diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 910febef55e84b2e8c43b5a478d56b35929a2d99..ba1410ced42044e7a1a10660fc330a63746c4a09 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -812,6 +812,93 @@ static int rdtgroup_mode_show(struct kernfs_open_file *of, 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. + */ +static 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; + if (closid_allocated(i) && i != closid) { + if (bitmap_intersects(cbm, ctrl_b, r->cache.cbm_len)) { + mode = rdtgroup_mode_by_closid(i); + 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) { @@ -834,11 +921,19 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, mode = rdtgrp->mode; - if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE)) + if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) || + (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE)) goto out; if (!strcmp(buf, "shareable")) { 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; + } + rdtgrp->mode = RDT_MODE_EXCLUSIVE; } else { rdt_last_cmd_printf("unknown/unsupported mode\n"); ret = -EINVAL;