#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/cacheinfo.h>
#include <linux/cpu.h>
+#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/sysfs.h>
#include <linux/kernfs.h>
static struct seq_buf last_cmd_status;
static char last_cmd_status_buf[512];
+struct dentry *debugfs_resctrl;
+
void rdt_last_cmd_clear(void)
{
lockdep_assert_held(&rdtgroup_mutex);
return closid;
}
-static void closid_free(int closid)
+void closid_free(int closid)
{
closid_free_map |= 1 << closid;
}
+/**
+ * closid_allocated - test if provided closid is in use
+ * @closid: closid to be tested
+ *
+ * Return: true if @closid is currently associated with a resource group,
+ * false if @closid is free
+ */
+static bool closid_allocated(unsigned int closid)
+{
+ return (closid_free_map & (1 << closid)) == 0;
+}
+
+/**
+ * rdtgroup_mode_by_closid - Return mode of resource group with closid
+ * @closid: closid if the resource group
+ *
+ * Each resource group is associated with a @closid. Here the mode
+ * of a resource group can be queried by searching for it using its closid.
+ *
+ * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
+ */
+enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
+{
+ struct rdtgroup *rdtgrp;
+
+ list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+ if (rdtgrp->closid == closid)
+ return rdtgrp->mode;
+ }
+
+ return RDT_NUM_MODES;
+}
+
+static const char * const rdt_mode_str[] = {
+ [RDT_MODE_SHAREABLE] = "shareable",
+ [RDT_MODE_EXCLUSIVE] = "exclusive",
+ [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup",
+ [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked",
+};
+
+/**
+ * rdtgroup_mode_str - Return the string representation of mode
+ * @mode: the resource group mode as &enum rdtgroup_mode
+ *
+ * Return: string representation of valid mode, "unknown" otherwise
+ */
+static const char *rdtgroup_mode_str(enum rdtgrp_mode mode)
+{
+ if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES)
+ return "unknown";
+
+ return rdt_mode_str[mode];
+}
+
/* set uid and gid of rdtgroup dirs and files to that of the creator */
static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
{
rdtgrp = rdtgroup_kn_lock_live(of->kn);
if (rdtgrp) {
- seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
- cpumask_pr_args(&rdtgrp->cpu_mask));
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
+ seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
+ cpumask_pr_args(&rdtgrp->plr->d->cpu_mask));
+ else
+ seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
+ cpumask_pr_args(&rdtgrp->cpu_mask));
} else {
ret = -ENOENT;
}
goto unlock;
}
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("pseudo-locking in progress\n");
+ goto unlock;
+ }
+
if (is_cpu_list(of))
ret = cpulist_parse(buf, newmask);
else
return ret;
}
+/**
+ * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
+ * @r: Resource group
+ *
+ * Return: 1 if tasks have been assigned to @r, 0 otherwise
+ */
+int rdtgroup_tasks_assigned(struct rdtgroup *r)
+{
+ struct task_struct *p, *t;
+ int ret = 0;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ rcu_read_lock();
+ for_each_process_thread(p, t) {
+ if ((r->type == RDTCTRL_GROUP && t->closid == r->closid) ||
+ (r->type == RDTMON_GROUP && t->rmid == r->mon.rmid)) {
+ ret = 1;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
static int rdtgroup_task_write_permission(struct task_struct *task,
struct kernfs_open_file *of)
{
if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
return -EINVAL;
rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
rdt_last_cmd_clear();
- if (rdtgrp)
- ret = rdtgroup_move_task(pid, rdtgrp, of);
- else
- ret = -ENOENT;
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("pseudo-locking in progress\n");
+ goto unlock;
+ }
+ ret = rdtgroup_move_task(pid, rdtgrp, of);
+
+unlock:
rdtgroup_kn_unlock(of->kn);
return ret ?: nbytes;
return 0;
}
+/**
+ * rdt_bit_usage_show - Display current usage of resources
+ *
+ * A domain is a shared resource that can now be allocated differently. Here
+ * we display the current regions of the domain as an annotated bitmask.
+ * For each domain of this resource its allocation bitmask
+ * is annotated as below to indicate the current usage of the corresponding bit:
+ * 0 - currently unused
+ * X - currently available for sharing and used by software and hardware
+ * H - currently used by hardware only but available for software use
+ * S - currently used and shareable by software only
+ * E - currently used exclusively by one resource group
+ * P - currently pseudo-locked by one resource group
+ */
+static int rdt_bit_usage_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+ u32 sw_shareable = 0, hw_shareable = 0;
+ u32 exclusive = 0, pseudo_locked = 0;
+ struct rdt_domain *dom;
+ int i, hwb, swb, excl, psl;
+ enum rdtgrp_mode mode;
+ bool sep = false;
+ u32 *ctrl;
+
+ mutex_lock(&rdtgroup_mutex);
+ hw_shareable = r->cache.shareable_bits;
+ list_for_each_entry(dom, &r->domains, list) {
+ if (sep)
+ seq_putc(seq, ';');
+ ctrl = dom->ctrl_val;
+ sw_shareable = 0;
+ exclusive = 0;
+ seq_printf(seq, "%d=", dom->id);
+ for (i = 0; i < r->num_closid; i++, ctrl++) {
+ if (!closid_allocated(i))
+ continue;
+ mode = rdtgroup_mode_by_closid(i);
+ switch (mode) {
+ case RDT_MODE_SHAREABLE:
+ sw_shareable |= *ctrl;
+ break;
+ case RDT_MODE_EXCLUSIVE:
+ exclusive |= *ctrl;
+ break;
+ case RDT_MODE_PSEUDO_LOCKSETUP:
+ /*
+ * RDT_MODE_PSEUDO_LOCKSETUP is possible
+ * here but not included since the CBM
+ * associated with this CLOSID in this mode
+ * is not initialized and no task or cpu can be
+ * assigned this CLOSID.
+ */
+ break;
+ case RDT_MODE_PSEUDO_LOCKED:
+ case RDT_NUM_MODES:
+ WARN(1,
+ "invalid mode for closid %d\n", i);
+ break;
+ }
+ }
+ for (i = r->cache.cbm_len - 1; i >= 0; i--) {
+ pseudo_locked = dom->plr ? dom->plr->cbm : 0;
+ hwb = test_bit(i, (unsigned long *)&hw_shareable);
+ swb = test_bit(i, (unsigned long *)&sw_shareable);
+ excl = test_bit(i, (unsigned long *)&exclusive);
+ psl = test_bit(i, (unsigned long *)&pseudo_locked);
+ if (hwb && swb)
+ seq_putc(seq, 'X');
+ else if (hwb && !swb)
+ seq_putc(seq, 'H');
+ else if (!hwb && swb)
+ seq_putc(seq, 'S');
+ else if (excl)
+ seq_putc(seq, 'E');
+ else if (psl)
+ seq_putc(seq, 'P');
+ else /* Unused bits remain */
+ seq_putc(seq, '0');
+ }
+ sep = true;
+ }
+ seq_putc(seq, '\n');
+ mutex_unlock(&rdtgroup_mutex);
+ return 0;
+}
+
static int rdt_min_bw_show(struct kernfs_open_file *of,
struct seq_file *seq, void *v)
{
return nbytes;
}
+/*
+ * rdtgroup_mode_show - Display mode of this resource group
+ */
+static int rdtgroup_mode_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+
+ seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode));
+
+ rdtgroup_kn_unlock(of->kn);
+ return 0;
+}
+
+/**
+ * rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
+ * @r: Resource to which domain instance @d belongs.
+ * @d: The domain instance for which @closid is being tested.
+ * @cbm: Capacity bitmask being tested.
+ * @closid: Intended closid for @cbm.
+ * @exclusive: Only check if overlaps with exclusive resource groups
+ *
+ * Checks if provided @cbm intended to be used for @closid on domain
+ * @d overlaps with any other closids or other hardware usage associated
+ * with this domain. If @exclusive is true then only overlaps with
+ * resource groups in exclusive mode will be considered. If @exclusive
+ * is false then overlaps with any resource group or hardware entities
+ * will be considered.
+ *
+ * Return: false if CBM does not overlap, true if it does.
+ */
+bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
+ u32 _cbm, int closid, bool exclusive)
+{
+ unsigned long *cbm = (unsigned long *)&_cbm;
+ unsigned long *ctrl_b;
+ enum rdtgrp_mode mode;
+ u32 *ctrl;
+ int i;
+
+ /* Check for any overlap with regions used by hardware directly */
+ if (!exclusive) {
+ if (bitmap_intersects(cbm,
+ (unsigned long *)&r->cache.shareable_bits,
+ r->cache.cbm_len))
+ return true;
+ }
+
+ /* Check for overlap with other resource groups */
+ ctrl = d->ctrl_val;
+ for (i = 0; i < r->num_closid; i++, ctrl++) {
+ ctrl_b = (unsigned long *)ctrl;
+ mode = rdtgroup_mode_by_closid(i);
+ if (closid_allocated(i) && i != closid &&
+ mode != RDT_MODE_PSEUDO_LOCKSETUP) {
+ if (bitmap_intersects(cbm, ctrl_b, r->cache.cbm_len)) {
+ if (exclusive) {
+ if (mode == RDT_MODE_EXCLUSIVE)
+ return true;
+ continue;
+ }
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+/**
+ * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive
+ *
+ * An exclusive resource group implies that there should be no sharing of
+ * its allocated resources. At the time this group is considered to be
+ * exclusive this test can determine if its current schemata supports this
+ * setting by testing for overlap with all other resource groups.
+ *
+ * Return: true if resource group can be exclusive, false if there is overlap
+ * with allocations of other resource groups and thus this resource group
+ * cannot be exclusive.
+ */
+static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
+{
+ int closid = rdtgrp->closid;
+ struct rdt_resource *r;
+ struct rdt_domain *d;
+
+ for_each_alloc_enabled_rdt_resource(r) {
+ list_for_each_entry(d, &r->domains, list) {
+ if (rdtgroup_cbm_overlaps(r, d, d->ctrl_val[closid],
+ rdtgrp->closid, false))
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/**
+ * rdtgroup_mode_write - Modify the resource group's mode
+ *
+ */
+static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdtgroup *rdtgrp;
+ enum rdtgrp_mode mode;
+ int ret = 0;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+ buf[nbytes - 1] = '\0';
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+
+ rdt_last_cmd_clear();
+
+ mode = rdtgrp->mode;
+
+ if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
+ (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
+ (!strcmp(buf, "pseudo-locksetup") &&
+ mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
+ (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
+ goto out;
+
+ if (mode == RDT_MODE_PSEUDO_LOCKED) {
+ rdt_last_cmd_printf("cannot change pseudo-locked group\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!strcmp(buf, "shareable")) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = rdtgroup_locksetup_exit(rdtgrp);
+ if (ret)
+ goto out;
+ }
+ rdtgrp->mode = RDT_MODE_SHAREABLE;
+ } else if (!strcmp(buf, "exclusive")) {
+ if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
+ rdt_last_cmd_printf("schemata overlaps\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = rdtgroup_locksetup_exit(rdtgrp);
+ if (ret)
+ goto out;
+ }
+ rdtgrp->mode = RDT_MODE_EXCLUSIVE;
+ } else if (!strcmp(buf, "pseudo-locksetup")) {
+ ret = rdtgroup_locksetup_enter(rdtgrp);
+ if (ret)
+ goto out;
+ rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
+ } else {
+ rdt_last_cmd_printf("unknown/unsupported mode\n");
+ ret = -EINVAL;
+ }
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+ return ret ?: nbytes;
+}
+
+/**
+ * rdtgroup_cbm_to_size - Translate CBM to size in bytes
+ * @r: RDT resource to which @d belongs.
+ * @d: RDT domain instance.
+ * @cbm: bitmask for which the size should be computed.
+ *
+ * The bitmask provided associated with the RDT domain instance @d will be
+ * translated into how many bytes it represents. The size in bytes is
+ * computed by first dividing the total cache size by the CBM length to
+ * determine how many bytes each bit in the bitmask represents. The result
+ * is multiplied with the number of bits set in the bitmask.
+ */
+unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
+ struct rdt_domain *d, u32 cbm)
+{
+ struct cpu_cacheinfo *ci;
+ unsigned int size = 0;
+ int num_b, i;
+
+ num_b = bitmap_weight((unsigned long *)&cbm, r->cache.cbm_len);
+ ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask));
+ for (i = 0; i < ci->num_leaves; i++) {
+ if (ci->info_list[i].level == r->cache_level) {
+ size = ci->info_list[i].size / r->cache.cbm_len * num_b;
+ break;
+ }
+ }
+
+ return size;
+}
+
+/**
+ * rdtgroup_size_show - Display size in bytes of allocated regions
+ *
+ * The "size" file mirrors the layout of the "schemata" file, printing the
+ * size in bytes of each region instead of the capacity bitmask.
+ *
+ */
+static int rdtgroup_size_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ struct rdt_domain *d;
+ unsigned int size;
+ bool sep = false;
+ u32 cbm;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+ seq_printf(s, "%*s:", max_name_width, rdtgrp->plr->r->name);
+ size = rdtgroup_cbm_to_size(rdtgrp->plr->r,
+ rdtgrp->plr->d,
+ rdtgrp->plr->cbm);
+ seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size);
+ goto out;
+ }
+
+ for_each_alloc_enabled_rdt_resource(r) {
+ seq_printf(s, "%*s:", max_name_width, r->name);
+ list_for_each_entry(d, &r->domains, list) {
+ if (sep)
+ seq_putc(s, ';');
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ size = 0;
+ } else {
+ cbm = d->ctrl_val[rdtgrp->closid];
+ size = rdtgroup_cbm_to_size(r, d, cbm);
+ }
+ seq_printf(s, "%d=%u", d->id, size);
+ sep = true;
+ }
+ seq_putc(s, '\n');
+ }
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+
+ return 0;
+}
+
/* rdtgroup information files for one cache resource. */
static struct rftype res_common_files[] = {
{
.seq_show = rdt_shareable_bits_show,
.fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
},
+ {
+ .name = "bit_usage",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_bit_usage_show,
+ .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
{
.name = "min_bandwidth",
.mode = 0444,
.seq_show = rdtgroup_schemata_show,
.fflags = RF_CTRL_BASE,
},
+ {
+ .name = "mode",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_mode_write,
+ .seq_show = rdtgroup_mode_show,
+ .fflags = RF_CTRL_BASE,
+ },
+ {
+ .name = "size",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_size_show,
+ .fflags = RF_CTRL_BASE,
+ },
+
};
static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
return ret;
}
+/**
+ * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
+ * @r: The resource group with which the file is associated.
+ * @name: Name of the file
+ *
+ * The permissions of named resctrl file, directory, or link are modified
+ * to not allow read, write, or execute by any user.
+ *
+ * WARNING: This function is intended to communicate to the user that the
+ * resctrl file has been locked down - that it is not relevant to the
+ * particular state the system finds itself in. It should not be relied
+ * on to protect from user access because after the file's permissions
+ * are restricted the user can still change the permissions using chmod
+ * from the command line.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name)
+{
+ struct iattr iattr = {.ia_valid = ATTR_MODE,};
+ struct kernfs_node *kn;
+ int ret = 0;
+
+ kn = kernfs_find_and_get_ns(r->kn, name, NULL);
+ if (!kn)
+ return -ENOENT;
+
+ switch (kernfs_type(kn)) {
+ case KERNFS_DIR:
+ iattr.ia_mode = S_IFDIR;
+ break;
+ case KERNFS_FILE:
+ iattr.ia_mode = S_IFREG;
+ break;
+ case KERNFS_LINK:
+ iattr.ia_mode = S_IFLNK;
+ break;
+ }
+
+ ret = kernfs_setattr(kn, &iattr);
+ kernfs_put(kn);
+ return ret;
+}
+
+/**
+ * rdtgroup_kn_mode_restore - Restore user access to named resctrl file
+ * @r: The resource group with which the file is associated.
+ * @name: Name of the file
+ * @mask: Mask of permissions that should be restored
+ *
+ * Restore the permissions of the named file. If @name is a directory the
+ * permissions of its parent will be used.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
+ umode_t mask)
+{
+ struct iattr iattr = {.ia_valid = ATTR_MODE,};
+ struct kernfs_node *kn, *parent;
+ struct rftype *rfts, *rft;
+ int ret, len;
+
+ rfts = res_common_files;
+ len = ARRAY_SIZE(res_common_files);
+
+ for (rft = rfts; rft < rfts + len; rft++) {
+ if (!strcmp(rft->name, name))
+ iattr.ia_mode = rft->mode & mask;
+ }
+
+ kn = kernfs_find_and_get_ns(r->kn, name, NULL);
+ if (!kn)
+ return -ENOENT;
+
+ switch (kernfs_type(kn)) {
+ case KERNFS_DIR:
+ parent = kernfs_get_parent(kn);
+ if (parent) {
+ iattr.ia_mode |= parent->mode;
+ kernfs_put(parent);
+ }
+ iattr.ia_mode |= S_IFDIR;
+ break;
+ case KERNFS_FILE:
+ iattr.ia_mode |= S_IFREG;
+ break;
+ case KERNFS_LINK:
+ iattr.ia_mode |= S_IFLNK;
+ break;
+ }
+
+ ret = kernfs_setattr(kn, &iattr);
+ kernfs_put(kn);
+ return ret;
+}
+
static int rdtgroup_mkdir_info_resdir(struct rdt_resource *r, char *name,
unsigned long fflags)
{
if (atomic_dec_and_test(&rdtgrp->waitcount) &&
(rdtgrp->flags & RDT_DELETED)) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
+ rdtgroup_pseudo_lock_remove(rdtgrp);
kernfs_unbreak_active_protection(kn);
kernfs_put(rdtgrp->kn);
kfree(rdtgrp);
rdtgroup_default.mon.mon_data_kn = kn_mondata;
}
+ ret = rdt_pseudo_lock_init();
+ if (ret) {
+ dentry = ERR_PTR(ret);
+ goto out_mondata;
+ }
+
dentry = kernfs_mount(fs_type, flags, rdt_root,
RDTGROUP_SUPER_MAGIC, NULL);
if (IS_ERR(dentry))
- goto out_mondata;
+ goto out_psl;
if (rdt_alloc_capable)
static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
goto out;
+out_psl:
+ rdt_pseudo_lock_release();
out_mondata:
if (rdt_mon_capable)
kernfs_remove(kn_mondata);
if (rdtgrp == &rdtgroup_default)
continue;
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
+ rdtgroup_pseudo_lock_remove(rdtgrp);
+
/*
* Give any CPUs back to the default group. We cannot copy
* cpu_online_mask because a CPU might have executed the
reset_all_ctrls(r);
cdp_disable_all();
rmdir_all_sub();
+ rdt_pseudo_lock_release();
+ rdtgroup_default.mode = RDT_MODE_SHAREABLE;
static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
static_branch_disable_cpuslocked(&rdt_mon_enable_key);
static_branch_disable_cpuslocked(&rdt_enable_key);
return ret;
}
+/**
+ * cbm_ensure_valid - Enforce validity on provided CBM
+ * @_val: Candidate CBM
+ * @r: RDT resource to which the CBM belongs
+ *
+ * The provided CBM represents all cache portions available for use. This
+ * may be represented by a bitmap that does not consist of contiguous ones
+ * and thus be an invalid CBM.
+ * Here the provided CBM is forced to be a valid CBM by only considering
+ * the first set of contiguous bits as valid and clearing all bits.
+ * The intention here is to provide a valid default CBM with which a new
+ * resource group is initialized. The user can follow this with a
+ * modification to the CBM if the default does not satisfy the
+ * requirements.
+ */
+static void cbm_ensure_valid(u32 *_val, struct rdt_resource *r)
+{
+ /*
+ * Convert the u32 _val to an unsigned long required by all the bit
+ * operations within this function. No more than 32 bits of this
+ * converted value can be accessed because all bit operations are
+ * additionally provided with cbm_len that is initialized during
+ * hardware enumeration using five bits from the EAX register and
+ * thus never can exceed 32 bits.
+ */
+ unsigned long *val = (unsigned long *)_val;
+ unsigned int cbm_len = r->cache.cbm_len;
+ unsigned long first_bit, zero_bit;
+
+ if (*val == 0)
+ return;
+
+ first_bit = find_first_bit(val, cbm_len);
+ zero_bit = find_next_zero_bit(val, cbm_len, first_bit);
+
+ /* Clear any remaining bits to ensure contiguous region */
+ bitmap_clear(val, zero_bit, cbm_len - zero_bit);
+}
+
+/**
+ * rdtgroup_init_alloc - Initialize the new RDT group's allocations
+ *
+ * A new RDT group is being created on an allocation capable (CAT)
+ * supporting system. Set this group up to start off with all usable
+ * allocations. That is, all shareable and unused bits.
+ *
+ * All-zero CBM is invalid. If there are no more shareable bits available
+ * on any domain then the entire allocation will fail.
+ */
+static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
+{
+ u32 used_b = 0, unused_b = 0;
+ u32 closid = rdtgrp->closid;
+ struct rdt_resource *r;
+ enum rdtgrp_mode mode;
+ struct rdt_domain *d;
+ int i, ret;
+ u32 *ctrl;
+
+ for_each_alloc_enabled_rdt_resource(r) {
+ list_for_each_entry(d, &r->domains, list) {
+ d->have_new_ctrl = false;
+ d->new_ctrl = r->cache.shareable_bits;
+ used_b = r->cache.shareable_bits;
+ ctrl = d->ctrl_val;
+ for (i = 0; i < r->num_closid; i++, ctrl++) {
+ if (closid_allocated(i) && i != closid) {
+ mode = rdtgroup_mode_by_closid(i);
+ if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
+ break;
+ used_b |= *ctrl;
+ if (mode == RDT_MODE_SHAREABLE)
+ d->new_ctrl |= *ctrl;
+ }
+ }
+ if (d->plr && d->plr->cbm > 0)
+ used_b |= d->plr->cbm;
+ unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
+ unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
+ d->new_ctrl |= unused_b;
+ /*
+ * Force the initial CBM to be valid, user can
+ * modify the CBM based on system availability.
+ */
+ cbm_ensure_valid(&d->new_ctrl, r);
+ if (bitmap_weight((unsigned long *) &d->new_ctrl,
+ r->cache.cbm_len) <
+ r->cache.min_cbm_bits) {
+ rdt_last_cmd_printf("no space on %s:%d\n",
+ r->name, d->id);
+ return -ENOSPC;
+ }
+ d->have_new_ctrl = true;
+ }
+ }
+
+ for_each_alloc_enabled_rdt_resource(r) {
+ ret = update_domains(r, rdtgrp->closid);
+ if (ret < 0) {
+ rdt_last_cmd_puts("failed to initialize allocations\n");
+ return ret;
+ }
+ rdtgrp->mode = RDT_MODE_SHAREABLE;
+ }
+
+ return 0;
+}
+
static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
struct kernfs_node *prgrp_kn,
const char *name, umode_t mode,
goto out_unlock;
}
+ if (rtype == RDTMON_GROUP &&
+ (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("pseudo-locking in progress\n");
+ goto out_unlock;
+ }
+
/* allocate the rdtgroup. */
rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
if (!rdtgrp) {
ret = 0;
rdtgrp->closid = closid;
+ ret = rdtgroup_init_alloc(rdtgrp);
+ if (ret < 0)
+ goto out_id_free;
+
list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
if (rdt_mon_capable) {
ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
if (ret) {
rdt_last_cmd_puts("kernfs subdir error\n");
- goto out_id_free;
+ goto out_del_list;
}
}
goto out_unlock;
+out_del_list:
+ list_del(&rdtgrp->rdtgroup_list);
out_id_free:
closid_free(closid);
- list_del(&rdtgrp->rdtgroup_list);
out_common_fail:
mkdir_rdt_prepare_clean(rdtgrp);
out_unlock:
return 0;
}
+static int rdtgroup_ctrl_remove(struct kernfs_node *kn,
+ struct rdtgroup *rdtgrp)
+{
+ rdtgrp->flags = RDT_DELETED;
+ list_del(&rdtgrp->rdtgroup_list);
+
+ /*
+ * one extra hold on this, will drop when we kfree(rdtgrp)
+ * in rdtgroup_kn_unlock()
+ */
+ kernfs_get(kn);
+ kernfs_remove(rdtgrp->kn);
+ return 0;
+}
+
static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp,
cpumask_var_t tmpmask)
{
cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
update_closid_rmid(tmpmask, NULL);
- rdtgrp->flags = RDT_DELETED;
closid_free(rdtgrp->closid);
free_rmid(rdtgrp->mon.rmid);
*/
free_all_child_rdtgrp(rdtgrp);
- list_del(&rdtgrp->rdtgroup_list);
-
- /*
- * one extra hold on this, will drop when we kfree(rdtgrp)
- * in rdtgroup_kn_unlock()
- */
- kernfs_get(kn);
- kernfs_remove(rdtgrp->kn);
+ rdtgroup_ctrl_remove(kn, rdtgrp);
return 0;
}
* If the rdtgroup is a mon group and parent directory
* is a valid "mon_groups" directory, remove the mon group.
*/
- if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn)
- ret = rdtgroup_rmdir_ctrl(kn, rdtgrp, tmpmask);
- else if (rdtgrp->type == RDTMON_GROUP &&
- is_mon_groups(parent_kn, kn->name))
+ if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+ ret = rdtgroup_ctrl_remove(kn, rdtgrp);
+ } else {
+ ret = rdtgroup_rmdir_ctrl(kn, rdtgrp, tmpmask);
+ }
+ } else if (rdtgrp->type == RDTMON_GROUP &&
+ is_mon_groups(parent_kn, kn->name)) {
ret = rdtgroup_rmdir_mon(kn, rdtgrp, tmpmask);
- else
+ } else {
ret = -EPERM;
+ }
out:
rdtgroup_kn_unlock(kn);
int ret;
rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
- KERNFS_ROOT_CREATE_DEACTIVATED,
+ KERNFS_ROOT_CREATE_DEACTIVATED |
+ KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
&rdtgroup_default);
if (IS_ERR(rdt_root))
return PTR_ERR(rdt_root);
if (ret)
goto cleanup_mountpoint;
+ /*
+ * Adding the resctrl debugfs directory here may not be ideal since
+ * it would let the resctrl debugfs directory appear on the debugfs
+ * filesystem before the resctrl filesystem is mounted.
+ * It may also be ok since that would enable debugging of RDT before
+ * resctrl is mounted.
+ * The reason why the debugfs directory is created here and not in
+ * rdt_mount() is because rdt_mount() takes rdtgroup_mutex and
+ * during the debugfs directory creation also &sb->s_type->i_mutex_key
+ * (the lockdep class of inode->i_rwsem). Other filesystem
+ * interactions (eg. SyS_getdents) have the lock ordering:
+ * &sb->s_type->i_mutex_key --> &mm->mmap_sem
+ * During mmap(), called with &mm->mmap_sem, the rdtgroup_mutex
+ * is taken, thus creating dependency:
+ * &mm->mmap_sem --> rdtgroup_mutex for the latter that can cause
+ * issues considering the other two lock dependencies.
+ * By creating the debugfs directory here we avoid a dependency
+ * that may cause deadlock (even though file operations cannot
+ * occur until the filesystem is mounted, but I do not know how to
+ * tell lockdep that).
+ */
+ debugfs_resctrl = debugfs_create_dir("resctrl", NULL);
+
return 0;
cleanup_mountpoint:
return ret;
}
+
+void __exit rdtgroup_exit(void)
+{
+ debugfs_remove_recursive(debugfs_resctrl);
+ unregister_filesystem(&rdt_fs_type);
+ sysfs_remove_mount_point(fs_kobj, "resctrl");
+ kernfs_destroy_root(rdt_root);
+}
git.samba.org / sfrench / cifs-2.6.git / blobdiff