Re: [PATCH 2/2] soc: mediatek: devapc: add devapc-mt6779 driver

Matthias Brugger
2020-07-06T11:29:07Z

CC linux-mediatek

Please you ./scripts/get_maintainers.pl to find out to whom you should send the
series.

On 06/07/2020 11:28, Neal Liu wrote:
> MT6779 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-mt6779 driver. The violation
> information is printed in order to find the murderer.
>

Please describe in more detail how this HW works.

> Signed-off-by: Neal Liu <neal.liu@mediatek.com>
> ---

copying my comments from the last revision, which weren't answered and are not
addressed here. If you are not OK with my sugguestions, no problem but please
provide your arguments so that we can come up with a solution. Otherwise you are
just wasting your and my time:

Please review your data structures and try to group the information in logical
structs. For example I don't understand why we need mtk_devapc_context. It seems
to me that all the values in there are SoC specific.

Why void __iomem *devapc_pd_base isn't part of the device_info?

> drivers/soc/mediatek/Kconfig | 6 +
> drivers/soc/mediatek/Makefile | 1 +
> drivers/soc/mediatek/devapc/Kconfig | 17 +
> drivers/soc/mediatek/devapc/Makefile | 10 +
> drivers/soc/mediatek/devapc/devapc-mt6779.c | 1111 +++++++++++++++++++++++++++

From the answers of the last revision it seems that this driver will be used for
more then one SoC. So we should not name it devapc-mt6779.c but for example
mtk-devapc.c.

By the way, what does the devapc stands for? It's not clear from the commit
message nor from the binding description.

> drivers/soc/mediatek/devapc/devapc-mt6779.h | 99 +++
> 6 files changed, 1244 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-mt6779.c
> create mode 100644 drivers/soc/mediatek/devapc/devapc-mt6779.h
>
> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> index 59a56cd..2c9ad1f 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -51,4 +51,10 @@ config MTK_MMSYS
> Say yes here to add support for the MediaTek Multimedia
> Subsystem (MMSYS).
>
> +menu "Security"
> +
> +source "drivers/soc/mediatek/devapc/Kconfig"
> +
> +endmenu # Security
> +
> endmenu
> diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
> index 01f9f87..d6717a81 100644
> --- a/drivers/soc/mediatek/Makefile
> +++ b/drivers/soc/mediatek/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
> +obj-$(CONFIG_MTK_DEVAPC) += devapc/

Why do we need a new folder for the driver?

> obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
> obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
> obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
> diff --git a/drivers/soc/mediatek/devapc/Kconfig b/drivers/soc/mediatek/devapc/Kconfig
> new file mode 100644
> index 0000000..b0f7d0e
> --- /dev/null
> +++ b/drivers/soc/mediatek/devapc/Kconfig
> @@ -0,0 +1,17 @@
> +config MTK_DEVAPC
> + tristate "Mediatek Device APC Support"
> + help
> + Device APC is a HW IP controlling internal device security.
> + MediaTek bus frabric provides TrustZone security support and data
> + protection to prevent slaves from being accessed by unexpected
> + bus masters.
> + Device APC prevents malicious access to internal devices.
> +
> +config DEVAPC_MT6779
> + tristate "Mediatek MT6779 Device APC driver"
> + select MTK_DEVAPC
> + help
> + Say yes here to enable support Mediatek MT6779 Device APC driver.
> + This driver mainly used to handle the violation with 1 DEVAPC AO/PDs.
> + The violation information are logged for further analysis or
> + countermeasures.
> diff --git a/drivers/soc/mediatek/devapc/Makefile b/drivers/soc/mediatek/devapc/Makefile
> new file mode 100644
> index 0000000..0336c1d
> --- /dev/null
> +++ b/drivers/soc/mediatek/devapc/Makefile
> @@ -0,0 +1,10 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +ifeq ($(CONFIG_MTK_GCOV_KERNEL),y)
> +GCOV_PROFILE := y
> +endif
> +
> +obj-$(CONFIG_MTK_DEVAPC) := devapc.o
> +
> +# Platform
> +devapc-$(CONFIG_DEVAPC_MT6779) += devapc-mt6779.o
> diff --git a/drivers/soc/mediatek/devapc/devapc-mt6779.c b/drivers/soc/mediatek/devapc/devapc-mt6779.c
> new file mode 100644
> index 0000000..a28b9f3
> --- /dev/null
> +++ b/drivers/soc/mediatek/devapc/devapc-mt6779.c
> @@ -0,0 +1,1111 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 MediaTek Inc.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
> +
> +#include "devapc-mt6779.h"
> +
> +static struct mtk_device_info mt6779_devices_infra[] = {

Looks like a candidate to put into the *.h file.

> + /* sys_idx, ctrl_idx, vio_idx */
> + /* 0 */
> + {0, 0, 0},
> + {0, 1, 1},
> + {0, 2, 2},
> + {0, 3, 3},
> + {0, 4, 4},
> + {0, 5, 5},
> + {0, 6, 6},
> + {0, 7, 7},
> + {0, 8, 8},
> + {0, 9, 9},
> +
> + /* 10 */
> + {0, 10, 10},
> + {0, 11, 11},
> + {0, 12, 12},
> + {0, 13, 13},
> + {0, 14, 14},
> + {0, 15, 15},
> + {0, 16, 16},
> + {0, 17, 17},
> + {0, 18, 18},
> + {0, 19, 19},
> +
> + /* 20 */
> + {0, 20, 20},
> + {0, 21, 21},
> + {0, 22, 22},
> + {0, 23, 23},
> + {0, 24, 24},
> + {0, 25, 25},
> + {0, 26, 26},
> + {0, 27, 27},
> + {0, 28, 28},
> + {0, 29, 29},
> +
> + /* 30 */
> + {0, 30, 30},
> + {0, 31, 31},
> + {0, 32, 32},
> + {0, 33, 77},
> + {0, 34, 78},
> + {0, 35, 79},
> + {0, 35, 80},
> + {0, 37, 37},
> + {0, 38, 38},
> + {0, 39, 39},
> +
> + /* 40 */
> + {0, 40, 40},
> + {0, 41, 41},
> + {0, 42, 42},
> + {0, 43, 43},
> + {0, 44, 44},
> + {0, 45, 45},
> + {0, 46, 46},
> + {0, 47, 47},
> + {0, 48, 48},
> + {0, 49, 49},
> +
> + /* 50 */
> + {0, 50, 50},
> + {0, 51, 51},
> + {0, 52, 52},
> + {0, 53, 53},
> + {0, 54, 54},
> + {0, 55, 55},
> + {0, 56, 56},
> + {0, 57, 57},
> + {0, 58, 58},
> + {0, 59, 59},
> +
> + /* 60 */
> + {0, 60, 60},
> + {0, 61, 61},
> + {0, 62, 62},
> + {0, 63, 63},
> + {0, 64, 64},
> + {0, 65, 70},
> + {0, 66, 71},
> + {0, 67, 72},
> + {0, 68, 73},
> + {0, 70, 81},
> +
> + /* 70 */
> + {0, 71, 82},
> + {0, 72, 83},
> + {0, 73, 84},
> + {0, 74, 85},
> + {0, 75, 86},
> + {0, 76, 87},
> + {0, 77, 88},
> + {0, 78, 89},
> + {0, 79, 90},
> + {0, 80, 91},
> +
> + /* 80 */
> + {0, 81, 92},
> + {0, 82, 93},
> + {0, 83, 94},
> + {0, 84, 95},
> + {0, 85, 96},
> + {0, 86, 97},
> + {0, 87, 98},
> + {0, 88, 99},
> + {0, 89, 100},
> + {0, 90, 101},
> +
> + /* 90 */
> + {0, 91, 102},
> + {0, 92, 103},
> + {0, 93, 104},
> + {0, 94, 105},
> + {0, 95, 106},
> + {0, 96, 107},
> + {0, 97, 108},
> + {0, 98, 109},
> + {0, 110, 110},
> + {0, 111, 111},
> +
> + /* 100 */

Comments maybe not needed, at least of added, they should represent the code.

> + {0, 112, 112},
> + {0, 113, 113},
> + {0, 114, 114},
> + {0, 115, 115},
> + {0, 116, 116},
> + {0, 117, 117},
> + {0, 118, 118},
> + {0, 119, 119},
> + {0, 120, 120},
> + {0, 121, 121},
> +
> + /* 110 */
> + {0, 122, 122},
> + {0, 123, 123},
> + {0, 124, 124},
> + {0, 125, 125},
> + {0, 126, 126},
> + {0, 127, 127},
> + {0, 128, 128},
> + {0, 129, 129},
> + {0, 130, 130},
> + {0, 131, 131},
> +
> + /* 120 */
> + {0, 132, 132},
> + {0, 133, 133},
> + {0, 134, 134},
> + {0, 135, 135},
> + {0, 136, 136},
> + {0, 137, 137},
> + {0, 138, 138},
> + {0, 139, 139},
> + {0, 140, 140},
> + {0, 141, 141},
> +
> + /* 130 */
> + {0, 142, 142},
> + {0, 143, 143},
> + {0, 144, 144},
> + {0, 145, 145},
> + {0, 146, 146},
> + {0, 147, 147},
> + {0, 148, 148},
> + {0, 149, 149},
> + {0, 150, 150},
> + {0, 151, 151},
> +
> + /* 140 */
> + {0, 152, 152},
> + {0, 153, 153},
> + {0, 154, 154},
> + {0, 155, 155},
> + {0, 156, 156},
> + {0, 157, 157},
> + {0, 158, 158},
> + {0, 159, 159},
> + {0, 160, 160},
> + {0, 161, 161},
> +
> + /* 150 */
> + {0, 162, 162},
> + {0, 163, 163},
> + {0, 164, 164},
> + {0, 165, 165},
> + {0, 166, 166},
> + {0, 167, 167},
> + {0, 168, 168},
> + {0, 169, 169},
> + {0, 170, 170},
> + {0, 171, 171},
> +
> + /* 160 */
> + {0, 172, 172},
> + {0, 173, 173},
> + {0, 174, 174},
> + {0, 175, 175},
> + {0, 176, 176},
> + {0, 177, 177},
> + {0, 178, 178},
> + {0, 179, 179},
> + {0, 180, 180},
> + {0, 181, 181},
> +
> + /* 170 */
> + {0, 182, 182},
> + {0, 183, 183},
> + {0, 184, 184},
> + {0, 185, 185},
> + {0, 186, 186},
> + {0, 187, 187},
> + {0, 188, 188},
> + {0, 189, 189},
> + {0, 190, 190},
> + {0, 191, 191},
> +
> + /* 180 */
> + {0, 192, 192},
> + {0, 193, 193},
> + {0, 194, 194},
> + {0, 195, 195},
> + {0, 196, 196},
> + {0, 197, 197},
> + {0, 198, 198},
> + {0, 199, 199},
> + {0, 200, 200},
> + {0, 201, 201},
> +
> + /* 190 */
> + {0, 202, 202},
> + {0, 203, 203},
> + {0, 204, 204},
> + {0, 205, 205},
> + {0, 206, 206},
> + {0, 207, 207},
> + {0, 208, 208},
> + {0, 209, 209},
> + {0, 210, 210},
> + {0, 211, 211},
> +
> + /* 200 */
> + {0, 212, 212},
> + {0, 213, 213},
> + {0, 214, 214},
> + {0, 215, 215},
> + {0, 216, 216},
> + {0, 217, 217},
> + {0, 218, 218},
> + {0, 219, 219},
> + {0, 220, 220},
> + {0, 221, 221},
> +
> + /* 210 */
> + {0, 222, 222},
> + {0, 223, 223},
> + {0, 224, 224},
> + {0, 225, 225},
> + {0, 226, 226},
> + {0, 227, 227},
> + {0, 228, 228},
> + {0, 229, 229},
> + {0, 230, 230},
> + {0, 231, 231},
> +
> + /* 220 */
> + {1, 0, 232},
> + {1, 1, 233},
> + {1, 2, 234},
> + {1, 3, 235},
> + {1, 4, 236},
> + {1, 5, 237},
> + {1, 6, 238},
> + {1, 7, 239},
> + {1, 8, 240},
> + {1, 9, 241},
> +
> + /* 230 */
> + {1, 10, 242},
> + {1, 11, 243},
> + {1, 12, 244},
> + {1, 13, 245},
> + {1, 14, 246},
> + {1, 15, 247},
> + {1, 16, 248},
> + {1, 17, 249},
> + {1, 18, 250},
> + {1, 19, 251},
> +
> + /* 240 */
> + {1, 20, 252},
> + {1, 21, 253},
> + {1, 22, 254},
> + {1, 23, 255},
> + {1, 24, 256},
> + {1, 25, 257},
> + {1, 26, 258},
> + {1, 27, 259},
> + {1, 28, 260},
> + {1, 29, 261},
> +
> + /* 250 */
> + {1, 30, 262},
> + {1, 31, 263},
> + {1, 32, 264},
> + {1, 33, 265},
> + {1, 34, 266},
> + {1, 35, 267},
> + {1, 36, 268},
> + {1, 37, 269},
> + {1, 38, 270},
> + {1, 39, 271},
> +
> + /* 260 */
> + {1, 40, 272},
> + {1, 41, 273},
> + {1, 42, 274},
> + {1, 43, 275},
> + {1, 44, 276},
> + {1, 45, 277},
> + {1, 46, 278},
> + {1, 47, 279},
> + {1, 48, 280},
> + {1, 49, 281},
> +
> + /* 270 */
> + {1, 50, 282},
> + {1, 51, 283},
> + {1, 52, 284},
> + {1, 53, 285},
> + {1, 54, 286},
> + {1, 55, 287},
> + {1, 56, 288},
> + {1, 57, 289},
> + {1, 58, 290},
> + {1, 59, 291},
> +
> + /* 280 */
> + {1, 60, 292},
> + {1, 61, 293},
> + {1, 62, 294},
> + {1, 63, 295},
> + {1, 64, 296},
> + {1, 65, 297},
> + {1, 66, 298},
> + {1, 67, 299},
> + {1, 68, 300},
> + {1, 69, 301},
> +
> + /* 290 */
> + {1, 70, 302},
> + {1, 71, 303},
> + {1, 72, 304},
> + {1, 73, 305},
> + {1, 74, 306},
> + {1, 75, 307},
> + {1, 76, 308},
> + {1, 77, 309},
> + {1, 78, 310},
> + {1, 79, 311},
> +
> + /* 300 */
> + {1, 80, 312},
> + {1, 81, 313},
> + {1, 82, 314},
> + {1, 83, 315},
> + {1, 84, 316},
> + {1, 85, 317},
> + {1, 86, 318},
> + {1, 87, 319},
> + {1, 88, 320},
> + {1, 89, 321},
> +
> + /* 310 */
> + {1, 90, 322},
> + {1, 91, 323},
> + {1, 92, 324},
> + {1, 93, 325},
> + {1, 94, 326},
> + {1, 95, 327},
> + {1, 96, 328},
> + {1, 97, 329},
> + {1, 98, 330},
> + {1, 99, 331},
> +
> + /* 320 */
> + {1, 100, 332},
> + {1, 101, 333},
> + {1, 102, 334},
> + {1, 103, 335},
> + {1, 104, 336},
> + {1, 105, 337},
> + {1, 106, 338},
> + {1, 107, 339},
> + {1, 108, 340},
> + {1, 109, 341},
> +
> + /* 330 */
> + {1, 110, 342},
> + {1, 111, 343},
> + {1, 112, 344},
> + {1, 113, 345},
> + {1, 114, 346},
> + {1, 115, 347},
> + {1, 116, 348},
> + {1, 117, 349},
> + {1, 118, 350},
> + {1, 119, 351},
> +
> + /* 340 */
> + {1, 120, 352},
> + {1, 121, 353},
> + {1, 122, 354},
> + {1, 123, 355},
> + {1, 124, 356},
> + {1, 125, 357},
> + {1, 126, 358},
> + {1, 127, 359},
> + {1, 128, 360},
> + {1, 129, 361},
> +
> + /* 350 */
> + {1, 130, 362},
> + {1, 131, 363},
> + {1, 132, 364},
> + {1, 133, 365},
> + {1, 134, 366},
> + {1, 135, 367},
> + {1, 136, 368},
> + {1, 137, 369},
> + {1, 138, 370},
> + {1, 139, 371},
> +
> + /* 360 */
> + {1, 140, 372},
> + {1, 141, 373},
> + {1, 142, 374},
> + {1, 143, 375},
> + {1, 144, 376},
> + {1, 145, 377},
> + {1, 146, 378},
> + {1, 147, 379},
> + {1, 148, 380},
> + {1, 149, 381},
> +
> + /* 370 */
> + {1, 150, 382},
> + {1, 151, 383},
> + {1, 152, 384},
> + {1, 153, 385},
> + {1, 154, 386},
> + {1, 155, 387},
> + {1, 156, 388},
> + {1, 157, 389},
> + {1, 158, 390},
> + {1, 159, 391},
> +
> + /* 380 */
> + {1, 160, 392},
> + {1, 161, 393},
> + {1, 162, 394},
> + {1, 163, 395},
> + {1, 164, 396},
> + {1, 165, 397},
> + {1, 166, 398},
> + {1, 167, 399},
> + {1, 168, 400},
> + {1, 169, 401},
> +
> + /* 390 */
> + {1, 170, 402},
> + {1, 171, 403},
> + {1, 172, 404},
> + {1, 173, 405},
> + {1, 174, 406},
> + {1, 175, 407},
> + {1, 176, 408},
> + {1, 177, 409},
> + {1, 178, 410},
> + {1, 179, 411},
> +
> + /* 400 */
> + {1, 180, 412},
> + {1, 181, 413},
> + {1, 182, 414},
> + {1, 183, 415},
> + {1, 184, 416},
> + {1, 185, 417},
> + {1, 186, 418},
> + {1, 187, 419},
> + {1, 188, 420},
> + {1, 189, 421},
> +
> + /* 410 */
> + {1, 190, 422},
> + {1, 191, 423},
> + {1, 192, 424},
> + {1, 193, 425},
> + {1, 194, 426},
> + {1, 195, 427},
> + {1, 196, 428},
> + {1, 197, 429},
> + {1, 198, 430},
> + {1, 199, 431},
> +
> + /* 420 */
> + {1, 200, 432},
> + {1, 201, 433},
> + {1, 202, 434},
> + {1, 203, 435},
> + {1, 204, 436},
> + {1, 205, 437},
> + {1, 206, 438},
> + {1, 207, 439},
> + {1, 208, 440},
> + {1, 209, 441},
> +
> + /* 430 */
> + {1, 210, 442},
> + {1, 211, 443},
> + {1, 212, 444},
> + {1, 213, 445},
> + {1, 214, 446},
> + {1, 215, 447},
> + {1, 216, 448},
> + {1, 217, 449},
> + {1, 218, 450},
> + {1, 219, 451},
> +
> + /* 440 */
> + {1, 220, 452},
> + {1, 221, 453},
> + {1, 222, 454},
> + {1, 223, 455},
> + {1, 224, 456},
> + {1, 225, 457},
> + {1, 226, 458},
> + {1, 227, 459},
> + {1, 228, 460},
> + {1, 229, 461},
> +
> + /* 450 */
> + {1, 230, 462},
> + {1, 231, 463},
> + {1, 232, 464},
> + {1, 233, 465},
> + {1, 234, 466},
> + {1, 235, 467},
> + {1, 236, 468},
> + {1, 237, 469},
> + {1, 238, 470},
> + {1, 239, 471},
> +
> + /* 460 */
> + {1, 240, 472},
> + {1, 241, 473},
> + {1, 242, 474},
> + {1, 243, 475},
> + {1, 244, 476},
> + {1, 245, 477},
> + {1, 246, 478},
> + {-1, -1, 479},
> + {-1, -1, 480},
> + {-1, -1, 481},
> +
> + /* 470 */
> + {-1, -1, 482},
> + {-1, -1, 483},
> + {-1, -1, 484},
> + {-1, -1, 485},
> + {-1, -1, 486},
> + {-1, -1, 487},
> + {-1, -1, 488},
> + {-1, -1, 489},
> + {-1, -1, 490},
> + {-1, -1, 491},
> +
> + /* 480 */
> + {-1, -1, 492},
> + {-1, -1, 493},
> + {-1, -1, 494},
> + {-1, -1, 495},
> + {-1, -1, 496},
> + {-1, -1, 497},
> + {-1, -1, 498},
> + {-1, -1, 499},
> + {-1, -1, 500},
> + {-1, -1, 501},
> +
> + /* 490 */
> + {-1, -1, 502},
> + {-1, -1, 503},
> + {-1, -1, 504},
> + {-1, -1, 505},
> + {-1, -1, 506},
> + {-1, -1, 507},
> + {-1, -1, 508},
> + {-1, -1, 509},
> + {-1, -1, 510},
> +
> +};
> +
> +static struct mtk_device_num mtk6779_devices_num[] = {
> + {SLAVE_TYPE_INFRA, VIO_SLAVE_NUM_INFRA},
> +};
> +
> +static int mtk_vio_mask_sta_num[] = {
> + VIO_MASK_STA_NUM_INFRA,
> +};
> +
> +static const struct mtk_infra_vio_dbg_desc mt6779_vio_dbgs = {
> + .vio_dbg_mstid = INFRA_VIO_DBG_MSTID,
> + .vio_dbg_mstid_start_bit = INFRA_VIO_DBG_MSTID_START_BIT,
> + .vio_dbg_dmnid = INFRA_VIO_DBG_DMNID,
> + .vio_dbg_dmnid_start_bit = INFRA_VIO_DBG_DMNID_START_BIT,
> + .vio_dbg_w_vio = INFRA_VIO_DBG_W_VIO,
> + .vio_dbg_w_vio_start_bit = INFRA_VIO_DBG_W_VIO_START_BIT,
> + .vio_dbg_r_vio = INFRA_VIO_DBG_R_VIO,
> + .vio_dbg_r_vio_start_bit = INFRA_VIO_DBG_R_VIO_START_BIT,
> + .vio_addr_high = INFRA_VIO_ADDR_HIGH,
> + .vio_addr_high_start_bit = INFRA_VIO_ADDR_HIGH_START_BIT,
> +};
> +
> +static const u32 mt6779_devapc_pds[] = {
> + PD_VIO_MASK_OFFSET,
> + PD_VIO_STA_OFFSET,
> + PD_VIO_DBG0_OFFSET,
> + PD_VIO_DBG1_OFFSET,
> + PD_APC_CON_OFFSET,
> + PD_SHIFT_STA_OFFSET,
> + PD_SHIFT_SEL_OFFSET,
> + PD_SHIFT_CON_OFFSET,
> +};
> +
> +static u32 mt6779_shift_group_get(u32 vio_idx)
> +{
> + if (vio_idx >= 0 && vio_idx <= 32)
> + return 0;
> + else if (vio_idx >= 33 && vio_idx <= 109)
> + return 1;
> + else if ((vio_idx >= 110 && vio_idx <= 121) ||
> + (vio_idx >= 470 && vio_idx <= 472))
> + return 2;
> + else if (vio_idx == 122 || vio_idx == 500)
> + return 3;
> + else if (vio_idx == 123)
> + return 4;
> + else if (vio_idx == 124)
> + return 5;
> + else if ((vio_idx >= 125 && vio_idx <= 155) ||
> + (vio_idx >= 486 && vio_idx <= 488))
> + return 6;
> + else if ((vio_idx >= 156 && vio_idx <= 157) ||
> + (vio_idx >= 159 && vio_idx <= 165))
> + return 7;
> + else if ((vio_idx >= 166 && vio_idx <= 181) ||
> + (vio_idx >= 473 && vio_idx <= 475))
> + return 8;
> + else if ((vio_idx >= 182 && vio_idx <= 197) ||
> + (vio_idx >= 476 && vio_idx <= 478))
> + return 9;
> + else if ((vio_idx >= 198 && vio_idx <= 205) ||
> + (vio_idx >= 479 && vio_idx <= 481))
> + return 10;
> + else if ((vio_idx >= 214 && vio_idx <= 229) ||
> + (vio_idx >= 482 && vio_idx <= 484))
> + return 11;
> + else if (vio_idx == 230)
> + return 12;
> + else if (vio_idx == 158)
> + return 13;
> + else if (vio_idx == 231 || vio_idx == 382)
> + return 14;
> + else if (vio_idx >= 232 && vio_idx <= 244)
> + return 15;
> + else if (vio_idx >= 245 && vio_idx <= 478)
> + return 16;
> + else if (vio_idx >= 504 && vio_idx <= 505)
> + return 17;
> + else if (vio_idx == 494)
> + return 18;
> + else if (vio_idx == 503)
> + return 19;
> + else if (vio_idx == 501)
> + return 20;
> + else if (vio_idx == 502)
> + return 21;
> + else if (vio_idx == 506)
> + return 22;
> + else if (vio_idx == 507)
> + return 23;
> + else if (vio_idx == 508)
> + return 24;
> + else if ((vio_idx >= 206 && vio_idx <= 213) ||
> + (vio_idx >= 498 && vio_idx <= 500))
> + return 25;
> +
> + return 31;
> +}
> +
> +/*
> + * mtk_devapc_pd_get - get devapc pd_types of register address.
> + *
> + * Returns the value of reg addr
> + */
> +static void __iomem *mtk_devapc_pd_get(struct mtk_devapc_context *devapc_ctx,
> + int slave_type,
> + enum DEVAPC_PD_REG_TYPE pd_reg_type,
> + u32 index)
> +{
> + const u32 *devapc_pds = mt6779_devapc_pds;
> + void __iomem *reg;
> +
> + reg = 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;
> +
> + return reg;
> +}
> +
> +static int check_vio_mask_sta(struct mtk_devapc_context *devapc_ctx,
> + int slave_type, u32 module, int pd_reg_type)
> +{
> + u32 apc_register_index, apc_set_index;
> + void __iomem *reg;
> + u32 value;
> +
> + apc_register_index = module / (MOD_NM_IN_1_DEVAPC * 2);
> + apc_set_index = module % (MOD_NM_IN_1_DEVAPC * 2);
> +
> + if (apc_register_index < mtk_vio_mask_sta_num[slave_type])
> + reg = mtk_devapc_pd_get(devapc_ctx, slave_type, pd_reg_type,
> + apc_register_index);
> + else
> + return -EOVERFLOW;

How could that happen?

> +
> + value = (readl(reg) & (0x1 << apc_set_index)) >> apc_set_index;
> +
> + return value;

value = readl(reg);
return ((value >> apc_set_index) & 0x1);

> +}
> +
> +static int check_vio_mask(struct mtk_devapc_context *devapc_ctx, int slave_type,
> + u32 module)
> +{
> + return check_vio_mask_sta(devapc_ctx, slave_type, module, VIO_MASK);
> +}
> +
> +static int check_vio_status(struct mtk_devapc_context *devapc_ctx,
> + int slave_type, u32 module)
> +{
> + return check_vio_mask_sta(devapc_ctx, slave_type, module, VIO_STA);
> +}
> +
> +static void clear_vio_status(struct mtk_devapc_context *devapc_ctx,
> + int slave_type, u32 module)
> +{
> + u32 apc_register_index, apc_set_index;
> + void __iomem *reg;
> +
> + apc_register_index = module / (MOD_NM_IN_1_DEVAPC * 2);
> + apc_set_index = module % (MOD_NM_IN_1_DEVAPC * 2);

What does MOD_NM_IN_1_DEVAPC stands for? Why do you define it with 16 when
afterwards you only use it with value 32? Do I understand correctly that this
calculates the register offset and bit in the register to write to?

> +
> + if (apc_register_index < mtk_vio_mask_sta_num[slave_type]) {

mtk_vio_mask_sta_num[slave_type] == maximum of registers that can be accessed?

> + reg = mtk_devapc_pd_get(devapc_ctx, slave_type, VIO_STA,
> + apc_register_index);
> + writel(0x1 << apc_set_index, reg);
> +
> + } else {
> + pr_err(PFX "%s: Out Of Boundary, slave_type:0x%x, module_index:0x%x\n",
> + __func__, slave_type, module);

Only used internally by the driver, why can't we suppose that the driver does
not implement module number outside of the accessible registers? I think this
can be dropped.

> + return;
> + }
> +
> + if (check_vio_status(devapc_ctx, slave_type, module))
> + pr_err(PFX "%s: Clear failed, slave_type:0x%x, module_index:0x%x\n",
> + __func__, slave_type, module);
> +}
> +
> +static void mask_module_irq(struct mtk_devapc_context *devapc_ctx,
> + int slave_type, u32 module, bool mask)
> +{
> + u32 apc_register_index, apc_set_index;
> + void __iomem *reg;
> +
> + apc_register_index = module / (MOD_NM_IN_1_DEVAPC * 2);
> + apc_set_index = module % (MOD_NM_IN_1_DEVAPC * 2);

Better add a macro for this and rename set_index into register_offset?

> +
> + if (apc_register_index < mtk_vio_mask_sta_num[slave_type]) {
> + reg = mtk_devapc_pd_get(devapc_ctx, slave_type, VIO_MASK,
> + apc_register_index);

I don't like this code all over the place, could add the correct offset to
mtk_device_info and just add it in readl/writel directly?

> +
> + if (mask)
> + writel(readl(reg) | (1 << apc_set_index), reg);
> + else
> + writel(readl(reg) & (~(1 << apc_set_index)), reg);

value = readl(reg);

if (mask)
value |= (0x1 << apc_set_index);
else
value &= ~(0x1 << apc_set_index);

writel(value);

> +
> + } else {
> + pr_err(PFX "%s: Out Of Boundary, slave_type:0x%x, module_index:0x%x, mask:%s\n",
> + __func__, slave_type, module, mask ? "true" : "false");
> + }
> +}
> +
> +/*
> + * sync_vio_dbg - start to get violation information by selecting violation
> + * group and enable violation shift.
> + *
> + * Returns sync done or not
> + */
> +static u32 sync_vio_dbg(struct mtk_devapc_context *devapc_ctx, int slave_type,
> + u32 shift_bit)
> +{
> + void __iomem *pd_vio_shift_sta_reg;
> + void __iomem *pd_vio_shift_sel_reg;
> + void __iomem *pd_vio_shift_con_reg;
> + u32 shift_count;
> + u32 sync_done;
> +
> + pd_vio_shift_sta_reg = mtk_devapc_pd_get(devapc_ctx, slave_type,
> + VIO_SHIFT_STA, 0);
> + pd_vio_shift_sel_reg = mtk_devapc_pd_get(devapc_ctx, slave_type,
> + VIO_SHIFT_SEL, 0);
> + pd_vio_shift_con_reg = mtk_devapc_pd_get(devapc_ctx, slave_type,
> + VIO_SHIFT_CON, 0);
> +
> + writel(0x1 << shift_bit, pd_vio_shift_sel_reg);
> + writel(0x1, pd_vio_shift_con_reg);
> +
> + for (shift_count = 0; (shift_count < 100) &&
> + ((readl(pd_vio_shift_con_reg) & 0x3) != 0x3);
> + ++shift_count)

Use read_poll_timeout here, we don't want to depend on the time 100 reads need,
as from my understanding this depends on the (dynamic) clock frequency.

> + ;
> +
> + if ((readl(pd_vio_shift_con_reg) & 0x3) == 0x3)

We can read the value via readl_poll_timeout. No need to read it again here.

> + sync_done = 1;
> + else
> + sync_done = 0;
> +
> + /* Disable shift mechanism */

What is the "shift mechanism"?

> + writel(0x0, pd_vio_shift_con_reg);
> + writel(0x0, pd_vio_shift_sel_reg);
> + writel(0x1 << shift_bit, pd_vio_shift_sta_reg);
> +
> + return sync_done;
> +}
> +
> +static void devapc_vio_info_print(struct mtk_devapc_context *devapc_ctx)
> +{
> + struct mtk_devapc_vio_info *vio_info = devapc_ctx->vio_info;
> +
> + /* Print violation information */
> + if (vio_info->write)
> + pr_info(PFX "Write Violation\n");
> + else if (vio_info->read)
> + pr_info(PFX "Read Violation\n");
> +
> + pr_info(PFX "%s%x, %s%x, %s%x, %s%x\n",
> + "Vio Addr:0x", vio_info->vio_addr,
> + "High:0x", vio_info->vio_addr_high,
> + "Bus ID:0x", vio_info->master_id,
> + "Dom ID:0x", vio_info->domain_id);
> +}
> +
> +static void devapc_extract_vio_dbg(struct mtk_devapc_context *devapc_ctx,
> + int slave_type)
> +{
> + void __iomem *vio_dbg0_reg, *vio_dbg1_reg;
> + const struct mtk_infra_vio_dbg_desc *vio_dbgs;
> + struct mtk_devapc_vio_info *vio_info;
> + u32 dbg0;
> +
> + vio_dbg0_reg = mtk_devapc_pd_get(devapc_ctx, slave_type, VIO_DBG0, 0);
> + vio_dbg1_reg = mtk_devapc_pd_get(devapc_ctx, slave_type, VIO_DBG1, 0);
> +
> + vio_dbgs = &mt6779_vio_dbgs;
> + vio_info = devapc_ctx->vio_info;
> +
> + /* Extract violation information */
> + dbg0 = readl(vio_dbg0_reg);
> + vio_info->vio_addr = readl(vio_dbg1_reg);
> +
> + vio_info->master_id = (dbg0 & vio_dbgs->vio_dbg_mstid) >>
> + vio_dbgs->vio_dbg_mstid_start_bit;
> + 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;

We can have read and write violation at a time?

> + vio_info->vio_addr_high = (dbg0 & vio_dbgs->vio_addr_high) >>
> + vio_dbgs->vio_addr_high_start_bit;
> +
> + devapc_vio_info_print(devapc_ctx);
> +}
> +
> +/*
> + * mtk_devapc_dump_vio_dbg - shift & dump the violation debug information.
> + */
> +static bool mtk_devapc_dump_vio_dbg(struct mtk_devapc_context *devapc_ctx,
> + int slave_type, int *vio_idx, int *index)
> +{
> + const struct mtk_device_info **device_info;
> + const struct mtk_device_num *ndevices;
> + void __iomem *pd_vio_shift_sta_reg;
> + u32 shift_bit;
> + int i;
> +
> + if (!vio_idx)
> + return NULL;
> +
> + device_info = devapc_ctx->device_info;
> + ndevices = mtk6779_devices_num;
> +
> + pd_vio_shift_sta_reg = mtk_devapc_pd_get(devapc_ctx, slave_type,
> + VIO_SHIFT_STA, 0);
> +
> + for (i = 0; i < ndevices[slave_type].vio_slave_num; i++) {
> + *vio_idx = device_info[slave_type][i].vio_index;
> +
> + if (check_vio_mask(devapc_ctx, slave_type, *vio_idx))
> + continue;
> +
> + if (check_vio_status(devapc_ctx, slave_type, *vio_idx) <= 0)
> + continue;
> +
> + shift_bit = mt6779_shift_group_get(*vio_idx);

shift_bit should be part of mtk_device_info data structure.
You can create two macros to define mtk_device_info entries, one which sets the
shift bit to 31 and another one, that allows for setting the bit explicitely.

> +
> + if (!sync_vio_dbg(devapc_ctx, slave_type, shift_bit))
> + continue;
> +
> + devapc_extract_vio_dbg(devapc_ctx, slave_type);
> + *index = i;
> +
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/*
> + * 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,
> + struct mtk_devapc_context *devapc_ctx)
> +{
> + const struct mtk_device_info **device_info = devapc_ctx->device_info;
> + int vio_idx = -1;
> + int index = -1;
> + int slave_type;
> +
> + for (slave_type = 0; slave_type < SLAVE_TYPE_NUM; slave_type++) {
> + if (!mtk_devapc_dump_vio_dbg(devapc_ctx, slave_type, &vio_idx,
> + &index))
> + continue;
> +
> + /* Ensure that violation info are written before
> + * further operations
> + */
> + smp_mb();
> +
> + mask_module_irq(devapc_ctx, slave_type, vio_idx, true);
> +
> + clear_vio_status(devapc_ctx, slave_type, vio_idx);
> +
> + pr_info(PFX "Violation - slave_type:0x%x, sys_index:0x%x, ctrl_index:0x%x, vio_index:0x%x\n",
> + slave_type,
> + device_info[slave_type][index].sys_index,
> + device_info[slave_type][index].ctrl_index,
> + device_info[slave_type][index].vio_index);

How will that then be used? Will there some kind of user-space daemon which will
parse the kernel log to see if a violation happens? What will it do with this
information?

I still don't understand why we need to do that in the kernel instead of in
TF-A. Can you please explain?

> +
> + mask_module_irq(devapc_ctx, slave_type, vio_idx, false);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +/*
> + * start_devapc - initialize devapc status and start receiving interrupt
> + * while devapc violation is triggered.
> + */
> +static void start_devapc(struct mtk_devapc_context *devapc_ctx)
> +{
> + const struct mtk_device_info **device_info;
> + const struct mtk_device_num *ndevices;
> + void __iomem *pd_vio_shift_sta_reg;
> + void __iomem *pd_apc_con_reg;
> + int slave_type, vio_idx, i;
> + u32 vio_shift_sta;
> +
> + devapc_ctx->device_info[0] = mt6779_devices_infra;

One element arry should be a simple pointer.
mt6779_devices_infra should be DT data for the mt6779 compatible.

> + device_info = devapc_ctx->device_info;
> + ndevices = mtk6779_devices_num;
> +
> + for (slave_type = 0; slave_type < SLAVE_TYPE_NUM; slave_type++) {

For loop not needed, we ony have one SLAVE_TYPE.

> + pd_apc_con_reg = mtk_devapc_pd_get(devapc_ctx, slave_type,
> + APC_CON, 0);
> + pd_vio_shift_sta_reg = mtk_devapc_pd_get(devapc_ctx, slave_type,
> + VIO_SHIFT_STA, 0);
> +
> + if (!pd_apc_con_reg || !pd_vio_shift_sta_reg)
> + return;
> +
> + /* Clear devapc violation status */
> + writel(BIT(31), pd_apc_con_reg);
> +
> + /* Clear violation shift status */
> + vio_shift_sta = readl(pd_vio_shift_sta_reg);
> + if (vio_shift_sta)
> + writel(vio_shift_sta, pd_vio_shift_sta_reg);
> +
> + /* Clear slave violation status */
> + for (i = 0; i < ndevices[slave_type].vio_slave_num; i++) {
> + vio_idx = device_info[slave_type][i].vio_index;
> +
> + clear_vio_status(devapc_ctx, slave_type, vio_idx);
> +
> + mask_module_irq(devapc_ctx, slave_type, vio_idx, false);
> + }
> + }
> +}
> +
> +static int mt6779_devapc_probe(struct platform_device *pdev)
> +{
> + struct device_node *node = pdev->dev.of_node;
> + struct mtk_devapc_context *devapc_ctx;
> + struct clk *devapc_infra_clk;
> + u32 devapc_irq;
> + int ret;
> +
> + if (IS_ERR(node))
> + return -ENODEV;
> +
> + devapc_ctx = devm_kzalloc(&pdev->dev, sizeof(struct mtk_devapc_context),
> + GFP_KERNEL);
> + if (!devapc_ctx)
> + return -ENOMEM;
> +
> + devapc_ctx->vio_info = devm_kzalloc(&pdev->dev,
> + sizeof(struct mtk_devapc_vio_info),
> + GFP_KERNEL);
> + if (!devapc_ctx->vio_info)
> + return -ENOMEM;
> +
> + devapc_ctx->devapc_pd_base[0] = of_iomap(node, 0);

No array needed, we only have one element...

> + if (!devapc_ctx->devapc_pd_base[0])
> + return -EINVAL;
> +
> + devapc_irq = irq_of_parse_and_map(node, 0);
> + if (!devapc_irq)
> + return -EINVAL;
> +
> + devapc_infra_clk = devm_clk_get(&pdev->dev, "devapc-infra-clock");
> +

No new line here, please check conding style and apply to all the code.

> + if (IS_ERR(devapc_infra_clk))
> + return -EINVAL;
> +
> + if (clk_prepare_enable(devapc_infra_clk))
> + return -EINVAL;
> +
> + start_devapc(devapc_ctx);
> +
> + ret = devm_request_irq(&pdev->dev, devapc_irq,
> + (irq_handler_t)devapc_violation_irq,
> + IRQF_TRIGGER_NONE, "devapc", devapc_ctx);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int mt6779_devapc_remove(struct platform_device *dev)
> +{
> + return 0;
> +}
> +
> +static const struct of_device_id mt6779_devapc_dt_match[] = {
> + { .compatible = "mediatek,mt6779-devapc" },
> + {},
> +};
> +
> +static struct platform_driver mt6779_devapc_driver = {
> + .probe = mt6779_devapc_probe,
> + .remove = mt6779_devapc_remove,
> + .driver = {
> + .name = KBUILD_MODNAME,
> + .of_match_table = mt6779_devapc_dt_match,
> + },
> +};
> +
> +module_platform_driver(mt6779_devapc_driver);
> +
> +MODULE_DESCRIPTION("Mediatek MT6779 Device APC Driver");
> +MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/soc/mediatek/devapc/devapc-mt6779.h b/drivers/soc/mediatek/devapc/devapc-mt6779.h
> new file mode 100644
> index 0000000..8c0e4e7
> --- /dev/null
> +++ b/drivers/soc/mediatek/devapc/devapc-mt6779.h
> @@ -0,0 +1,99 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020 MediaTek Inc.
> + */
> +
> +#ifndef __DEVAPC_MT6779_H__
> +#define __DEVAPC_MT6779_H__
> +
> +#define PFX "[DEVAPC]: "
> +#define MOD_NM_IN_1_DEVAPC 16
> +
> +enum DEVAPC_SLAVE_TYPE {
> + SLAVE_TYPE_INFRA = 0,
> + SLAVE_TYPE_NUM,
> +};
> +
> +enum DEVAPC_PD_REG_TYPE {
> + VIO_MASK = 0,
> + VIO_STA,
> + VIO_DBG0,
> + VIO_DBG1,
> + APC_CON,
> + VIO_SHIFT_STA,
> + VIO_SHIFT_SEL,
> + VIO_SHIFT_CON,
> + PD_REG_TYPE_NUM,
> +};
> +
> +enum DEVAPC_VIO_MASK_STA_NUM {
> + VIO_MASK_STA_NUM_INFRA = 17,

#define instead of enum

> +};
> +
> +enum DEVAPC_VIO_SLAVE_NUM {
> + VIO_SLAVE_NUM_INFRA = 499,

#define instead of enum.

> +};
> +
> +enum DEVAPC_PD_OFFSET {
> + PD_VIO_MASK_OFFSET = 0x0,
> + PD_VIO_STA_OFFSET = 0x400,
> + PD_VIO_DBG0_OFFSET = 0x900,
> + PD_VIO_DBG1_OFFSET = 0x904,
> + PD_APC_CON_OFFSET = 0xF00,
> + PD_SHIFT_STA_OFFSET = 0xF10,
> + PD_SHIFT_SEL_OFFSET = 0xF14,
> + PD_SHIFT_CON_OFFSET = 0xF20,

#define instead of enum
I think this should be part of mtk_device_info on a per SoC base (provided via
DT data).

> +};
> +
> +struct mtk_device_num {
> + int slave_type;
> + u32 vio_slave_num;
> +};
> +
> +struct mtk_devapc_vio_info {
> + bool read;
> + bool write;
> + u32 vio_addr;
> + u32 vio_addr_high;
> + u32 master_id;
> + u32 domain_id;
> +};
> +
> +struct mtk_infra_vio_dbg_desc {
> + u32 vio_dbg_mstid;
> + u8 vio_dbg_mstid_start_bit;
> + u32 vio_dbg_dmnid;
> + u8 vio_dbg_dmnid_start_bit;
> + u32 vio_dbg_w_vio;
> + u8 vio_dbg_w_vio_start_bit;
> + u32 vio_dbg_r_vio;
> + u8 vio_dbg_r_vio_start_bit;
> + u32 vio_addr_high;
> + u8 vio_addr_high_start_bit;
> +};
> +
> +struct mtk_device_info {
> + int sys_index;
> + int ctrl_index;
> + int vio_index;

A quick check showed me that the vio_index == the index in the array. Drop it.

> +};
> +
> +struct mtk_devapc_context {
> + void __iomem *devapc_pd_base[SLAVE_TYPE_NUM];
> + const struct mtk_device_info *device_info[SLAVE_TYPE_NUM];
> + struct mtk_devapc_vio_info *vio_info;
> +};
> +
> +/* For Infra VIO_DBG */
> +#define INFRA_VIO_DBG_MSTID 0x0000FFFF
> +#define INFRA_VIO_DBG_MSTID_START_BIT 0
> +#define INFRA_VIO_DBG_DMNID 0x003F0000
> +#define INFRA_VIO_DBG_DMNID_START_BIT 16
> +#define INFRA_VIO_DBG_W_VIO 0x00400000
> +#define INFRA_VIO_DBG_W_VIO_START_BIT 22
> +#define INFRA_VIO_DBG_R_VIO 0x00800000
> +#define INFRA_VIO_DBG_R_VIO_START_BIT 23
> +#define INFRA_VIO_ADDR_HIGH 0x0F000000
> +#define INFRA_VIO_ADDR_HIGH_START_BIT 24
> +
> +#endif /* __DEVAPC_MT6779_H__ */