From: "David E. Box" <david.e.box@xxxxxxxxxxxxxxx> - Exports intel_pmc_ipc() for host access to the PMC IPC mailbox - Add support to use IPC command allows host to access SoC registers through PMC firmware that are otherwise inaccessible to the host due to security policies. Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx> Signed-off-by: Chao Qin <chao.qin@xxxxxxxxx> Signed-off-by: Choong Yong Liang <yong.liang.choong@xxxxxxxxxxxxxxx> --- MAINTAINERS | 2 + arch/x86/Kconfig | 9 +++ arch/x86/platform/intel/Makefile | 1 + arch/x86/platform/intel/pmc_ipc.c | 75 +++++++++++++++++++ .../linux/platform_data/x86/intel_pmc_ipc.h | 34 +++++++++ 5 files changed, 121 insertions(+) create mode 100644 arch/x86/platform/intel/pmc_ipc.c create mode 100644 include/linux/platform_data/x86/intel_pmc_ipc.h diff --git a/MAINTAINERS b/MAINTAINERS index 2b775f4369e0..0276f1d53caf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10996,8 +10996,10 @@ M: Rajneesh Bhardwaj <irenic.rajneesh@xxxxxxxxx> M: David E Box <david.e.box@xxxxxxxxx> L: platform-driver-x86@xxxxxxxxxxxxxxx S: Maintained +F: arch/x86/platform/intel/pmc_ipc.c F: Documentation/ABI/testing/sysfs-platform-intel-pmc F: drivers/platform/x86/intel/pmc/ +F: linux/platform_data/x86/intel_pmc_ipc.h INTEL PMIC GPIO DRIVERS M: Andy Shevchenko <andy@xxxxxxxxxx> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5edec175b9bf..bceae28b9381 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -666,6 +666,15 @@ config X86_AMD_PLATFORM_DEVICE I2C and UART depend on COMMON_CLK to set clock. GPIO driver is implemented under PINCTRL subsystem. +config INTEL_PMC_IPC + tristate "Intel Core SoC Power Management Controller IPC mailbox" + depends on ACPI + help + This option enables sideband register access support for Intel SoC + power management controller IPC mailbox. + + If you don't require the option or are in doubt, say N. + config IOSF_MBI tristate "Intel SoC IOSF Sideband support for SoC platforms" depends on PCI diff --git a/arch/x86/platform/intel/Makefile b/arch/x86/platform/intel/Makefile index dbee3b00f9d0..470fc68de6ba 100644 --- a/arch/x86/platform/intel/Makefile +++ b/arch/x86/platform/intel/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_IOSF_MBI) += iosf_mbi.o +obj-$(CONFIG_INTEL_PMC_IPC) += pmc_ipc.o \ No newline at end of file diff --git a/arch/x86/platform/intel/pmc_ipc.c b/arch/x86/platform/intel/pmc_ipc.c new file mode 100644 index 000000000000..a96234982710 --- /dev/null +++ b/arch/x86/platform/intel/pmc_ipc.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Intel Core SoC Power Management Controller IPC mailbox + * + * Copyright (c) 2023, Intel Corporation. + * All Rights Reserved. + * + * Authors: Choong Yong Liang <yong.liang.choong@xxxxxxxxxxxxxxx> + * David E. Box <david.e.box@xxxxxxxxxxxxxxx> + */ +#include <linux/module.h> +#include <linux/acpi.h> +#include <linux/platform_data/x86/intel_pmc_ipc.h> + +#define PMC_IPCS_PARAM_COUNT 7 + +int intel_pmc_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf) +{ + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object params[PMC_IPCS_PARAM_COUNT] = { + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + }; + struct acpi_object_list arg_list = { PMC_IPCS_PARAM_COUNT, params }; + union acpi_object *obj; + int status; + + if (!ipc_cmd || !rbuf) + return -EINVAL; + + /* + * 0: IPC Command + * 1: IPC Sub Command + * 2: Size + * 3-6: Write Buffer for offset + */ + params[0].integer.value = ipc_cmd->cmd; + params[1].integer.value = ipc_cmd->sub_cmd; + params[2].integer.value = ipc_cmd->size; + params[3].integer.value = ipc_cmd->wbuf[0]; + params[4].integer.value = ipc_cmd->wbuf[1]; + params[5].integer.value = ipc_cmd->wbuf[2]; + params[6].integer.value = ipc_cmd->wbuf[3]; + + status = acpi_evaluate_object(NULL, "\\IPCS", &arg_list, &buffer); + if (ACPI_FAILURE(status)) + return -ENODEV; + + obj = buffer.pointer; + /* Check if the number of elements in package is 5 */ + if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) { + const union acpi_object *objs = obj->package.elements; + + if ((u8)objs[0].integer.value != 0) + return -EINVAL; + + rbuf[0] = objs[1].integer.value; + rbuf[1] = objs[2].integer.value; + rbuf[2] = objs[3].integer.value; + rbuf[3] = objs[4].integer.value; + } else { + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL(intel_pmc_ipc); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Intel PMC IPC Mailbox accessor"); diff --git a/include/linux/platform_data/x86/intel_pmc_ipc.h b/include/linux/platform_data/x86/intel_pmc_ipc.h new file mode 100644 index 000000000000..d47b89f873fc --- /dev/null +++ b/include/linux/platform_data/x86/intel_pmc_ipc.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Intel Core SoC Power Management Controller Header File + * + * Copyright (c) 2023, Intel Corporation. + * All Rights Reserved. + * + * Authors: Choong Yong Liang <yong.liang.choong@xxxxxxxxxxxxxxx> + * David E. Box <david.e.box@xxxxxxxxxxxxxxx> + */ +#ifndef INTEL_PMC_IPC_H +#define INTEL_PMC_IPC_H + +#define IPC_SOC_REGISTER_ACCESS 0xAA +#define IPC_SOC_SUB_CMD_READ 0x00 +#define IPC_SOC_SUB_CMD_WRITE 0x01 + +struct pmc_ipc_cmd { + u32 cmd; + u32 sub_cmd; + u32 size; + u32 wbuf[4]; +}; + +/** + * intel_pmc_ipc() - PMC IPC Mailbox accessor + * @ipc_cmd: struct pmc_ipc_cmd prepared with input to send + * @rbuf: Allocated u32[4] array for returned IPC data + * + * Return: 0 on success. Non-zero on mailbox error + */ +int intel_pmc_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf); + +#endif /* INTEL_PMC_IPC_H */ -- 2.34.1