* [PATCH v8 02/12] iommu/exynos: add missing cache flush for removed page table entries
@ 2013-07-26 11:26 Cho KyongHo
2013-07-26 15:58 ` Grant Grundler
0 siblings, 1 reply; 2+ messages in thread
From: Cho KyongHo @ 2013-07-26 11:26 UTC (permalink / raw)
To: 'Linux ARM Kernel', 'Linux IOMMU',
'Linux Kernel', 'Linux Samsung SOC'
Cc: 'Hyunwoong Kim', 'Joerg Roedel',
'Kukjin Kim', 'Prathyush', 'Rahul Sharma',
'Subash Patel', 'Keyyoung Park',
'Grant Grundler', 'Antonios Motakis', kvmarm,
'Sachin Kamat'
This commit adds cache flush for removed small and large page entries
in exynos_iommu_unmap(). Missing cache flush of removed page table
entries can cause missing page fault interrupt when a master IP
accesses an unmapped area.
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
---
drivers/iommu/exynos-iommu.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 233f382..e3be3e5 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -1002,6 +1002,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
if (lv2ent_small(ent)) {
*ent = 0;
size = SPAGE_SIZE;
+ pgtable_flush(ent, ent +1);
priv->lv2entcnt[lv1ent_offset(iova)] += 1;
goto done;
}
@@ -1010,6 +1011,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
BUG_ON(size < LPAGE_SIZE);
memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
+ pgtable_flush(ent, ent + SPAGES_PER_LPAGE);
size = LPAGE_SIZE;
priv->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
--
1.7.2.5
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v8 02/12] iommu/exynos: add missing cache flush for removed page table entries
2013-07-26 11:26 [PATCH v8 02/12] iommu/exynos: add missing cache flush for removed page table entries Cho KyongHo
@ 2013-07-26 15:58 ` Grant Grundler
0 siblings, 0 replies; 2+ messages in thread
From: Grant Grundler @ 2013-07-26 15:58 UTC (permalink / raw)
To: Cho KyongHo
Cc: Linux ARM Kernel, Linux IOMMU, Linux Kernel, Linux Samsung SOC,
Hyunwoong Kim, Joerg Roedel, Kukjin Kim, Prathyush, Rahul Sharma,
Subash Patel, Keyyoung Park, Grant Grundler, Antonios Motakis,
kvmarm, Sachin Kamat
On Fri, Jul 26, 2013 at 4:26 AM, Cho KyongHo <pullip.cho@samsung.com> wrote:
> This commit adds cache flush for removed small and large page entries
> in exynos_iommu_unmap(). Missing cache flush of removed page table
> entries can cause missing page fault interrupt when a master IP
> accesses an unmapped area.
>
> Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
Tested-by: Grant Grundler <grundler@chromium.org>
I'm convinced this is a critical fix to apply. Any time we touch the
IOMMU Page Table, we need to flush so the change is immediately
visible to the IOMMU.
thanks,
grant
> ---
> drivers/iommu/exynos-iommu.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index 233f382..e3be3e5 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -1002,6 +1002,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
> if (lv2ent_small(ent)) {
> *ent = 0;
> size = SPAGE_SIZE;
> + pgtable_flush(ent, ent +1);
> priv->lv2entcnt[lv1ent_offset(iova)] += 1;
> goto done;
> }
> @@ -1010,6 +1011,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
> BUG_ON(size < LPAGE_SIZE);
>
> memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
> + pgtable_flush(ent, ent + SPAGES_PER_LPAGE);
>
> size = LPAGE_SIZE;
> priv->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
> --
> 1.7.2.5
>
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2013-07-26 15:59 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-07-26 11:26 [PATCH v8 02/12] iommu/exynos: add missing cache flush for removed page table entries Cho KyongHo
2013-07-26 15:58 ` Grant Grundler
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox