| Message ID | 20250218190822.1039982-5-superm1@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | Add support for AMD hardware feedback interface | expand |
On Tue, 18 Feb 2025, Mario Limonciello wrote: > From: Perry Yuan <Perry.Yuan@amd.com> > > The AMD Heterogeneous core design and Hardware Feedback Interface (HFI) > provide behavioral classification and a dynamically updated ranking table > for the scheduler to use when choosing cores for tasks. > > There are two CPU core types defined: `Classic Core` and `Dense Core`. > "Classic" cores are the standard performance cores, while "Dense" cores > are optimized for area and efficiency. > > Heterogeneous compute refers to CPU implementations that are comprised > of more than one architectural class, each with two capabilities. This > means each CPU reports two separate capabilities: "perf" and "eff". > > Each capability lists all core ranking numbers between 0 and 255, where > a higher number represents a higher capability. > > Heterogeneous systems can also extend to more than two architectural > classes. > > The purpose of the scheduling feedback mechanism is to provide information > to the operating system scheduler in real time, allowing the scheduler to > direct threads to the optimal core during task scheduling. > > All core ranking data are provided by the PMFW via a shared memory ranking > table, which the driver reads and uses to update core capabilities to the > scheduler. When the hardware updates the table, it generates a platform > interrupt to notify the OS to read the new ranking table. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 > Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> > Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > Co-developed-by: Mario Limonciello <mario.limonciello@amd.com> > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > --- > v8: > * s,devm_kzalloc,devm_kcalloc, > * fold newlines from patch 5 into this patch > * Drop ->cpu member, push to later patch > * s,for_each_present_cpu,for_each_possible_cpu, > v7: > * Adjust Kconfig to 80 characters > --- > drivers/platform/x86/amd/Kconfig | 1 + > drivers/platform/x86/amd/Makefile | 1 + > drivers/platform/x86/amd/hfi/Kconfig | 20 ++++ > drivers/platform/x86/amd/hfi/Makefile | 7 ++ > drivers/platform/x86/amd/hfi/hfi.c | 162 ++++++++++++++++++++++++++ > 5 files changed, 191 insertions(+) > create mode 100644 drivers/platform/x86/amd/hfi/Kconfig > create mode 100644 drivers/platform/x86/amd/hfi/Makefile > create mode 100644 drivers/platform/x86/amd/hfi/hfi.c > > diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig > index c3e086ea64fc6..589d61ebf726b 100644 > --- a/drivers/platform/x86/amd/Kconfig > +++ b/drivers/platform/x86/amd/Kconfig > @@ -6,6 +6,7 @@ > source "drivers/platform/x86/amd/hsmp/Kconfig" > source "drivers/platform/x86/amd/pmf/Kconfig" > source "drivers/platform/x86/amd/pmc/Kconfig" > +source "drivers/platform/x86/amd/hfi/Kconfig" > > config AMD_3D_VCACHE > tristate "AMD 3D V-Cache Performance Optimizer Driver" > diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile > index 56f62fc9c97b4..c50e93c3334cf 100644 > --- a/drivers/platform/x86/amd/Makefile > +++ b/drivers/platform/x86/amd/Makefile > @@ -10,3 +10,4 @@ obj-$(CONFIG_AMD_PMC) += pmc/ > obj-$(CONFIG_AMD_HSMP) += hsmp/ > obj-$(CONFIG_AMD_PMF) += pmf/ > obj-$(CONFIG_AMD_WBRF) += wbrf.o > +obj-$(CONFIG_AMD_HFI) += hfi/ > diff --git a/drivers/platform/x86/amd/hfi/Kconfig b/drivers/platform/x86/amd/hfi/Kconfig > new file mode 100644 > index 0000000000000..532939eb08a6a > --- /dev/null > +++ b/drivers/platform/x86/amd/hfi/Kconfig > @@ -0,0 +1,20 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +# > +# AMD Hardware Feedback Interface Driver > +# > + > +config AMD_HFI > + bool "AMD Hetero Core Hardware Feedback Driver" > + depends on ACPI > + depends on CPU_SUP_AMD > + help > + Select this option to enable the AMD Heterogeneous Core Hardware > + Feedback Interface. If selected, hardware provides runtime thread > + classification guidance to the operating system on the performance and > + energy efficiency capabilities of each heterogeneous CPU core. These > + capabilities may vary due to the inherent differences in the core types > + and can also change as a result of variations in the operating > + conditions of the system such as power and thermal limits. If selected, This says the capabilities can change but metadata is only read and scores updated during probe? > + the kernel relays updates in heterogeneous CPUs' capabilities to > + userspace, allowing for more optimal task scheduling and resource > + allocation, leveraging the diverse set of cores available. How are the capabilities communicated to userspace as mentioned here? I'm asking this because I only noted debugfs interface, and that commit claimed the debug fs interface was to troubleshoot scheduler issues. > diff --git a/drivers/platform/x86/amd/hfi/Makefile b/drivers/platform/x86/amd/hfi/Makefile > new file mode 100644 > index 0000000000000..672c6ac106e95 > --- /dev/null > +++ b/drivers/platform/x86/amd/hfi/Makefile > @@ -0,0 +1,7 @@ > +# SPDX-License-Identifier: GPL-2.0 > +# > +# AMD Hardware Feedback Interface Driver > +# > + > +obj-$(CONFIG_AMD_HFI) += amd_hfi.o > +amd_hfi-objs := hfi.o > diff --git a/drivers/platform/x86/amd/hfi/hfi.c b/drivers/platform/x86/amd/hfi/hfi.c > new file mode 100644 > index 0000000000000..426f7e520b76c > --- /dev/null > +++ b/drivers/platform/x86/amd/hfi/hfi.c > @@ -0,0 +1,162 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * AMD Hardware Feedback Interface Driver > + * > + * Copyright (C) 2024 Advanced Micro Devices, Inc. All Rights Reserved. 2025 ? > + * > + * Authors: Perry Yuan <Perry.Yuan@amd.com> > + * Mario Limonciello <mario.limonciello@amd.com> > + */ > + > +#define pr_fmt(fmt) "amd-hfi: " fmt > + > +#include <linux/acpi.h> > +#include <linux/cpu.h> > +#include <linux/cpumask.h> > +#include <linux/gfp.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/platform_device.h> > +#include <linux/smp.h> > + > +#define AMD_HFI_DRIVER "amd_hfi" > + > +#define AMD_HETERO_CPUID_27 0x80000027 > + > +static struct platform_device *device; > + > +struct amd_hfi_data { > + const char *name; > + struct device *dev; > + struct mutex lock; Please mention what this protects. > +}; > + > +struct amd_hfi_classes { > + u32 perf; > + u32 eff; > +}; > + > +/** > + * struct amd_hfi_cpuinfo - HFI workload class info per CPU > + * @cpu: cpu index > + * @class_index: workload class ID index > + * @nr_class: max number of workload class supported > + * @amd_hfi_classes: current cpu workload class ranking data > + * > + * Parameters of a logical processor linked with hardware feedback class missing . > + */ > +struct amd_hfi_cpuinfo { > + int cpu; > + s16 class_index; > + u8 nr_class; > + struct amd_hfi_classes *amd_hfi_classes; > +}; > + > +static DEFINE_PER_CPU(struct amd_hfi_cpuinfo, amd_hfi_cpuinfo) = {.class_index = -1}; > + > +static int amd_hfi_alloc_class_data(struct platform_device *pdev) > +{ > + struct amd_hfi_cpuinfo *hfi_cpuinfo; > + struct device *dev = &pdev->dev; > + int idx; > + int nr_class_id; > + > + nr_class_id = cpuid_eax(AMD_HETERO_CPUID_27); > + if (nr_class_id < 0 || nr_class_id > 255) { Is the signed type correct for this? > + dev_err(dev, "failed to get number of supported classes: %d\n", > + nr_class_id); I'd reword the error message as the number of classes was just too large / outside the allowed range. > + return -EINVAL; > + } > + > + for_each_possible_cpu(idx) { > + struct amd_hfi_classes *classes; > + > + classes = devm_kcalloc(dev, > + nr_class_id, > + sizeof(struct amd_hfi_classes), > + GFP_KERNEL); > + if (!classes) > + return -ENOMEM; > + hfi_cpuinfo = per_cpu_ptr(&amd_hfi_cpuinfo, idx); > + hfi_cpuinfo->amd_hfi_classes = classes; > + hfi_cpuinfo->nr_class = nr_class_id; > + } > + > + return 0; > +} > + > +static const struct acpi_device_id amd_hfi_platform_match[] = { > + {"AMDI0104", 0}, > + { } > +}; > +MODULE_DEVICE_TABLE(acpi, amd_hfi_platform_match); > + > +static int amd_hfi_probe(struct platform_device *pdev) > +{ > + struct amd_hfi_data *amd_hfi_data; > + int ret; > + > + if (!acpi_match_device(amd_hfi_platform_match, &pdev->dev)) > + return -ENODEV; > + > + amd_hfi_data = devm_kzalloc(&pdev->dev, sizeof(*amd_hfi_data), GFP_KERNEL); > + if (!amd_hfi_data) > + return -ENOMEM; > + > + amd_hfi_data->dev = &pdev->dev; > + ret = devm_mutex_init(&pdev->dev, &amd_hfi_data->lock); > + if (ret) > + return ret; > + platform_set_drvdata(pdev, amd_hfi_data); > + > + ret = amd_hfi_alloc_class_data(pdev); > + if (ret) > + return ret; > + > + return 0; > +} > + > +static struct platform_driver amd_hfi_driver = { > + .driver = { > + .name = AMD_HFI_DRIVER, > + .owner = THIS_MODULE, > + .acpi_match_table = ACPI_PTR(amd_hfi_platform_match), > + }, > + .probe = amd_hfi_probe, > +}; > + > +static int __init amd_hfi_init(void) > +{ > + int ret; > + > + if (acpi_disabled || > + !cpu_feature_enabled(X86_FEATURE_AMD_HETEROGENEOUS_CORES) || > + !cpu_feature_enabled(X86_FEATURE_AMD_WORKLOAD_CLASS)) > + return -ENODEV; > + > + device = platform_device_register_simple(AMD_HFI_DRIVER, -1, NULL, 0); > + if (IS_ERR(device)) { > + pr_err("unable to register HFI platform device\n"); > + return PTR_ERR(device); > + } > + > + ret = platform_driver_register(&amd_hfi_driver); > + if (ret) > + pr_err("failed to register HFI driver\n"); > + > + return ret; > +} > + > +static __exit void amd_hfi_exit(void) > +{ > + platform_device_unregister(device); > + platform_driver_unregister(&amd_hfi_driver); Why are these not in the opposite order than in init? > +} > +module_init(amd_hfi_init); > +module_exit(amd_hfi_exit); > + > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("AMD Hardware Feedback Interface Driver"); >
On 3/19/2025 09:03, Ilpo Järvinen wrote: > On Tue, 18 Feb 2025, Mario Limonciello wrote: > >> From: Perry Yuan <Perry.Yuan@amd.com> >> >> The AMD Heterogeneous core design and Hardware Feedback Interface (HFI) >> provide behavioral classification and a dynamically updated ranking table >> for the scheduler to use when choosing cores for tasks. >> >> There are two CPU core types defined: `Classic Core` and `Dense Core`. >> "Classic" cores are the standard performance cores, while "Dense" cores >> are optimized for area and efficiency. >> >> Heterogeneous compute refers to CPU implementations that are comprised >> of more than one architectural class, each with two capabilities. This >> means each CPU reports two separate capabilities: "perf" and "eff". >> >> Each capability lists all core ranking numbers between 0 and 255, where >> a higher number represents a higher capability. >> >> Heterogeneous systems can also extend to more than two architectural >> classes. >> >> The purpose of the scheduling feedback mechanism is to provide information >> to the operating system scheduler in real time, allowing the scheduler to >> direct threads to the optimal core during task scheduling. >> >> All core ranking data are provided by the PMFW via a shared memory ranking >> table, which the driver reads and uses to update core capabilities to the >> scheduler. When the hardware updates the table, it generates a platform >> interrupt to notify the OS to read the new ranking table. >> >> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 >> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> >> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> >> Signed-off-by: Perry Yuan <perry.yuan@amd.com> >> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com> >> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> >> --- >> v8: >> * s,devm_kzalloc,devm_kcalloc, >> * fold newlines from patch 5 into this patch >> * Drop ->cpu member, push to later patch >> * s,for_each_present_cpu,for_each_possible_cpu, >> v7: >> * Adjust Kconfig to 80 characters >> --- >> drivers/platform/x86/amd/Kconfig | 1 + >> drivers/platform/x86/amd/Makefile | 1 + >> drivers/platform/x86/amd/hfi/Kconfig | 20 ++++ >> drivers/platform/x86/amd/hfi/Makefile | 7 ++ >> drivers/platform/x86/amd/hfi/hfi.c | 162 ++++++++++++++++++++++++++ >> 5 files changed, 191 insertions(+) >> create mode 100644 drivers/platform/x86/amd/hfi/Kconfig >> create mode 100644 drivers/platform/x86/amd/hfi/Makefile >> create mode 100644 drivers/platform/x86/amd/hfi/hfi.c >> >> diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig >> index c3e086ea64fc6..589d61ebf726b 100644 >> --- a/drivers/platform/x86/amd/Kconfig >> +++ b/drivers/platform/x86/amd/Kconfig >> @@ -6,6 +6,7 @@ >> source "drivers/platform/x86/amd/hsmp/Kconfig" >> source "drivers/platform/x86/amd/pmf/Kconfig" >> source "drivers/platform/x86/amd/pmc/Kconfig" >> +source "drivers/platform/x86/amd/hfi/Kconfig" >> >> config AMD_3D_VCACHE >> tristate "AMD 3D V-Cache Performance Optimizer Driver" >> diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile >> index 56f62fc9c97b4..c50e93c3334cf 100644 >> --- a/drivers/platform/x86/amd/Makefile >> +++ b/drivers/platform/x86/amd/Makefile >> @@ -10,3 +10,4 @@ obj-$(CONFIG_AMD_PMC) += pmc/ >> obj-$(CONFIG_AMD_HSMP) += hsmp/ >> obj-$(CONFIG_AMD_PMF) += pmf/ >> obj-$(CONFIG_AMD_WBRF) += wbrf.o >> +obj-$(CONFIG_AMD_HFI) += hfi/ >> diff --git a/drivers/platform/x86/amd/hfi/Kconfig b/drivers/platform/x86/amd/hfi/Kconfig >> new file mode 100644 >> index 0000000000000..532939eb08a6a >> --- /dev/null >> +++ b/drivers/platform/x86/amd/hfi/Kconfig >> @@ -0,0 +1,20 @@ >> +# SPDX-License-Identifier: GPL-2.0-only >> +# >> +# AMD Hardware Feedback Interface Driver >> +# >> + >> +config AMD_HFI >> + bool "AMD Hetero Core Hardware Feedback Driver" >> + depends on ACPI >> + depends on CPU_SUP_AMD >> + help >> + Select this option to enable the AMD Heterogeneous Core Hardware >> + Feedback Interface. If selected, hardware provides runtime thread >> + classification guidance to the operating system on the performance and >> + energy efficiency capabilities of each heterogeneous CPU core. These >> + capabilities may vary due to the inherent differences in the core types >> + and can also change as a result of variations in the operating >> + conditions of the system such as power and thermal limits. If selected, > > This says the capabilities can change but metadata is only read and scores > updated during probe? > >> + the kernel relays updates in heterogeneous CPUs' capabilities to >> + userspace, allowing for more optimal task scheduling and resource >> + allocation, leveraging the diverse set of cores available. > > How are the capabilities communicated to userspace as mentioned here? I'm > asking this because I only noted debugfs interface, and that commit > claimed the debug fs interface was to troubleshoot scheduler issues. This is one of those cases that the split into multiple parts shows. Thinking through I feel it makes more sense to adjust for now and then we can change it again on the next part. > >> diff --git a/drivers/platform/x86/amd/hfi/Makefile b/drivers/platform/x86/amd/hfi/Makefile >> new file mode 100644 >> index 0000000000000..672c6ac106e95 >> --- /dev/null >> +++ b/drivers/platform/x86/amd/hfi/Makefile >> @@ -0,0 +1,7 @@ >> +# SPDX-License-Identifier: GPL-2.0 >> +# >> +# AMD Hardware Feedback Interface Driver >> +# >> + >> +obj-$(CONFIG_AMD_HFI) += amd_hfi.o >> +amd_hfi-objs := hfi.o >> diff --git a/drivers/platform/x86/amd/hfi/hfi.c b/drivers/platform/x86/amd/hfi/hfi.c >> new file mode 100644 >> index 0000000000000..426f7e520b76c >> --- /dev/null >> +++ b/drivers/platform/x86/amd/hfi/hfi.c >> @@ -0,0 +1,162 @@ >> +// SPDX-License-Identifier: GPL-2.0-or-later >> +/* >> + * AMD Hardware Feedback Interface Driver >> + * >> + * Copyright (C) 2024 Advanced Micro Devices, Inc. All Rights Reserved. > > 2025 ? Ack. Heh, earlier versions started in 2024! > >> + * >> + * Authors: Perry Yuan <Perry.Yuan@amd.com> >> + * Mario Limonciello <mario.limonciello@amd.com> >> + */ >> + >> +#define pr_fmt(fmt) "amd-hfi: " fmt >> + >> +#include <linux/acpi.h> >> +#include <linux/cpu.h> >> +#include <linux/cpumask.h> >> +#include <linux/gfp.h> >> +#include <linux/init.h> >> +#include <linux/io.h> >> +#include <linux/kernel.h> >> +#include <linux/module.h> >> +#include <linux/mutex.h> >> +#include <linux/platform_device.h> >> +#include <linux/smp.h> >> + >> +#define AMD_HFI_DRIVER "amd_hfi" >> + >> +#define AMD_HETERO_CPUID_27 0x80000027 >> + >> +static struct platform_device *device; >> + >> +struct amd_hfi_data { >> + const char *name; >> + struct device *dev; >> + struct mutex lock; > > Please mention what this protects. As a comment at the end like this, right? struct mutex lock; /* lock the foo */ > >> +}; >> + >> +struct amd_hfi_classes { >> + u32 perf; >> + u32 eff; >> +}; >> + >> +/** >> + * struct amd_hfi_cpuinfo - HFI workload class info per CPU >> + * @cpu: cpu index >> + * @class_index: workload class ID index >> + * @nr_class: max number of workload class supported >> + * @amd_hfi_classes: current cpu workload class ranking data >> + * >> + * Parameters of a logical processor linked with hardware feedback class > > missing . Ack > >> + */ >> +struct amd_hfi_cpuinfo { >> + int cpu; >> + s16 class_index; >> + u8 nr_class; >> + struct amd_hfi_classes *amd_hfi_classes; >> +}; >> + >> +static DEFINE_PER_CPU(struct amd_hfi_cpuinfo, amd_hfi_cpuinfo) = {.class_index = -1}; >> + >> +static int amd_hfi_alloc_class_data(struct platform_device *pdev) >> +{ >> + struct amd_hfi_cpuinfo *hfi_cpuinfo; >> + struct device *dev = &pdev->dev; >> + int idx; >> + int nr_class_id; >> + >> + nr_class_id = cpuid_eax(AMD_HETERO_CPUID_27); >> + if (nr_class_id < 0 || nr_class_id > 255) { > > Is the signed type correct for this? > >> + dev_err(dev, "failed to get number of supported classes: %d\n", >> + nr_class_id); > > I'd reword the error message as the number of classes was just too > large / outside the allowed range. OK. > >> + return -EINVAL; >> + } >> + >> + for_each_possible_cpu(idx) { >> + struct amd_hfi_classes *classes; >> + >> + classes = devm_kcalloc(dev, >> + nr_class_id, >> + sizeof(struct amd_hfi_classes), >> + GFP_KERNEL); >> + if (!classes) >> + return -ENOMEM; >> + hfi_cpuinfo = per_cpu_ptr(&amd_hfi_cpuinfo, idx); >> + hfi_cpuinfo->amd_hfi_classes = classes; >> + hfi_cpuinfo->nr_class = nr_class_id; >> + } >> + >> + return 0; >> +} >> + >> +static const struct acpi_device_id amd_hfi_platform_match[] = { >> + {"AMDI0104", 0}, >> + { } >> +}; >> +MODULE_DEVICE_TABLE(acpi, amd_hfi_platform_match); >> + >> +static int amd_hfi_probe(struct platform_device *pdev) >> +{ >> + struct amd_hfi_data *amd_hfi_data; >> + int ret; >> + >> + if (!acpi_match_device(amd_hfi_platform_match, &pdev->dev)) >> + return -ENODEV; >> + >> + amd_hfi_data = devm_kzalloc(&pdev->dev, sizeof(*amd_hfi_data), GFP_KERNEL); >> + if (!amd_hfi_data) >> + return -ENOMEM; >> + >> + amd_hfi_data->dev = &pdev->dev; >> + ret = devm_mutex_init(&pdev->dev, &amd_hfi_data->lock); >> + if (ret) >> + return ret; >> + platform_set_drvdata(pdev, amd_hfi_data); >> + >> + ret = amd_hfi_alloc_class_data(pdev); >> + if (ret) >> + return ret; >> + >> + return 0; >> +} >> + >> +static struct platform_driver amd_hfi_driver = { >> + .driver = { >> + .name = AMD_HFI_DRIVER, >> + .owner = THIS_MODULE, >> + .acpi_match_table = ACPI_PTR(amd_hfi_platform_match), >> + }, >> + .probe = amd_hfi_probe, >> +}; >> + >> +static int __init amd_hfi_init(void) >> +{ >> + int ret; >> + >> + if (acpi_disabled || >> + !cpu_feature_enabled(X86_FEATURE_AMD_HETEROGENEOUS_CORES) || >> + !cpu_feature_enabled(X86_FEATURE_AMD_WORKLOAD_CLASS)) >> + return -ENODEV; >> + >> + device = platform_device_register_simple(AMD_HFI_DRIVER, -1, NULL, 0); >> + if (IS_ERR(device)) { >> + pr_err("unable to register HFI platform device\n"); >> + return PTR_ERR(device); >> + } >> + >> + ret = platform_driver_register(&amd_hfi_driver); >> + if (ret) >> + pr_err("failed to register HFI driver\n"); >> + >> + return ret; >> +} >> + >> +static __exit void amd_hfi_exit(void) >> +{ >> + platform_device_unregister(device); >> + platform_driver_unregister(&amd_hfi_driver); > > Why are these not in the opposite order than in init? Oversight. Will fix it. > >> +} >> +module_init(amd_hfi_init); >> +module_exit(amd_hfi_exit); >> + >> +MODULE_LICENSE("GPL"); >> +MODULE_DESCRIPTION("AMD Hardware Feedback Interface Driver"); >> >
On Thu, 20 Mar 2025, Mario Limonciello wrote: > On 3/19/2025 09:03, Ilpo Järvinen wrote: > > On Tue, 18 Feb 2025, Mario Limonciello wrote: > > > > > From: Perry Yuan <Perry.Yuan@amd.com> > > > > > > The AMD Heterogeneous core design and Hardware Feedback Interface (HFI) > > > provide behavioral classification and a dynamically updated ranking table > > > for the scheduler to use when choosing cores for tasks. > > > > > > There are two CPU core types defined: `Classic Core` and `Dense Core`. > > > "Classic" cores are the standard performance cores, while "Dense" cores > > > are optimized for area and efficiency. > > > > > > Heterogeneous compute refers to CPU implementations that are comprised > > > of more than one architectural class, each with two capabilities. This > > > means each CPU reports two separate capabilities: "perf" and "eff". > > > > > > Each capability lists all core ranking numbers between 0 and 255, where > > > a higher number represents a higher capability. > > > > > > Heterogeneous systems can also extend to more than two architectural > > > classes. > > > > > > The purpose of the scheduling feedback mechanism is to provide information > > > to the operating system scheduler in real time, allowing the scheduler to > > > direct threads to the optimal core during task scheduling. > > > > > > All core ranking data are provided by the PMFW via a shared memory ranking > > > table, which the driver reads and uses to update core capabilities to the > > > scheduler. When the hardware updates the table, it generates a platform > > > interrupt to notify the OS to read the new ranking table. > > > > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 > > > Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> > > > Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> > > > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > > > Co-developed-by: Mario Limonciello <mario.limonciello@amd.com> > > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > > > --- > > > v8: > > > * s,devm_kzalloc,devm_kcalloc, > > > * fold newlines from patch 5 into this patch > > > * Drop ->cpu member, push to later patch > > > * s,for_each_present_cpu,for_each_possible_cpu, > > > v7: > > > * Adjust Kconfig to 80 characters > > > --- > > > drivers/platform/x86/amd/Kconfig | 1 + > > > drivers/platform/x86/amd/Makefile | 1 + > > > drivers/platform/x86/amd/hfi/Kconfig | 20 ++++ > > > drivers/platform/x86/amd/hfi/Makefile | 7 ++ > > > drivers/platform/x86/amd/hfi/hfi.c | 162 ++++++++++++++++++++++++++ > > > 5 files changed, 191 insertions(+) > > > create mode 100644 drivers/platform/x86/amd/hfi/Kconfig > > > create mode 100644 drivers/platform/x86/amd/hfi/Makefile > > > create mode 100644 drivers/platform/x86/amd/hfi/hfi.c > > > > > > diff --git a/drivers/platform/x86/amd/Kconfig > > > b/drivers/platform/x86/amd/Kconfig > > > index c3e086ea64fc6..589d61ebf726b 100644 > > > --- a/drivers/platform/x86/amd/Kconfig > > > +++ b/drivers/platform/x86/amd/Kconfig > > > @@ -6,6 +6,7 @@ > > > source "drivers/platform/x86/amd/hsmp/Kconfig" > > > source "drivers/platform/x86/amd/pmf/Kconfig" > > > source "drivers/platform/x86/amd/pmc/Kconfig" > > > +source "drivers/platform/x86/amd/hfi/Kconfig" > > > config AMD_3D_VCACHE > > > tristate "AMD 3D V-Cache Performance Optimizer Driver" > > > diff --git a/drivers/platform/x86/amd/Makefile > > > b/drivers/platform/x86/amd/Makefile > > > index 56f62fc9c97b4..c50e93c3334cf 100644 > > > --- a/drivers/platform/x86/amd/Makefile > > > +++ b/drivers/platform/x86/amd/Makefile > > > @@ -10,3 +10,4 @@ obj-$(CONFIG_AMD_PMC) += pmc/ > > > obj-$(CONFIG_AMD_HSMP) += hsmp/ > > > obj-$(CONFIG_AMD_PMF) += pmf/ > > > obj-$(CONFIG_AMD_WBRF) += wbrf.o > > > +obj-$(CONFIG_AMD_HFI) += hfi/ > > > diff --git a/drivers/platform/x86/amd/hfi/Kconfig > > > b/drivers/platform/x86/amd/hfi/Kconfig > > > new file mode 100644 > > > index 0000000000000..532939eb08a6a > > > --- /dev/null > > > +++ b/drivers/platform/x86/amd/hfi/Kconfig > > > @@ -0,0 +1,20 @@ > > > +# SPDX-License-Identifier: GPL-2.0-only > > > +# > > > +# AMD Hardware Feedback Interface Driver > > > +# > > > + > > > +config AMD_HFI > > > + bool "AMD Hetero Core Hardware Feedback Driver" > > > + depends on ACPI > > > + depends on CPU_SUP_AMD > > > + help > > > + Select this option to enable the AMD Heterogeneous Core Hardware > > > + Feedback Interface. If selected, hardware provides runtime thread > > > + classification guidance to the operating system on the performance > > > and > > > + energy efficiency capabilities of each heterogeneous CPU core. These > > > + capabilities may vary due to the inherent differences in the core > > > types > > > + and can also change as a result of variations in the operating > > > + conditions of the system such as power and thermal limits. If > > > selected, > > > > This says the capabilities can change but metadata is only read and scores > > updated during probe? > > > > > + the kernel relays updates in heterogeneous CPUs' capabilities to > > > + userspace, allowing for more optimal task scheduling and resource > > > + allocation, leveraging the diverse set of cores available. > > > > How are the capabilities communicated to userspace as mentioned here? I'm > > asking this because I only noted debugfs interface, and that commit > > claimed the debug fs interface was to troubleshoot scheduler issues. > > This is one of those cases that the split into multiple parts shows. Thinking > through I feel it makes more sense to adjust for now and then we can change it > again on the next part. > > > > > > diff --git a/drivers/platform/x86/amd/hfi/Makefile > > > b/drivers/platform/x86/amd/hfi/Makefile > > > new file mode 100644 > > > index 0000000000000..672c6ac106e95 > > > --- /dev/null > > > +++ b/drivers/platform/x86/amd/hfi/Makefile > > > @@ -0,0 +1,7 @@ > > > +# SPDX-License-Identifier: GPL-2.0 > > > +# > > > +# AMD Hardware Feedback Interface Driver > > > +# > > > + > > > +obj-$(CONFIG_AMD_HFI) += amd_hfi.o > > > +amd_hfi-objs := hfi.o > > > diff --git a/drivers/platform/x86/amd/hfi/hfi.c > > > b/drivers/platform/x86/amd/hfi/hfi.c > > > new file mode 100644 > > > index 0000000000000..426f7e520b76c > > > --- /dev/null > > > +++ b/drivers/platform/x86/amd/hfi/hfi.c > > > @@ -0,0 +1,162 @@ > > > +// SPDX-License-Identifier: GPL-2.0-or-later > > > +/* > > > + * AMD Hardware Feedback Interface Driver > > > + * > > > + * Copyright (C) 2024 Advanced Micro Devices, Inc. All Rights Reserved. > > > > 2025 ? > > Ack. > > Heh, earlier versions started in 2024! > > > > + * > > > + * Authors: Perry Yuan <Perry.Yuan@amd.com> > > > + * Mario Limonciello <mario.limonciello@amd.com> > > > + */ > > > + > > > +#define pr_fmt(fmt) "amd-hfi: " fmt > > > + > > > +#include <linux/acpi.h> > > > +#include <linux/cpu.h> > > > +#include <linux/cpumask.h> > > > +#include <linux/gfp.h> > > > +#include <linux/init.h> > > > +#include <linux/io.h> > > > +#include <linux/kernel.h> > > > +#include <linux/module.h> > > > +#include <linux/mutex.h> > > > +#include <linux/platform_device.h> > > > +#include <linux/smp.h> > > > + > > > +#define AMD_HFI_DRIVER "amd_hfi" > > > + > > > +#define AMD_HETERO_CPUID_27 0x80000027 > > > + > > > +static struct platform_device *device; > > > + > > > +struct amd_hfi_data { > > > + const char *name; > > > + struct device *dev; > > > + struct mutex lock; > > > > Please mention what this protects. > > As a comment at the end like this, right? > > struct mutex lock; /* lock the foo */ Yes.
diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig index c3e086ea64fc6..589d61ebf726b 100644 --- a/drivers/platform/x86/amd/Kconfig +++ b/drivers/platform/x86/amd/Kconfig @@ -6,6 +6,7 @@ source "drivers/platform/x86/amd/hsmp/Kconfig" source "drivers/platform/x86/amd/pmf/Kconfig" source "drivers/platform/x86/amd/pmc/Kconfig" +source "drivers/platform/x86/amd/hfi/Kconfig" config AMD_3D_VCACHE tristate "AMD 3D V-Cache Performance Optimizer Driver" diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile index 56f62fc9c97b4..c50e93c3334cf 100644 --- a/drivers/platform/x86/amd/Makefile +++ b/drivers/platform/x86/amd/Makefile @@ -10,3 +10,4 @@ obj-$(CONFIG_AMD_PMC) += pmc/ obj-$(CONFIG_AMD_HSMP) += hsmp/ obj-$(CONFIG_AMD_PMF) += pmf/ obj-$(CONFIG_AMD_WBRF) += wbrf.o +obj-$(CONFIG_AMD_HFI) += hfi/ diff --git a/drivers/platform/x86/amd/hfi/Kconfig b/drivers/platform/x86/amd/hfi/Kconfig new file mode 100644 index 0000000000000..532939eb08a6a --- /dev/null +++ b/drivers/platform/x86/amd/hfi/Kconfig @@ -0,0 +1,20 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# AMD Hardware Feedback Interface Driver +# + +config AMD_HFI + bool "AMD Hetero Core Hardware Feedback Driver" + depends on ACPI + depends on CPU_SUP_AMD + help + Select this option to enable the AMD Heterogeneous Core Hardware + Feedback Interface. If selected, hardware provides runtime thread + classification guidance to the operating system on the performance and + energy efficiency capabilities of each heterogeneous CPU core. These + capabilities may vary due to the inherent differences in the core types + and can also change as a result of variations in the operating + conditions of the system such as power and thermal limits. If selected, + the kernel relays updates in heterogeneous CPUs' capabilities to + userspace, allowing for more optimal task scheduling and resource + allocation, leveraging the diverse set of cores available. diff --git a/drivers/platform/x86/amd/hfi/Makefile b/drivers/platform/x86/amd/hfi/Makefile new file mode 100644 index 0000000000000..672c6ac106e95 --- /dev/null +++ b/drivers/platform/x86/amd/hfi/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# AMD Hardware Feedback Interface Driver +# + +obj-$(CONFIG_AMD_HFI) += amd_hfi.o +amd_hfi-objs := hfi.o diff --git a/drivers/platform/x86/amd/hfi/hfi.c b/drivers/platform/x86/amd/hfi/hfi.c new file mode 100644 index 0000000000000..426f7e520b76c --- /dev/null +++ b/drivers/platform/x86/amd/hfi/hfi.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * AMD Hardware Feedback Interface Driver + * + * Copyright (C) 2024 Advanced Micro Devices, Inc. All Rights Reserved. + * + * Authors: Perry Yuan <Perry.Yuan@amd.com> + * Mario Limonciello <mario.limonciello@amd.com> + */ + +#define pr_fmt(fmt) "amd-hfi: " fmt + +#include <linux/acpi.h> +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/gfp.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/smp.h> + +#define AMD_HFI_DRIVER "amd_hfi" + +#define AMD_HETERO_CPUID_27 0x80000027 + +static struct platform_device *device; + +struct amd_hfi_data { + const char *name; + struct device *dev; + struct mutex lock; +}; + +struct amd_hfi_classes { + u32 perf; + u32 eff; +}; + +/** + * struct amd_hfi_cpuinfo - HFI workload class info per CPU + * @cpu: cpu index + * @class_index: workload class ID index + * @nr_class: max number of workload class supported + * @amd_hfi_classes: current cpu workload class ranking data + * + * Parameters of a logical processor linked with hardware feedback class + */ +struct amd_hfi_cpuinfo { + int cpu; + s16 class_index; + u8 nr_class; + struct amd_hfi_classes *amd_hfi_classes; +}; + +static DEFINE_PER_CPU(struct amd_hfi_cpuinfo, amd_hfi_cpuinfo) = {.class_index = -1}; + +static int amd_hfi_alloc_class_data(struct platform_device *pdev) +{ + struct amd_hfi_cpuinfo *hfi_cpuinfo; + struct device *dev = &pdev->dev; + int idx; + int nr_class_id; + + nr_class_id = cpuid_eax(AMD_HETERO_CPUID_27); + if (nr_class_id < 0 || nr_class_id > 255) { + dev_err(dev, "failed to get number of supported classes: %d\n", + nr_class_id); + return -EINVAL; + } + + for_each_possible_cpu(idx) { + struct amd_hfi_classes *classes; + + classes = devm_kcalloc(dev, + nr_class_id, + sizeof(struct amd_hfi_classes), + GFP_KERNEL); + if (!classes) + return -ENOMEM; + hfi_cpuinfo = per_cpu_ptr(&amd_hfi_cpuinfo, idx); + hfi_cpuinfo->amd_hfi_classes = classes; + hfi_cpuinfo->nr_class = nr_class_id; + } + + return 0; +} + +static const struct acpi_device_id amd_hfi_platform_match[] = { + {"AMDI0104", 0}, + { } +}; +MODULE_DEVICE_TABLE(acpi, amd_hfi_platform_match); + +static int amd_hfi_probe(struct platform_device *pdev) +{ + struct amd_hfi_data *amd_hfi_data; + int ret; + + if (!acpi_match_device(amd_hfi_platform_match, &pdev->dev)) + return -ENODEV; + + amd_hfi_data = devm_kzalloc(&pdev->dev, sizeof(*amd_hfi_data), GFP_KERNEL); + if (!amd_hfi_data) + return -ENOMEM; + + amd_hfi_data->dev = &pdev->dev; + ret = devm_mutex_init(&pdev->dev, &amd_hfi_data->lock); + if (ret) + return ret; + platform_set_drvdata(pdev, amd_hfi_data); + + ret = amd_hfi_alloc_class_data(pdev); + if (ret) + return ret; + + return 0; +} + +static struct platform_driver amd_hfi_driver = { + .driver = { + .name = AMD_HFI_DRIVER, + .owner = THIS_MODULE, + .acpi_match_table = ACPI_PTR(amd_hfi_platform_match), + }, + .probe = amd_hfi_probe, +}; + +static int __init amd_hfi_init(void) +{ + int ret; + + if (acpi_disabled || + !cpu_feature_enabled(X86_FEATURE_AMD_HETEROGENEOUS_CORES) || + !cpu_feature_enabled(X86_FEATURE_AMD_WORKLOAD_CLASS)) + return -ENODEV; + + device = platform_device_register_simple(AMD_HFI_DRIVER, -1, NULL, 0); + if (IS_ERR(device)) { + pr_err("unable to register HFI platform device\n"); + return PTR_ERR(device); + } + + ret = platform_driver_register(&amd_hfi_driver); + if (ret) + pr_err("failed to register HFI driver\n"); + + return ret; +} + +static __exit void amd_hfi_exit(void) +{ + platform_device_unregister(device); + platform_driver_unregister(&amd_hfi_driver); +} +module_init(amd_hfi_init); +module_exit(amd_hfi_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("AMD Hardware Feedback Interface Driver");