Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH v6 1/1] powerpc/pseries: Interface to represent PAPR firmware attributes | From | Pratik Sampat <> | Date | Tue, 20 Jul 2021 19:25:57 +0530 |
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On 20/07/21 7:02 pm, kajoljain wrote: > > On 7/20/21 11:04 AM, Pratik R. Sampat wrote: >> Adds a generic interface to represent the energy and frequency related >> PAPR attributes on the system using the new H_CALL >> "H_GET_ENERGY_SCALE_INFO". >> >> H_GET_EM_PARMS H_CALL was previously responsible for exporting this >> information in the lparcfg, however the H_GET_EM_PARMS H_CALL >> will be deprecated P10 onwards. >> >> The H_GET_ENERGY_SCALE_INFO H_CALL is of the following call format: >> hcall( >> uint64 H_GET_ENERGY_SCALE_INFO, // Get energy scale info >> uint64 flags, // Per the flag request >> uint64 firstAttributeId,// The attribute id >> uint64 bufferAddress, // Guest physical address of the output buffer >> uint64 bufferSize // The size in bytes of the output buffer >> ); >> >> This H_CALL can query either all the attributes at once with >> firstAttributeId = 0, flags = 0 as well as query only one attribute >> at a time with firstAttributeId = id, flags = 1. >> >> The output buffer consists of the following >> 1. number of attributes - 8 bytes >> 2. array offset to the data location - 8 bytes >> 3. version info - 1 byte >> 4. A data array of size num attributes, which contains the following: >> a. attribute ID - 8 bytes >> b. attribute value in number - 8 bytes >> c. attribute name in string - 64 bytes >> d. attribute value in string - 64 bytes >> >> The new H_CALL exports information in direct string value format, hence >> a new interface has been introduced in >> /sys/firmware/papr/energy_scale_info to export this information to >> userspace in an extensible pass-through format. >> >> The H_CALL returns the name, numeric value and string value (if exists) >> >> The format of exposing the sysfs information is as follows: >> /sys/firmware/papr/energy_scale_info/ >> |-- <id>/ >> |-- desc >> |-- value >> |-- value_desc (if exists) >> |-- <id>/ >> |-- desc >> |-- value >> |-- value_desc (if exists) >> ... >> >> The energy information that is exported is useful for userspace tools >> such as powerpc-utils. Currently these tools infer the >> "power_mode_data" value in the lparcfg, which in turn is obtained from >> the to be deprecated H_GET_EM_PARMS H_CALL. >> On future platforms, such userspace utilities will have to look at the >> data returned from the new H_CALL being populated in this new sysfs >> interface and report this information directly without the need of >> interpretation. >> >> Signed-off-by: Pratik R. Sampat <psampat@linux.ibm.com> >> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> >> --- >> .../sysfs-firmware-papr-energy-scale-info | 26 ++ >> arch/powerpc/include/asm/hvcall.h | 24 +- >> arch/powerpc/kvm/trace_hv.h | 1 + >> arch/powerpc/platforms/pseries/Makefile | 3 +- >> .../pseries/papr_platform_attributes.c | 312 ++++++++++++++++++ >> 5 files changed, 364 insertions(+), 2 deletions(-) >> create mode 100644 Documentation/ABI/testing/sysfs-firmware-papr-energy-scale-info >> create mode 100644 arch/powerpc/platforms/pseries/papr_platform_attributes.c >> >> diff --git a/Documentation/ABI/testing/sysfs-firmware-papr-energy-scale-info b/Documentation/ABI/testing/sysfs-firmware-papr-energy-scale-info >> new file mode 100644 >> index 000000000000..139a576c7c9d >> --- /dev/null >> +++ b/Documentation/ABI/testing/sysfs-firmware-papr-energy-scale-info >> @@ -0,0 +1,26 @@ >> +What: /sys/firmware/papr/energy_scale_info >> +Date: June 2021 >> +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> >> +Description: Directory hosting a set of platform attributes like >> + energy/frequency on Linux running as a PAPR guest. >> + >> + Each file in a directory contains a platform >> + attribute hierarchy pertaining to performance/ >> + energy-savings mode and processor frequency. >> + >> +What: /sys/firmware/papr/energy_scale_info/<id> >> + /sys/firmware/papr/energy_scale_info/<id>/desc >> + /sys/firmware/papr/energy_scale_info/<id>/value >> + /sys/firmware/papr/energy_scale_info/<id>/value_desc >> +Date: June 2021 >> +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> >> +Description: Energy, frequency attributes directory for POWERVM servers >> + >> + This directory provides energy, frequency, folding information. It >> + contains below sysfs attributes: >> + >> + - desc: String description of the attribute <id> >> + >> + - value: Numeric value of attribute <id> >> + >> + - value_desc: String value of attribute <id> >> diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h >> index e3b29eda8074..c91714ea6719 100644 >> --- a/arch/powerpc/include/asm/hvcall.h >> +++ b/arch/powerpc/include/asm/hvcall.h >> @@ -316,7 +316,8 @@ >> #define H_SCM_PERFORMANCE_STATS 0x418 >> #define H_RPT_INVALIDATE 0x448 >> #define H_SCM_FLUSH 0x44C >> -#define MAX_HCALL_OPCODE H_SCM_FLUSH >> +#define H_GET_ENERGY_SCALE_INFO 0x450 >> +#define MAX_HCALL_OPCODE H_GET_ENERGY_SCALE_INFO >> >> /* Scope args for H_SCM_UNBIND_ALL */ >> #define H_UNBIND_SCOPE_ALL (0x1) >> @@ -631,6 +632,27 @@ struct hv_gpci_request_buffer { >> uint8_t bytes[HGPCI_MAX_DATA_BYTES]; >> } __packed; >> >> +#define ESI_VERSION 0x1 >> +#define MAX_ESI_ATTRS 10 >> +#define MAX_BUF_SZ (sizeof(struct h_energy_scale_info_hdr) + \ >> + (sizeof(struct energy_scale_attribute) * MAX_ESI_ATTRS)) >> + >> +struct energy_scale_attribute { >> + __be64 id; >> + __be64 value; >> + unsigned char desc[64]; >> + unsigned char value_desc[64]; >> +} __packed; >> + >> +struct h_energy_scale_info_hdr { >> + __be64 num_attrs; >> + __be64 array_offset; >> + __u8 data_header_version; >> +} __packed; >> + >> +/* /sys/firmware/papr */ >> +extern struct kobject *papr_kobj; >> + >> #endif /* __ASSEMBLY__ */ >> #endif /* __KERNEL__ */ >> #endif /* _ASM_POWERPC_HVCALL_H */ >> diff --git a/arch/powerpc/kvm/trace_hv.h b/arch/powerpc/kvm/trace_hv.h >> index 830a126e095d..38cd0ed0a617 100644 >> --- a/arch/powerpc/kvm/trace_hv.h >> +++ b/arch/powerpc/kvm/trace_hv.h >> @@ -115,6 +115,7 @@ >> {H_VASI_STATE, "H_VASI_STATE"}, \ >> {H_ENABLE_CRQ, "H_ENABLE_CRQ"}, \ >> {H_GET_EM_PARMS, "H_GET_EM_PARMS"}, \ >> + {H_GET_ENERGY_SCALE_INFO, "H_GET_ENERGY_SCALE_INFO"}, \ >> {H_SET_MPP, "H_SET_MPP"}, \ >> {H_GET_MPP, "H_GET_MPP"}, \ >> {H_HOME_NODE_ASSOCIATIVITY, "H_HOME_NODE_ASSOCIATIVITY"}, \ >> diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile >> index c8a2b0b05ac0..d14fca89ac25 100644 >> --- a/arch/powerpc/platforms/pseries/Makefile >> +++ b/arch/powerpc/platforms/pseries/Makefile >> @@ -6,7 +6,8 @@ obj-y := lpar.o hvCall.o nvram.o reconfig.o \ >> of_helpers.o \ >> setup.o iommu.o event_sources.o ras.o \ >> firmware.o power.o dlpar.o mobility.o rng.o \ >> - pci.o pci_dlpar.o eeh_pseries.o msi.o >> + pci.o pci_dlpar.o eeh_pseries.o msi.o \ >> + papr_platform_attributes.o >> obj-$(CONFIG_SMP) += smp.o >> obj-$(CONFIG_SCANLOG) += scanlog.o >> obj-$(CONFIG_KEXEC_CORE) += kexec.o >> diff --git a/arch/powerpc/platforms/pseries/papr_platform_attributes.c b/arch/powerpc/platforms/pseries/papr_platform_attributes.c >> new file mode 100644 >> index 000000000000..d0373925ad32 >> --- /dev/null >> +++ b/arch/powerpc/platforms/pseries/papr_platform_attributes.c >> @@ -0,0 +1,312 @@ >> +// SPDX-License-Identifier: GPL-2.0-or-later >> +/* >> + * Platform energy and frequency attributes driver >> + * >> + * This driver creates a sys file at /sys/firmware/papr/ which encapsulates a >> + * directory structure containing files in keyword - value pairs that specify >> + * energy and frequency configuration of the system. >> + * >> + * The format of exposing the sysfs information is as follows: >> + * /sys/firmware/papr/energy_scale_info/ >> + * |-- <id>/ >> + * |-- desc >> + * |-- value >> + * |-- value_desc (if exists) >> + * |-- <id>/ >> + * |-- desc >> + * |-- value >> + * |-- value_desc (if exists) >> + * >> + * Copyright 2021 IBM Corp. >> + */ >> + >> +#include <asm/hvcall.h> >> +#include <asm/machdep.h> >> + >> +#include "pseries.h" >> + >> +/* >> + * Flag attributes to fetch either all or one attribute from the HCALL >> + * flag = BE(0) => fetch all attributes with firstAttributeId = 0 >> + * flag = BE(1) => fetch a single attribute with firstAttributeId = id >> + */ >> +#define ESI_FLAGS_ALL 0 >> +#define ESI_FLAGS_SINGLE PPC_BIT(0) >> + >> +#define MAX_ATTRS 3 >> + >> +struct papr_attr { >> + u64 id; >> + struct kobj_attribute kobj_attr; >> +}; >> +struct papr_group { >> + struct attribute_group pg; >> + struct papr_attr pgattrs[MAX_ATTRS]; >> +} *pgs; >> + >> +/* /sys/firmware/papr */ >> +struct kobject *papr_kobj; >> +/* /sys/firmware/papr/energy_scale_info */ >> +struct kobject *esi_kobj; >> + >> +/* >> + * Extract and export the description of the energy scale attributes >> + */ >> +static ssize_t papr_show_desc(struct kobject *kobj, >> + struct kobj_attribute *kobj_attr, >> + char *buf) >> +{ >> + struct papr_attr *pattr = container_of(kobj_attr, struct papr_attr, >> + kobj_attr); >> + struct h_energy_scale_info_hdr *t_hdr; >> + struct energy_scale_attribute *t_esi; >> + char *t_buf; >> + int ret = 0; >> + >> + t_buf = kmalloc(MAX_BUF_SZ, GFP_KERNEL); >> + if (t_buf == NULL) >> + return -ENOMEM; >> + >> + ret = plpar_hcall_norets(H_GET_ENERGY_SCALE_INFO, ESI_FLAGS_SINGLE, >> + pattr->id, virt_to_phys(t_buf), >> + MAX_BUF_SZ); >> + >> + if (ret != H_SUCCESS) { >> + pr_warn("hcall failed: H_GET_ENERGY_SCALE_INFO"); >> + goto out; >> + } >> + >> + t_hdr = (struct h_energy_scale_info_hdr *) t_buf; >> + t_esi = (struct energy_scale_attribute *) >> + (t_buf + be64_to_cpu(t_hdr->array_offset)); >> + >> + ret = snprintf(buf, sizeof(t_esi->desc), "%s\n", t_esi->desc); >> + if (ret < 0) >> + ret = -EIO; >> +out: >> + kfree(t_buf); >> + >> + return ret; >> +} >> + >> +/* >> + * Extract and export the numeric value of the energy scale attributes >> + */ >> +static ssize_t papr_show_value(struct kobject *kobj, >> + struct kobj_attribute *kobj_attr, >> + char *buf) >> +{ >> + struct papr_attr *pattr = container_of(kobj_attr, struct papr_attr, >> + kobj_attr); >> + struct h_energy_scale_info_hdr *t_hdr; >> + struct energy_scale_attribute *t_esi; >> + char *t_buf; >> + int ret = 0; >> + >> + t_buf = kmalloc(MAX_BUF_SZ, GFP_KERNEL); >> + if (t_buf == NULL) >> + return -ENOMEM; >> + >> + ret = plpar_hcall_norets(H_GET_ENERGY_SCALE_INFO, ESI_FLAGS_SINGLE, >> + pattr->id, virt_to_phys(t_buf), >> + MAX_BUF_SZ); >> + >> + if (ret != H_SUCCESS) { >> + pr_warn("hcall failed: H_GET_ENERGY_SCALE_INFO"); >> + goto out; >> + } >> + >> + t_hdr = (struct h_energy_scale_info_hdr *) t_buf; >> + t_esi = (struct energy_scale_attribute *) >> + (t_buf + be64_to_cpu(t_hdr->array_offset)); >> + >> + ret = snprintf(buf, sizeof(t_esi->value), "%llu\n", >> + be64_to_cpu(t_esi->value)); >> + if (ret < 0) >> + ret = -EIO; >> +out: >> + kfree(t_buf); >> + >> + return ret; >> +} >> + >> +/* >> + * Extract and export the value description in string format of the energy >> + * scale attributes >> + */ >> +static ssize_t papr_show_value_desc(struct kobject *kobj, >> + struct kobj_attribute *kobj_attr, >> + char *buf) >> +{ >> + struct papr_attr *pattr = container_of(kobj_attr, struct papr_attr, >> + kobj_attr); >> + struct h_energy_scale_info_hdr *t_hdr; >> + struct energy_scale_attribute *t_esi; >> + char *t_buf; >> + int ret = 0; >> + >> + t_buf = kmalloc(MAX_BUF_SZ, GFP_KERNEL); >> + if (t_buf == NULL) >> + return -ENOMEM; >> + >> + ret = plpar_hcall_norets(H_GET_ENERGY_SCALE_INFO, ESI_FLAGS_SINGLE, >> + pattr->id, virt_to_phys(t_buf), >> + MAX_BUF_SZ); >> + >> + if (ret != H_SUCCESS) { >> + pr_warn("hcall failed: H_GET_ENERGY_SCALE_INFO"); >> + goto out; >> + } >> + >> + t_hdr = (struct h_energy_scale_info_hdr *) t_buf; >> + t_esi = (struct energy_scale_attribute *) >> + (t_buf + be64_to_cpu(t_hdr->array_offset)); >> + >> + ret = snprintf(buf, sizeof(t_esi->value_desc), "%s\n", >> + t_esi->value_desc); >> + if (ret < 0) >> + ret = -EIO; >> +out: >> + kfree(t_buf); >> + >> + return ret; >> +} >> + >> +static struct papr_ops_info { >> + const char *attr_name; >> + ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *kobj_attr, >> + char *buf); >> +} ops_info[MAX_ATTRS] = { >> + { "desc", papr_show_desc }, >> + { "value", papr_show_value }, >> + { "value_desc", papr_show_value_desc }, >> +}; >> + >> +static void add_attr(u64 id, int index, struct papr_attr *attr) >> +{ >> + attr->id = id; >> + sysfs_attr_init(&attr->kobj_attr.attr); >> + attr->kobj_attr.attr.name = ops_info[index].attr_name; >> + attr->kobj_attr.attr.mode = 0444; >> + attr->kobj_attr.show = ops_info[index].show; >> +} >> + >> +static int add_attr_group(u64 id, struct papr_group *pg, bool show_val_desc) >> +{ >> + int i; >> + >> + for (i = 0; i < MAX_ATTRS; i++) { >> + if (!strcmp(ops_info[i].attr_name, "value_desc") && >> + !show_val_desc) { >> + continue; >> + } >> + add_attr(id, i, &pg->pgattrs[i]); >> + pg->pg.attrs[i] = &pg->pgattrs[i].kobj_attr.attr; >> + } >> + >> + return sysfs_create_group(esi_kobj, &pg->pg); >> +} >> + >> +static int __init papr_init(void) >> +{ >> + struct h_energy_scale_info_hdr *esi_hdr; >> + struct energy_scale_attribute *esi_attrs; >> + uint64_t num_attrs; >> + int ret, idx, i; >> + char *esi_buf; >> + >> + if (!firmware_has_feature(FW_FEATURE_LPAR)) >> + return -ENXIO; >> + >> + esi_buf = kmalloc(MAX_BUF_SZ, GFP_KERNEL); >> + if (esi_buf == NULL) >> + return -ENOMEM; >> + /* >> + * hcall( >> + * uint64 H_GET_ENERGY_SCALE_INFO, // Get energy scale info >> + * uint64 flags, // Per the flag request >> + * uint64 firstAttributeId, // The attribute id >> + * uint64 bufferAddress, // Guest physical address of the output buffer >> + * uint64 bufferSize); // The size in bytes of the output buffer >> + */ >> + ret = plpar_hcall_norets(H_GET_ENERGY_SCALE_INFO, ESI_FLAGS_ALL, 0, >> + virt_to_phys(esi_buf), MAX_BUF_SZ); >> + if (ret != H_SUCCESS) { >> + pr_warn("hcall failed: H_GET_ENERGY_SCALE_INFO"); >> + goto out; >> + } >> + >> + esi_hdr = (struct h_energy_scale_info_hdr *) esi_buf; >> + if (esi_hdr->data_header_version != ESI_VERSION) { >> + pr_warn("H_GET_ENERGY_SCALE_INFO VER MISMATCH - EXP: 0x%x, REC: 0x%x", >> + ESI_VERSION, esi_hdr->data_header_version); >> + } >> + >> + num_attrs = be64_to_cpu(esi_hdr->num_attrs); >> + esi_attrs = (struct energy_scale_attribute *) >> + (esi_buf + be64_to_cpu(esi_hdr->array_offset)); >> + >> + pgs = kcalloc(num_attrs, sizeof(*pgs), GFP_KERNEL); >> + if (!pgs) >> + goto out; >> + >> + papr_kobj = kobject_create_and_add("papr", firmware_kobj); >> + if (!papr_kobj) { >> + pr_warn("kobject_create_and_add papr failed\n"); >> + goto out_pgs; >> + } >> + >> + esi_kobj = kobject_create_and_add("energy_scale_info", papr_kobj); >> + if (!esi_kobj) { >> + pr_warn("kobject_create_and_add energy_scale_info failed\n"); >> + goto out_kobj; >> + } >> + >> + for (idx = 0; idx < num_attrs; idx++) { >> + bool show_val_desc = true; >> + >> + pgs[idx].pg.attrs = kcalloc(MAX_ATTRS + 1, >> + sizeof(*pgs[idx].pg.attrs), >> + GFP_KERNEL); >> + if (!pgs[idx].pg.attrs) { >> + goto out_pgattrs; >> + } >> + >> + pgs[idx].pg.name = kasprintf(GFP_KERNEL, "%lld", >> + be64_to_cpu(esi_attrs[idx].id)); >> + if (pgs[idx].pg.name == NULL) { >> + goto out_pgattrs; >> + } >> + /* Do not add the value description if it does not exist */ >> + if (strnlen(esi_attrs[idx].value_desc, >> + sizeof(esi_attrs[idx].value_desc)) == 0) >> + show_val_desc = false; >> + >> + if (add_attr_group(be64_to_cpu(esi_attrs[idx].id), &pgs[idx], >> + show_val_desc)) { >> + pr_warn("Failed to create papr attribute group %s\n", >> + pgs[idx].pg.name); >> + goto out_pgattrs; >> + } >> + } >> + >> + kfree(esi_buf); >> + return 0; >> + >> +out_pgattrs: > Hi Pratik, > Just a nit optimization, Can't we run this loop till idx rather then going all the way till > num_attrs as you are allocating memory sequentially?
Thank you for your review.
Yeah you're right, if we fail I do bail out then and there and I can iterate until idx instead of all the attributes.
~Pratik
> Thanks, > Kajol Jain > >> + for (i = 0; i < num_attrs ; i++) { >> + kfree(pgs[i].pg.attrs); >> + kfree(pgs[i].pg.name); >> + } >> + kobject_put(esi_kobj); >> +out_kobj: >> + kobject_put(papr_kobj); >> +out_pgs: >> + kfree(pgs); >> +out: >> + kfree(esi_buf); >> + >> + return -ENOMEM; >> +} >> + >> +machine_device_initcall(pseries, papr_init); >>
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