diff mbox

[RFC] irqchip/gic-v3-its:Fix the bug while calculating the page number of ITS table

Message ID 1450768223-10860-1-git-send-email-majun258@huawei.com
State New
Headers show

Commit Message

majun (F) Dec. 22, 2015, 7:10 a.m. UTC 
From: Ma Jun <majun258@huawei.com>


Hi Marc, Robert:

Maybe there is a bug introduced by commit
"irqchip/gicv3-its: Add range check for number of allocated pages"
30f2136346cab91e1ffd9ee6370d76809f20487a

I think, before setting the page number, the variable "alloc_pages"
should be calculated and checked again. 
Or else, the page number programmed into GITS_BASER register is always
the number of 64KB even though the page size is 16KB or 4KB.

Signed-off-by: Ma Jun <majun258@huawei.com>

---
 drivers/irqchip/irq-gic-v3-its.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

-- 
1.7.1



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Comments

majun (F) Dec. 25, 2015, 8:24 a.m. UTC | #1 
Hi Marc:

在 2015/12/24 21:48, Marc Zyngier 写道:
> On Tue, 22 Dec 2015 15:10:23 +0800
> MaJun <majun258@huawei.com> wrote:
> 
[...]
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index e23d1d1..3447549 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;
>  			}
>  		}
>  
> 
> 
> I haven't tested it, but it looks less invasive. Care to give it a go?
> 

This patch works fine on my board.
Tested-by: Ma Jun <majun258@huawei.com>

Thanks
Ma Jun





> Thanks,
> 
> 	M.
>
diff mbox

Patch

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index e23d1d1..100181b 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -879,7 +879,7 @@  static int its_alloc_tables(const char *node_name, struct its_node *its)
 		if (alloc_pages > GITS_BASER_PAGES_MAX) {
 			alloc_pages = GITS_BASER_PAGES_MAX;
 			order = get_order(GITS_BASER_PAGES_MAX * psz);
-			pr_warn("%s: Device Table too large, reduce its page order to %u (%u pages)\n",
+			pr_warn("%s: Table too large, reduce its page order to %u (%u pages)\n",
 				node_name, order, alloc_pages);
 		}
 
@@ -911,6 +911,13 @@  retry_baser:
 			break;
 		}
 
+               alloc_pages = (alloc_size / psz);
+                if (alloc_pages > GITS_BASER_PAGES_MAX) {
+                        alloc_pages = GITS_BASER_PAGES_MAX;
+                        pr_warn("%s: Table too large, reduce its page number to %u pages\n",
+                                node_name, alloc_pages);
+                }
+
 		val |= alloc_pages - 1;
 
 		writeq_relaxed(val, its->base + GITS_BASER + i * 8);