[PATCH v4 8/9] powerpc/pseries/vas: sysfs interface to export capabilities
Nicholas Piggin
npiggin at gmail.com
Wed Feb 23 18:29:13 AEDT 2022
Excerpts from Haren Myneni's message of February 20, 2022 6:01 am:
>
> The hypervisor provides the available VAS GZIP capabilities such
> as default or QoS window type and the target available credits in
> each type. This patch creates sysfs entries and exports the target,
> used and the available credits for each feature.
>
> This interface can be used by the user space to determine the credits
> usage or to set the target credits in the case of QoS type (for DLPAR).
>
> /sys/devices/vas/vas0/gzip/default_capabilities (default GZIP capabilities)
> nr_total_credits /* Total credits available. Can be
> /* changed with DLPAR operation */
> nr_used_credits /* Used credits */
>
> /sys/devices/vas/vas0/gzip/qos_capabilities (QoS GZIP capabilities)
> nr_total_credits
> nr_used_credits
>
Looks good, thanks
Reviewed-by: Nicholas Piggin <npiggin at gmail.com>
> Signed-off-by: Haren Myneni <haren at linux.ibm.com>
> ---
> arch/powerpc/platforms/pseries/Makefile | 2 +-
> arch/powerpc/platforms/pseries/vas-sysfs.c | 226 +++++++++++++++++++++
> arch/powerpc/platforms/pseries/vas.c | 6 +
> arch/powerpc/platforms/pseries/vas.h | 6 +
> 4 files changed, 239 insertions(+), 1 deletion(-)
> create mode 100644 arch/powerpc/platforms/pseries/vas-sysfs.c
>
> diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
> index ee60b59024b4..29b522d2c755 100644
> --- a/arch/powerpc/platforms/pseries/Makefile
> +++ b/arch/powerpc/platforms/pseries/Makefile
> @@ -29,6 +29,6 @@ obj-$(CONFIG_PPC_SVM) += svm.o
> obj-$(CONFIG_FA_DUMP) += rtas-fadump.o
>
> obj-$(CONFIG_SUSPEND) += suspend.o
> -obj-$(CONFIG_PPC_VAS) += vas.o
> +obj-$(CONFIG_PPC_VAS) += vas.o vas-sysfs.o
>
> obj-$(CONFIG_ARCH_HAS_CC_PLATFORM) += cc_platform.o
> diff --git a/arch/powerpc/platforms/pseries/vas-sysfs.c b/arch/powerpc/platforms/pseries/vas-sysfs.c
> new file mode 100644
> index 000000000000..e24d3edb3021
> --- /dev/null
> +++ b/arch/powerpc/platforms/pseries/vas-sysfs.c
> @@ -0,0 +1,226 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2022-23 IBM Corp.
> + */
> +
> +#define pr_fmt(fmt) "vas: " fmt
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/miscdevice.h>
> +#include <linux/kobject.h>
> +#include <linux/slab.h>
> +#include <linux/mm.h>
> +
> +#include "vas.h"
> +
> +#ifdef CONFIG_SYSFS
> +static struct kobject *pseries_vas_kobj;
> +static struct kobject *gzip_caps_kobj;
> +
> +struct vas_caps_entry {
> + struct kobject kobj;
> + struct vas_cop_feat_caps *caps;
> +};
> +
> +#define to_caps_entry(entry) container_of(entry, struct vas_caps_entry, kobj)
> +
> +#define sysfs_caps_entry_read(_name) \
> +static ssize_t _name##_show(struct vas_cop_feat_caps *caps, char *buf) \
> +{ \
> + return sprintf(buf, "%d\n", atomic_read(&caps->_name)); \
> +}
> +
> +struct vas_sysfs_entry {
> + struct attribute attr;
> + ssize_t (*show)(struct vas_cop_feat_caps *, char *);
> + ssize_t (*store)(struct vas_cop_feat_caps *, const char *, size_t);
> +};
> +
> +#define VAS_ATTR_RO(_name) \
> + sysfs_caps_entry_read(_name); \
> + static struct vas_sysfs_entry _name##_attribute = __ATTR(_name, \
> + 0444, _name##_show, NULL);
> +
> +/*
> + * Create sysfs interface:
> + * /sys/devices/vas/vas0/gzip/default_capabilities
> + * This directory contains the following VAS GZIP capabilities
> + * for the defaule credit type.
> + * /sys/devices/vas/vas0/gzip/default_capabilities/nr_total_credits
> + * Total number of default credits assigned to the LPAR which
> + * can be changed with DLPAR operation.
> + * /sys/devices/vas/vas0/gzip/default_capabilities/nr_used_credits
> + * Number of credits used by the user space. One credit will
> + * be assigned for each window open.
> + *
> + * /sys/devices/vas/vas0/gzip/qos_capabilities
> + * This directory contains the following VAS GZIP capabilities
> + * for the Quality of Service (QoS) credit type.
> + * /sys/devices/vas/vas0/gzip/qos_capabilities/nr_total_credits
> + * Total number of QoS credits assigned to the LPAR. The user
> + * has to define this value using HMC interface. It can be
> + * changed dynamically by the user.
> + * /sys/devices/vas/vas0/gzip/qos_capabilities/nr_used_credits
> + * Number of credits used by the user space.
> + */
> +
> +VAS_ATTR_RO(nr_total_credits);
> +VAS_ATTR_RO(nr_used_credits);
> +
> +static struct attribute *vas_capab_attrs[] = {
> + &nr_total_credits_attribute.attr,
> + &nr_used_credits_attribute.attr,
> + NULL,
> +};
> +
> +static ssize_t vas_type_show(struct kobject *kobj, struct attribute *attr,
> + char *buf)
> +{
> + struct vas_caps_entry *centry;
> + struct vas_cop_feat_caps *caps;
> + struct vas_sysfs_entry *entry;
> +
> + centry = to_caps_entry(kobj);
> + caps = centry->caps;
> + entry = container_of(attr, struct vas_sysfs_entry, attr);
> +
> + if (!entry->show)
> + return -EIO;
> +
> + return entry->show(caps, buf);
> +}
> +
> +static ssize_t vas_type_store(struct kobject *kobj, struct attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct vas_caps_entry *centry;
> + struct vas_cop_feat_caps *caps;
> + struct vas_sysfs_entry *entry;
> +
> + centry = to_caps_entry(kobj);
> + caps = centry->caps;
> + entry = container_of(attr, struct vas_sysfs_entry, attr);
> + if (!entry->store)
> + return -EIO;
> +
> + return entry->store(caps, buf, count);
> +}
> +
> +static void vas_type_release(struct kobject *kobj)
> +{
> + struct vas_caps_entry *centry = to_caps_entry(kobj);
> + kfree(centry);
> +}
> +
> +static const struct sysfs_ops vas_sysfs_ops = {
> + .show = vas_type_show,
> + .store = vas_type_store,
> +};
> +
> +static struct kobj_type vas_attr_type = {
> + .release = vas_type_release,
> + .sysfs_ops = &vas_sysfs_ops,
> + .default_attrs = vas_capab_attrs,
> +};
> +
> +static char *vas_caps_kobj_name(struct vas_cop_feat_caps *caps,
> + struct kobject **kobj)
> +{
> + if (caps->descriptor == VAS_GZIP_QOS_CAPABILITIES) {
> + *kobj = gzip_caps_kobj;
> + return "qos_capabilities";
> + } else if (caps->descriptor == VAS_GZIP_DEFAULT_CAPABILITIES) {
> + *kobj = gzip_caps_kobj;
> + return "default_capabilities";
> + } else
> + return "Unknown";
> +}
> +
> +/*
> + * Add feature specific capability dir entry.
> + * Ex: VDefGzip or VQosGzip
> + */
> +int sysfs_add_vas_caps(struct vas_cop_feat_caps *caps)
> +{
> + struct vas_caps_entry *centry;
> + struct kobject *kobj = NULL;
> + int ret = 0;
> + char *name;
> +
> + centry = kzalloc(sizeof(*centry), GFP_KERNEL);
> + if (!centry)
> + return -ENOMEM;
> +
> + kobject_init(¢ry->kobj, &vas_attr_type);
> + centry->caps = caps;
> + name = vas_caps_kobj_name(caps, &kobj);
> +
> + if (kobj) {
> + ret = kobject_add(¢ry->kobj, kobj, "%s", name);
> +
> + if (ret) {
> + pr_err("VAS: sysfs kobject add / event failed %d\n",
> + ret);
> + kobject_put(¢ry->kobj);
> + }
> + }
> +
> + return ret;
> +}
> +
> +static struct miscdevice vas_miscdev = {
> + .minor = MISC_DYNAMIC_MINOR,
> + .name = "vas",
> +};
> +
> +/*
> + * Add VAS and VasCaps (overall capabilities) dir entries.
> + */
> +int __init sysfs_pseries_vas_init(struct vas_all_caps *vas_caps)
> +{
> + int ret;
> +
> + ret = misc_register(&vas_miscdev);
> + if (ret < 0) {
> + pr_err("%s: register vas misc device failed\n", __func__);
> + return ret;
> + }
> +
> + /*
> + * The hypervisor does not expose multiple VAS instances, but can
> + * see multiple VAS instances on PowerNV. So create 'vas0' directory
> + * on pseries.
> + */
> + pseries_vas_kobj = kobject_create_and_add("vas0",
> + &vas_miscdev.this_device->kobj);
> + if (!pseries_vas_kobj) {
> + pr_err("Failed to create VAS sysfs entry\n");
> + return -ENOMEM;
> + }
> +
> + if ((vas_caps->feat_type & VAS_GZIP_QOS_FEAT_BIT) ||
> + (vas_caps->feat_type & VAS_GZIP_DEF_FEAT_BIT)) {
> + gzip_caps_kobj = kobject_create_and_add("gzip",
> + pseries_vas_kobj);
> + if (!gzip_caps_kobj) {
> + pr_err("Failed to create VAS GZIP capability entry\n");
> + kobject_put(pseries_vas_kobj);
> + return -ENOMEM;
> + }
> + }
> +
> + return 0;
> +}
> +
> +#else
> +int sysfs_add_vas_caps(struct vas_cop_feat_caps *caps)
> +{
> + return 0;
> +}
> +
> +int __init sysfs_pseries_vas_init(struct vas_all_caps *vas_caps)
> +{
> + return 0;
> +}
> +#endif
> diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c
> index 96178dd58adf..ca0ad191229d 100644
> --- a/arch/powerpc/platforms/pseries/vas.c
> +++ b/arch/powerpc/platforms/pseries/vas.c
> @@ -560,6 +560,10 @@ static int __init get_vas_capabilities(u8 feat, enum vas_cop_feat_type type,
> }
> }
>
> + rc = sysfs_add_vas_caps(caps);
> + if (rc)
> + return rc;
> +
> copypaste_feat = true;
>
> return 0;
> @@ -844,6 +848,8 @@ static int __init pseries_vas_init(void)
> caps_all.descriptor = be64_to_cpu(hv_caps->descriptor);
> caps_all.feat_type = be64_to_cpu(hv_caps->feat_type);
>
> + sysfs_pseries_vas_init(&caps_all);
> +
> hv_cop_caps = kmalloc(sizeof(*hv_cop_caps), GFP_KERNEL);
> if (!hv_cop_caps) {
> rc = -ENOMEM;
> diff --git a/arch/powerpc/platforms/pseries/vas.h b/arch/powerpc/platforms/pseries/vas.h
> index 701363cfd7c1..f1bdb776021e 100644
> --- a/arch/powerpc/platforms/pseries/vas.h
> +++ b/arch/powerpc/platforms/pseries/vas.h
> @@ -30,6 +30,9 @@
> #define VAS_COPY_PASTE_USER_MODE 0x00000001
> #define VAS_COP_OP_USER_MODE 0x00000010
>
> +#define VAS_GZIP_QOS_CAPABILITIES 0x56516F73477A6970
> +#define VAS_GZIP_DEFAULT_CAPABILITIES 0x56446566477A6970
> +
> /*
> * Co-processor feature - GZIP QoS windows or GZIP default windows
> */
> @@ -125,4 +128,7 @@ struct pseries_vas_window {
> char *name;
> int fault_virq;
> };
> +
> +int sysfs_add_vas_caps(struct vas_cop_feat_caps *caps);
> +int __init sysfs_pseries_vas_init(struct vas_all_caps *vas_caps);
> #endif /* _VAS_H */
> --
> 2.27.0
>
>
>
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