Re: [PATCH v3 03/11] iommu/mediatek: Improve comment for the current region/bank

From: AngeloGioacchino Del Regno
Date: Tue Feb 14 2023 - 04:50:20 EST


Il 14/02/23 04:11, Yong Wu ha scritto:
No functional change. Just add more comment about the current region/bank
in the code.

Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
drivers/iommu/mtk_iommu.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index d5a4955910ff..ab53edcb221f 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -197,12 +197,33 @@ struct mtk_iommu_plat_data {
char *pericfg_comp_str;
struct list_head *hw_list;
- unsigned int iova_region_nr;
- const struct mtk_iommu_iova_region *iova_region;
- u8 banks_num;
- bool banks_enable[MTK_IOMMU_BANK_MAX];
- unsigned int banks_portmsk[MTK_IOMMU_BANK_MAX];
+ /*
+ * The IOMMU HW may support 16GB iova. In order to balance the IOVA ranges,
+ * different masters will be put in different iova ranges, for example vcodec
+ * is in 4G-8G and cam is in 8G-12G. Meanwhile, some masters may have the
+ * special IOVA range requirement, like CCU can only support the address
+ * 0x40000000-0x44000000.
+ * Here list the iova ranges this SoC supports and which larbs/ports are in
+ * which region.
+ *
+ * 16GB iova all use one pgtable, but each a region is a iommu group.
+ */
+ struct {
+ unsigned int iova_region_nr;
+ const struct mtk_iommu_iova_region *iova_region;
+ };
+
+ /*
+ * The IOMMU HW may have 5 banks. Each bank has a indenpendent pgtable.

You got a typo here: `inde*n*pendent` - after fixing that:

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>