On Tue, Jun 07, 2022 at 09:05:25PM +0900, Kohei Tarumizu wrote: > 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); So you create this device structure and then throw it away? > + > + 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"); That's bold, how do you know that your device really has that name? That's not how you do device lifecycle management. You have a list of the devices you control and go from there. But larger question is, why do you need a device at all? Shouldn't the attribute group name work properly for all of this? The attributes should be on the CPU device, not on a random child device, right? thanks, greg k-h
