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

Chun-Kuang Hu
2020-06-09T16:02:17Z

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>
> ---
> drivers/soc/mediatek/Kconfig | 6 +
> drivers/soc/mediatek/Makefile | 1 +
> drivers/soc/mediatek/devapc/Kconfig | 25 +
> drivers/soc/mediatek/devapc/Makefile | 13 +
> drivers/soc/mediatek/devapc/devapc-mt6873.c | 1733 +++++++++++++++++++++
> drivers/soc/mediatek/devapc/devapc-mt6873.h | 130 ++
> drivers/soc/mediatek/devapc/devapc-mtk-multi-ao.c | 1019 ++++++++++++
> drivers/soc/mediatek/devapc/devapc-mtk-multi-ao.h | 183 +++
> include/linux/soc/mediatek/devapc_public.h | 41 +
> 9 files changed, 3151 insertions(+)
> create mode 100644 drivers/soc/mediatek/devapc/Kconfig
> create mode 100644 drivers/soc/mediatek/devapc/Makefile
> create mode 100644 drivers/soc/mediatek/devapc/devapc-mt6873.c
> create mode 100644 drivers/soc/mediatek/devapc/devapc-mt6873.h
> create mode 100644 drivers/soc/mediatek/devapc/devapc-mtk-multi-ao.c
> create mode 100644 drivers/soc/mediatek/devapc/devapc-mtk-multi-ao.h
> create mode 100644 include/linux/soc/mediatek/devapc_public.h
>
> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> index 2114b56..cc46f50 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -44,4 +44,10 @@ config MTK_SCPSYS
> Say yes here to add support for the MediaTek SCPSYS power domain
> driver.
>
> +menu "Security"
> +
> +source "drivers/soc/mediatek/devapc/Kconfig"
> +
> +endmenu # Security
> +
> endmenu
> diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
> index b017330..7154a2a 100644
> --- a/drivers/soc/mediatek/Makefile
> +++ b/drivers/soc/mediatek/Makefile
> @@ -3,3 +3,4 @@ obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
> obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
> obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
> obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
> +obj-$(CONFIG_MTK_DEVAPC) += devapc/

alphabetic order.

> diff --git a/drivers/soc/mediatek/devapc/Kconfig b/drivers/soc/mediatek/devapc/Kconfig
> new file mode 100644
> index 0000000..9428360
> --- /dev/null
> +++ b/drivers/soc/mediatek/devapc/Kconfig
> @@ -0,0 +1,25 @@
> +config MTK_DEVAPC
> + tristate "Mediatek Device APC Support"
> + help
> + Device APC is a kernel driver controlling internal device security.
> + If someone tries to access a device, which is not allowed by the
> + device, it cannot access the device and will get a violation
> + interrupt. Device APC prevents malicious access to internal devices.
> +
> +config DEVAPC_ARCH_MULTI
> + tristate "Mediatek Device APC driver architecture multi"
> + help
> + Say yes here to enable support Mediatek
> + Device APC driver which is based on Infra
> + architecture.
> + This architecture supports multiple Infra AO.
> +
> +config DEVAPC_MT6873
> + tristate "Mediatek MT6873 Device APC driver"
> + select MTK_DEVAPC
> + select DEVAPC_ARCH_MULTI
> + help
> + Say yes here to enable support Mediatek MT6873
> + Device APC driver.
> + This driver is combined with DEVAPC_ARCH_MULTI for
> + common handle flow.

[snip]

> +static struct mtk_devapc_context {
> + struct clk *devapc_infra_clk;
> + u32 devapc_irq;
> +
> + /* HW reg mapped addr */
> + void __iomem *devapc_pd_base[4];
> + void __iomem *infracfg_base;
> +
> + struct mtk_devapc_soc *soc;
> +} mtk_devapc_ctx[1];
> +
> +static LIST_HEAD(viocb_list);
> +static DEFINE_SPINLOCK(devapc_lock);

Move global variable into struct mtk_devapc_context .

> +
> +/*
> + * mtk_devapc_pd_get - get devapc pd_types of register address.
> + *
> + * Returns the value of reg addr
> + */
> +static void __iomem *mtk_devapc_pd_get(int slave_type,
> + enum DEVAPC_PD_REG_TYPE pd_reg_type,
> + u32 index)
> +{
> + struct mtk_devapc_vio_info *vio_info = mtk_devapc_ctx->soc->vio_info;
> + u32 slave_type_num = mtk_devapc_ctx->soc->slave_type_num;
> + const u32 *devapc_pds = mtk_devapc_ctx->soc->devapc_pds;
> + void __iomem *reg;
> +
> + if (!devapc_pds)
> + return NULL;
> +
> + if ((slave_type < slave_type_num &&
> + index < vio_info->vio_mask_sta_num[slave_type]) &&
> + pd_reg_type < PD_REG_TYPE_NUM) {
> + reg = mtk_devapc_ctx->devapc_pd_base[slave_type] +
> + devapc_pds[pd_reg_type];
> +
> + if (pd_reg_type == VIO_MASK || pd_reg_type == VIO_STA)
> + reg += 0x4 * index;
> +
> + } else {
> + pr_err(PFX "%s:0x%x or %s:0x%x or %s:0x%x is out of boundary\n",
> + "slave_type", slave_type,

Move "slave_type" into format string.

> + "pd_reg_type", pd_reg_type,
> + "index", index);
> + return NULL;
> + }
> +
> + return reg;
> +}
> +

[snip]

> +
> +/*
> + * devapc_violation_irq - the devapc Interrupt Service Routine (ISR) will dump
> + * violation information including which master violates
> + * access slave.
> + */
> +static irqreturn_t devapc_violation_irq(int irq_number, void *dev_id)
> +{
> + u32 slave_type_num = mtk_devapc_ctx->soc->slave_type_num;
> + const struct mtk_device_info **device_info;
> + struct mtk_devapc_vio_info *vio_info;
> + int slave_type, vio_idx, index;
> + const char *vio_master;
> + unsigned long flags;
> + bool normal;
> + u8 perm;
> +
> + spin_lock_irqsave(&devapc_lock, flags);
> +
> + device_info = mtk_devapc_ctx->soc->device_info;
> + vio_info = mtk_devapc_ctx->soc->vio_info;
> + normal = false;
> + vio_idx = -1;
> + index = -1;
> +
> + /* There are multiple DEVAPC_PD */
> + for (slave_type = 0; slave_type < slave_type_num; slave_type++) {
> + if (!check_type2_vio_status(slave_type, &vio_idx, &index))
> + if (!mtk_devapc_dump_vio_dbg(slave_type, &vio_idx,
> + &index))
> + continue;
> +
> + /* Ensure that violation info are written before
> + * further operations
> + */
> + smp_mb();
> + normal = true;
> +
> + mask_module_irq(slave_type, vio_idx, true);
> +
> + if (clear_vio_status(slave_type, vio_idx))
> + pr_warn(PFX "%s, %s:0x%x, %s:0x%x\n",
> + "clear vio status failed",
> + "slave_type", slave_type,
> + "vio_index", vio_idx);
> +
> + perm = get_permission(slave_type, index, vio_info->domain_id);
> +
> + vio_master = mtk_devapc_ctx->soc->master_get
> + (vio_info->master_id,
> + vio_info->vio_addr,
> + slave_type,
> + vio_info->shift_sta_bit,
> + vio_info->domain_id);

Call mt6873_bus_id_to_master() directly. For first patch, make things
as simple as possible.

> +
> + if (!vio_master) {
> + pr_warn(PFX "master_get failed\n");
> + vio_master = "UNKNOWN_MASTER";
> + }
> +
> + pr_info(PFX "%s - %s:0x%x, %s:0x%x, %s:0x%x, %s:0x%x\n",
> + "Violation", "slave_type", slave_type,
> + "sys_index",
> + device_info[slave_type][index].sys_index,
> + "ctrl_index",
> + device_info[slave_type][index].ctrl_index,
> + "vio_index",
> + device_info[slave_type][index].vio_index);
> +
> + pr_info(PFX "%s %s %s %s\n",
> + "Violation - master:", vio_master,
> + "access violation slave:",
> + device_info[slave_type][index].device);
> +
> + devapc_vio_reason(perm);
> +
> + devapc_extra_handler(slave_type, vio_master, vio_idx,
> + vio_info->vio_addr);
> +
> + mask_module_irq(slave_type, vio_idx, false);
> + }
> +
> + if (normal) {
> + spin_unlock_irqrestore(&devapc_lock, flags);
> + return IRQ_HANDLED;
> + }
> +
> + spin_unlock_irqrestore(&devapc_lock, flags);
> + return IRQ_HANDLED;
> +}
> +

[snip]

> +uint32_t devapc_vio_check(void);
> +void dump_dbg_info(void);
> +void register_devapc_vio_callback(struct devapc_vio_callbacks *viocb);
> +void devapc_catch_illegal_range(phys_addr_t phys_addr, size_t size);

devapc_catch_illegal_range() is useless, so remove it.

Regards,
Chun-Kuang.

> +
> +#endif /* __DEVAPC_PUBLIC_H__ */
> +
> --
> 1.7.9.5
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