Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751611AbdGYWjI (ORCPT ); Tue, 25 Jul 2017 18:39:08 -0400 Received: from mga02.intel.com ([134.134.136.20]:27607 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750839AbdGYWjH (ORCPT ); Tue, 25 Jul 2017 18:39:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,412,1496127600"; d="scan'208";a="111946025" From: "Luck, Tony" To: Thomas Gleixner Cc: vikas.shivappa@linux.intel.com, x86@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, peterz@infradead.org, ravi.v.shankar@intel.com, tony.luck@intel.com, fenghua.yu@intel.com, eranian@google.com, davidcc@google.com, ak@linux.intel.com, reinette.chatre@intel.com Subject: [PATCH] x86/intel_rdt: Show bitmask of shareable resource with other executing units Date: Tue, 25 Jul 2017 15:39:04 -0700 Message-Id: <20170725223904.12996-1-tony.luck@intel.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <1501017287-28083-1-git-send-email-vikas.shivappa@linux.intel.com> References: <1501017287-28083-1-git-send-email-vikas.shivappa@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4997 Lines: 130 From: Fenghua Yu CPUID.(EAX=0x10, ECX=res#):EBX[31:0] reports a bit mask for a resource. Each set bit within the length of the CBM indicates the corresponding unit of the resource allocation may be used by other entities in the platform (e.g. an integrated graphics engine or hardware units outside the processor core and have direct access to the resource). Each cleared bit within the length of the CBM indicates the corresponding allocation unit can be configured to implement a priority-based allocation scheme without interference with other hardware agents in the system. Bits outside the length of the CBM are reserved. More details on the bit mask are described in x86 Software Developer's Manual. The bitmask is shown in "info" directory for each resource. It's up to user to decide how to use the bitmask within a CBM in a partition to share or isolate a resource with other executing units. Suggested-by: Reinette Chatre Signed-off-by: Fenghua Yu Signed-off-by: Tony Luck --- [This is the "patch from Reinette" mentioned in part 00/28 of the series to add RDT monitoring "Cqm3 patch series"). It's been sitting around here for a while, but isn't really a part of that series, just a general improvement to RDT/CAT. Applies on top of the 28 parts because it uses the new structure names and methods to create a file in RDT directories] Documentation/x86/intel_rdt_ui.txt | 7 +++++++ arch/x86/kernel/cpu/intel_rdt.c | 2 ++ arch/x86/kernel/cpu/intel_rdt.h | 3 +++ arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 16 ++++++++++++++++ 4 files changed, 28 insertions(+) diff --git a/Documentation/x86/intel_rdt_ui.txt b/Documentation/x86/intel_rdt_ui.txt index 76f21e2ac176..4d8848e4e224 100644 --- a/Documentation/x86/intel_rdt_ui.txt +++ b/Documentation/x86/intel_rdt_ui.txt @@ -48,6 +48,13 @@ related to allocation: "min_cbm_bits": The minimum number of consecutive bits which must be set when writing a mask. +"shareable_bits": Bitmask of shareable resource with other executing + entities (e.g. I/O). User can use this when + setting up exclusive cache partitions. Note that + some platforms support devices that have their + own settings for cache use which can over-ride + these bits. + Memory bandwitdh(MB) subdirectory contains the following files with respect to allocation: diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c index b906e0e3eb57..91917c18a8c2 100644 --- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -193,6 +193,7 @@ static inline bool cache_alloc_hsw_probe(void) r->num_closid = 4; r->default_ctrl = max_cbm; r->cache.cbm_len = 20; + r->cache.shareable_bits = 0xc0000; r->cache.min_cbm_bits = 2; r->alloc_capable = true; r->alloc_enabled = true; @@ -260,6 +261,7 @@ static void rdt_get_cache_alloc_config(int idx, struct rdt_resource *r) r->num_closid = edx.split.cos_max + 1; r->cache.cbm_len = eax.split.cbm_len + 1; r->default_ctrl = BIT_MASK(eax.split.cbm_len + 1) - 1; + r->cache.shareable_bits = ebx & r->default_ctrl; r->data_width = (r->cache.cbm_len + 3) / 4; r->alloc_capable = true; r->alloc_enabled = true; diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h index 94e488af082e..4040bf1a075c 100644 --- a/arch/x86/kernel/cpu/intel_rdt.h +++ b/arch/x86/kernel/cpu/intel_rdt.h @@ -227,12 +227,15 @@ struct msr_param { * @cbm_idx_offset: Offset of CBM index. CBM index is computed by: * closid * cbm_idx_multi + cbm_idx_offset * in a cache bit mask + * @shareable_bits: Bitmask of shareable resource with other + * executing entities */ struct rdt_cache { unsigned int cbm_len; unsigned int min_cbm_bits; unsigned int cbm_idx_mult; unsigned int cbm_idx_offset; + unsigned int shareable_bits; }; /** diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 8266ef61dd99..83c126be83bf 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -596,6 +596,15 @@ static int rdt_min_cbm_bits_show(struct kernfs_open_file *of, return 0; } +static int rdt_shareable_bits_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = of->kn->parent->priv; + + seq_printf(seq, "%x\n", r->cache.shareable_bits); + return 0; +} + static int rdt_min_bw_show(struct kernfs_open_file *of, struct seq_file *seq, void *v) { @@ -712,6 +721,13 @@ static struct rftype res_common_files[] = { .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE, }, { + .name = "shareable_bits", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_shareable_bits_show, + .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { .name = "min_bandwidth", .mode = 0444, .kf_ops = &rdtgroup_kf_single_ops, -- 2.11.0