From f0d339db56478e3bcd98d5e985d3d69cacf27549 Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Tue, 5 May 2020 15:36:14 -0700 Subject: x86/resctrl: Remove unnecessary RMID checks The cache and memory bandwidth monitoring properties are read using CPUID on every CPU. After the information is read from the system a sanity check is run to (1) ensure that the RMID data is initialized for the boot CPU in case the information was not available on the boot CPU and (2) the boot CPU's RMID is set to the minimum of RMID obtained from all CPUs. Every known platform that supports resctrl has the same maximum RMID on all CPUs. Both sanity checks found in x86_init_cache_qos() can thus safely be removed. Suggested-by: Borislav Petkov Signed-off-by: Reinette Chatre Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/c9a3b60d34091840c8b0bd1c6fab15e5ba92cb17.1588715690.git.reinette.chatre@intel.com --- arch/x86/kernel/cpu/common.c | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'arch/x86/kernel/cpu/common.c') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index a8f0f22ee5c1..556a96d05a6c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1354,20 +1354,6 @@ static void generic_identify(struct cpuinfo_x86 *c) #endif } -static void x86_init_cache_qos(struct cpuinfo_x86 *c) -{ - /* - * The heavy lifting of max_rmid and cache_occ_scale are handled - * in get_cpu_cap(). Here we just set the max_rmid for the boot_cpu - * in case CQM bits really aren't there in this CPU. - */ - if (c != &boot_cpu_data) { - boot_cpu_data.x86_cache_max_rmid = - min(boot_cpu_data.x86_cache_max_rmid, - c->x86_cache_max_rmid); - } -} - /* * Validate that ACPI/mptables have the same information about the * effective APIC id and update the package map. @@ -1480,7 +1466,6 @@ static void identify_cpu(struct cpuinfo_x86 *c) #endif x86_init_rdrand(c); - x86_init_cache_qos(c); setup_pku(c); /* -- cgit v1.2.3