On 14/07/2022 04:28, Krzysztof Kozlowski wrote:
> On 13/07/2022 06:55, Dongjin Yang wrote:
> > Introduce a driver to provide calls into secure monitor mode.
> > This driver is used for SoCs produced by Samsung Foundry to provide
> > SMC call. This patch supports register read/write request to secure
> > monitor. Also, SMC call request which uses shared memory to exchange
> > the data between kernel and secure monitor.
> >
> > Signed-off-by: Dongjin Yang <dj76.yang@xxxxxxxxxxx>
> > ---
> > MAINTAINERS | 2 +
> > drivers/firmware/Kconfig | 11 +++
> > drivers/firmware/Makefile | 1 +
> > drivers/firmware/samsung-smc-svc.c | 154 +++++++++++++++++++++++++++++++
> > include/linux/firmware/samsung-smc-svc.h | 59 ++++++++++++
> > 5 files changed, 227 insertions(+)
> > create mode 100644 drivers/firmware/samsung-smc-svc.c
> > create mode 100644 include/linux/firmware/samsung-smc-svc.h
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 6763746c349f..d173043ffb46 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -1868,8 +1868,10 @@ F: arch/arm/boot/dts/artpec6*
> > F: arch/arm/mach-artpec
> > F: drivers/clk/axis
> > F: drivers/crypto/axis
> > +F: drivers/firmware/samsung-smc-svc.c
> > F: drivers/mmc/host/usdhi6rol0.c
> > F: drivers/pinctrl/pinctrl-artpec*
> > +F: include/linux/firmware/samsung-smc-svc.h
>
> Same as for bindings - not related to Artpec platforms. Either add
> dedicated entry or put it under Samsung SoC.
>
This patch is for Artpec8 SoC.
> >
> > ARM/ASPEED I2C DRIVER
> > M: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> > diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> > index e5cfb01353d8..4b0f2d033f58 100644
> > --- a/drivers/firmware/Kconfig
> > +++ b/drivers/firmware/Kconfig
> > @@ -217,6 +217,17 @@ config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
> >
> > Say Y here to enable "download mode" by default.
> >
> > +config SAMSUNG_SECURE_SERVICE
> > + bool "Samsung Foundry Secure Service Layer"
> > + depends on HAVE_ARM_SMCCC
> > + default n
> > + help
> > + Support secure service layer for SoCs which is manufactured by
> > + Samsung Foundry.
> > +
> > + This option provide support of secure monitor service call using
> > + Trusted Foundations.
> > +
> > config SYSFB
> > bool
> > default y
> > diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
> > index 4e58cb474a68..985e30a9665f 100644
> > --- a/drivers/firmware/Makefile
> > +++ b/drivers/firmware/Makefile
> > @@ -19,6 +19,7 @@ obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o
> > obj-$(CONFIG_FW_CFG_SYSFS) += qemu_fw_cfg.o
> > obj-$(CONFIG_QCOM_SCM) += qcom-scm.o
> > qcom-scm-objs += qcom_scm.o qcom_scm-smc.o qcom_scm-legacy.o
> > +obj-$(CONFIG_SAMSUNG_SECURE_SERVICE) += samsung-smc-svc.o
> > obj-$(CONFIG_SYSFB) += sysfb.o
> > obj-$(CONFIG_SYSFB_SIMPLEFB) += sysfb_simplefb.o
> > obj-$(CONFIG_TI_SCI_PROTOCOL) += ti_sci.o
> > diff --git a/drivers/firmware/samsung-smc-svc.c b/drivers/firmware/samsung-smc-svc.c
> > new file mode 100644
> > index 000000000000..eb3a5285cf2b
> > --- /dev/null
> > +++ b/drivers/firmware/samsung-smc-svc.c
> > @@ -0,0 +1,154 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2019 Samsung Electronics Co., Ltd.
> > + * Author: Kihyun Yoon<kihyun.yoon@xxxxxxxxxxx>
> > + * Author: Dongjin Yang<dj76.yang@xxxxxxxxxxx>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
>
> Drop boiler plate with trailing empty '*' comment.
>
Yes,
> > + */
> > +
> > +#include <linux/types.h>
> > +#include <linux/errno.h>
> > +#include <linux/module.h>
> > +#include <linux/io.h>
> > +#include <linux/of.h>
> > +#include <linux/of_device.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/firmware/samsung-smc-svc.h>
>
> Order the headers by name.
>
Yes I will,
> > +
> > +struct samsung_smc_version {
> > + u32 major;
> > + u32 minor;
> > +};
> > +
> > +struct samsung_smc_data {
> > + struct samsung_smc_version version;
> > + u32 svc_cmd_list[SAMSUNG_SIP_NR_SIP];
> > +};
> > +
> > +struct samsung_smc_data *svc_data;
>
> No, no globals. Even no static variables.
>
Yes, let me change the driver
> > +
> > +static int samsung_smc_svc_init(void);
> > +
> > +static int __samsung_get_svc_cmd(u32 cmd_idx)
> > +{
> > + if (cmd_idx >= SAMSUNG_SIP_NR_SIP)
> > + return SAMSUNG_SIP_NOT_SUPPORTED;
> > +
> > + /* Initialize this driver if it is not ready */
> > + if (!svc_data && samsung_smc_svc_init()) {
> > + pr_err("samsung,smccc_service initialization is failed\n");
> > + return SAMSUNG_SIP_NOT_SUPPORTED;
> > + }
> > +
> > + return svc_data->svc_cmd_list[cmd_idx];
> > +}
> > +
> > +int samsung_smc_call(u32 cmd_idx,
> > + unsigned long a0, unsigned long a1,
> > + unsigned long a2, unsigned long a3,
> > + u32 *val)
> > +
> > +{
> > + struct arm_smccc_res res;
> > + u32 cmd = __samsung_get_svc_cmd(cmd_idx);
> > +
> > + if (cmd == SAMSUNG_SIP_NOT_SUPPORTED)
> > + return -EOPNOTSUPP;
> > +
> > + arm_smccc_smc(cmd, a0, a1, a2, a3, 0, 0, 0, &res);
> > + if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
> > + return -EINVAL;
> > +
> > + if (val)
> > + *val = (u32)res.a1;
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL(samsung_smc_call);
>
> EXPORT_SYMBOL_GPL
>
> You need kerneldoc for all these.
>
Yes,
> > +
> > +int samsung_smc_reg_read(void *base, u32 reg, u32 *val)
> > +{
> > + return samsung_smc_call(SAMSUNG_SIP_READ_REG,
> > + (unsigned long)base, reg, 0, 0, val);
> > +}
> > +EXPORT_SYMBOL(samsung_smc_reg_read);
> > +
> > +int samsung_smc_reg_write(void *base, u32 reg, u32 val)
> > +{
> > + return samsung_smc_call(SAMSUNG_SIP_WRITE_REG,
> > + (unsigned long)base, reg, val, 0, NULL);
> > +}
> > +EXPORT_SYMBOL(samsung_smc_reg_write);
> > +
> > +static int samsung_smc_check_version(struct samsung_smc_version *ver)
> > +{
> > + struct arm_smccc_res res;
> > +
> > + arm_smccc_smc(SAMSUNG_SIP_SVC_VERSION, 0, 0, 0, 0, 0, 0, 0, &res);
> > +
> > + if ((u32)res.a0 != ver->major || (u32)res.a1 != ver->minor)
> > + return -EINVAL;
> > +
> > + pr_info("Samsung SVC version [%d.%d] is detected\n",
> > + ver->major, ver->minor);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct samsung_smc_data svc_0_1 = {
> > + .version = {
> > + .major = 0,
> > + .minor = 1
> > + },
> > + .svc_cmd_list = {
> > + [SAMSUNG_SIP_READ_REG] = 0x82000020,
> > + [SAMSUNG_SIP_WRITE_REG] = 0x82000021,
> > + /* TODO: SMC call for clock driver should be added */
> > + }
> > +};
> > +
> > +static const struct of_device_id samsung_smc_of_match[] = {
> > + { .compatible = "samsung,smccc-svc", .data = &svc_0_1 },
> > + { /* sentinel */ }
> > +};
> > +
> > +static int samsung_smc_svc_init(void)
> > +{
> > + struct device_node *fw_np;
> > + struct device_node *np;
> > + const struct of_device_id *match;
> > + int ret;
> > +
> > + if (svc_data) {
> > + pr_info("samsung,smccc_service is already initialized\n");
> > + return 0;
> > + }
> > +
> > + fw_np = of_find_node_by_name(NULL, "firmware");
> > + if (!fw_np)
> > + return -ENODEV;
> > +
> > + np = of_find_matching_node_and_match(fw_np, samsung_smc_of_match,
> > + &match);
> > + if (!np)
> > + return -ENODEV;
> > +
> > + svc_data = (struct samsung_smc_data *)match->data;
> > + if (!svc_data)
> > + return -ENODEV;
> > +
> > + ret = samsung_smc_check_version(&svc_data->version);
> > + if (ret) {
> > + pr_err("samsung svc version is not matched\n");
> > + return ret;
> > + }
> > +
> > + pr_info("samsung smc svc is initialized\n");
>
> No useless success printks. We have tracing and sysfs for that.
>
Ok,
> > + return 0;
> > +}
> > +
> > +early_initcall(samsung_smc_svc_init);
>
> No. Make it a platform driver.
>
Ok, I will change,
> > diff --git a/include/linux/firmware/samsung-smc-svc.h b/include/linux/firmware/samsung-smc-svc.h
> > new file mode 100644
> > index 000000000000..9c94fd3e10a2
> > --- /dev/null
> > +++ b/include/linux/firmware/samsung-smc-svc.h
> > @@ -0,0 +1,59 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +
> > +#ifndef __SAMSUNG_SMC_H
> > +#define __SAMSUNG_SMC_H
>
> Extend the header gaurd to match path.
>
Yes,
> > +
> > +#include <linux/arm-smccc.h>
> > +
> > +#ifdef CONFIG_SAMSUNG_SECURE_SERVICE
>
> No ifdefs in headers. This is not a subsystem.
>
Yes, I will remove,
> > +
> > +#define SAMSUNG_SIP_CALL_VAL(x) \
> > + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
> > + ARM_SMCCC_SMC_32, ARM_SMCCC_OWNER_SIP, x)
>
> Need kerneldoc.
>
Yes, I will add kerneldoc.
> > +
> > +/* Common SIP SVC number */
> > +#define SAMSUING_SIP_SVC_CALL_COUNT SAMSUNG_SIP_CALL_VAL(0xff00)
> > +#define SAMSUING_SIP_SVC_UID SAMSUNG_SIP_CALL_VAL(0xff01)
> > +#define SAMSUNG_SIP_SVC_VERSION SAMSUNG_SIP_CALL_VAL(0xff03)
> > +#define SAMSUNG_SIP_NOT_SUPPORTED 0x0
>
> Need kerneldoc.
>
>
> > +
> > +enum {
> > + /* SIP enumeration for V0.1 */
> > + SAMSUNG_SIP_READ_REG,
> > + SAMSUNG_SIP_WRITE_REG,
> > + /* Add here for later version */
> > + SAMSUNG_SIP_NR_SIP
> > +};
>
> Need kerneldoc.
>
>
> > +
> > +int samsung_smc_call(u32 cmd_idx,
> > + unsigned long a0, unsigned long a1,
> > + unsigned long a2, unsigned long a3,
> > + u32 *val);
> > +int samsung_smc_reg_read(void *addr, unsigned int reg, u32 *val);
> > +int samsung_smc_reg_write(void *addr, unsigned int reg, u32 val);
> > +
>
> Need kerneldoc in the driver.
>
>
> > +#else
> > +
>
> No stubs, no ifdefs. It's not a subsystem.
>
>
>
> Best regards,
> Krzysztof
