Thread (27 messages) 27 messages, 3 authors, 2020-07-03

Re: [PATCH v5 06/10] iommu/mediatek: Add sub_comm id in translation fault

From: Yong Wu <yong.wu@mediatek.com>
Date: 2020-06-30 10:55:50
Also in: linux-devicetree, linux-iommu, linux-mediatek, lkml

On Mon, 2020-06-29 at 15:13 +0800, Chao Hao wrote:
The max larb number that a iommu HW support is 8(larb0~larb7 in the below
diagram).
If the larb's number is over 8, we use a sub_common for merging
several larbs into one larb. At this case, we will extend larb_id:
bit[11:9] means common-id;
bit[8:7] means subcommon-id;
From these two variables, we could get the real larb number when
translation fault happen.
The diagram is as below:
		 EMI
		  |
		IOMMU
		  |
           -----------------
	   |               |
	common1   	common0
	   |		   |
	   -----------------
		  |
             smi common
		  |
  ------------------------------------
  |       |       |       |     |    |
 3'd0    3'd1    3'd2    3'd3  ...  3'd7   <-common_id(max is 8)
  |       |       |       |     |    |
Larb0   Larb1     |     Larb3  ... Larb7
		  |
	    smi sub common
		  |
     --------------------------
     |        |       |       |
    2'd0     2'd1    2'd2    2'd3   <-sub_common_id(max is 4)
     |        |       |       |
   Larb8    Larb9   Larb10  Larb11

In this patch we extend larb_remap[] to larb_remap[8][4] for this.
larb_remap[x][y]: x means common-id above, y means subcommon_id above.

We can also distinguish if the M4U HW has sub_common by HAS_SUB_COMM
macro.

Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Chao Hao <redacted>
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c  | 20 +++++++++++++-------
 drivers/iommu/mtk_iommu.h  |  3 ++-
 include/soc/mediatek/smi.h |  2 ++
 3 files changed, 17 insertions(+), 8 deletions(-)
[snip]
quoted hunk ↗ jump to hunk
@@ -48,7 +49,7 @@ struct mtk_iommu_plat_data {
 	enum mtk_iommu_plat m4u_plat;
 	u32                 flags;
 	u32                 inv_sel_reg;
-	unsigned char       larbid_remap[MTK_LARB_NR_MAX];
+	unsigned char       larbid_remap[MTK_LARB_COM_MAX][MTK_LARB_SUBCOM_MAX];
 };
 
 struct mtk_iommu_domain;
diff --git a/include/soc/mediatek/smi.h b/include/soc/mediatek/smi.h
index 5a34b87d89e3..fa65a55468e2 100644
--- a/include/soc/mediatek/smi.h
+++ b/include/soc/mediatek/smi.h
@@ -12,6 +12,8 @@
 #ifdef CONFIG_MTK_SMI
 
 #define MTK_LARB_NR_MAX		16
+#define MTK_LARB_COM_MAX	8
+#define MTK_LARB_SUBCOM_MAX	4
Both are only used in mtk_iommu.h, and I don't think smi has plan to use
them. thus we could move them into mtk_iommu.h
 
 #define MTK_SMI_MMU_EN(port)	BIT(port)
 
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