Commit-ID: 4cb205c0c50f613e2de91f0eb19d5247ed003e89
Gitweb: https://git.kernel.org/tip/4cb205c0c50f613e2de91f0eb19d5247ed003e89
Author: Jia He <[email protected]>
AuthorDate: Tue, 28 Aug 2018 12:53:26 +0800
Committer: Thomas Gleixner <[email protected]>
CommitDate: Thu, 6 Sep 2018 20:31:59 +0200
irqchip/gic-v3-its: Cap lpi_id_bits to reduce memory footprint
Commit fe8e93504ce8 ("irqchip/gic-v3-its: Use full range of LPIs"), removes
the cap for lpi_id_bits, which causes the following warning to trigger on a
QDF2400 server:
WARNING: CPU: 0 PID: 0 at mm/page_alloc.c:4066 __alloc_pages_nodemask
...
Call trace:
__alloc_pages_nodemask+0x2d8/0x1188
alloc_pages_current+0x8c/0xd8
its_allocate_prop_table+0x5c/0xb8
its_init+0x220/0x3c0
gic_init_bases+0x250/0x380
gic_acpi_init+0x16c/0x2a4
In its_alloc_lpi_tables(), lpi_id_bits is 24 in QDF2400. The allocation in
allocate_prop_table() tries therefore to allocate 16M (order 12 if
pagesize=4k), which triggers the warning.
As said by MarcL
Capping lpi_id_bits at 16 (which is what we had before) is plenty,
will save a some memory, and gives some margin before we need to push
it up again.
Bring the upper limit of lpi_id_bits back to prevent
Fixes: fe8e93504ce8 ("irqchip/gic-v3-its: Use full range of LPIs")
Suggested-by: Marc Zyngier <[email protected]>
Signed-off-by: Jia He <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Tested-by: Olof Johansson <[email protected]>
Cc: Jason Cooper <[email protected]>
Cc: [email protected]
Link:
https://lkml.kernel.org/r/[email protected]
---
drivers/irqchip/irq-gic-v3-its.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 316a57530f6d..c2df341ff6fa 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1439,6 +1439,7 @@ static struct irq_chip its_irq_chip = {
* The consequence of the above is that allocation is cost is low, but
* freeing is expensive. We assumes that freeing rarely occurs.
*/
+#define ITS_MAX_LPI_NRBITS 16 /* 64K LPIs */
static DEFINE_MUTEX(lpi_range_lock);
static LIST_HEAD(lpi_range_list);
@@ -1625,7 +1626,8 @@ static int __init its_alloc_lpi_tables(void)
{
phys_addr_t paddr;
- lpi_id_bits = GICD_TYPER_ID_BITS(gic_rdists->gicd_typer);
+ lpi_id_bits = min_t(u32, GICD_TYPER_ID_BITS(gic_rdists->gicd_typer),
+ ITS_MAX_LPI_NRBITS);
gic_rdists->prop_page = its_allocate_prop_table(GFP_NOWAIT);
if (!gic_rdists->prop_page) {
pr_err("Failed to allocate PROPBASE\n");
