Re: [PATCH v4 5/7] iommu/mediatek: Add sub_comm id in translation fault

From: Matthias Brugger
Date: Wed Jun 17 2020 - 05:17:24 EST




On 17/06/2020 05:00, 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 variable, 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 extern larb_remap[] to larb_remap[8][4] for this.

extern -> extend

> larb_remap[x][y]: x mean common-id above, y means subcommon_id above.

mean -> means

>
> We can also distinguish if the M4U HW has sub_common by has_sub_comm
> property.
>
> Signed-off-by: Chao Hao <chao.hao@xxxxxxxxxxxx>
> Reviewed-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> ---
> drivers/iommu/mtk_iommu.c | 20 +++++++++++++-------
> drivers/iommu/mtk_iommu.h | 3 ++-
> 2 files changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index f23919feba4e..a687e8db0e51 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)
>
> @@ -229,7 +231,7 @@ 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 */
> @@ -245,10 +247,14 @@ 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 (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)) {
> @@ -778,7 +784,7 @@ static const struct mtk_iommu_plat_data mt2712_data = {
> .has_bclk = true,
> .has_vld_pa_rng = true,
> .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 = {
> @@ -787,14 +793,14 @@ static const struct mtk_iommu_plat_data mt8173_data = {
> .has_bclk = true,
> .reset_axi = true,
> .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,
> .reset_axi = true,
> .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 afd7a2de5c1e..d51ff99c2c71 100644
> --- a/drivers/iommu/mtk_iommu.h
> +++ b/drivers/iommu/mtk_iommu.h
> @@ -41,10 +41,11 @@ struct mtk_iommu_plat_data {
> /* HW will use the EMI clock if there isn't the "bclk". */
> bool has_bclk;
> bool has_misc_ctrl;
> + bool has_sub_comm;
> bool has_vld_pa_rng;
> bool reset_axi;
> u32 inv_sel_reg;
> - unsigned char larbid_remap[MTK_LARB_NR_MAX];
> + unsigned char larbid_remap[8][4];

MTK_LARB_NR_MAX is 16, why do you decrease it to 8?
Should we use a define for the subcommon as well?

Regards,
Matthias

> };
>
> struct mtk_iommu_domain;
>