13 @@ 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);
+ if (itt && !IS_ALIGNED(virt_to_phys(itt), ITS_ITT_ALIGN)) {
+ kfree(itt);
+ itt = kzalloc(sz + ITS_ITT_ALIGN - 1, 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);
--
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