Re: [PATCH v6 06/10] iommu/mediatek: Add sub_comm id in translation fault

[Matthias Brugger]

On 03/07/2020 06:41, 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@xxxxxxxxx>
> Signed-off-by: Chao Hao <chao.hao@xxxxxxxxxxxx>
> Reviewed-by: Yong Wu <yong.wu@xxxxxxxxxxxx>

Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>

> ---
>  drivers/iommu/mtk_iommu.c | 21 ++++++++++++++-------
>  drivers/iommu/mtk_iommu.h |  5 ++++-
>  2 files changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 533b8f76f592..0d96dcd8612b 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -91,6 +91,8 @@
>  #define REG_MMU1_INVLD_PA			0x148
>  #define REG_MMU0_INT_ID				0x150
>  #define REG_MMU1_INT_ID				0x154
> +#define F_MMU_INT_ID_COMM_ID(a)			(((a) >> 9) & 0x7)
> +#define F_MMU_INT_ID_SUB_COMM_ID(a)		(((a) >> 7) & 0x3)
>  #define F_MMU_INT_ID_LARB_ID(a)			(((a) >> 7) & 0x7)
>  #define F_MMU_INT_ID_PORT_ID(a)			(((a) >> 2) & 0x1f)
>  
> @@ -109,6 +111,7 @@
>  #define HAS_VLD_PA_RNG			BIT(2)
>  #define RESET_AXI			BIT(3)
>  #define OUT_ORDER_WR_EN			BIT(4)
> +#define HAS_SUB_COMM			BIT(5)
>  
>  #define MTK_IOMMU_HAS_FLAG(pdata, _x) \
>  		((((pdata)->flags) & (_x)) == (_x))
> @@ -239,7 +242,7 @@ static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
>  	struct mtk_iommu_data *data = dev_id;
>  	struct mtk_iommu_domain *dom = data->m4u_dom;
>  	u32 int_state, regval, fault_iova, fault_pa;
> -	unsigned int fault_larb, fault_port;
> +	unsigned int fault_larb, fault_port, sub_comm = 0;
>  	bool layer, write;
>  
>  	/* Read error info from registers */
> @@ -255,10 +258,14 @@ static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
>  	}
>  	layer = fault_iova & F_MMU_FAULT_VA_LAYER_BIT;
>  	write = fault_iova & F_MMU_FAULT_VA_WRITE_BIT;
> -	fault_larb = F_MMU_INT_ID_LARB_ID(regval);
>  	fault_port = F_MMU_INT_ID_PORT_ID(regval);
> -
> -	fault_larb = data->plat_data->larbid_remap[fault_larb];
> +	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_SUB_COMM)) {
> +		fault_larb = F_MMU_INT_ID_COMM_ID(regval);
> +		sub_comm = F_MMU_INT_ID_SUB_COMM_ID(regval);
> +	} else {
> +		fault_larb = F_MMU_INT_ID_LARB_ID(regval);
> +	}
> +	fault_larb = data->plat_data->larbid_remap[fault_larb][sub_comm];
>  
>  	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
>  			       write ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ)) {
> @@ -785,21 +792,21 @@ static const struct mtk_iommu_plat_data mt2712_data = {
>  	.m4u_plat     = M4U_MT2712,
>  	.flags        = HAS_4GB_MODE | HAS_BCLK | HAS_VLD_PA_RNG,
>  	.inv_sel_reg  = REG_MMU_INV_SEL_GEN1,
> -	.larbid_remap = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
> +	.larbid_remap = {{0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}},
>  };
>  
>  static const struct mtk_iommu_plat_data mt8173_data = {
>  	.m4u_plat     = M4U_MT8173,
>  	.flags	      = HAS_4GB_MODE | HAS_BCLK | RESET_AXI,
>  	.inv_sel_reg  = REG_MMU_INV_SEL_GEN1,
> -	.larbid_remap = {0, 1, 2, 3, 4, 5}, /* Linear mapping. */
> +	.larbid_remap = {{0}, {1}, {2}, {3}, {4}, {5}}, /* Linear mapping. */
>  };
>  
>  static const struct mtk_iommu_plat_data mt8183_data = {
>  	.m4u_plat     = M4U_MT8183,
>  	.flags        = RESET_AXI,
>  	.inv_sel_reg  = REG_MMU_INV_SEL_GEN1,
> -	.larbid_remap = {0, 4, 5, 6, 7, 2, 3, 1},
> +	.larbid_remap = {{0}, {4}, {5}, {6}, {7}, {2}, {3}, {1}},
>  };
>  
>  static const struct of_device_id mtk_iommu_of_ids[] = {
> diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
> index cf53f5e80d22..46d0d47b22e1 100644
> --- a/drivers/iommu/mtk_iommu.h
> +++ b/drivers/iommu/mtk_iommu.h
> @@ -17,6 +17,9 @@
>  #include <linux/spinlock.h>
>  #include <soc/mediatek/smi.h>
>  
> +#define MTK_LARB_COM_MAX	8
> +#define MTK_LARB_SUBCOM_MAX	4
> +
>  struct mtk_iommu_suspend_reg {
>  	union {
>  		u32			standard_axi_mode;/* v1 */
> @@ -41,7 +44,7 @@ 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;
>