Adds module init/exit code to create sysfs attributes for A64FX with "stream_detect_prefetcher_enable", "stream_detect_prefetcher_strong" and "stream_detect_prefetcher_dist". This driver works only if part number is FUJITSU_CPU_PART_A64FX. The details of the registers to be read and written in this patch are described below. "https://github.com/fujitsu/A64FX/tree/master/doc/"; A64FX_Specification_HPC_Extension_v1_EN.pdf Signed-off-by: Kohei Tarumizu <tarumizu.kohei@xxxxxxxxxxx> --- drivers/soc/fujitsu/a64fx-pfctl.c | 484 ++++++++++++++++++++++++++++++ 1 file changed, 484 insertions(+) create mode 100644 drivers/soc/fujitsu/a64fx-pfctl.c diff --git a/drivers/soc/fujitsu/a64fx-pfctl.c b/drivers/soc/fujitsu/a64fx-pfctl.c new file mode 100644 index 000000000000..1bb45a365c0f --- /dev/null +++ b/drivers/soc/fujitsu/a64fx-pfctl.c @@ -0,0 +1,484 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2022 FUJITSU LIMITED + * + * A64FX Hardware Prefetch Control support + */ +#include <asm/cputype.h> +#include <linux/cacheinfo.h> +#include <linux/cpu.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/smp.h> +#include <linux/sysfs.h> + +/* + * Constants for these add the "A64FX_SDPF" prefix to the name described in + * section "1.3.4.2. IMP_PF_STREAM_DETECT_CTRL_EL0" of "A64FX specification". + * (https://github.com/fujitsu/A64FX/tree/master/doc/A64FX_Specification_HPC_Extension_v1_EN.pdf";) + * See this document for register specification details. + */ +#define A64FX_SDPF_IMP_PF_STREAM_DETECT_CTRL_EL0 sys_reg(3, 3, 11, 4, 0) +#define A64FX_SDPF_V BIT_ULL(63) +#define A64FX_SDPF_L1PF_DIS BIT_ULL(59) +#define A64FX_SDPF_L2PF_DIS BIT_ULL(58) +#define A64FX_SDPF_L1W BIT_ULL(55) +#define A64FX_SDPF_L2W BIT_ULL(54) +#define A64FX_SDPF_L1_DIST GENMASK_ULL(27, 24) +#define A64FX_SDPF_L2_DIST GENMASK_ULL(19, 16) + +#define PFCTL_MIN_L1_DIST 256 +#define PFCTL_MIN_L2_DIST 1024 +#define PFCTL_DIST_AUTO_VAL 0 +#define PFCTL_STRONG_VAL 0 +#define PFCTL_WEAK_VAL 1 + +/* + * Define bitfield access macros for non-constant mask, because macros such as + * FIELD_FIT defined in include/linux/bitfield.h require constant mask. + */ +#define NC_FIELD_FIT(_mask, _val) \ + !((((typeof(_mask))_val) << __bf_shf(_mask)) & ~(_mask)) + +#define NC_FIELD_PREP(_mask, _val) \ + (((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask)) + +#define NC_FIELD_GET(_mask, _reg) \ + ((typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask))) + +struct a64fx_pfctl_attr { + struct device_attribute attr; + u64 mask; + void *data; +}; + +struct pfctl_group { + unsigned int level; + enum cache_type type; + const struct attribute_group **groups; +}; + +enum cpuhp_state hp_online; + +static const char strength_strong_string[] = "strong"; +static const char strength_weak_string[] = "weak"; +static const char dist_auto_string[] = "auto"; + +static inline unsigned int pfctl_dev_get_cpu(struct device *pfctl_dev) +{ + return *(u32 *)dev_get_drvdata(pfctl_dev); +} + +/* Enable the value written to the A64FX_SDPF_IMP_PF_STREAM_DETECT_CTRL_EL0 */ +static inline void enable_verify(u64 *reg) +{ + *reg |= NC_FIELD_PREP(A64FX_SDPF_V, 1); +} + +static void _pfctl_read_mask(void *_reg) +{ + u64 *reg = (u64 *)_reg; + + *reg = read_sysreg_s(A64FX_SDPF_IMP_PF_STREAM_DETECT_CTRL_EL0); +} + +static u64 pfctl_read_mask(unsigned int cpu, u64 mask) +{ + u64 reg; + + smp_call_function_single(cpu, _pfctl_read_mask, ®, true); + + return NC_FIELD_GET(mask, reg); +} + +struct write_info { + u64 mask; + u64 val; +}; + +static void _pfctl_write_mask(void *info) +{ + struct write_info *winfo = info; + u64 reg; + + reg = read_sysreg_s(A64FX_SDPF_IMP_PF_STREAM_DETECT_CTRL_EL0); + + reg &= ~winfo->mask; + reg |= NC_FIELD_PREP(winfo->mask, winfo->val); + + enable_verify(®); + + write_sysreg_s(reg, A64FX_SDPF_IMP_PF_STREAM_DETECT_CTRL_EL0); +} + +static int pfctl_write_mask(unsigned int cpu, u64 mask, u64 val) +{ + struct write_info info = { + .mask = mask, + .val = val, + }; + + if (!NC_FIELD_FIT(mask, val)) + return -EINVAL; + + smp_call_function_single(cpu, _pfctl_write_mask, &info, true); + + return 0; +} + +static ssize_t +pfctl_enable_show(struct device *pfctl_dev, struct device_attribute *attr, + char *buf) +{ + unsigned int cpu = pfctl_dev_get_cpu(pfctl_dev); + struct a64fx_pfctl_attr *aa; + bool val; + + aa = container_of(attr, struct a64fx_pfctl_attr, attr); + + val = (bool)pfctl_read_mask(cpu, aa->mask); + + return sysfs_emit(buf, "%d\n", val ? 0 : 1); +} + +static ssize_t +pfctl_enable_store(struct device *pfctl_dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + unsigned int cpu = pfctl_dev_get_cpu(pfctl_dev); + struct a64fx_pfctl_attr *aa; + bool val; + int ret; + + aa = container_of(attr, struct a64fx_pfctl_attr, attr); + + if (strtobool(buf, &val) < 0) + return -EINVAL; + + ret = pfctl_write_mask(cpu, aa->mask, val ? 0 : 1); + if (ret < 0) + return ret; + + return size; +} + +#define A64FX_PFCTL_ENABLE_ATTR(_level, _mask) \ + struct a64fx_pfctl_attr attr_l##_level##_enable = { \ + .attr = __ATTR(stream_detect_prefetcher_enable, 0600, \ + pfctl_enable_show, pfctl_enable_store), \ + .mask = _mask, } + + +static A64FX_PFCTL_ENABLE_ATTR(1, A64FX_SDPF_L1PF_DIS); +static A64FX_PFCTL_ENABLE_ATTR(2, A64FX_SDPF_L2PF_DIS); + +static ssize_t +pfctl_dist_show(struct device *pfctl_dev, struct device_attribute *attr, + char *buf) +{ + unsigned int cpu = pfctl_dev_get_cpu(pfctl_dev); + struct a64fx_pfctl_attr *aa; + u64 val, min_dist; + + aa = container_of(attr, struct a64fx_pfctl_attr, attr); + min_dist = (u64)aa->data; + + val = pfctl_read_mask(cpu, aa->mask); + + if (val == PFCTL_DIST_AUTO_VAL) + return sysfs_emit(buf, "%s\n", dist_auto_string); + else + return sysfs_emit(buf, "%llu\n", val * min_dist); +} + +static ssize_t +pfctl_dist_store(struct device *pfctl_dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + unsigned int cpu = pfctl_dev_get_cpu(pfctl_dev); + struct a64fx_pfctl_attr *aa; + u64 min_dist, val; + int ret; + + aa = container_of(attr, struct a64fx_pfctl_attr, attr); + min_dist = (u64)aa->data; + + if (sysfs_streq(buf, dist_auto_string)) { + val = PFCTL_DIST_AUTO_VAL; + } else { + ret = kstrtoull(buf, 10, &val); + if (ret < 0 || val < 1) + return -EINVAL; + } + + val = roundup(val, min_dist) / min_dist; + + if (!NC_FIELD_FIT(aa->mask, val)) + return -EINVAL; + + ret = pfctl_write_mask(cpu, aa->mask, val); + if (ret < 0) + return ret; + + return size; +} + +#define PFCTL_DIST_ATTR(_level, _mask, _min_dist) \ + struct a64fx_pfctl_attr attr_l##_level##_dist = { \ + .attr = __ATTR(stream_detect_prefetcher_dist, 0600, \ + pfctl_dist_show, pfctl_dist_store), \ + .mask = _mask, \ + .data = (void *)(u64)_min_dist, } + +static PFCTL_DIST_ATTR(1, A64FX_SDPF_L1_DIST, PFCTL_MIN_L1_DIST); +static PFCTL_DIST_ATTR(2, A64FX_SDPF_L2_DIST, PFCTL_MIN_L2_DIST); + +static ssize_t +pfctl_strength_show(struct device *pfctl_dev, struct device_attribute *attr, + char *buf) +{ + unsigned int cpu = pfctl_dev_get_cpu(pfctl_dev); + struct a64fx_pfctl_attr *aa; + u64 val; + + aa = container_of(attr, struct a64fx_pfctl_attr, attr); + + val = pfctl_read_mask(cpu, aa->mask); + + switch (val) { + case PFCTL_STRONG_VAL: + return sysfs_emit(buf, "%s\n", strength_strong_string); + case PFCTL_WEAK_VAL: + return sysfs_emit(buf, "%s\n", strength_weak_string); + default: + return -EINVAL; + } +} + +static ssize_t +pfctl_strength_store(struct device *pfctl_dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + unsigned int cpu = pfctl_dev_get_cpu(pfctl_dev); + struct a64fx_pfctl_attr *aa; + u64 val; + int ret; + + aa = container_of(attr, struct a64fx_pfctl_attr, attr); + + if (sysfs_streq(buf, strength_strong_string)) + val = PFCTL_STRONG_VAL; + else if (sysfs_streq(buf, strength_weak_string)) + val = PFCTL_WEAK_VAL; + else + return -EINVAL; + + ret = pfctl_write_mask(cpu, aa->mask, val); + if (ret < 0) + return ret; + + return size; +} + +#define PFCTL_STRENGTH_ATTR(_level, _mask) \ + struct a64fx_pfctl_attr attr_l##_level##_strength = { \ + .attr = __ATTR(stream_detect_prefetcher_strength, 0600, \ + pfctl_strength_show, \ + pfctl_strength_store), \ + .mask = _mask, } + +static PFCTL_STRENGTH_ATTR(1, A64FX_SDPF_L1W); +static PFCTL_STRENGTH_ATTR(2, A64FX_SDPF_L2W); + +static ssize_t +pfctl_strength_available_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s %s\n", strength_strong_string, + strength_weak_string); +} + +/* + * A64FX has same kind of available strength for any caches, so define only one + * attribute. + */ +struct a64fx_pfctl_attr attr_strength_available = { + .attr = __ATTR(stream_detect_prefetcher_strength_available, 0400, + pfctl_strength_available_show, NULL), }; + +static struct attribute *l1_attrs[] = { + &attr_l1_enable.attr.attr, + &attr_l1_dist.attr.attr, + &attr_l1_strength.attr.attr, + &attr_strength_available.attr.attr, + NULL, +}; + +static struct attribute *l2_attrs[] = { + &attr_l2_enable.attr.attr, + &attr_l2_dist.attr.attr, + &attr_l2_strength.attr.attr, + &attr_strength_available.attr.attr, + NULL, +}; + +static struct attribute_group l1_group = { + .attrs = l1_attrs, +}; + +static struct attribute_group l2_group = { + .attrs = l2_attrs, +}; + +static const struct attribute_group *l1_groups[] = { + &l1_group, + NULL, +}; + +static const struct attribute_group *l2_groups[] = { + &l2_group, + NULL, +}; + +static const struct pfctl_group pfctl_groups[] = { + { + .level = 1, + .type = CACHE_TYPE_DATA, + .groups = l1_groups, + }, + { + .level = 2, + .type = CACHE_TYPE_UNIFIED, + .groups = l2_groups, + }, + { + .groups = NULL, + }, +}; + +static const struct attribute_group ** +get_pfctl_attribute_groups(unsigned int level, enum cache_type type) +{ + int i; + + for (i = 0; pfctl_groups[i].groups; i++) + if ((level == pfctl_groups[i].level) && + (type == pfctl_groups[i].type)) + return pfctl_groups[i].groups; + + return NULL; +} + +static int create_pfctl_attr(struct device *index_dev, void *data) +{ + struct cacheinfo *leaf = dev_get_drvdata(index_dev); + const struct attribute_group **groups; + struct device *pfctl_dev; + + groups = get_pfctl_attribute_groups(leaf->level, leaf->type); + if (!groups) + return 0; + + pfctl_dev = cpu_device_create(index_dev, data, groups, + "prefetch_control"); + if (IS_ERR(pfctl_dev)) + return PTR_ERR(pfctl_dev); + + return 0; +} + +static int remove_pfctl_attr(struct device *index_dev, void *data) +{ + struct device *pfctl_dev; + + pfctl_dev = device_find_child_by_name(index_dev, "prefetch_control"); + if (!pfctl_dev) + return 0; + + device_unregister(pfctl_dev); + put_device(pfctl_dev); + + return 0; +} + +static int pfctl_online(unsigned int cpu) +{ + struct device *cpu_dev = get_cpu_device(cpu); + struct device *cache_dev; + int ret; + + cache_dev = device_find_child_by_name(cpu_dev, "cache"); + if (!cache_dev) + return -ENODEV; + + ret = device_for_each_child(cache_dev, &cpu_dev->id, create_pfctl_attr); + + put_device(cache_dev); + + return ret; +} + +static int pfctl_prepare_down(unsigned int cpu) +{ + struct device *cpu_dev = get_cpu_device(cpu); + struct device *cache_dev; + + cache_dev = device_find_child_by_name(cpu_dev, "cache"); + if (!cache_dev) + return 0; + + device_for_each_child(cache_dev, NULL, remove_pfctl_attr); + + put_device(cache_dev); + + return 0; +} + +static const struct midr_range pfctl_list[] __initconst = { + MIDR_ALL_VERSIONS(MIDR_FUJITSU_A64FX), +}; + +/* + * This driver returns a negative value if it does not support the Hardware + * Prefetch Control or if it is running on a VM guest. + */ +static int __init a64fx_pfctl_init(void) +{ + int ret; + + if (!is_kernel_in_hyp_mode()) + return -EINVAL; + + if (!is_midr_in_range_list(read_cpuid_id(), pfctl_list)) + return -ENODEV; + + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "soc/a64fx-pfctl:online", + pfctl_online, pfctl_prepare_down); + if (ret < 0) { + pr_err("failed to register hotplug callbacks\n"); + return ret; + } + + hp_online = ret; + + return 0; +} + +static void __exit a64fx_pfctl_exit(void) +{ + cpuhp_remove_state(hp_online); +} + +late_initcall(a64fx_pfctl_init); +module_exit(a64fx_pfctl_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("FUJITSU LIMITED"); +MODULE_DESCRIPTION("A64FX Hardware Prefetch Control Driver"); + +static const struct acpi_device_id fujitsu_acpi_match[] = { + { "FUJI2006", }, + {} +}; +MODULE_DEVICE_TABLE(acpi, fujitsu_acpi_match); -- 2.27.0
