Commit-ID: d4223b381c10bff94dc7491806b6108429831fc6 Gitweb: http://git.kernel.org/tip/d4223b381c10bff94dc7491806b6108429831fc6 Author: Fenghua Yu <fenghua...@intel.com> AuthorDate: Thu, 17 Dec 2015 14:46:10 -0800 Committer: H. Peter Anvin <h...@linux.intel.com> CommitDate: Fri, 18 Dec 2015 13:17:56 -0800
x86/intel_rdt: Add Class of service management From: Vikas Shivappa <vikas.shiva...@linux.intel.com> Adds some data-structures and APIs to support Class of service management(closid). There is a new clos_cbm table which keeps a 1:1 mapping between closid and capacity bit mask (cbm) and a count of usage of closid. Each task would be associated with a Closid at a time and this patch adds a new field closid to task_struct to keep track of the same. Signed-off-by: Vikas Shivappa <vikas.shiva...@linux.intel.com> Link: http://lkml.kernel.org/r/1450392376-6397-6-git-send-email-fenghua...@intel.com Signed-off-by: Fenghua Yu <fenghua...@intel.com> --- arch/x86/include/asm/intel_rdt.h | 12 ++++++ arch/x86/kernel/cpu/intel_rdt.c | 82 +++++++++++++++++++++++++++++++++++++++- include/linux/sched.h | 3 ++ 3 files changed, 95 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h new file mode 100644 index 0000000..88b7643 --- /dev/null +++ b/arch/x86/include/asm/intel_rdt.h @@ -0,0 +1,12 @@ +#ifndef _RDT_H_ +#define _RDT_H_ + +#ifdef CONFIG_INTEL_RDT + +struct clos_cbm_table { + unsigned long l3_cbm; + unsigned int clos_refcnt; +}; + +#endif +#endif diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c index f49e970..d79213a 100644 --- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -24,17 +24,95 @@ #include <linux/slab.h> #include <linux/err.h> +#include <asm/intel_rdt.h> + +/* + * cctable maintains 1:1 mapping between CLOSid and cache bitmask. + */ +static struct clos_cbm_table *cctable; +/* + * closid availability bit map. + */ +unsigned long *closmap; +static DEFINE_MUTEX(rdt_group_mutex); + +static inline void closid_get(u32 closid) +{ + struct clos_cbm_table *cct = &cctable[closid]; + + lockdep_assert_held(&rdt_group_mutex); + + cct->clos_refcnt++; +} + +static int closid_alloc(u32 *closid) +{ + u32 maxid; + u32 id; + + lockdep_assert_held(&rdt_group_mutex); + + maxid = boot_cpu_data.x86_cache_max_closid; + id = find_first_zero_bit(closmap, maxid); + if (id == maxid) + return -ENOSPC; + + set_bit(id, closmap); + closid_get(id); + *closid = id; + + return 0; +} + +static inline void closid_free(u32 closid) +{ + clear_bit(closid, closmap); + cctable[closid].l3_cbm = 0; +} + +static void closid_put(u32 closid) +{ + struct clos_cbm_table *cct = &cctable[closid]; + + lockdep_assert_held(&rdt_group_mutex); + if (WARN_ON(!cct->clos_refcnt)) + return; + + if (!--cct->clos_refcnt) + closid_free(closid); +} static int __init intel_rdt_late_init(void) { struct cpuinfo_x86 *c = &boot_cpu_data; + u32 maxid, max_cbm_len; + int err = 0, size; if (!cpu_has(c, X86_FEATURE_CAT_L3)) return -ENODEV; - pr_info("Intel cache allocation detected\n"); + maxid = c->x86_cache_max_closid; + max_cbm_len = c->x86_cache_max_cbm_len; - return 0; + size = maxid * sizeof(struct clos_cbm_table); + cctable = kzalloc(size, GFP_KERNEL); + if (!cctable) { + err = -ENOMEM; + goto out_err; + } + + size = BITS_TO_LONGS(maxid) * sizeof(long); + closmap = kzalloc(size, GFP_KERNEL); + if (!closmap) { + kfree(cctable); + err = -ENOMEM; + goto out_err; + } + + pr_info("Intel cache allocation enabled\n"); +out_err: + + return err; } late_initcall(intel_rdt_late_init); diff --git a/include/linux/sched.h b/include/linux/sched.h index edad7a4..0a6db46 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1668,6 +1668,9 @@ struct task_struct { /* cg_list protected by css_set_lock and tsk->alloc_lock */ struct list_head cg_list; #endif +#ifdef CONFIG_INTEL_RDT + u32 closid; +#endif #ifdef CONFIG_FUTEX struct robust_list_head __user *robust_list; #ifdef CONFIG_COMPAT -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
