From b045c215866393419fb960432ed6be69a0113ee1 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:15 +0000 Subject: [PATCH] x86/resctrl: Abstract and use supports_mba_mbps() To determine whether the mba_MBps option to resctrl should be supported, resctrl tests the boot CPUs' x86_vendor. This isn't portable, and needs abstracting behind a helper so this check can be part of the filesystem code that moves to /fs/. Re-use the tests set_mba_sc() does to determine if the mba_sc is supported on this system. An 'alloc_capable' test is added so that support for the controls isn't implied by the 'delay_linear' property, which is always true for MPAM. Because mbm_update() only update mba_sc if the mbm_local counters are enabled, supports_mba_mbps() checks is_mbm_local_enabled(). (instead of using is_mbm_enabled(), which checks both). Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-8-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index b32ceff..4ee2626 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1890,17 +1890,26 @@ void rdt_domain_reconfigure_cdp(struct rdt_resource *r) } /* - * Enable or disable the MBA software controller - * which helps user specify bandwidth in MBps. * MBA software controller is supported only if * MBM is supported and MBA is in linear scale. */ +static bool supports_mba_mbps(void) +{ + struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; + + return (is_mbm_local_enabled() && + r->alloc_capable && is_mba_linear()); +} + +/* + * Enable or disable the MBA software controller + * which helps user specify bandwidth in MBps. + */ static int set_mba_sc(bool mba_sc) { struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; - if (!is_mbm_enabled() || !is_mba_linear() || - mba_sc == is_mba_sc(r)) + if (!supports_mba_mbps() || mba_sc == is_mba_sc(r)) return -EINVAL; r->membw.mba_sc = mba_sc; @@ -2255,7 +2264,7 @@ static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) ctx->enable_cdpl2 = true; return 0; case Opt_mba_mbps: - if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) + if (!supports_mba_mbps()) return -EINVAL; ctx->enable_mba_mbps = true; return 0; -- 2.7.4