From 18aa60ce2751c95d3412ed06a58b8b6cfb6f88f2 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 26 Jan 2016 14:24:15 +0000 Subject: [PATCH] irqchip/gic-v3-its: Recompute the number of pages on page size change When the programming of a GITS_BASERn register fails because of an unsupported ITS page size, we retry it with a smaller page size. Unfortunately, we don't recompute the number of allocated ITS pages, indicating the wrong value computed in the original allocation. A convenient fix is to free the pages we allocated, update the page size, and restart the allocation. This will ensure that we always allocate the right amount in the case of a device table, specially if we have to reduce the allocation order to stay within the boundaries of the ITS maximum allocation. Reported-and-tested-by: Ma Jun Signed-off-by: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org Cc: Jason Cooper Link: http://lkml.kernel.org/r/1453818255-1289-1-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner --- drivers/irqchip/irq-gic-v3-its.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index e23d1d18f9d6..3447549fcc93 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -875,6 +875,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its) } alloc_size = (1 << order) * PAGE_SIZE; +retry_alloc_baser: alloc_pages = (alloc_size / psz); if (alloc_pages > GITS_BASER_PAGES_MAX) { alloc_pages = GITS_BASER_PAGES_MAX; @@ -938,13 +939,16 @@ retry_baser: * size and retry. If we reach 4K, then * something is horribly wrong... */ + free_pages((unsigned long)base, order); + its->tables[i] = NULL; + switch (psz) { case SZ_16K: psz = SZ_4K; - goto retry_baser; + goto retry_alloc_baser; case SZ_64K: psz = SZ_16K; - goto retry_baser; + goto retry_alloc_baser; } }