Commit-ID: 05b93417ce5b924c6652de19fdcc27439ab37c90 Gitweb: http://git.kernel.org/tip/05b93417ce5b924c6652de19fdcc27439ab37c90 Author: Vikas Shivappa <vikas.shiva...@linux.intel.com> AuthorDate: Fri, 7 Apr 2017 17:33:53 -0700 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Fri, 14 Apr 2017 16:10:08 +0200
x86/intel_rdt/mba: Add primary support for Memory Bandwidth Allocation (MBA) The MBA feature details like minimum bandwidth supported, bandwidth granularity etc are obtained via executing CPUID with EAX=10H ,ECX=3. Setup and initialize the MBA specific extensions to data structures like global list of RDT resources, RDT resource structure and RDT domain structure. [ tglx: Split out the seperate structure and the CBM related parts ] Signed-off-by: Vikas Shivappa <vikas.shiva...@linux.intel.com> Cc: ravi.v.shan...@intel.com Cc: tony.l...@intel.com Cc: fenghua...@intel.com Cc: vikas.shiva...@intel.com Link: http://lkml.kernel.org/r/1491611637-20417-5-git-send-email-vikas.shiva...@linux.intel.com Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- arch/x86/include/asm/intel_rdt.h | 24 ++++++++++- arch/x86/kernel/cpu/intel_rdt.c | 89 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 110 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h index 6295594..0620fc9 100644 --- a/arch/x86/include/asm/intel_rdt.h +++ b/arch/x86/include/asm/intel_rdt.h @@ -12,6 +12,7 @@ #define IA32_L3_QOS_CFG 0xc81 #define IA32_L3_CBM_BASE 0xc90 #define IA32_L2_CBM_BASE 0xd10 +#define IA32_MBA_THRTL_BASE 0xd50 #define L3_QOS_CDP_ENABLE 0x01ULL @@ -120,6 +121,23 @@ struct rdt_cache { }; /** + * struct rdt_membw - Memory bandwidth allocation related data + * @max_delay: Max throttle delay. Delay is the hardware + * representation for memory bandwidth. + * @min_bw: Minimum memory bandwidth percentage user can request + * @bw_gran: Granularity at which the memory bandwidth is allocated + * @delay_linear: True if memory B/W delay is in linear scale + * @mb_map: Mapping of memory B/W percentage to memory B/W delay + */ +struct rdt_membw { + u32 max_delay; + u32 min_bw; + u32 bw_gran; + u32 delay_linear; + u32 *mb_map; +}; + +/** * struct rdt_resource - attributes of an RDT resource * @enabled: Is this feature enabled on this machine * @capable: Is this feature available on this machine @@ -145,7 +163,10 @@ struct rdt_resource { struct rdt_resource *r); int data_width; struct list_head domains; - struct rdt_cache cache; + union { + struct rdt_cache cache; + struct rdt_membw membw; + }; }; extern struct mutex rdtgroup_mutex; @@ -161,6 +182,7 @@ enum { RDT_RESOURCE_L3DATA, RDT_RESOURCE_L3CODE, RDT_RESOURCE_L2, + RDT_RESOURCE_MBA, /* Must be the last */ RDT_NUM_RESOURCES, diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c index 82eafd6..ae1aec1 100644 --- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -32,6 +32,9 @@ #include <asm/intel-family.h> #include <asm/intel_rdt.h> +#define MAX_MBA_BW 100u +#define MBA_IS_LINEAR 0x4 + /* Mutex to protect rdtgroup access. */ DEFINE_MUTEX(rdtgroup_mutex); @@ -44,6 +47,8 @@ DEFINE_PER_CPU_READ_MOSTLY(int, cpu_closid); int max_name_width, max_data_width; static void +mba_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r); +static void cat_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r); #define domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].domains) @@ -97,6 +102,13 @@ struct rdt_resource rdt_resources_all[] = { .cbm_idx_offset = 0, }, }, + { + .name = "MB", + .domains = domain_init(RDT_RESOURCE_MBA), + .msr_base = IA32_MBA_THRTL_BASE, + .msr_update = mba_wrmsr, + .cache_level = 3, + }, }; static unsigned int cbm_idx(struct rdt_resource *r, unsigned int closid) @@ -151,6 +163,53 @@ static inline bool cache_alloc_hsw_probe(void) return false; } +/* + * rdt_get_mb_table() - get a mapping of bandwidth(b/w) percentage values + * exposed to user interface and the h/w understandable delay values. + * + * The non-linear delay values have the granularity of power of two + * and also the h/w does not guarantee a curve for configured delay + * values vs. actual b/w enforced. + * Hence we need a mapping that is pre calibrated so the user can + * express the memory b/w as a percentage value. + */ +static inline bool rdt_get_mb_table(struct rdt_resource *r) +{ + /* + * There are no Intel SKUs as of now to support non-linear delay. + */ + pr_info("MBA b/w map not implemented for cpu:%d, model:%d", + boot_cpu_data.x86, boot_cpu_data.x86_model); + + return false; +} + +static bool rdt_get_mem_config(struct rdt_resource *r) +{ + union cpuid_0x10_3_eax eax; + union cpuid_0x10_x_edx edx; + u32 ebx, ecx; + + cpuid_count(0x00000010, 3, &eax.full, &ebx, &ecx, &edx.full); + r->num_closid = edx.split.cos_max + 1; + r->membw.max_delay = eax.split.max_delay + 1; + r->default_ctrl = MAX_MBA_BW; + if (ecx & MBA_IS_LINEAR) { + r->membw.delay_linear = true; + r->membw.min_bw = MAX_MBA_BW - r->membw.max_delay; + r->membw.bw_gran = MAX_MBA_BW - r->membw.max_delay; + } else { + if (!rdt_get_mb_table(r)) + return false; + } + r->data_width = 3; + + r->capable = true; + r->enabled = true; + + return true; +} + static void rdt_get_cache_config(int idx, struct rdt_resource *r) { union cpuid_0x10_1_eax eax; @@ -196,6 +255,30 @@ static int get_cache_id(int cpu, int level) return -1; } +/* + * Map the memory b/w percentage value to delay values + * that can be written to QOS_MSRs. + * There are currently no SKUs which support non linear delay values. + */ +static u32 delay_bw_map(unsigned long bw, struct rdt_resource *r) +{ + if (r->membw.delay_linear) + return MAX_MBA_BW - bw; + + pr_warn_once("Non Linear delay-bw map not supported but queried\n"); + return r->default_ctrl; +} + +static void +mba_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r) +{ + unsigned int i; + + /* Write the delay values for mba. */ + for (i = m->low; i < m->high; i++) + wrmsrl(r->msr_base + i, delay_bw_map(d->ctrl_val[i], r)); +} + static void cat_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r) { @@ -431,8 +514,10 @@ static __init bool get_rdt_resources(void) ret = true; } - if (boot_cpu_has(X86_FEATURE_MBA)) - ret = true; + if (boot_cpu_has(X86_FEATURE_MBA)) { + if (rdt_get_mem_config(&rdt_resources_all[RDT_RESOURCE_MBA])) + ret = true; + } return ret; }
