The initial implementation of IFS is model specific. Enumeration is via a combination of family-model-stepping and a check for a bit in the CORE_CAPABILITIES MSR. Linux has handled this lack of enumeration before with a code stub to create a device. See arch/x86/kernel/pmem.c. Use the same approach here. Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> --- MAINTAINERS | 7 +++ drivers/platform/x86/intel/Kconfig | 1 + drivers/platform/x86/intel/Makefile | 1 + drivers/platform/x86/intel/ifs/Kconfig | 2 + drivers/platform/x86/intel/ifs/Makefile | 1 + .../platform/x86/intel/ifs/intel_ifs_device.c | 50 +++++++++++++++++++ 6 files changed, 62 insertions(+) create mode 100644 drivers/platform/x86/intel/ifs/Kconfig create mode 100644 drivers/platform/x86/intel/ifs/Makefile create mode 100644 drivers/platform/x86/intel/ifs/intel_ifs_device.c diff --git a/MAINTAINERS b/MAINTAINERS index 40fa1955ca3f..9e372a960fa5 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9861,6 +9861,13 @@ B: https://bugzilla.kernel.org T: git git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux.git F: drivers/idle/intel_idle.c +INTEL IN FIELD SCAN (IFS) DRIVER +M: Jithu Joseph <jithu.joseph@xxxxxxxxx> +R: Ashok Raj <ashok.raj@xxxxxxxxx> +R: Tony Luck <tony.luck@xxxxxxxxx> +S: Maintained +F: drivers/platform/x86/intel/ifs + INTEL INTEGRATED SENSOR HUB DRIVER M: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> M: Jiri Kosina <jikos@xxxxxxxxxx> diff --git a/drivers/platform/x86/intel/Kconfig b/drivers/platform/x86/intel/Kconfig index 1f01a8a23c57..794968bda115 100644 --- a/drivers/platform/x86/intel/Kconfig +++ b/drivers/platform/x86/intel/Kconfig @@ -4,6 +4,7 @@ # source "drivers/platform/x86/intel/atomisp2/Kconfig" +source "drivers/platform/x86/intel/ifs/Kconfig" source "drivers/platform/x86/intel/int1092/Kconfig" source "drivers/platform/x86/intel/int3472/Kconfig" source "drivers/platform/x86/intel/pmc/Kconfig" diff --git a/drivers/platform/x86/intel/Makefile b/drivers/platform/x86/intel/Makefile index c61bc3e97121..10285d0fd16a 100644 --- a/drivers/platform/x86/intel/Makefile +++ b/drivers/platform/x86/intel/Makefile @@ -5,6 +5,7 @@ # obj-$(CONFIG_INTEL_ATOMISP2_PDX86) += atomisp2/ +obj-y += ifs/ obj-$(CONFIG_INTEL_SAR_INT1092) += int1092/ obj-$(CONFIG_INTEL_SKL_INT3472) += int3472/ obj-$(CONFIG_INTEL_PMC_CORE) += pmc/ diff --git a/drivers/platform/x86/intel/ifs/Kconfig b/drivers/platform/x86/intel/ifs/Kconfig new file mode 100644 index 000000000000..51325b699563 --- /dev/null +++ b/drivers/platform/x86/intel/ifs/Kconfig @@ -0,0 +1,2 @@ +config INTEL_IFS_DEVICE + bool diff --git a/drivers/platform/x86/intel/ifs/Makefile b/drivers/platform/x86/intel/ifs/Makefile new file mode 100644 index 000000000000..12c2f5ce9925 --- /dev/null +++ b/drivers/platform/x86/intel/ifs/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_INTEL_IFS_DEVICE) += intel_ifs_device.o diff --git a/drivers/platform/x86/intel/ifs/intel_ifs_device.c b/drivers/platform/x86/intel/ifs/intel_ifs_device.c new file mode 100644 index 000000000000..64a143871d72 --- /dev/null +++ b/drivers/platform/x86/intel/ifs/intel_ifs_device.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2022 Intel Corporation. */ + +#include <linux/platform_device.h> +#include <linux/init.h> +#include <asm/cpu_device_id.h> + +#define MSR_IA32_CORE_CAPS_INTEGRITY_BIT 2 +#define MSR_IA32_CORE_CAPS_INTEGRITY BIT(MSR_IA32_CORE_CAPS_INTEGRITY_BIT) + +#define X86_MATCH(model) \ + X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, \ + INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL) + +static const struct x86_cpu_id ifs_cpu_ids[] __initconst = { + X86_MATCH(SAPPHIRERAPIDS_X), + {} +}; + +static __init int register_ifs_device(void) +{ + struct platform_device *pdev; + const struct x86_cpu_id *m; + u64 ia32_core_caps; + + m = x86_match_cpu(ifs_cpu_ids); + if (!m) + return -ENODEV; + + if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &ia32_core_caps)) + return -ENODEV; + + if (ia32_core_caps & MSR_IA32_CORE_CAPS_INTEGRITY) { + pdev = platform_device_alloc("intel_ifs", 0); + if (pdev) { + if (platform_device_add(pdev)) + platform_device_put(pdev); + } + } + + /* + * Failure here will be visible by a missing device + * in sysfs. Returning an error code would not make + * that any easier to diagnose. Would also complicate + * future implementations that may support a subset of + * the types of tests. + */ + return 0; +} +device_initcall(register_ifs_device); -- 2.35.1
