[PATCH v7 03/14] iommu/mediatek: Improve comment for the current region/bank

Yong Wu
2023-04-11T09:33:22Z

No functional change. Just add more comment about the current region/bank
in the code.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
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..aa4bdcb65ea7 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 independent pgtable.
+ * Here list how many banks this SoC supports/enables and which ports are in which bank.
+ */
+ struct {
+ u8 banks_num;
+ bool banks_enable[MTK_IOMMU_BANK_MAX];
+ unsigned int banks_portmsk[MTK_IOMMU_BANK_MAX];
+ };
+
unsigned char larbid_remap[MTK_LARB_COM_MAX][MTK_LARB_SUBCOM_MAX];
};

--
2.25.1