[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v3 05/15] xen/x86: introduce "cpufreq=amd-cppc" xen cmdline
Users need to set "cpufreq=amd-cppc" in xen cmdline to enable amd-cppc driver, which selects ACPI Collaborative Performance and Power Control (CPPC) on supported AMD hardware to provide a finer grained frequency control mechanism. `verbose` option can also be included to support verbose print. When users setting "cpufreq=amd-cppc", a new amd-cppc driver shall be registered and used. Actual implmentation will be introduced in the following commits. Xen is not expected to support both or mixed mode (CPPC & legacy PSS, _PCT, _PPC) operations, only one cpufreq driver gets registerd, either amd-cppc or legacy P-states driver, which is reflected and asserted by the incompatible flags XEN_PROCESSOR_PM_PX and XEN_PROCESSOR_PM_CPPC. Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx> --- v1 -> v2: - Obey to alphabetic sorting and also strict it with CONFIG_AMD - Remove unnecessary empty comment line - Use __initconst_cf_clobber for pre-filled structure cpufreq_driver - Make new switch-case code apply to Hygon CPUs too - Change ENOSYS with EOPNOTSUPP - Blanks around binary operator - Change all amd_/-pstate defined values to amd_/-cppc --- v2 -> v3 - refactor too long lines - Make sure XEN_PROCESSOR_PM_PX and XEN_PROCESSOR_PM_CPPC incompatible flags after cpufreq register registrantion --- docs/misc/xen-command-line.pandoc | 16 +++-- xen/arch/x86/acpi/cpufreq/Makefile | 1 + xen/arch/x86/acpi/cpufreq/acpi.c | 12 +++- xen/arch/x86/acpi/cpufreq/amd-cppc.c | 78 +++++++++++++++++++++++ xen/arch/x86/acpi/cpufreq/cpufreq.c | 34 +++++++++- xen/arch/x86/platform_hypercall.c | 11 +++- xen/drivers/cpufreq/cpufreq.c | 17 +++++ xen/include/acpi/cpufreq/cpufreq.h | 4 ++ xen/include/acpi/cpufreq/processor_perf.h | 7 +- xen/include/public/sysctl.h | 1 + 10 files changed, 169 insertions(+), 12 deletions(-) create mode 100644 xen/arch/x86/acpi/cpufreq/amd-cppc.c diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc index a440042471..b3c3ca2377 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -515,7 +515,7 @@ If set, force use of the performance counters for oprofile, rather than detectin available support. ### cpufreq -> `= none | {{ <boolean> | xen } { [:[powersave|performance|ondemand|userspace][,[<maxfreq>]][,[<minfreq>]]] } [,verbose]} | dom0-kernel | hwp[:[<hdc>][,verbose]]` +> `= none | {{ <boolean> | xen } { [:[powersave|performance|ondemand|userspace][,[<maxfreq>]][,[<minfreq>]]] } [,verbose]} | dom0-kernel | hwp[:[<hdc>][,verbose]] | amd-cppc[:[verbose]]` > Default: `xen` @@ -526,7 +526,7 @@ choice of `dom0-kernel` is deprecated and not supported by all Dom0 kernels. * `<maxfreq>` and `<minfreq>` are integers which represent max and min processor frequencies respectively. * `verbose` option can be included as a string or also as `verbose=<integer>` - for `xen`. It is a boolean for `hwp`. + for `xen`. It is a boolean for `hwp` and `amd-cppc`. * `hwp` selects Hardware-Controlled Performance States (HWP) on supported Intel hardware. HWP is a Skylake+ feature which provides better CPU power management. The default is disabled. If `hwp` is selected, but hardware @@ -534,13 +534,17 @@ choice of `dom0-kernel` is deprecated and not supported by all Dom0 kernels. * `<hdc>` is a boolean to enable Hardware Duty Cycling (HDC). HDC enables the processor to autonomously force physical package components into idle state. The default is enabled, but the option only applies when `hwp` is enabled. +* `amd-cppc` selects ACPI Collaborative Performance and Power Control (CPPC) + on supported AMD hardware to provide finer grained frequency control + mechanism. The default is disabled. User could use `;`-separated options to support universal options which they would like to try on any agnostic platform, *but* under priority order, like -`cpufreq=hwp;xen,verbose`. This first tries `hwp` and falls back to `xen` if -unavailable. Note: The `verbose` suboption is handled globally. Setting it -for either the primary or fallback option applies to both irrespective of where -it is specified. +`cpufreq=hwp;amd-cppc;xen,verbose`. This first tries `hwp` on Intel, or +`amd-cppc` on AMD, and it will fall back to `xen` if unavailable. Note: +The `verbose` suboption is handled globally. Setting it for either the +primary or fallback option applies to both irrespective of where it is +specified. Note: grub2 requires to escape or quote ';', so `"cpufreq=hwp;xen"` should be specified within double quotes inside grub.cfg. Refer to the grub2 diff --git a/xen/arch/x86/acpi/cpufreq/Makefile b/xen/arch/x86/acpi/cpufreq/Makefile index e7dbe434a8..a2ba34bda0 100644 --- a/xen/arch/x86/acpi/cpufreq/Makefile +++ b/xen/arch/x86/acpi/cpufreq/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_INTEL) += acpi.o +obj-$(CONFIG_AMD) += amd-cppc.o obj-y += cpufreq.o obj-$(CONFIG_INTEL) += hwp.o obj-$(CONFIG_AMD) += powernow.o diff --git a/xen/arch/x86/acpi/cpufreq/acpi.c b/xen/arch/x86/acpi/cpufreq/acpi.c index 0cf94ab2d6..49c1795b25 100644 --- a/xen/arch/x86/acpi/cpufreq/acpi.c +++ b/xen/arch/x86/acpi/cpufreq/acpi.c @@ -13,6 +13,7 @@ #include <xen/errno.h> #include <xen/delay.h> +#include <xen/domain.h> #include <xen/param.h> #include <xen/types.h> @@ -514,5 +515,14 @@ acpi_cpufreq_driver = { int __init acpi_cpufreq_register(void) { - return cpufreq_register_driver(&acpi_cpufreq_driver); + int ret; + + ret = cpufreq_register_driver(&acpi_cpufreq_driver); + if ( ret ) + return ret; + + if ( IS_ENABLED(CONFIG_AMD) ) + xen_processor_pmbits &= ~XEN_PROCESSOR_PM_CPPC; + + return ret; } diff --git a/xen/arch/x86/acpi/cpufreq/amd-cppc.c b/xen/arch/x86/acpi/cpufreq/amd-cppc.c new file mode 100644 index 0000000000..7d482140a2 --- /dev/null +++ b/xen/arch/x86/acpi/cpufreq/amd-cppc.c @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * amd-cppc.c - AMD Processor CPPC Frequency Driver + * + * Copyright (C) 2025 Advanced Micro Devices, Inc. All Rights Reserved. + * + * Author: Penny Zheng <penny.zheng@xxxxxxx> + * + * AMD CPPC cpufreq driver introduces a new CPU performance scaling design + * for AMD processors using the ACPI Collaborative Performance and Power + * Control (CPPC) feature which provides finer grained frequency control range. + */ + +#include <xen/domain.h> +#include <xen/init.h> +#include <xen/param.h> +#include <acpi/cpufreq/cpufreq.h> + +static bool __init amd_cppc_handle_option(const char *s, const char *end) +{ + int ret; + + ret = parse_boolean("verbose", s, end); + if ( ret >= 0 ) + { + cpufreq_verbose = ret; + return true; + } + + return false; +} + +int __init amd_cppc_cmdline_parse(const char *s, const char *e) +{ + do + { + const char *end = strpbrk(s, ",;"); + + if ( !amd_cppc_handle_option(s, end) ) + { + printk(XENLOG_WARNING + "cpufreq/amd-cppc: option '%.*s' not recognized\n", + (int)((end ?: e) - s), s); + + return -EINVAL; + } + + s = end ? end + 1 : NULL; + } while ( s && s < e ); + + return 0; +} + +static const struct cpufreq_driver __initconst_cf_clobber +amd_cppc_cpufreq_driver = +{ + .name = XEN_AMD_CPPC_DRIVER_NAME, +}; + +int __init amd_cppc_register_driver(void) +{ + int ret; + + if ( !cpu_has_cppc ) + { + xen_processor_pmbits &= ~XEN_PROCESSOR_PM_CPPC; + return -ENODEV; + } + + ret = cpufreq_register_driver(&amd_cppc_cpufreq_driver); + if ( ret ) + return ret; + + /* Remove possible fallback option */ + xen_processor_pmbits &= ~XEN_PROCESSOR_PM_PX; + + return ret; +} diff --git a/xen/arch/x86/acpi/cpufreq/cpufreq.c b/xen/arch/x86/acpi/cpufreq/cpufreq.c index 61e98b67bd..690a285f11 100644 --- a/xen/arch/x86/acpi/cpufreq/cpufreq.c +++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c @@ -148,6 +148,10 @@ static int __init cf_check cpufreq_driver_init(void) case CPUFREQ_none: ret = 0; break; + default: + printk(XENLOG_WARNING + "Unsupported cpufreq driver for vendor Intel\n"); + break; } if ( ret != -ENODEV ) @@ -157,7 +161,35 @@ static int __init cf_check cpufreq_driver_init(void) case X86_VENDOR_AMD: case X86_VENDOR_HYGON: - ret = IS_ENABLED(CONFIG_AMD) ? powernow_register_driver() : -ENODEV; + if ( !IS_ENABLED(CONFIG_AMD) ) + { + ret = -ENODEV; + break; + } + ret = -ENOENT; + + for ( unsigned int i = 0; i < cpufreq_xen_cnt; i++ ) + { + switch ( cpufreq_xen_opts[i] ) + { + case CPUFREQ_xen: + ret = powernow_register_driver(); + break; + case CPUFREQ_amd_cppc: + ret = amd_cppc_register_driver(); + break; + case CPUFREQ_none: + ret = 0; + break; + default: + printk(XENLOG_WARNING + "Unsupported cpufreq driver for vendor AMD\n"); + break; + } + + if ( ret != -ENODEV ) + break; + } break; } } diff --git a/xen/arch/x86/platform_hypercall.c b/xen/arch/x86/platform_hypercall.c index 77390a0dbd..5dd1ba2949 100644 --- a/xen/arch/x86/platform_hypercall.c +++ b/xen/arch/x86/platform_hypercall.c @@ -542,6 +542,7 @@ ret_t do_platform_op( ret = -ENOSYS; break; } + ASSERT(!(xen_processor_pmbits & XEN_PROCESSOR_PM_CPPC)); ret = set_px_pminfo(op->u.set_pminfo.id, &op->u.set_pminfo.u.perf); break; @@ -572,7 +573,8 @@ ret_t do_platform_op( break; } case XEN_PM_PSD: - if ( !(xen_processor_pmbits & XEN_PROCESSOR_PM_PX) ) + if ( !(xen_processor_pmbits & (XEN_PROCESSOR_PM_PX | + XEN_PROCESSOR_PM_CPPC)) ) { ret = -EOPNOTSUPP; break; @@ -584,6 +586,13 @@ ret_t do_platform_op( break; case XEN_PM_CPPC: + if ( !(xen_processor_pmbits & XEN_PROCESSOR_PM_CPPC) ) + { + ret = -EOPNOTSUPP; + break; + } + ASSERT(!(xen_processor_pmbits & XEN_PROCESSOR_PM_PX)); + ret = set_cppc_pminfo(op->u.set_pminfo.id, &op->u.set_pminfo.u.cppc_data); break; diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c index cfae16c15f..792e4dc02c 100644 --- a/xen/drivers/cpufreq/cpufreq.c +++ b/xen/drivers/cpufreq/cpufreq.c @@ -111,6 +111,19 @@ static int __init cpufreq_cmdline_parse_hwp(const char *arg, const char *end) return ret; } +static int __init cpufreq_cmdline_parse_cppc(const char *arg, const char *end) +{ + int ret = 0; + + xen_processor_pmbits |= XEN_PROCESSOR_PM_CPPC; + cpufreq_controller = FREQCTL_xen; + cpufreq_xen_opts[cpufreq_xen_cnt++] = CPUFREQ_amd_cppc; + if ( arg[0] && arg[1] ) + ret = amd_cppc_cmdline_parse(arg + 1, end); + + return ret; +} + static int __init cf_check setup_cpufreq_option(const char *str) { const char *arg = strpbrk(str, ",:;"); @@ -159,6 +172,10 @@ static int __init cf_check setup_cpufreq_option(const char *str) !cmdline_strcmp(str, "hwp") && !cpufreq_opts_contain(CPUFREQ_hwp) ) ret = cpufreq_cmdline_parse_hwp(arg, end); + else if ( IS_ENABLED(CONFIG_AMD) && choice < 0 && + !cmdline_strcmp(str, "amd-cppc") && + !cpufreq_opts_contain(CPUFREQ_amd_cppc) ) + ret = cpufreq_cmdline_parse_cppc(arg, end); else ret = -EINVAL; diff --git a/xen/include/acpi/cpufreq/cpufreq.h b/xen/include/acpi/cpufreq/cpufreq.h index 3f1b05a02e..a6fb10ea27 100644 --- a/xen/include/acpi/cpufreq/cpufreq.h +++ b/xen/include/acpi/cpufreq/cpufreq.h @@ -28,6 +28,7 @@ enum cpufreq_xen_opt { CPUFREQ_none, CPUFREQ_xen, CPUFREQ_hwp, + CPUFREQ_amd_cppc, }; extern enum cpufreq_xen_opt cpufreq_xen_opts[2]; extern unsigned int cpufreq_xen_cnt; @@ -267,4 +268,7 @@ int set_hwp_para(struct cpufreq_policy *policy, int acpi_cpufreq_register(void); +int amd_cppc_cmdline_parse(const char *s, const char *e); +int amd_cppc_register_driver(void); + #endif /* __XEN_CPUFREQ_PM_H__ */ diff --git a/xen/include/acpi/cpufreq/processor_perf.h b/xen/include/acpi/cpufreq/processor_perf.h index 33edf112a0..ee12e0192b 100644 --- a/xen/include/acpi/cpufreq/processor_perf.h +++ b/xen/include/acpi/cpufreq/processor_perf.h @@ -6,9 +6,10 @@ #include <xen/acpi.h> /* ability bits */ -#define XEN_PROCESSOR_PM_CX 1 -#define XEN_PROCESSOR_PM_PX 2 -#define XEN_PROCESSOR_PM_TX 4 +#define XEN_PROCESSOR_PM_CX 1 +#define XEN_PROCESSOR_PM_PX 2 +#define XEN_PROCESSOR_PM_TX 4 +#define XEN_PROCESSOR_PM_CPPC 8 #define XEN_CPPC_INIT 0x40000000U #define XEN_PX_INIT 0x80000000U diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index b0fec271d3..42997252ef 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -423,6 +423,7 @@ struct xen_set_cppc_para { uint32_t activity_window; }; +#define XEN_AMD_CPPC_DRIVER_NAME "amd-cppc" #define XEN_HWP_DRIVER_NAME "hwp" /* -- 2.34.1
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