[PATCH v8 05/21] iommu/mediatek: Fix iova_to_phys PA start for 4GB mode

Yong Wu
2019-06-29T02:12:41Z

In the 4GB mode, the physical address is remapped,

Here is the detailed remap relationship.
CPU PA -> HW PA
0x4000_0000 0x1_4000_0000 (Add bit32)
0x8000_0000 0x1_8000_0000 ...
0xc000_0000 0x1_c000_0000 ...
0x1_0000_0000 0x1_0000_0000 (No change)

The PA in the iova_to_phys that is got from v7s always is u32, But
from the CPU point of view, PA should add BIT(32) when PA < 0x4000_0000.

Fixes: 30e2fccf9512 ("iommu/mediatek: Enlarge the validate PA range
for 4GB mode")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
drivers/iommu/mtk_iommu.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 1ddb2b7..fefc2e0 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -115,6 +115,19 @@ struct mtk_iommu_domain {

static const struct iommu_ops mtk_iommu_ops;

+/*
+ * In M4U 4GB mode, the physical address is remapped as below:
+ * CPU PA -> M4U HW PA
+ * 0x4000_0000 0x1_4000_0000 (Add bit32)
+ * 0x8000_0000 0x1_8000_0000 ...
+ * 0xc000_0000 0x1_c000_0000 ...
+ * 0x1_0000_0000 0x1_0000_0000 (No change)
+ *
+ * The PA in the iova_to_phys that is got from v7s always is u32, But from
+ * the CPU point of view, PA should add BIT(32) when PA < 0x4000_0000.
+ */
+#define MTK_IOMMU_4GB_MODE_REMAP_BASE 0x40000000
+
static LIST_HEAD(m4ulist); /* List all the M4U HWs */

#define for_each_m4u(data) list_for_each_entry(data, &m4ulist, list)
@@ -409,7 +422,7 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
pa = dom->iop->iova_to_phys(dom->iop, iova);
spin_unlock_irqrestore(&dom->pgtlock, flags);

- if (data->enable_4GB)
+ if (data->enable_4GB && pa < MTK_IOMMU_4GB_MODE_REMAP_BASE)
pa |= BIT_ULL(32);

return pa;