Re: [PATCH 2/2] soc: mediatek: devapc: add devapc-mt6873 driver

Neal Liu
2020-06-15T02:43:56Z

Hi Chun-Kuang,

On Sun, 2020-06-14 at 11:26 +0800, Chun-Kuang Hu wrote:
> Hi, Neal:
>
> Neal Liu <neal.liu@mediatek.com> 於 2020年6月9日 週二 下午6:25寫道：
> >
> > MT6873 bus frabric provides TrustZone security support and data
> > protection to prevent slaves from being accessed by unexpected
> > masters.
> > The security violations are logged and sent to the processor for
> > further analysis or countermeasures.
> >
> > Any occurrence of security violation would raise an interrupt, and
> > it will be handled by devapc-mt6873 driver. The violation
> > information is printed in order to find the murderer.
> >
> > Signed-off-by: Neal Liu <neal.liu@mediatek.com>
> > ---
>
> [snip]
>
> > +
> > + /* 50 */
> > + {-1, -1, 50, "OOB_way_en", true},
> > + {-1, -1, 51, "OOB_way_en", true},
> > + {-1, -1, 52, "OOB_way_en", true},
> > + {-1, -1, 53, "OOB_way_en", true},
> > + {-1, -1, 54, "OOB_way_en", true},
> > + {-1, -1, 55, "OOB_way_en", true},
> > + {-1, -1, 56, "Decode_error", true},
> > + {-1, -1, 57, "Decode_error", true},
> > + {-1, -1, 58, "DISP_PWM", false},
> > + {-1, -1, 59, "IMP_IIC_WRAP", false},
> > +
> > + /* 60 */
> > + {-1, -1, 60, "DEVICE_APC_PERI_PAR__AO", false},
> > + {-1, -1, 61, "DEVICE_APC_PERI_PAR_PDN", false},
>
> You does not process the item whose enable_vio_irq is false, so I
> think you should remove these items and remove enable_vio_irq because
> the rest item's enable_vio_irq would always be true.

In some users, they can decide which slaves they want to enable or
disable violation irq in different product. We remain this property for
compatibility.

>
> > +};
> > +
> > +static struct mtk_device_num mtk6873_devices_num[] = {
> > + {SLAVE_TYPE_INFRA, VIO_SLAVE_NUM_INFRA},
> > + {SLAVE_TYPE_PERI, VIO_SLAVE_NUM_PERI},
> > + {SLAVE_TYPE_PERI2, VIO_SLAVE_NUM_PERI2},
> > + {SLAVE_TYPE_PERI_PAR, VIO_SLAVE_NUM_PERI_PAR},
> > +};
> > +
> > +static struct PERIAXI_ID_INFO peri_mi_id_to_master[] = {
> > + {"THERM2", { 0, 0, 0 } },
> > + {"SPM", { 0, 1, 0 } },
> > + {"CCU", { 0, 0, 1 } },
> > + {"THERM", { 0, 1, 1 } },
> > + {"SPM_DRAMC", { 1, 1, 0 } },
>
> The bits { 1, 1, 0 } equal to a number 0x3, I thiink you should use a
> number instead of bits and everything would be more easy.

We would like to keep it because the bit value contains more than 0/1,
it might be '2' in some cases. '2' means it can be 0 or 1. This totally
by hardware design & implementation.

> > +};
> > +
>
> [snip]
>
> > +
> > +/*
> > + * mtk_devapc_vio_check - check violation shift status is raised or not.
> > + *
> > + * Returns the value of violation shift status reg
> > + */
> > +static void mtk_devapc_vio_check(int slave_type, int *shift_bit)
> > +{
> > + u32 slave_type_num = mtk_devapc_ctx->soc->slave_type_num;
> > + struct mtk_devapc_vio_info *vio_info;
> > + u32 vio_shift_sta;
> > + int i;
> > +
> > + if (slave_type >= slave_type_num) {
>
> This never happen, so remove it.

Indeed, thanks

>
> > + pr_err(PFX "%s: param check failed, %s:0x%x\n",
> > + __func__, "slave_type", slave_type);
> > + return;
> > + }
> > +
> > + vio_info = mtk_devapc_ctx->soc->vio_info;
> > + vio_shift_sta = readl(mtk_devapc_pd_get(slave_type, VIO_SHIFT_STA, 0));
> > +
> > + if (!vio_shift_sta) {
> > + pr_info(PFX "violation is triggered before. %s:0x%x\n",
> > + "shift_bit", *shift_bit);
> > +
> > + } else if (vio_shift_sta & (0x1UL << *shift_bit)) {
> > + pr_debug(PFX "%s: 0x%x is matched with %s:%d\n",
> > + "vio_shift_sta", vio_shift_sta,
> > + "shift_bit", *shift_bit);
> > +
> > + } else {
> > + pr_info(PFX "%s: 0x%x is not matched with %s:%d\n",
> > + "vio_shift_sta", vio_shift_sta,
> > + "shift_bit", *shift_bit);
> > +
> > + for (i = 0; i < MOD_NO_IN_1_DEVAPC * 2; i++) {
> > + if (vio_shift_sta & (0x1 << i)) {
> > + *shift_bit = i;
> > + break;
> > + }
> > + }
> > + }
> > +
> > + vio_info->shift_sta_bit = *shift_bit;
> > +}
> > +
> > +static void devapc_extract_vio_dbg(int slave_type)
> > +{
> > + u32 slave_type_num = mtk_devapc_ctx->soc->slave_type_num;
> > + void __iomem *vio_dbg0_reg, *vio_dbg1_reg, *vio_dbg2_reg;
> > + const struct mtk_infra_vio_dbg_desc *vio_dbgs;
> > + struct mtk_devapc_vio_info *vio_info;
> > + u32 dbg0;
> > +
> > + if (slave_type >= slave_type_num) {
>
> Ditto.

Indeed, thanks

>
> Regards,
> Chun-Kuang.
>
> > + pr_err(PFX "%s: param check failed, %s:0x%x\n",
> > + __func__, "slave_type", slave_type);
> > + return;
> > + }
> > +
> > + vio_dbg0_reg = mtk_devapc_pd_get(slave_type, VIO_DBG0, 0);
> > + vio_dbg1_reg = mtk_devapc_pd_get(slave_type, VIO_DBG1, 0);
> > + vio_dbg2_reg = mtk_devapc_pd_get(slave_type, VIO_DBG2, 0);
> > +
> > + vio_dbgs = mtk_devapc_ctx->soc->vio_dbgs;
> > + vio_info = mtk_devapc_ctx->soc->vio_info;
> > +
> > + /* Extract violation information */
> > + dbg0 = readl(vio_dbg0_reg);
> > + vio_info->master_id = readl(vio_dbg1_reg);
> > + vio_info->vio_addr = readl(vio_dbg2_reg);
> > +
> > + vio_info->domain_id = (dbg0 & vio_dbgs->vio_dbg_dmnid)
> > + >> vio_dbgs->vio_dbg_dmnid_start_bit;
> > + vio_info->write = ((dbg0 & vio_dbgs->vio_dbg_w_vio)
> > + >> vio_dbgs->vio_dbg_w_vio_start_bit) == 1;
> > + vio_info->read = ((dbg0 & vio_dbgs->vio_dbg_r_vio)
> > + >> vio_dbgs->vio_dbg_r_vio_start_bit) == 1;
> > + vio_info->vio_addr_high = (dbg0 & vio_dbgs->vio_addr_high)
> > + >> vio_dbgs->vio_addr_high_start_bit;
> > +
> > + devapc_vio_info_print();
> > +}
> > +
> > +/*